Fable review of JSON API consistency and subsequent improvements

Merge PR #2824

datasette/__init__.py

@@ -1,7 +1,7 @@
 from datasette.permissions import Permission  # noqa
 from datasette.version import __version_info__, __version__  # noqa
 from datasette.events import Event  # noqa
-from datasette.tokens import TokenHandler, TokenRestrictions  # noqa
+from datasette.tokens import TokenHandler, TokenInvalid, TokenRestrictions  # noqa
 from datasette.utils.asgi import (  # noqa
     Forbidden,
     NotFound,

datasette/app.py

@@ -111,6 +111,7 @@ from .utils import (
     baseconv,
     call_with_supported_arguments,
     detect_json1,
+    add_cors_headers,
     display_actor,
     escape_css_string,
     escape_sqlite,
@@ -130,6 +131,7 @@ from .utils import (
     redact_keys,
     row_sql_params_pks,
 )
+from .tokens import TokenInvalid
 from .utils.asgi import (
     AsgiLifespan,
     Forbidden,
@@ -910,7 +912,9 @@ class Datasette:
         Verify an API token by trying all registered token handlers.
 
         Returns an actor dict from the first handler that recognizes the
-        token, or None if no handler accepts it.
+        token, or None if no handler accepts it. A handler may raise
+        TokenInvalid for a token it recognizes but rejects (bad signature,
+        expired) - Datasette turns that into a 401 response.
         """
         for token_handler in self._token_handlers():
             result = await token_handler.verify_token(self, token)
@@ -2173,6 +2177,18 @@ class Datasette:
             for name, d in self.databases.items()
         ]
 
+    async def _connected_databases_for_actor(self, actor):
+        page = await self.allowed_resources("view-database", actor)
+        allowed_names = {resource.parent async for resource in page.all()}
+        return [
+            database
+            for database in self._connected_databases()
+            if database["name"] in allowed_names
+        ]
+
+    async def _databases_data(self, request):
+        return {"databases": await self._connected_databases_for_actor(request.actor)}
+
     def _versions(self):
         conn = sqlite3.connect(":memory:")
         self._prepare_connection(conn, "_memory")
@@ -2519,8 +2535,8 @@ class Datasette:
         def add_route(view, regex):
             routes.append((regex, view))
 
-        add_route(IndexView.as_view(self), r"/(\.(?P<format>jsono?))?$")
-        add_route(IndexView.as_view(self), r"/-/(\.(?P<format>jsono?))?$")
+        add_route(IndexView.as_view(self), r"/(\.(?P<format>json))?$")
+        add_route(IndexView.as_view(self), r"/-/(\.(?P<format>json))?$")
         add_route(permanent_redirect("/-/"), r"/-$")
         add_route(favicon, "/favicon.ico")
 
@@ -2556,7 +2572,10 @@ class Datasette:
         )
         add_route(
             JsonDataView.as_view(
-                self, "plugins.json", self._plugins, needs_request=True
+                self,
+                "plugins.json",
+                lambda request: {"plugins": self._plugins(request)},
+                needs_request=True,
             ),
             r"/-/plugins(\.(?P<format>json))?$",
         )
@@ -2569,11 +2588,18 @@ class Datasette:
             r"/-/config(\.(?P<format>json))?$",
         )
         add_route(
-            JsonDataView.as_view(self, "threads.json", self._threads),
+            JsonDataView.as_view(
+                self, "threads.json", self._threads, permission="permissions-debug"
+            ),
             r"/-/threads(\.(?P<format>json))?$",
         )
         add_route(
-            JsonDataView.as_view(self, "databases.json", self._connected_databases),
+            JsonDataView.as_view(
+                self,
+                "databases.json",
+                self._databases_data,
+                needs_request=True,
+            ),
             r"/-/databases(\.(?P<format>json))?$",
         )
         add_route(
@@ -2586,7 +2612,7 @@ class Datasette:
             JsonDataView.as_view(
                 self,
                 "actions.json",
-                self._actions,
+                lambda: {"actions": self._actions()},
                 template="debug_actions.html",
                 permission="permissions-debug",
             ),
@@ -2876,13 +2902,24 @@ class DatasetteRouter:
         # Handle authentication
         default_actor = scope.get("actor") or None
         actor = None
+        token_error = None
         results = pm.hook.actor_from_request(datasette=self.ds, request=request)
         for result in results:
-            result = await await_me_maybe(result)
+            try:
+                result = await await_me_maybe(result)
+            except TokenInvalid as ex:
+                # A presented token was recognized but rejected - fail the
+                # request with a 401 even if another credential is valid,
+                # but keep awaiting the remaining coroutines first
+                if token_error is None:
+                    token_error = ex
+                continue
             if result and actor is None:
                 actor = result
                 # Don't break — we must await all coroutines to avoid
                 # "coroutine was never awaited" warnings
+        if token_error is not None:
+            return await self.handle_401(request, send, token_error)
         scope_modifications["actor"] = actor or default_actor
         scope = dict(scope, **scope_modifications)
 
@@ -2914,6 +2951,15 @@ class DatasetteRouter:
         except Exception as exception:
             return await self.handle_exception(request, send, exception)
 
+    async def handle_401(self, request, send, exception):
+        # A presented bearer token was recognized by a handler but rejected.
+        # Bearer tokens are API credentials, so this is always JSON.
+        headers = {"www-authenticate": 'Bearer error="invalid_token"'}
+        if self.ds.cors:
+            add_cors_headers(headers)
+        response = Response.error([str(exception)], 401, headers=headers)
+        await response.asgi_send(send)
+
     async def handle_404(self, request, send, exception=None):
         # If path contains % encoding, redirect to tilde encoding
         if "%" in request.path:

datasette/extras.py

@@ -5,6 +5,8 @@ from typing import ClassVar
 
 from asyncinject import Registry
 
+from datasette.utils.asgi import BadRequest
+
 
 def extra_names_from_request(request):
     extra_bits = request.args.getlist("_extra")
@@ -113,6 +115,17 @@ class ExtraRegistry:
             self._allowed_names[key] = names
         return names
 
+    def validate_requested(self, requested, scope):
+        """
+        Raise BadRequest if any requested extra name is not a public extra
+        for this scope. Used by data formats such as .json - HTML pages
+        silently ignore unknown names instead.
+        """
+        allowed = self._allowed_names_for_scope(scope, include_internal=False)
+        unknown = sorted(name for name in requested if name not in allowed)
+        if unknown:
+            raise BadRequest("Unknown _extra: {}".format(", ".join(unknown)))
+
     async def resolve(self, requested, context, scope, include_internal=False):
         allowed_names = self._allowed_names_for_scope(scope, include_internal)
         requested_names = [name for name in requested if name in allowed_names]

datasette/forbidden.py

@@ -1,9 +1,19 @@
 from datasette import hookimpl, Response
+from .utils import add_cors_headers
 
 
 @hookimpl(trylast=True)
 def forbidden(datasette, request, message):
     async def inner():
+        if (
+            request.path.split("?")[0].endswith(".json")
+            or "application/json" in (request.headers.get("accept") or "")
+            or request.headers.get("content-type") == "application/json"
+        ):
+            headers = {}
+            if datasette.cors:
+                add_cors_headers(headers)
+            return Response.error(message, 403, headers=headers)
         return Response.html(
             await datasette.render_template(
                 "error.html",

datasette/handle_exception.py

@@ -1,5 +1,5 @@
 from datasette import hookimpl, Response
-from .utils import add_cors_headers
+from .utils import add_cors_headers, error_body
 from .utils.asgi import (
     Base400,
 )
@@ -28,6 +28,7 @@ def handle_exception(datasette, request, exception):
             rich.get_console().print_exception(show_locals=True)
 
         title = None
+        plain_message = None
         if isinstance(exception, Base400):
             status = exception.status
             info = {}
@@ -36,6 +37,7 @@ def handle_exception(datasette, request, exception):
             status = exception.status
             info = exception.error_dict
             message = exception.message
+            plain_message = exception.plain_message
             if exception.message_is_html:
                 message = Markup(message)
             title = exception.title
@@ -45,6 +47,13 @@ def handle_exception(datasette, request, exception):
             message = str(exception)
             traceback.print_exc()
         templates = [f"{status}.html", "error.html"]
+        headers = {}
+        if datasette.cors:
+            add_cors_headers(headers)
+        if request.path.split("?")[0].endswith(".json"):
+            body = dict(info)
+            body.update(error_body(plain_message or message, status))
+            return Response.json(body, status=status, headers=headers)
         info.update(
             {
                 "ok": False,
@@ -53,24 +62,18 @@ def handle_exception(datasette, request, exception):
                 "title": title,
             }
         )
-        headers = {}
-        if datasette.cors:
-            add_cors_headers(headers)
-        if request.path.split("?")[0].endswith(".json"):
-            return Response.json(info, status=status, headers=headers)
-        else:
-            environment = datasette.get_jinja_environment(request)
-            template = environment.select_template(templates)
-            return Response.html(
-                await template.render_async(
-                    dict(
-                        info,
-                        urls=datasette.urls,
-                        menu_links=lambda: [],
-                    )
-                ),
-                status=status,
-                headers=headers,
-            )
+        environment = datasette.get_jinja_environment(request)
+        template = environment.select_template(templates)
+        return Response.html(
+            await template.render_async(
+                dict(
+                    info,
+                    urls=datasette.urls,
+                    menu_links=lambda: [],
+                )
+            ),
+            status=status,
+            headers=headers,
+        )
 
     return inner

datasette/renderer.py

@@ -1,6 +1,7 @@
 import json
 from datasette.extras import extra_names_from_request
 from datasette.utils import (
+    error_body,
     value_as_boolean,
     remove_infinites,
     CustomJSONEncoder,
@@ -52,8 +53,7 @@ def json_renderer(request, args, data, error, truncated=None):
     if error:
         shape = "objects"
         status_code = 400
-        data["error"] = error
-        data["ok"] = False
+        data.update(error_body(error, status_code))
 
     if truncated is not None:
         data["truncated"] = truncated
@@ -87,7 +87,8 @@ def json_renderer(request, args, data, error, truncated=None):
                         object_rows[pk_string] = row
                     data = object_rows
             if shape_error:
-                data = {"ok": False, "error": shape_error}
+                status_code = 400
+                data = error_body(shape_error, status_code)
         elif shape == "array":
             data = data["rows"]
 
@@ -100,12 +101,7 @@ def json_renderer(request, args, data, error, truncated=None):
             data["rows"] = [list(row.values()) for row in data["rows"]]
     else:
         status_code = 400
-        data = {
-            "ok": False,
-            "error": f"Invalid _shape: {shape}",
-            "status": 400,
-            "title": None,
-        }
+        data = error_body(f"Invalid _shape: {shape}", status_code)
 
     # Don't include "columns" in output
     # https://github.com/simonw/datasette/issues/2136

datasette/stored_queries.py

@@ -62,7 +62,6 @@ def stored_query_to_dict(query: StoredQuery) -> dict[str, Any]:
         "description_html": query.description_html,
         "hide_sql": query.hide_sql,
         "fragment": query.fragment,
-        "params": list(query.parameters),
         "parameters": list(query.parameters),
         "is_write": query.is_write,
         "is_private": query.is_private,
@@ -84,7 +83,6 @@ def stored_query_page_to_dict(page: StoredQueryPage) -> dict[str, Any]:
     return {
         "queries": [stored_query_to_dict(query) for query in page.queries],
         "next": page.next,
-        "has_more": page.has_more,
         "limit": page.limit,
     }
 

datasette/templates/debug_actions.html

@@ -9,7 +9,7 @@
 {% include "_permissions_debug_tabs.html" %}
 
 <p style="margin-bottom: 2em;">
-  This Datasette instance has registered {{ data|length }} action{{ data|length != 1 and "s" or "" }}.
+  This Datasette instance has registered {{ data.actions|length }} action{{ data.actions|length != 1 and "s" or "" }}.
   Actions are used by the permission system to control access to different features.
 </p>
 
@@ -26,7 +26,7 @@
     </tr>
   </thead>
   <tbody>
-    {% for action in data %}
+    {% for action in data.actions %}
     <tr>
       <td><strong>{{ action.name }}</strong></td>
       <td>{% if action.abbr %}<code>{{ action.abbr }}</code>{% endif %}</td>

datasette/templates/debug_allowed.html

@@ -49,7 +49,7 @@
 
         <div class="form-section">
             <label for="page_size">Page size:</label>
-            <input type="number" id="page_size" name="page_size" value="50" min="1" max="200" style="max-width: 100px;">
+            <input type="number" id="page_size" name="_size" value="50" min="1" max="200" style="max-width: 100px;">
             <small>Number of results per page (max 200)</small>
         </div>
 
@@ -88,7 +88,7 @@ const hasDebugPermission = {{ 'true' if has_debug_permission else 'false' }};
 (function() {
     const params = populateFormFromURL();
     const action = params.get('action');
-    const page = params.get('page');
+    const page = params.get('_page');
     if (action) {
         fetchResults(page ? parseInt(page) : 1);
     }
@@ -102,14 +102,14 @@ async function fetchResults(page = 1) {
     const params = new URLSearchParams();
 
     for (const [key, value] of formData.entries()) {
-        if (value && key !== 'page_size') {
+        if (value && key !== '_size' && key !== '_page') {
             params.append(key, value);
         }
     }
 
     const pageSize = document.getElementById('page_size').value || '50';
-    params.append('page', page.toString());
-    params.append('page_size', pageSize);
+    params.append('_page', page.toString());
+    params.append('_size', pageSize);
 
     try {
         const response = await fetch('{{ urls.path("-/allowed.json") }}?' + params.toString(), {

datasette/templates/debug_rules.html

@@ -37,7 +37,7 @@
 
         <div class="form-section">
             <label for="page_size">Page size:</label>
-            <input type="number" id="page_size" name="page_size" value="50" min="1" max="200" style="max-width: 100px;">
+            <input type="number" id="page_size" name="_size" value="50" min="1" max="200" style="max-width: 100px;">
             <small>Number of results per page (max 200)</small>
         </div>
 
@@ -75,7 +75,7 @@ const submitBtn = document.getElementById('submit-btn');
 (function() {
     const params = populateFormFromURL();
     const action = params.get('action');
-    const page = params.get('page');
+    const page = params.get('_page');
     if (action) {
         fetchResults(page ? parseInt(page) : 1);
     }
@@ -89,14 +89,14 @@ async function fetchResults(page = 1) {
     const params = new URLSearchParams();
 
     for (const [key, value] of formData.entries()) {
-        if (value && key !== 'page_size') {
+        if (value && key !== '_size' && key !== '_page') {
             params.append(key, value);
         }
     }
 
     const pageSize = document.getElementById('page_size').value || '50';
-    params.append('page', page.toString());
-    params.append('page_size', pageSize);
+    params.append('_page', page.toString());
+    params.append('_size', pageSize);
 
     try {
         const response = await fetch('{{ urls.path("-/rules.json") }}?' + params.toString(), {

datasette/tokens.py

@@ -18,6 +18,21 @@ if TYPE_CHECKING:
     from datasette.app import Datasette
 
 
+class TokenInvalid(Exception):
+    """
+    Raised by a TokenHandler when a token it recognizes is invalid -
+    for example a bad signature, malformed payload or expired token.
+
+    Datasette responds to this with an HTTP 401 error. Handlers should
+    return None instead for tokens they do not recognize at all, so that
+    other registered handlers get a chance to verify them.
+    """
+
+    def __init__(self, message="Invalid token"):
+        self.message = message
+        super().__init__(message)
+
+
 @dataclasses.dataclass
 class TokenRestrictions:
     """
@@ -108,8 +123,12 @@ class TokenHandler:
 
     async def verify_token(self, datasette: "Datasette", token: str) -> Optional[dict]:
         """
-        Verify a token and return an actor dict, or None if this handler
-        does not recognize the token.
+        Verify a token and return an actor dict.
+
+        Return None if this handler does not recognize the token at all,
+        so other handlers can try it. Raise TokenInvalid if the token is
+        recognized but invalid (bad signature, malformed, expired) - the
+        request will fail with a 401 error.
         """
         raise NotImplementedError
 
@@ -147,29 +166,32 @@ class SignedTokenHandler(TokenHandler):
     async def verify_token(self, datasette: "Datasette", token: str) -> Optional[dict]:
         prefix = "dstok_"
 
-        if not datasette.setting("allow_signed_tokens"):
+        if not token.startswith(prefix):
+            # Not one of our tokens - leave it for other handlers
             return None
 
+        if not datasette.setting("allow_signed_tokens"):
+            raise TokenInvalid(
+                "Signed tokens are not enabled for this Datasette instance"
+            )
+
         max_signed_tokens_ttl = datasette.setting("max_signed_tokens_ttl")
 
-        if not token.startswith(prefix):
-            return None
-
         raw = token[len(prefix) :]
         try:
             decoded = datasette.unsign(raw, namespace="token")
         except itsdangerous.BadSignature:
-            return None
+            raise TokenInvalid("Invalid token signature")
 
         if "t" not in decoded:
-            return None
+            raise TokenInvalid("Invalid token: no timestamp")
         created = decoded["t"]
         if not isinstance(created, int):
-            return None
+            raise TokenInvalid("Invalid token: invalid timestamp")
 
         duration = decoded.get("d")
         if duration is not None and not isinstance(duration, int):
-            return None
+            raise TokenInvalid("Invalid token: invalid duration")
 
         if (duration is None and max_signed_tokens_ttl) or (
             duration is not None
@@ -180,7 +202,7 @@ class SignedTokenHandler(TokenHandler):
 
         if duration:
             if time.time() - created > duration:
-                return None
+                raise TokenInvalid("Token has expired")
 
         actor = {"id": decoded["a"], "token": "dstok"}
 

datasette/utils/__init__.py

@@ -1318,6 +1318,54 @@ async def derive_named_parameters(db: "Database", sql: str) -> List[str]:
     return named_parameters(sql)
 
 
+def parse_size_limit(value, default, maximum, name="_size"):
+    """
+    Parse a page-size parameter using the same semantics as the table
+    view's ?_size=: blank means default, "max" means maximum, integers
+    must be 0 or greater and no larger than maximum. Raises ValueError
+    with a message suitable for a 400 response.
+    """
+    if value in (None, ""):
+        return default
+    if value == "max":
+        return maximum
+    try:
+        size = int(value)
+        if size < 0:
+            raise ValueError
+    except ValueError:
+        raise ValueError("{} must be a positive integer".format(name))
+    if size > maximum:
+        raise ValueError("{} must be <= {}".format(name, maximum))
+    return size
+
+
+UNSTABLE_API_MESSAGE = (
+    "This API is not part of Datasette's stable interface and may change at any time"
+)
+
+
+def error_body(messages, status):
+    """
+    The canonical JSON error body used by every Datasette JSON error response:
+
+        {"ok": False, "error": "...", "errors": ["...", ...], "status": 400}
+
+    "error" is all of the messages joined with "; ", "errors" is the full
+    list, "status" matches the HTTP status code. Callers may add extra
+    context keys to the returned dictionary but must not remove these four.
+    """
+    if isinstance(messages, str):
+        messages = [messages]
+    messages = [str(message) for message in messages]
+    return {
+        "ok": False,
+        "error": "; ".join(messages),
+        "errors": messages,
+        "status": status,
+    }
+
+
 def add_cors_headers(headers):
     headers["Access-Control-Allow-Origin"] = "*"
     headers["Access-Control-Allow-Headers"] = "Authorization, Content-Type"

datasette/utils/asgi.py

@@ -1,6 +1,6 @@
 import json
 from typing import Optional
-from datasette.utils import MultiParams, calculate_etag, sha256_file
+from datasette.utils import MultiParams, calculate_etag, error_body, sha256_file
 from datasette.utils.multipart import (
     parse_form_data,
     MultipartParseError,
@@ -575,6 +575,18 @@ class Response:
             content_type="application/json; charset=utf-8",
         )
 
+    @classmethod
+    def error(cls, messages, status=400, headers=None):
+        """
+        A JSON error response using Datasette's standard error format.
+
+        messages can be a single string or a list of strings. For errors
+        that should content-negotiate between JSON and HTML, raise
+        Forbidden, NotFound, BadRequest or DatasetteError instead and let
+        Datasette's error handling hooks build the response.
+        """
+        return cls.json(error_body(messages, status), status=status, headers=headers)
+
     @classmethod
     def redirect(cls, path, status=302, headers=None):
         headers = headers or {}

datasette/views/base.py

@@ -28,12 +28,15 @@ class DatasetteError(Exception):
         status=500,
         template=None,
         message_is_html=False,
+        plain_message=None,
     ):
         self.message = message
         self.title = title
         self.error_dict = error_dict or {}
         self.status = status
         self.message_is_html = message_is_html
+        # Plain text used for JSON error responses when message is HTML
+        self.plain_message = plain_message
 
 
 class View:
@@ -49,9 +52,7 @@ class View:
             request.path.endswith(".json")
             or request.headers.get("content-type") == "application/json"
         ):
-            response = Response.json(
-                {"ok": False, "error": "Method not allowed"}, status=405
-            )
+            response = Response.error("Method not allowed", 405)
         else:
             response = Response.text("Method not allowed", status=405)
         return response
@@ -90,9 +91,7 @@ class BaseView:
             request.path.endswith(".json")
             or request.headers.get("content-type") == "application/json"
         ):
-            response = Response.json(
-                {"ok": False, "error": "Method not allowed"}, status=405
-            )
+            response = Response.error("Method not allowed", 405)
         else:
             response = Response.text("Method not allowed", status=405)
         return response
@@ -180,10 +179,6 @@ class BaseView:
         return view
 
 
-def _error(messages, status=400):
-    return Response.json({"ok": False, "errors": messages}, status=status)
-
-
 async def stream_csv(datasette, fetch_data, request, database):
     kwargs = {}
     stream = request.args.get("_stream")

datasette/views/database.py

@@ -8,7 +8,7 @@ import markupsafe
 import os
 import textwrap
 
-from datasette.extras import extra_names_from_request
+from datasette.extras import extra_names_from_request, ExtraScope
 from datasette.database import QueryInterrupted
 from datasette.resources import DatabaseResource, QueryResource
 from datasette.stored_queries import StoredQuery, stored_query_to_dict
@@ -16,6 +16,7 @@ from datasette.write_sql import QueryWriteRejected
 from datasette.utils import (
     add_cors_headers,
     await_me_maybe,
+    error_body,
     call_with_supported_arguments,
     named_parameters as derive_named_parameters,
     format_bytes,
@@ -607,11 +608,7 @@ class QueryView(View):
                 "_json"
             ):
                 return Response.json(
-                    {
-                        "ok": False,
-                        "message": ex.message,
-                        "redirect": None,
-                    },
+                    dict(error_body([ex.message], 403), redirect=None),
                     status=403,
                 )
             datasette.add_message(request, ex.message, datasette.ERROR)
@@ -681,12 +678,17 @@ class QueryView(View):
             redirect_url = stored_query.on_error_redirect
             ok = False
         if should_return_json:
+            if ok:
+                return Response.json(
+                    {
+                        "ok": True,
+                        "message": message,
+                        "redirect": redirect_url,
+                    }
+                )
             return Response.json(
-                {
-                    "ok": ok,
-                    "message": message,
-                    "redirect": redirect_url,
-                }
+                dict(error_body([message], 400), redirect=redirect_url),
+                status=400,
             )
         else:
             datasette.add_message(request, message, message_type)
@@ -817,6 +819,10 @@ class QueryView(View):
                     title="SQL Interrupted",
                     status=400,
                     message_is_html=True,
+                    plain_message=(
+                        "SQL query took too long. The time limit is"
+                        " controlled by the sql_time_limit_ms setting."
+                    ),
                 )
             except sqlite3.DatabaseError as ex:
                 query_error = str(ex)
@@ -849,8 +855,11 @@ class QueryView(View):
 
             return await stream_csv(datasette, fetch_data_for_csv, request, db.name)
         elif format_ in datasette.renderers.keys():
+            if not sql:
+                raise DatasetteError("?sql= is required", status=400)
             data = {"ok": True, "rows": rows, "columns": columns}
             extras = extra_names_from_request(request)
+            table_extra_registry.validate_requested(extras, ExtraScope.QUERY)
             if extras:
                 query_extra_context = QueryExtraContext(
                     datasette=datasette,

datasette/views/execute_write.py

@@ -2,10 +2,10 @@ import re
 from urllib.parse import urlencode
 
 from datasette.resources import DatabaseResource
-from datasette.utils import sqlite3
+from datasette.utils import UNSTABLE_API_MESSAGE, sqlite3
 from datasette.utils.asgi import Response
 
-from .base import BaseView, _error
+from .base import BaseView
 from .database import display_rows as display_query_rows
 from .query_helpers import (
     QueryValidationError,
@@ -348,7 +348,7 @@ class ExecuteWriteView(BaseView):
         )
         if not db.is_mutable:
             return _block_framing(
-                _error(
+                Response.error(
                     ["Cannot execute write SQL because this database is immutable."],
                     403,
                 )
@@ -367,10 +367,10 @@ class ExecuteWriteView(BaseView):
             actor=request.actor,
         ):
             return _block_framing(
-                _error(["Permission denied: need execute-write-sql"], 403)
+                Response.error(["Permission denied: need execute-write-sql"], 403)
             )
         if not db.is_mutable:
-            return _block_framing(_error(["Database is immutable"], 403))
+            return _block_framing(Response.error(["Database is immutable"], 403))
 
         data = {}
         is_json = request.headers.get("content-type", "").startswith("application/json")
@@ -384,7 +384,7 @@ class ExecuteWriteView(BaseView):
             )
         except QueryValidationError as ex:
             if _wants_json(request, is_json, data):
-                return _block_framing(_error([ex.message], ex.status))
+                return _block_framing(Response.error([ex.message], ex.status))
             if ex.flash:
                 self.ds.add_message(request, ex.message, self.ds.ERROR)
             return await self._render_form(
@@ -405,7 +405,7 @@ class ExecuteWriteView(BaseView):
         except sqlite3.DatabaseError as ex:
             message = str(ex)
             if wants_json:
-                return _block_framing(_error([message], 400))
+                return _block_framing(Response.error([message], 400))
             return await self._render_form(
                 request,
                 db,
@@ -488,20 +488,18 @@ class ExecuteWriteAnalyzeView(BaseView):
             actor=request.actor,
         ):
             return _block_framing(
-                _error(["Permission denied: need execute-write-sql"], 403)
+                Response.error(["Permission denied: need execute-write-sql"], 403)
             )
 
         invalid_keys = set(request.args) - {"sql"}
         if invalid_keys:
             return _block_framing(
-                _error(
+                Response.error(
                     ["Invalid keys: {}".format(", ".join(sorted(invalid_keys)))],
                     400,
                 )
             )
         sql = request.args.get("sql") or ""
-        return _block_framing(
-            Response.json(
-                await _execute_write_analysis_data(self.ds, db, sql, request.actor)
-            )
-        )
+        analysis = await _execute_write_analysis_data(self.ds, db, sql, request.actor)
+        analysis["unstable"] = UNSTABLE_API_MESSAGE
+        return _block_framing(Response.json(analysis))

datasette/views/index.py

@@ -6,6 +6,7 @@ from datasette.utils import (
     await_me_maybe,
     make_slot_function,
     CustomJSONEncoder,
+    UNSTABLE_API_MESSAGE,
 )
 from datasette.utils.asgi import Response
 from datasette.version import __version__
@@ -151,7 +152,9 @@ class IndexView(BaseView):
             return Response(
                 json.dumps(
                     {
-                        "databases": {db["name"]: db for db in databases},
+                        "ok": True,
+                        "unstable": UNSTABLE_API_MESSAGE,
+                        "databases": databases,
                         "metadata": await self.ds.get_instance_metadata(),
                     },
                     cls=CustomJSONEncoder,

datasette/views/query_helpers.py

@@ -13,6 +13,7 @@ from datasette.write_sql import (
     operation_is_write,
 )
 from datasette.utils import (
+    parse_size_limit,
     named_parameters as derive_named_parameters,
     escape_sqlite,
     path_from_row_pks,
@@ -32,7 +33,6 @@ _query_fields = {
     "hide_sql",
     "fragment",
     "parameters",
-    "params",
     "is_private",
     "on_success_message",
     "on_success_redirect",
@@ -94,13 +94,11 @@ def _as_optional_bool(value, name):
     raise QueryValidationError("{} must be 0 or 1".format(name))
 
 
-def _query_list_limit(value, default=50):
-    if value in (None, ""):
-        return default
+def _query_list_limit(value, default, maximum):
     try:
-        return min(max(1, int(value)), 1000)
+        return parse_size_limit(value, default, maximum)
     except ValueError as ex:
-        raise QueryValidationError("_size must be an integer") from ex
+        raise QueryValidationError(str(ex)) from ex
 
 
 def _derived_query_parameters(sql):
@@ -541,7 +539,7 @@ async def _prepare_query_create(datasette, request, db, data):
         raise QueryValidationError("Writable query fields require writable SQL")
 
     parameters = _coerce_query_parameters(
-        data.get("parameters", data.get("params")),
+        data.get("parameters"),
         derived,
     )
     return {
@@ -586,9 +584,9 @@ async def _prepare_query_update(datasette, request, db, existing: StoredQuery, u
             actor=request.actor,
         )
 
-    if "parameters" in update or "params" in update:
+    if "parameters" in update:
         parameters = _coerce_query_parameters(
-            update.get("parameters", update.get("params")),
+            update.get("parameters"),
             derived,
         )
     elif "sql" in update:

datasette/views/row.py

@@ -12,7 +12,7 @@ from datasette.utils.asgi import NotFound, Forbidden, PayloadTooLarge, Response
 from datasette.database import QueryInterrupted
 from datasette.events import UpdateRowEvent, DeleteRowEvent
 from datasette.resources import TableResource
-from .base import BaseView, DatasetteError, _error, stream_csv
+from .base import BaseView, DatasetteError, stream_csv
 from datasette.utils import (
     add_cors_headers,
     await_me_maybe,
@@ -23,7 +23,6 @@ from datasette.utils import (
     InvalidSql,
     make_slot_function,
     path_from_row_pks,
-    path_with_added_args,
     path_with_format,
     path_with_removed_args,
     to_css_class,
@@ -201,6 +200,10 @@ class RowView(BaseView):
                 title="SQL Interrupted",
                 status=400,
                 message_is_html=True,
+                plain_message=(
+                    "SQL query took too long. The time limit is"
+                    " controlled by the sql_time_limit_ms setting."
+                ),
             )
         except (sqlite3.OperationalError, InvalidSql) as e:
             raise DatasetteError(str(e), title="Invalid SQL", status=400)
@@ -212,18 +215,6 @@ class RowView(BaseView):
         end = time.perf_counter()
         data["query_ms"] = (end - start) * 1000
 
-        # Special case for .jsono extension - redirect to _shape=objects
-        if format_ == "jsono":
-            return self.redirect(
-                request,
-                path_with_added_args(
-                    request,
-                    {"_shape": "objects"},
-                    path=request.path.rsplit(".jsono", 1)[0] + ".json",
-                ),
-                forward_querystring=False,
-            )
-
         if format_ in self.ds.renderers.keys():
             # Dispatch request to the correct output format renderer
             # (CSV is not handled here due to streaming)
@@ -612,6 +603,9 @@ class RowView(BaseView):
         }
 
         extras = extra_names_from_request(request)
+        if request.url_vars.get("format"):
+            # Data formats reject unknown extras; HTML ignores them
+            table_extra_registry.validate_requested(extras, ExtraScope.ROW)
 
         # Process extras
         row_extra_context = RowExtraContext(
@@ -721,11 +715,13 @@ async def _resolve_row_and_check_permission(datasette, request, permission):
     try:
         resolved = await datasette.resolve_row(request)
     except DatabaseNotFound as e:
-        return False, _error(["Database not found: {}".format(e.database_name)], 404)
+        return False, Response.error(
+            ["Database not found: {}".format(e.database_name)], 404
+        )
     except TableNotFound as e:
-        return False, _error(["Table not found: {}".format(e.table)], 404)
+        return False, Response.error(["Table not found: {}".format(e.table)], 404)
     except RowNotFound as e:
-        return False, _error(["Record not found: {}".format(e.pk_values)], 404)
+        return False, Response.error(["Record not found: {}".format(e.pk_values)], 404)
 
     # Ensure user has permission to delete this row
     if not await datasette.allowed(
@@ -733,7 +729,7 @@ async def _resolve_row_and_check_permission(datasette, request, permission):
         resource=TableResource(database=resolved.db.name, table=resolved.table),
         actor=request.actor,
     ):
-        return False, _error(["Permission denied"], 403)
+        return False, Response.error(["Permission denied"], 403)
 
     return True, resolved
 
@@ -758,7 +754,7 @@ class RowDeleteView(BaseView):
         try:
             await resolved.db.execute_write_fn(delete_row, request=request)
         except Exception as e:
-            return _error([str(e)], 500)
+            return Response.error([str(e)], 400)
 
         await self.ds.track_event(
             DeleteRowEvent(
@@ -797,24 +793,24 @@ class RowUpdateView(BaseView):
         try:
             data = await request.json()
         except json.JSONDecodeError as e:
-            return _error(["Invalid JSON: {}".format(e)])
+            return Response.error(["Invalid JSON: {}".format(e)])
         except PayloadTooLarge as e:
-            return _error([str(e)], 413)
+            return Response.error([str(e)], 413)
 
         if not isinstance(data, dict):
-            return _error(["JSON must be a dictionary"])
+            return Response.error(["JSON must be a dictionary"])
         if "update" not in data or not isinstance(data["update"], dict):
-            return _error(["JSON must contain an update dictionary"])
+            return Response.error(["JSON must contain an update dictionary"])
 
         invalid_keys = set(data.keys()) - {"update", "return", "alter"}
         if invalid_keys:
-            return _error(["Invalid keys: {}".format(", ".join(invalid_keys))])
+            return Response.error(["Invalid keys: {}".format(", ".join(invalid_keys))])
 
         update = data["update"]
         try:
             update = decode_write_json_row(update)
         except WriteJsonValueError as e:
-            return _error([str(e)], 400)
+            return Response.error([str(e)], 400)
 
         # Validate column types
         from datasette.views.table import _validate_column_types
@@ -823,7 +819,7 @@ class RowUpdateView(BaseView):
             self.ds, resolved.db.name, resolved.table, [update]
         )
         if ct_errors:
-            return _error(ct_errors, 400)
+            return Response.error(ct_errors, 400)
 
         alter = data.get("alter")
         if alter and not await self.ds.allowed(
@@ -831,7 +827,7 @@ class RowUpdateView(BaseView):
             resource=TableResource(database=resolved.db.name, table=resolved.table),
             actor=request.actor,
         ):
-            return _error(["Permission denied for alter-table"], 403)
+            return Response.error(["Permission denied for alter-table"], 403)
 
         def update_row(conn):
             sqlite_utils.Database(conn)[resolved.table].update(
@@ -841,7 +837,7 @@ class RowUpdateView(BaseView):
         try:
             await resolved.db.execute_write_fn(update_row, request=request)
         except Exception as e:
-            return _error([str(e)], 400)
+            return Response.error([str(e)], 400)
 
         result = {"ok": True}
         returned_row = None
@@ -850,7 +846,7 @@ class RowUpdateView(BaseView):
                 resolved.sql, resolved.params, truncate=True
             )
             returned_row = results.dicts()[0]
-            result["row"] = returned_row
+            result["rows"] = [returned_row]
 
         await self.ds.track_event(
             UpdateRowEvent(

datasette/views/special.py

@@ -6,9 +6,12 @@ from datasette.events import LogoutEvent, LoginEvent, CreateTokenEvent
 from datasette.resources import DatabaseResource, TableResource
 from datasette.utils.asgi import Response, Forbidden
 from datasette.utils import (
+    UNSTABLE_API_MESSAGE,
     actor_matches_allow,
+    parse_size_limit,
     add_cors_headers,
     await_me_maybe,
+    error_body,
     tilde_encode,
     tilde_decode,
 )
@@ -52,9 +55,9 @@ class JsonDataView(BaseView):
         if self.permission:
             await self.ds.ensure_permission(action=self.permission, actor=request.actor)
         if self.needs_request:
-            data = self.data_callback(request)
+            data = await await_me_maybe(self.data_callback(request))
         else:
-            data = self.data_callback()
+            data = await await_me_maybe(self.data_callback())
 
         # Return JSON or HTML depending on format parameter
         as_format = request.url_vars.get("format")
@@ -62,6 +65,8 @@ class JsonDataView(BaseView):
             headers = {}
             if self.ds.cors:
                 add_cors_headers(headers)
+            if isinstance(data, dict):
+                data = {"ok": True, **data}
             return Response.json(data, headers=headers)
         else:
             context = {
@@ -292,6 +297,12 @@ class PermissionsDebugView(BaseView):
         response, status = await _check_permission_for_actor(
             self.ds, permission, parent, child, actor
         )
+        if response.get("ok"):
+            response = {
+                "ok": True,
+                "unstable": UNSTABLE_API_MESSAGE,
+                **response,
+            }
         return Response.json(response, status=status)
 
 
@@ -348,29 +359,32 @@ class AllowedResourcesView(BaseView):
     async def _allowed_payload(self, request, has_debug_permission):
         action = request.args.get("action")
         if not action:
-            return {"error": "action parameter is required"}, 400
+            return error_body("action parameter is required", 400), 400
         if action not in self.ds.actions:
-            return {"error": f"Unknown action: {action}"}, 404
+            return error_body(f"Unknown action: {action}", 404), 404
 
         actor = request.actor if isinstance(request.actor, dict) else None
         actor_id = actor.get("id") if actor else None
         parent_filter = request.args.get("parent")
         child_filter = request.args.get("child")
         if child_filter and not parent_filter:
-            return {"error": "parent must be provided when child is specified"}, 400
+            return (
+                error_body("parent must be provided when child is specified", 400),
+                400,
+            )
 
         try:
-            page = int(request.args.get("page", "1"))
-            page_size = int(request.args.get("page_size", "50"))
+            page = int(request.args.get("_page", "1"))
+            if page < 1:
+                raise ValueError
         except ValueError:
-            return {"error": "page and page_size must be integers"}, 400
-        if page < 1:
-            return {"error": "page must be >= 1"}, 400
-        if page_size < 1:
-            return {"error": "page_size must be >= 1"}, 400
-        max_page_size = 200
-        if page_size > max_page_size:
-            page_size = max_page_size
+            return error_body("_page must be a positive integer", 400), 400
+        try:
+            page_size = parse_size_limit(
+                request.args.get("_size"), default=50, maximum=200
+            )
+        except ValueError as ex:
+            return error_body(str(ex), 400), 400
         offset = (page - 1) * page_size
 
         # Use the simplified allowed_resources method
@@ -410,6 +424,7 @@ class AllowedResourcesView(BaseView):
             # If catalog tables don't exist yet, return empty results
             return (
                 {
+                    "ok": True,
                     "action": action,
                     "actor_id": actor_id,
                     "page": page,
@@ -434,16 +449,17 @@ class AllowedResourcesView(BaseView):
         def build_page_url(page_number):
             pairs = []
             for key in request.args:
-                if key in {"page", "page_size"}:
+                if key in {"_page", "_size"}:
                     continue
                 for value in request.args.getlist(key):
                     pairs.append((key, value))
-            pairs.append(("page", str(page_number)))
-            pairs.append(("page_size", str(page_size)))
+            pairs.append(("_page", str(page_number)))
+            pairs.append(("_size", str(page_size)))
             query = urllib.parse.urlencode(pairs)
             return f"{request.path}?{query}"
 
         response = {
+            "ok": True,
             "action": action,
             "actor_id": actor_id,
             "page": page,
@@ -485,26 +501,24 @@ class PermissionRulesView(BaseView):
         # JSON API - action parameter is required
         action = request.args.get("action")
         if not action:
-            return Response.json({"error": "action parameter is required"}, status=400)
+            return Response.error("action parameter is required", 400)
         if action not in self.ds.actions:
-            return Response.json({"error": f"Unknown action: {action}"}, status=404)
+            return Response.error(f"Unknown action: {action}", 404)
 
         actor = request.actor if isinstance(request.actor, dict) else None
 
         try:
-            page = int(request.args.get("page", "1"))
-            page_size = int(request.args.get("page_size", "50"))
+            page = int(request.args.get("_page", "1"))
+            if page < 1:
+                raise ValueError
         except ValueError:
-            return Response.json(
-                {"error": "page and page_size must be integers"}, status=400
+            return Response.error("_page must be a positive integer", 400)
+        try:
+            page_size = parse_size_limit(
+                request.args.get("_size"), default=50, maximum=200
             )
-        if page < 1:
-            return Response.json({"error": "page must be >= 1"}, status=400)
-        if page_size < 1:
-            return Response.json({"error": "page_size must be >= 1"}, status=400)
-        max_page_size = 200
-        if page_size > max_page_size:
-            page_size = max_page_size
+        except ValueError as ex:
+            return Response.error(str(ex), 400)
         offset = (page - 1) * page_size
 
         from datasette.utils.actions_sql import build_permission_rules_sql
@@ -555,16 +569,17 @@ class PermissionRulesView(BaseView):
         def build_page_url(page_number):
             pairs = []
             for key in request.args:
-                if key in {"page", "page_size"}:
+                if key in {"_page", "_size"}:
                     continue
                 for value in request.args.getlist(key):
                     pairs.append((key, value))
-            pairs.append(("page", str(page_number)))
-            pairs.append(("page_size", str(page_size)))
+            pairs.append(("_page", str(page_number)))
+            pairs.append(("_size", str(page_size)))
             query = urllib.parse.urlencode(pairs)
             return f"{request.path}?{query}"
 
         response = {
+            "ok": True,
             "action": action,
             "actor_id": (actor or {}).get("id") if actor else None,
             "page": page,
@@ -587,15 +602,15 @@ class PermissionRulesView(BaseView):
 async def _check_permission_for_actor(ds, action, parent, child, actor):
     """Shared logic for checking permissions. Returns a dict with check results."""
     if action not in ds.actions:
-        return {"error": f"Unknown action: {action}"}, 404
+        return error_body(f"Unknown action: {action}", 404), 404
 
     if child and not parent:
-        return {"error": "parent is required when child is provided"}, 400
+        return error_body("parent is required when child is provided", 400), 400
 
     # Use the action's properties to create the appropriate resource object
     action_obj = ds.actions.get(action)
     if not action_obj:
-        return {"error": f"Unknown action: {action}"}, 400
+        return error_body(f"Unknown action: {action}", 400), 400
 
     # Global actions (no resource_class) don't have a resource
     if action_obj.resource_class is None:
@@ -610,11 +625,12 @@ async def _check_permission_for_actor(ds, action, parent, child, actor):
         resource_obj = action_obj.resource_class(parent)
     else:
         # This shouldn't happen given validation in Action.__post_init__
-        return {"error": f"Invalid action configuration: {action}"}, 500
+        return error_body(f"Invalid action configuration: {action}", 500), 500
 
     allowed = await ds.allowed(action=action, resource=resource_obj, actor=actor)
 
     response = {
+        "ok": True,
         "action": action,
         "allowed": bool(allowed),
         "resource": {
@@ -651,7 +667,7 @@ class PermissionCheckView(BaseView):
         # JSON API - action parameter is required
         action = request.args.get("action")
         if not action:
-            return Response.json({"error": "action parameter is required"}, status=400)
+            return Response.error("action parameter is required", 400)
 
         parent = request.args.get("parent")
         child = request.args.get("child")
@@ -1198,7 +1214,7 @@ class JumpView(BaseView):
                 match["display_name"] = row["display_name"]
             matches.append(match)
 
-        return Response.json({"matches": matches, "truncated": truncated})
+        return Response.json({"ok": True, "matches": matches, "truncated": truncated})
 
 
 class SchemaBaseView(BaseView):
@@ -1220,7 +1236,7 @@ class SchemaBaseView(BaseView):
         headers = {}
         if self.ds.cors:
             add_cors_headers(headers)
-        return Response.json(data, headers=headers)
+        return Response.json({"ok": True, **data}, headers=headers)
 
     def format_error_response(self, error_message, format_, status=404):
         """Format error response based on requested format."""
@@ -1229,7 +1245,7 @@ class SchemaBaseView(BaseView):
             if self.ds.cors:
                 add_cors_headers(headers)
             return Response.json(
-                {"ok": False, "error": error_message}, status=status, headers=headers
+                error_body(error_message, status), status=status, headers=headers
             )
         else:
             return Response.text(error_message, status=status)
@@ -1305,17 +1321,17 @@ class DatabaseSchemaView(SchemaBaseView):
         database_name = request.url_vars["database"]
         format_ = request.url_vars.get("format") or "html"
 
-        # Check if database exists
-        if database_name not in self.ds.databases:
-            return self.format_error_response("Database not found", format_)
-
-        # Check view-database permission
+        # Permission check comes first, so actors without view-database
+        # cannot distinguish existing databases from missing ones
         await self.ds.ensure_permission(
             action="view-database",
             resource=DatabaseResource(database=database_name),
             actor=request.actor,
         )
 
+        if database_name not in self.ds.databases:
+            return self.format_error_response("Database not found", format_)
+
         schema = await self.get_database_schema(database_name)
 
         if format_ == "json":
@@ -1349,6 +1365,9 @@ class TableSchemaView(SchemaBaseView):
             actor=request.actor,
         )
 
+        if database_name not in self.ds.databases:
+            return self.format_error_response("Database not found", format_)
+
         # Get schema for the table
         db = self.ds.databases[database_name]
         result = await db.execute(

datasette/views/stored_queries.py

@@ -2,10 +2,10 @@ from urllib.parse import parse_qsl, urlencode
 
 from datasette.resources import DatabaseResource, QueryResource
 from datasette.stored_queries import stored_query_to_dict
-from datasette.utils import sqlite3, tilde_decode
+from datasette.utils import UNSTABLE_API_MESSAGE, sqlite3, tilde_decode
 from datasette.utils.asgi import Response
 
-from .base import BaseView, _error
+from .base import BaseView
 from .query_helpers import (
     QueryValidationError,
     _as_bool,
@@ -34,12 +34,14 @@ class QueryParametersView(BaseView):
             resource=DatabaseResource(db.name),
             actor=request.actor,
         ):
-            return _block_framing(_error(["Permission denied: need execute-sql"], 403))
+            return _block_framing(
+                Response.error(["Permission denied: need execute-sql"], 403)
+            )
 
         invalid_keys = set(request.args) - {"sql"}
         if invalid_keys:
             return _block_framing(
-                _error(
+                Response.error(
                     ["Invalid keys: {}".format(", ".join(sorted(invalid_keys)))],
                     400,
                 )
@@ -47,8 +49,16 @@ class QueryParametersView(BaseView):
         try:
             parameters = _derived_query_parameters(request.args.get("sql") or "")
         except QueryValidationError as ex:
-            return _block_framing(_error([ex.message], ex.status))
-        return _block_framing(Response.json({"ok": True, "parameters": parameters}))
+            return _block_framing(Response.error([ex.message], ex.status))
+        return _block_framing(
+            Response.json(
+                {
+                    "ok": True,
+                    "unstable": UNSTABLE_API_MESSAGE,
+                    "parameters": parameters,
+                }
+            )
+        )
 
 
 def _query_list_url(path, query_string, *, set_args=None, remove_args=None):
@@ -82,11 +92,12 @@ class QueryListView(BaseView):
             limit = _query_list_limit(
                 request.args.get("_size"),
                 default=20 if format_ == "html" else 50,
+                maximum=self.ds.max_returned_rows,
             )
             is_write = _as_optional_bool(request.args.get("is_write"), "is_write")
             is_private = _as_optional_bool(request.args.get("is_private"), "is_private")
         except QueryValidationError as ex:
-            return _error([ex.message], ex.status)
+            return Response.error([ex.message], ex.status)
 
         page = await self.ds.list_queries(
             database,
@@ -111,9 +122,9 @@ class QueryListView(BaseView):
                 if key != "_next"
             ]
             pairs.append(("_next", page.next))
-            next_url = "{}?{}".format(
-                query_list_path,
-                urlencode(pairs),
+            next_url = self.ds.absolute_url(
+                request,
+                "{}?{}".format(request.path, urlencode(pairs)),
             )
 
         current_filters = {
@@ -199,7 +210,6 @@ class QueryListView(BaseView):
             "queries": page.queries,
             "next": page.next,
             "next_url": next_url,
-            "has_more": page.has_more,
             "limit": page.limit,
             "show_private_note": any(query.is_private for query in page.queries),
             "show_trusted_note": any(query.is_trusted for query in page.queries),
@@ -298,28 +308,30 @@ class QueryCreateAnalyzeView(BaseView):
             resource=DatabaseResource(db.name),
             actor=request.actor,
         ):
-            return _block_framing(_error(["Permission denied: need execute-sql"], 403))
+            return _block_framing(
+                Response.error(["Permission denied: need execute-sql"], 403)
+            )
         if not await self.ds.allowed(
             action="store-query",
             resource=DatabaseResource(db.name),
             actor=request.actor,
         ):
-            return _block_framing(_error(["Permission denied: need store-query"], 403))
+            return _block_framing(
+                Response.error(["Permission denied: need store-query"], 403)
+            )
 
         invalid_keys = set(request.args) - {"sql"}
         if invalid_keys:
             return _block_framing(
-                _error(
+                Response.error(
                     ["Invalid keys: {}".format(", ".join(sorted(invalid_keys)))],
                     400,
                 )
             )
         sql = request.args.get("sql") or ""
-        return _block_framing(
-            Response.json(
-                await _query_create_analysis_data(self.ds, db, sql, request.actor)
-            )
-        )
+        analysis = await _query_create_analysis_data(self.ds, db, sql, request.actor)
+        analysis["unstable"] = UNSTABLE_API_MESSAGE
+        return _block_framing(Response.json(analysis))
 
 
 class QueryStoreView(QueryCreateView):
@@ -346,13 +358,13 @@ class QueryStoreView(QueryCreateView):
             resource=DatabaseResource(db.name),
             actor=request.actor,
         ):
-            return _error(["Permission denied: need execute-sql"], 403)
+            return Response.error(["Permission denied: need execute-sql"], 403)
         if not await self.ds.allowed(
             action="store-query",
             resource=DatabaseResource(db.name),
             actor=request.actor,
         ):
-            return _error(["Permission denied: need store-query"], 403)
+            return Response.error(["Permission denied: need store-query"], 403)
 
         is_json = False
         query_data = {}
@@ -369,7 +381,7 @@ class QueryStoreView(QueryCreateView):
                 return await self._error_response(
                     request, db, query_data, ex.message, ex.status
                 )
-            return _error([ex.message], ex.status)
+            return Response.error([ex.message], ex.status)
 
         prepared.pop("analysis")
         name = prepared.pop("name")
@@ -378,13 +390,18 @@ class QueryStoreView(QueryCreateView):
         except sqlite3.IntegrityError as ex:
             if not is_json and isinstance(query_data, dict):
                 return await self._error_response(request, db, query_data, str(ex), 400)
-            return _error([str(ex)], 400)
+            return Response.error([str(ex)], 400)
 
         query = await self.ds.get_query(db.name, name)
         assert query is not None
         if is_json:
             return Response.json(
-                {"ok": True, "query": stored_query_to_dict(query)}, status=201
+                {
+                    "ok": True,
+                    "unstable": UNSTABLE_API_MESSAGE,
+                    "query": stored_query_to_dict(query),
+                },
+                status=201,
             )
         self.ds.add_message(request, "Query saved", self.ds.INFO)
         return Response.redirect(self.ds.urls.path(self.ds.urls.table(db.name, name)))
@@ -398,14 +415,20 @@ class QueryDefinitionView(BaseView):
         query_name = tilde_decode(request.url_vars["query"])
         query = await self.ds.get_query(db.name, query_name)
         if query is None:
-            return _error(["Query not found: {}".format(query_name)], 404)
+            return Response.error(["Query not found: {}".format(query_name)], 404)
         if not await self.ds.allowed(
             action="view-query",
             resource=QueryResource(db.name, query_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied"], 403)
-        return Response.json({"ok": True, "query": stored_query_to_dict(query)})
+            return Response.error(["Permission denied"], 403)
+        return Response.json(
+            {
+                "ok": True,
+                "unstable": UNSTABLE_API_MESSAGE,
+                "query": stored_query_to_dict(query),
+            }
+        )
 
 
 class QueryUpdateView(BaseView):
@@ -416,15 +439,17 @@ class QueryUpdateView(BaseView):
         query_name = tilde_decode(request.url_vars["query"])
         existing = await self.ds.get_query(db.name, query_name)
         if existing is None:
-            return _error(["Query not found: {}".format(query_name)], 404)
+            return Response.error(["Query not found: {}".format(query_name)], 404)
         if not await self.ds.allowed(
             action="update-query",
             resource=QueryResource(db.name, query_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied: need update-query"], 403)
+            return Response.error(["Permission denied: need update-query"], 403)
         if existing.is_trusted:
-            return _error(["Trusted queries cannot be updated using the API"], 403)
+            return Response.error(
+                ["Trusted queries cannot be updated using the API"], 403
+            )
 
         try:
             data, _ = await _json_or_form_payload(request)
@@ -450,7 +475,7 @@ class QueryUpdateView(BaseView):
                 self.ds, request, db, existing, update
             )
         except QueryValidationError as ex:
-            return _error([ex.message], ex.status)
+            return Response.error([ex.message], ex.status)
 
         await self.ds.update_query(db.name, query_name, **update_kwargs)
         if data.get("return"):
@@ -507,32 +532,32 @@ class QueryEditView(BaseView):
     async def get(self, request):
         db, query_name, existing = await self._load(request)
         if existing is None:
-            return _error(["Query not found: {}".format(query_name)], 404)
+            return Response.error(["Query not found: {}".format(query_name)], 404)
         await self.ds.ensure_permission(
             action="update-query",
             resource=QueryResource(db.name, query_name),
             actor=request.actor,
         )
         if existing.is_trusted:
-            return _error(["Trusted queries cannot be edited"], 403)
+            return Response.error(["Trusted queries cannot be edited"], 403)
         return await self._render_form(request, db, existing)
 
     async def post(self, request):
         db, query_name, existing = await self._load(request)
         if existing is None:
-            return _error(["Query not found: {}".format(query_name)], 404)
+            return Response.error(["Query not found: {}".format(query_name)], 404)
         if not await self.ds.allowed(
             action="update-query",
             resource=QueryResource(db.name, query_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied: need update-query"], 403)
+            return Response.error(["Permission denied: need update-query"], 403)
         if existing.is_trusted:
-            return _error(["Trusted queries cannot be edited"], 403)
+            return Response.error(["Trusted queries cannot be edited"], 403)
 
         data, _ = await _json_or_form_payload(request)
         if not isinstance(data, dict):
-            return _error(["Invalid form submission"], 400)
+            return Response.error(["Invalid form submission"], 400)
         sql = data.get("sql")
         sql = existing.sql if sql is None else sql.strip()
         title = data.get("title") or ""
@@ -604,12 +629,16 @@ class QueryDeleteView(BaseView):
     async def get(self, request):
         db, query_name, existing = await self._load(request)
         if existing is None:
-            return _error(["Query not found: {}".format(query_name)], 404)
+            return Response.error(["Query not found: {}".format(query_name)], 404)
         await self.ds.ensure_permission(
             action="delete-query",
             resource=QueryResource(db.name, query_name),
             actor=request.actor,
         )
+        if existing.is_trusted:
+            return Response.error(
+                ["Trusted queries cannot be deleted using the API"], 403
+            )
         return await self.render(
             ["query_delete.html"],
             request,
@@ -624,13 +653,17 @@ class QueryDeleteView(BaseView):
     async def post(self, request):
         db, query_name, existing = await self._load(request)
         if existing is None:
-            return _error(["Query not found: {}".format(query_name)], 404)
+            return Response.error(["Query not found: {}".format(query_name)], 404)
         if not await self.ds.allowed(
             action="delete-query",
             resource=QueryResource(db.name, query_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied: need delete-query"], 403)
+            return Response.error(["Permission denied: need delete-query"], 403)
+        if existing.is_trusted:
+            return Response.error(
+                ["Trusted queries cannot be deleted using the API"], 403
+            )
 
         data, is_json = await _json_or_form_payload(request)
         await self.ds.remove_query(db.name, query_name)

datasette/views/table.py

@@ -60,7 +60,7 @@ from dataclasses import dataclass, field
 
 from datasette.extras import ExtraScope
 from . import Context, from_extra
-from .base import BaseView, DatasetteError, _error, stream_csv
+from .base import BaseView, DatasetteError, stream_csv
 from .database import QueryView
 from .table_create_alter import (
     ALTER_TABLE_COLUMN_TYPES,
@@ -72,6 +72,7 @@ from .table_create_alter import (
 from .table_extras import (
     TABLE_EXTRA_BUNDLES,
     TableExtraContext,
+    count_is_truncated,
     precompute_database_action_permissions,
     precompute_table_action_permissions,
     resolve_table_extras,
@@ -106,7 +107,6 @@ class TableContext(Context):
     human_description_en: str = from_extra()
     is_view: bool = from_extra()
     metadata: dict = from_extra()
-    next_url: str = from_extra()
     primary_keys: list = from_extra()
     private: bool = from_extra()
     query: dict = from_extra()
@@ -123,6 +123,11 @@ class TableContext(Context):
         metadata={"help": "True if the data for this page was retrieved without errors"}
     )
     next: str = field(metadata={"help": "Pagination token for the next page, or None"})
+    next_url: str = field(
+        metadata={
+            "help": "Full URL for the next page of results, or None if there are no more pages. See :ref:`json_api_pagination`."
+        }
+    )
     count_truncated: bool = field(
         metadata={
             "help": "True if ``count`` is a capped lower bound rather than an exact total, because Datasette stopped counting after its configured row-count limit."
@@ -950,9 +955,7 @@ class TableInsertView(BaseView):
         def _errors(errors):
             return None, errors, {}
 
-        if not request.headers.get("content-type").startswith("application/json"):
-            # TODO: handle form-encoded data
-            return _errors(["Invalid content-type, must be application/json"])
+        # The body is parsed as JSON regardless of the Content-Type header
         try:
             data = await request.json()
         except json.JSONDecodeError as e:
@@ -1036,7 +1039,7 @@ class TableInsertView(BaseView):
         try:
             resolved = await self.ds.resolve_table(request)
         except NotFound as e:
-            return _error([e.args[0]], 404)
+            return Response.error([e.args[0]], 404)
         db = resolved.db
         database_name = db.name
         table_name = resolved.table
@@ -1044,7 +1047,7 @@ class TableInsertView(BaseView):
         # Table must exist (may handle table creation in the future)
         db = self.ds.get_database(database_name)
         if not await db.table_exists(table_name):
-            return _error(["Table not found: {}".format(table_name)], 404)
+            return Response.error(["Table not found: {}".format(table_name)], 404)
 
         if upsert:
             # Must have insert-row AND upsert-row permissions
@@ -1060,7 +1063,7 @@ class TableInsertView(BaseView):
                     actor=request.actor,
                 )
             ):
-                return _error(
+                return Response.error(
                     ["Permission denied: need both insert-row and update-row"], 403
                 )
         else:
@@ -1070,10 +1073,10 @@ class TableInsertView(BaseView):
                 resource=TableResource(database=database_name, table=table_name),
                 actor=request.actor,
             ):
-                return _error(["Permission denied"], 403)
+                return Response.error(["Permission denied"], 403)
 
         if not db.is_mutable:
-            return _error(["Database is immutable"], 403)
+            return Response.error(["Database is immutable"], 403)
 
         pks = await db.primary_keys(table_name)
 
@@ -1082,20 +1085,20 @@ class TableInsertView(BaseView):
                 request, db, table_name, pks, upsert
             )
         except PayloadTooLarge as e:
-            return _error([str(e)], 413)
+            return Response.error([str(e)], 413)
         if errors:
-            return _error(errors, 400)
+            return Response.error(errors, 400)
         try:
             rows = decode_write_json_rows(rows)
         except WriteJsonValueError as e:
-            return _error([str(e)], 400)
+            return Response.error([str(e)], 400)
 
         # Validate column types
         ct_errors = await _validate_column_types(
             self.ds, database_name, table_name, rows
         )
         if ct_errors:
-            return _error(ct_errors, 400)
+            return Response.error(ct_errors, 400)
 
         num_rows = len(rows)
 
@@ -1109,14 +1112,16 @@ class TableInsertView(BaseView):
         alter = extras.get("alter")
 
         if upsert and (ignore or replace):
-            return _error(["Upsert does not support ignore or replace"], 400)
+            return Response.error(["Upsert does not support ignore or replace"], 400)
 
         if replace and not await self.ds.allowed(
             action="update-row",
             resource=TableResource(database=database_name, table=table_name),
             actor=request.actor,
         ):
-            return _error(['Permission denied: need update-row to use "replace"'], 403)
+            return Response.error(
+                ['Permission denied: need update-row to use "replace"'], 403
+            )
 
         initial_schema = None
         if alter:
@@ -1126,7 +1131,7 @@ class TableInsertView(BaseView):
                 resource=TableResource(database=database_name, table=table_name),
                 actor=request.actor,
             ):
-                return _error(["Permission denied for alter-table"], 403)
+                return Response.error(["Permission denied for alter-table"], 403)
             # Track initial schema to check if it changed later
             initial_schema = await db.execute_fn(
                 lambda conn: sqlite_utils.Database(conn)[table_name].schema
@@ -1166,7 +1171,7 @@ class TableInsertView(BaseView):
         try:
             rows = await db.execute_write_fn(insert_or_upsert_rows, request=request)
         except Exception as e:
-            return _error([str(e)])
+            return Response.error([str(e)])
         result = {"ok": True}
         if should_return:
             if upsert:
@@ -1247,7 +1252,7 @@ class TableSetColumnTypeView(BaseView):
         try:
             resolved = await self.ds.resolve_table(request)
         except NotFound as e:
-            return _error([e.args[0]], 404)
+            return Response.error([e.args[0]], 404)
 
         database_name = resolved.db.name
         table_name = resolved.table
@@ -1257,43 +1262,39 @@ class TableSetColumnTypeView(BaseView):
             resource=TableResource(database=database_name, table=table_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied"], 403)
-
-        content_type = request.headers.get("content-type") or ""
-        if not content_type.startswith("application/json"):
-            return _error(["Invalid content-type, must be application/json"], 400)
+            return Response.error(["Permission denied"], 403)
 
         try:
             data = await request.json()
         except json.JSONDecodeError as e:
-            return _error(["Invalid JSON: {}".format(e)], 400)
+            return Response.error(["Invalid JSON: {}".format(e)], 400)
         except PayloadTooLarge as e:
-            return _error([str(e)], 413)
+            return Response.error([str(e)], 413)
 
         if not isinstance(data, dict):
-            return _error(["JSON must be a dictionary"], 400)
+            return Response.error(["JSON must be a dictionary"], 400)
 
         invalid_keys = set(data.keys()) - {"column", "column_type"}
         if invalid_keys:
-            return _error(
+            return Response.error(
                 ['Invalid parameter: "{}"'.format('", "'.join(sorted(invalid_keys)))],
                 400,
             )
 
         if "column" not in data:
-            return _error(['"column" is required'], 400)
+            return Response.error(['"column" is required'], 400)
         column = data["column"]
         if not isinstance(column, str):
-            return _error(['"column" must be a string'], 400)
+            return Response.error(['"column" must be a string'], 400)
 
         if "column_type" not in data:
-            return _error(['"column_type" is required'], 400)
+            return Response.error(['"column_type" is required'], 400)
 
         column_details = await self.ds._get_resource_column_details(
             database_name, table_name
         )
         if column not in column_details:
-            return _error(["Column not found: {}".format(column)], 400)
+            return Response.error(["Column not found: {}".format(column)], 400)
 
         column_type_data = data["column_type"]
         if column_type_data is None:
@@ -1310,11 +1311,11 @@ class TableSetColumnTypeView(BaseView):
             )
 
         if not isinstance(column_type_data, dict):
-            return _error(['"column_type" must be an object or null'], 400)
+            return Response.error(['"column_type" must be an object or null'], 400)
 
         invalid_column_type_keys = set(column_type_data.keys()) - {"type", "config"}
         if invalid_column_type_keys:
-            return _error(
+            return Response.error(
                 [
                     'Invalid column_type parameter: "{}"'.format(
                         '", "'.join(sorted(invalid_column_type_keys))
@@ -1324,24 +1325,24 @@ class TableSetColumnTypeView(BaseView):
             )
 
         if "type" not in column_type_data:
-            return _error(['"column_type.type" is required'], 400)
+            return Response.error(['"column_type.type" is required'], 400)
         column_type = column_type_data["type"]
         if not isinstance(column_type, str):
-            return _error(['"column_type.type" must be a string'], 400)
+            return Response.error(['"column_type.type" must be a string'], 400)
 
         config = column_type_data.get("config")
         if config is not None and not isinstance(config, dict):
-            return _error(['"column_type.config" must be a dictionary'], 400)
+            return Response.error(['"column_type.config" must be a dictionary'], 400)
 
         if column_type not in self.ds._column_types:
-            return _error(["Unknown column type: {}".format(column_type)], 400)
+            return Response.error(["Unknown column type: {}".format(column_type)], 400)
 
         try:
             await self.ds.set_column_type(
                 database_name, table_name, column, column_type, config
             )
         except ValueError as e:
-            return _error([str(e)], 400)
+            return Response.error([str(e)], 400)
 
         return Response.json(
             {
@@ -1365,22 +1366,22 @@ class TableDropView(BaseView):
         try:
             resolved = await self.ds.resolve_table(request)
         except NotFound as e:
-            return _error([e.args[0]], 404)
+            return Response.error([e.args[0]], 404)
         db = resolved.db
         database_name = db.name
         table_name = resolved.table
         # Table must exist
         db = self.ds.get_database(database_name)
         if not await db.table_exists(table_name):
-            return _error(["Table not found: {}".format(table_name)], 404)
+            return Response.error(["Table not found: {}".format(table_name)], 404)
         if not await self.ds.allowed(
             action="drop-table",
             resource=TableResource(database=database_name, table=table_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied"], 403)
+            return Response.error(["Permission denied"], 403)
         if not db.is_mutable:
-            return _error(["Database is immutable"], 403)
+            return Response.error(["Database is immutable"], 403)
         confirm = False
         try:
             data = await request.json()
@@ -1388,7 +1389,7 @@ class TableDropView(BaseView):
         except json.JSONDecodeError:
             pass
         except PayloadTooLarge as e:
-            return _error([str(e)], 413)
+            return Response.error([str(e)], 413)
 
         if not confirm:
             return Response.json(
@@ -1565,7 +1566,7 @@ class TableAutocompleteView(BaseView):
             and value_as_boolean(initial_arg)
         )
         if not q and not initial:
-            return Response.json({"rows": []})
+            return Response.json({"ok": True, "rows": []})
         params = {
             "q": q,
             "like": "%{}%".format(_escape_like(q)),
@@ -1628,10 +1629,13 @@ class TableAutocompleteView(BaseView):
                     custom_time_limit=AUTOCOMPLETE_TIME_LIMIT_MS,
                 )
             except QueryInterrupted:
-                return Response.json({"rows": []})
+                return Response.json({"ok": True, "rows": []})
 
         return Response.json(
-            {"rows": _autocomplete_response_rows(results.rows, pks, label_column)}
+            {
+                "ok": True,
+                "rows": _autocomplete_response_rows(results.rows, pks, label_column),
+            }
         )
 
 
@@ -2290,10 +2294,16 @@ async def table_view_data(
 
     # Resolve extras
     extras = extra_names_from_request(request)
+    if not extra_extras:
+        # Data formats reject unknown extras; the HTML path (which passes
+        # extra_extras={"_html"}) resolves internal extras of its own
+        table_extra_registry.validate_requested(extras, ExtraScope.TABLE)
     if any(k for k in request.args.keys() if k == "_facet" or k.startswith("_facet_")):
         extras.add("facet_results")
     if request.args.get("_shape") == "object":
         extras.add("primary_keys")
+    if "count" in extras:
+        extras.add("count_truncated")
     if extra_extras:
         extras.update(extra_extras)
 
@@ -2348,6 +2358,7 @@ async def table_view_data(
     data = {
         "ok": True,
         "next": next_value and str(next_value) or None,
+        "next_url": next_url,
     }
     data.update(
         await resolve_table_extras(
@@ -2372,7 +2383,7 @@ async def table_view_data(
     data["rows"] = transformed_rows
 
     if context_for_html_hack:
-        data["count_truncated"] = _count_truncated_for_table_page(
+        data["count_truncated"] = count_is_truncated(
             datasette, db, database_name, table_name, count_sql, data.get("count")
         )
         data.update(extra_context_from_filters)
@@ -2440,24 +2451,6 @@ async def table_view_data(
     return data, rows[:page_size], columns, expanded_columns, sql, next_url
 
 
-def _count_truncated_for_table_page(
-    datasette, db, database_name, table_name, count_sql, count
-):
-    if count != db.count_limit + 1:
-        return False
-    if (
-        not db.is_mutable
-        and datasette.inspect_data
-        and count_sql == f"select count(*) from {table_name} "
-    ):
-        try:
-            datasette.inspect_data[database_name]["tables"][table_name]["count"]
-            return False
-        except KeyError:
-            pass
-    return True
-
-
 async def _next_value_and_url(
     datasette,
     db,

datasette/views/table_create_alter.py

@@ -29,7 +29,7 @@ from datasette.utils import (
 from datasette.utils.asgi import NotFound, PayloadTooLarge, Response
 from datasette.utils.sqlite import sqlite_hidden_table_names
 
-from .base import BaseView, _error
+from .base import BaseView
 
 CREATE_TABLE_COLUMN_TYPES = ["text", "integer", "float", "blob"]
 CREATE_TABLE_SQLITE_TYPES = {
@@ -805,22 +805,22 @@ class TableCreateView(BaseView):
             resource=DatabaseResource(database=database_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied"], 403)
+            return Response.error(["Permission denied"], 403)
 
         try:
             data = await request.json()
         except json.JSONDecodeError as e:
-            return _error(["Invalid JSON: {}".format(e)])
+            return Response.error(["Invalid JSON: {}".format(e)])
         except PayloadTooLarge as e:
-            return _error([str(e)], 413)
+            return Response.error([str(e)], 413)
 
         if not isinstance(data, dict):
-            return _error(["JSON must be an object"])
+            return Response.error(["JSON must be an object"])
 
         try:
             create_request = CreateTableRequest.model_validate(data)
         except ValidationError as e:
-            return _error(_create_table_pydantic_errors(e))
+            return Response.error(_create_table_pydantic_errors(e))
 
         ignore = create_request.ignore
         replace = create_request.replace
@@ -832,7 +832,7 @@ class TableCreateView(BaseView):
                 resource=DatabaseResource(database=database_name),
                 actor=request.actor,
             ):
-                return _error(["Permission denied: need update-row"], 403)
+                return Response.error(["Permission denied: need update-row"], 403)
 
         table_name = create_request.table
         table_exists = await db.table_exists(table_name)
@@ -846,11 +846,11 @@ class TableCreateView(BaseView):
                 resource=DatabaseResource(database=database_name),
                 actor=request.actor,
             ):
-                return _error(["Permission denied: need insert-row"], 403)
+                return Response.error(["Permission denied: need insert-row"], 403)
             try:
                 rows = decode_write_json_rows(rows)
             except WriteJsonValueError as e:
-                return _error([str(e)], 400)
+                return Response.error([str(e)], 400)
 
         alter = False
         if rows:
@@ -865,7 +865,9 @@ class TableCreateView(BaseView):
                         resource=DatabaseResource(database=database_name),
                         actor=request.actor,
                     ):
-                        return _error(["Permission denied: need alter-table"], 403)
+                        return Response.error(
+                            ["Permission denied: need alter-table"], 403
+                        )
                     alter = True
 
         pk = create_request.pk
@@ -881,7 +883,7 @@ class TableCreateView(BaseView):
             elif len(actual_pks) > 1 and pks and set(pks) != set(actual_pks):
                 bad_pks = True
             if bad_pks:
-                return _error(["pk cannot be changed for existing table"])
+                return Response.error(["pk cannot be changed for existing table"])
             pks = actual_pks
 
         initial_schema = None
@@ -924,7 +926,7 @@ class TableCreateView(BaseView):
         try:
             schema = await db.execute_write_fn(create_table, request=request)
         except Exception as e:
-            return _error([str(e)])
+            return Response.error([str(e)])
 
         if initial_schema is not None and initial_schema != schema:
             await self.ds.track_event(
@@ -999,7 +1001,7 @@ class DatabaseForeignKeyTargetsView(BaseView):
                 actor=request.actor,
             )
         if not (can_create_table or can_alter_table):
-            return _error(["Permission denied: need create-table"], 403)
+            return Response.error(["Permission denied: need create-table"], 403)
 
         hidden_tables = await db.execute_fn(
             lambda conn: set(sqlite_hidden_table_names(conn))
@@ -1028,21 +1030,21 @@ class TableForeignKeySuggestionsView(BaseView):
         try:
             resolved = await self.ds.resolve_table(request)
         except NotFound as e:
-            return _error([e.args[0]], 404)
+            return Response.error([e.args[0]], 404)
 
         db = resolved.db
         database_name = db.name
         table_name = resolved.table
 
         if resolved.is_view:
-            return _error(["Cannot suggest foreign keys for a view"], 400)
+            return Response.error(["Cannot suggest foreign keys for a view"], 400)
 
         if not await self.ds.allowed(
             action="alter-table",
             resource=TableResource(database=database_name, table=table_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied: need alter-table"], 403)
+            return Response.error(["Permission denied: need alter-table"], 403)
 
         source_columns, targets, current_by_column = await db.execute_fn(
             lambda conn: _foreign_key_suggestion_metadata(conn, table_name)
@@ -1150,7 +1152,7 @@ class TableAlterView(BaseView):
         try:
             resolved = await self.ds.resolve_table(request)
         except NotFound as e:
-            return _error([e.args[0]], 404)
+            return Response.error([e.args[0]], 404)
 
         db = resolved.db
         database_name = db.name
@@ -1161,29 +1163,25 @@ class TableAlterView(BaseView):
             resource=TableResource(database=database_name, table=table_name),
             actor=request.actor,
         ):
-            return _error(["Permission denied: need alter-table"], 403)
+            return Response.error(["Permission denied: need alter-table"], 403)
 
         if not db.is_mutable:
-            return _error(["Database is immutable"], 403)
-
-        content_type = request.headers.get("content-type") or ""
-        if not content_type.startswith("application/json"):
-            return _error(["Invalid content-type, must be application/json"], 400)
+            return Response.error(["Database is immutable"], 403)
 
         try:
             data = await request.json()
         except json.JSONDecodeError as e:
-            return _error(["Invalid JSON: {}".format(e)], 400)
+            return Response.error(["Invalid JSON: {}".format(e)], 400)
         except PayloadTooLarge as e:
-            return _error([str(e)], 413)
+            return Response.error([str(e)], 413)
 
         if not isinstance(data, dict):
-            return _error(["JSON must be a dictionary"], 400)
+            return Response.error(["JSON must be a dictionary"], 400)
 
         try:
             alter_request = AlterTableRequest.model_validate(data)
         except ValidationError as e:
-            return _error(_pydantic_errors(e), 400)
+            return Response.error(_pydantic_errors(e), 400)
 
         def alter_table(conn):
             before_schema = _table_schema_from_conn(conn, table_name)
@@ -1332,7 +1330,7 @@ class TableAlterView(BaseView):
                 alter_table, request=request
             )
         except Exception as e:
-            return _error([str(e)], 400)
+            return Response.error([str(e)], 400)
 
         altered = before_schema != after_schema
         if altered:

datasette/views/table_extras.py

@@ -141,6 +141,39 @@ class CountExtra(Extra):
         return count
 
 
+def count_is_truncated(datasette, db, database_name, table_name, count_sql, count):
+    if count != db.count_limit + 1:
+        return False
+    if (
+        not db.is_mutable
+        and datasette.inspect_data
+        and count_sql == f"select count(*) from {table_name} "
+    ):
+        try:
+            datasette.inspect_data[database_name]["tables"][table_name]["count"]
+            return False
+        except KeyError:
+            pass
+    return True
+
+
+class CountTruncatedExtra(Extra):
+    description = "True if the count hit Datasette's counting limit, meaning the real number of matching rows is at least the reported count."
+    example = ExtraExample("/fixtures/facetable.json?_extra=count,count_truncated")
+    scopes = {ExtraScope.TABLE}
+    expensive = True
+
+    async def resolve(self, context, count):
+        return count_is_truncated(
+            context.datasette,
+            context.db,
+            context.database_name,
+            context.table_name,
+            context.count_sql,
+            count,
+        )
+
+
 class FacetInstancesProvider(Provider):
     scopes = {ExtraScope.TABLE}
 
@@ -288,21 +321,6 @@ class HumanDescriptionEnExtra(Extra):
         return human_description_en
 
 
-class NextUrlExtra(Extra):
-    description = "Full URL for the next page of results"
-    example = ExtraExample(
-        "/fixtures/facetable.json?_size=1&_extra=next_url",
-        note=(
-            "``null`` if there are no more pages of results. "
-            "See :ref:`json_api_pagination`."
-        ),
-    )
-    scopes = {ExtraScope.TABLE}
-
-    async def resolve(self, context):
-        return context.next_url
-
-
 class ColumnsExtra(Extra):
     description = "List of column names returned by this table, row or query."
     example = ExtraExample("/fixtures/facetable.json?_extra=columns")
@@ -1217,7 +1235,6 @@ TABLE_EXTRA_BUNDLES = {
         "count",
         "count_sql",
         "human_description_en",
-        "next_url",
         "metadata",
         "query",
         "columns",
@@ -1246,13 +1263,13 @@ TABLE_EXTRA_BUNDLES = {
 
 TABLE_EXTRA_CLASSES = [
     CountExtra,
+    CountTruncatedExtra,
     CountSqlExtra,
     FacetResultsExtra,
     FacetsTimedOutExtra,
     SuggestedFacetsExtra,
     FacetInstancesProvider,
     HumanDescriptionEnExtra,
-    NextUrlExtra,
     ColumnsExtra,
     AllColumnsExtra,
     PrimaryKeysExtra,

docs/authentication.rst

@@ -991,7 +991,9 @@ The ``/-/create-token`` page cannot be accessed by actors that are authenticated
 
 Datasette plugins that implement their own form of API token authentication should follow this convention.
 
-You can disable the signed token feature entirely using the :ref:`allow_signed_tokens <setting_allow_signed_tokens>` setting.
+If a request presents a token that a token handler recognizes but rejects - an invalid signature, a malformed payload or an expired token - Datasette responds with a ``401`` status, the :ref:`standard JSON error format <json_api_errors>` and a ``WWW-Authenticate: Bearer error="invalid_token"`` header. This means API clients can distinguish "your token needs to be renewed" (``401``) from "your token does not grant this permission" (``403``). A ``Bearer`` token that no registered handler recognizes at all is ignored, since it may be intended for an authentication plugin.
+
+You can disable the signed token feature entirely using the :ref:`allow_signed_tokens <setting_allow_signed_tokens>` setting. Requests presenting a ``dstok_`` token while the feature is disabled receive a ``401``.
 
 .. _authentication_cli_create_token:
 
@@ -1149,6 +1151,8 @@ It also provides an interface for running hypothetical permission checks against
 
 This is designed to help administrators and plugin authors understand exactly how permission checks are being carried out, in order to effectively configure Datasette's permission system.
 
+These debug endpoints are exempt from the :ref:`JSON API stability promise <json_api_stability>` - their JSON shapes may change in future releases.
+
 .. _AllowedResourcesView:
 
 Allowed resources view
@@ -1158,7 +1162,7 @@ The ``/-/allowed`` endpoint displays resources that the current actor can access
 
 This endpoint provides an interactive HTML form interface. Add ``.json`` to the URL path (e.g. ``/-/allowed.json``) to get the raw JSON response instead.
 
-Pass ``?action=view-table`` (or another action) to select the action. Optional ``parent=`` and ``child=`` query parameters can narrow the results to a specific database/table pair.
+Pass ``?action=view-table`` (or another action) to select the action. Optional ``parent=`` and ``child=`` query parameters can narrow the results to a specific database/table pair. Results are paginated: ``?_size=`` sets the page size (default 50, maximum 200, ``max`` for the maximum) and ``?_page=`` selects a page.
 
 This endpoint is publicly accessible to help users understand their own permissions. The potentially sensitive ``reason`` field is only shown to users with the ``permissions-debug`` permission - it shows the plugins and explanatory reasons that were responsible for each decision.
 
@@ -1171,7 +1175,7 @@ The ``/-/rules`` endpoint displays all permission rules (both allow and deny) fo
 
 This endpoint provides an interactive HTML form interface. Add ``.json`` to the URL path (e.g. ``/-/rules.json?action=view-table``) to get the raw JSON response instead.
 
-Pass ``?action=`` as a query parameter to specify which action to check.
+Pass ``?action=`` as a query parameter to specify which action to check. The ``?_size=`` and ``?_page=`` pagination parameters work the same as on ``/-/allowed``.
 
 This endpoint requires the ``permissions-debug`` permission.
 

docs/changelog.rst

@@ -17,6 +17,42 @@ Unreleased
 - The table and row JSON APIs now support ``?_extra=column_details`` for returning SQLite schema details for columns, including declared type, SQLite affinity, primary key, ``NOT NULL``, default and hidden-column metadata.
 - POST bodies that Datasette reads fully into memory - such as JSON submitted to the write API - are now capped by the new :ref:`setting_max_post_body_bytes` setting, defaulting to 2MB. Oversized requests are rejected with an HTTP 413 error as soon as the limit is exceeded, protecting smaller servers from memory exhaustion. File uploads are unaffected - ``request.form()`` streams those to disk and has its own separate limits.
 
+This release also includes the results of a `detailed consistency review <https://github.com/simonw/datasette/pull/2824>`__ of Datasette's JSON API in preparation for the 1.0 stable release. Several of these changes are backwards-incompatible with previous 1.0 alphas. The new :ref:`API stability documentation <json_api_stability>` describes exactly which parts of the JSON API are covered by the 1.0 stability promise.
+
+JSON API: breaking changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- JSON error responses now use a single canonical format across every endpoint: ``{"ok": false, "error": "...", "errors": [...], "status": 400}``. The ``error`` key joins all error messages together, ``errors`` is the full list of messages and ``status`` always matches the HTTP status code. The legacy ``title`` key is no longer included in JSON errors (it remains available to the HTML error template), and endpoints that previously returned bare ``{"error": ...}`` objects have been updated. See :ref:`json_api_errors`.
+- Every JSON object success response now includes ``"ok": true``, including introspection endpoints such as ``/-/versions`` and ``/-/settings``.
+- ``/-/plugins.json``, ``/-/databases.json`` and ``/-/actions.json`` now return objects - ``{"ok": true, "plugins": [...]}`` and equivalents - instead of top-level JSON arrays, so these responses can gain additional keys in the future without a breaking change. The ``datasette plugins`` CLI command still outputs a plain array.
+- ``/-/databases`` now only lists databases the current actor is allowed to view. It previously listed every attached database, including their filesystem paths, to any actor with ``view-instance``.
+- Requests with an invalid or expired ``Authorization: Bearer`` token now receive a ``401`` status with the standard error body and a ``WWW-Authenticate: Bearer error="invalid_token"`` header, instead of being silently treated as unauthenticated. Bearer tokens that no registered token handler recognizes are still ignored, so authentication plugins with their own token formats keep working. Plugin :ref:`token handlers <plugin_hook_register_token_handler>` can raise the new ``datasette.TokenInvalid`` exception to trigger the same behavior.
+- Permission errors for JSON requests now return the standard JSON error format with a ``403`` status. The default forbidden handling previously rendered an HTML error page even for ``.json`` requests.
+- ``POST`` to a write canned query now returns a ``400`` error when the SQL fails to execute, instead of a ``200`` status with ``"ok": false`` in the body. The error response includes the standard error keys plus a ``"redirect"`` key.
+- The :ref:`row update API <RowUpdateView>` with ``"return": true`` now responds with a ``"rows"`` list, matching insert and upsert, instead of a singular ``"row"`` object.
+- Row delete write failures - such as a constraint violation raised by a trigger - now return ``400`` instead of ``500``, matching the other write endpoints.
+- ``/<database>/-/query.json`` with a missing or blank ``?sql=`` parameter now returns a ``400`` error, as the CSV format already did, instead of a ``200`` with empty rows.
+- Unknown ``?_extra=`` names now return a ``400`` error for JSON and other data formats, instead of being silently ignored. HTML pages continue to ignore unknown names.
+- Table JSON responses now include ``next_url`` alongside ``next`` by default - both are ``null`` on the final page. The now-redundant ``?_extra=next_url`` parameter has been removed.
+- The stored query list JSON no longer includes ``has_more`` - ``"next": null`` is the end-of-results signal across the whole API. This change also uncovered and fixed a bug where the query list ``next_url`` pointed at the HTML page and was a relative path; it is now an absolute URL that preserves the requested format.
+- Stored query JSON objects no longer duplicate the list of parameter names as both ``params`` and ``parameters`` - only ``parameters`` remains. The query create and update APIs no longer accept ``params`` as an input alias either; ``params`` is still the documented key for :ref:`queries defined in configuration <queries_named_parameters>`.
+- Page size parameters are now consistent across the API: the stored query lists accept ``?_size=max`` and return a ``400`` error for values over the maximum instead of silently clamping them, and the ``/-/allowed`` and ``/-/rules`` permission debug endpoints renamed their ``page`` and ``page_size`` parameters to ``_page`` and ``_size``, matching the underscore grammar used by every other Datasette system parameter.
+- ``/-/threads`` now requires the ``permissions-debug`` permission, since it exposes runtime internals such as file paths. It previously only required ``view-instance``.
+- Trusted stored queries - those defined in configuration - can no longer be deleted through the JSON API or web interface, matching the existing restriction on editing them.
+- The ``/<database>/-/schema`` endpoints now check the ``view-database`` permission before checking whether the database exists, so unauthorized actors can no longer probe for the existence of databases.
+- SQL time limit errors in JSON responses are now a plain text message. The error string previously embedded an HTML fragment.
+- The undocumented homepage JSON at ``/.json`` now returns ``databases`` as a list of objects rather than an object keyed by database name, matching every other collection in the API.
+- The legacy ``.jsono`` format extension, long since superseded by ``?_shape=``, has been removed.
+
+JSON API: other improvements
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- The :ref:`write API <json_api_write>` endpoints now parse the request body as JSON regardless of the ``Content-Type`` header, so ``curl -d`` invocations work without remembering to set it. Invalid JSON is a ``400`` error. Cross-site request forgery remains prevented by Datasette's ``Origin`` and ``Sec-Fetch-Site`` checks. This also fixes a ``500`` error from the insert API when the ``Content-Type`` header was missing entirely.
+- New ``Response.error(messages, status=400)`` helper for plugins that need to return a JSON error in Datasette's standard format. See :ref:`internals_response`.
+- New ``count_truncated`` extra for table JSON, included automatically whenever ``count`` is requested. ``true`` means the count reached Datasette's counting limit and the real number of rows may be higher. See :ref:`json_api_extra`.
+- JSON endpoints that are not part of the documented stable API now declare themselves with an ``"unstable"`` key in their responses.
+- New documentation covering the grammar for :ref:`boolean query string arguments <json_api_table_arguments>`, the reason :ref:`upsert <TableUpsertView>` returns ``200`` where insert returns ``201``, and advice for plugin authors on :ref:`naming secret configuration keys <plugins_configuration_secret>` so that ``/-/config`` redacts them automatically.
+
 .. _v1_0_a35:
 
 1.0a35 (2026-06-23)

docs/internals.rst

@@ -284,7 +284,7 @@ For example:
         content_type="application/xml; charset=utf-8",
     )
 
-The quickest way to create responses is using the ``Response.text(...)``, ``Response.html(...)``, ``Response.json(...)`` or ``Response.redirect(...)`` helper methods:
+The quickest way to create responses is using the ``Response.text(...)``, ``Response.html(...)``, ``Response.json(...)``, ``Response.error(...)`` or ``Response.redirect(...)`` helper methods:
 
 .. code-block:: python
 
@@ -295,6 +295,8 @@ The quickest way to create responses is using the ``Response.text(...)``, ``Resp
     text_response = Response.text(
         "This will become utf-8 encoded text"
     )
+    # A JSON error in Datasette's standard error format:
+    error_response = Response.error("Cannot do that", 400)
     # Redirects are served as 302, unless you pass status=301:
     redirect_response = Response.redirect(
         "https://latest.datasette.io/"
@@ -304,6 +306,8 @@ Each of these responses will use the correct corresponding content-type - ``text
 
 Each of the helper methods take optional ``status=`` and ``headers=`` arguments, documented above.
 
+``Response.error(messages, status=400)`` returns a JSON error in the :ref:`standard Datasette error format <json_api_errors>`. ``messages`` can be a single string or a list of strings. Use this for JSON-only endpoints; if your error should content-negotiate between JSON and HTML, raise ``Forbidden``, ``NotFound``, ``BadRequest`` or ``DatasetteError`` instead and Datasette's error handling will build the appropriate response.
+
 .. _internals_response_asgi_send:
 
 Returning a response with .asgi_send(send)

docs/introspection.rst

@@ -7,6 +7,10 @@ Datasette includes some pages and JSON API endpoints for introspecting the curre
 
 Each of these pages can be viewed in your browser. Add ``.json`` to the URL to get back the contents as JSON.
 
+JSON responses that return an object include an ``"ok": true`` key, consistent with the rest of the :ref:`JSON API <json_api>`.
+
+The introspection endpoints documented on this page are covered by the :ref:`JSON API stability promise <json_api_stability>`, with the exception of the debug endpoints ``/-/threads`` and ``/-/actions``, whose shapes may change in future releases.
+
 .. _JsonDataView_metadata:
 
 /-/metadata
@@ -37,6 +41,7 @@ Shows the version of Datasette, Python and SQLite. `Versions example <https://la
 .. code-block:: json
 
     {
+        "ok": true,
         "datasette": {
             "version": "0.60"
         },
@@ -75,15 +80,18 @@ Shows a list of currently installed plugins and their versions. `Plugins example
 
 .. code-block:: json
 
-    [
-        {
-            "name": "datasette_cluster_map",
-            "static": true,
-            "templates": false,
-            "version": "0.10",
-            "hooks": ["extra_css_urls", "extra_js_urls", "extra_body_script"]
-        }
-    ]
+    {
+        "ok": true,
+        "plugins": [
+            {
+                "name": "datasette_cluster_map",
+                "static": true,
+                "templates": false,
+                "version": "0.10",
+                "hooks": ["extra_css_urls", "extra_js_urls", "extra_body_script"]
+            }
+        ]
+    }
 
 Add ``?all=1`` to include details of the default plugins baked into Datasette.
 
@@ -97,6 +105,7 @@ Shows the :ref:`settings` for this instance of Datasette. `Settings example <htt
 .. code-block:: json
 
     {
+        "ok": true,
         "default_facet_size": 30,
         "default_page_size": 100,
         "facet_suggest_time_limit_ms": 50,
@@ -115,6 +124,7 @@ Shows the :ref:`configuration <configuration>` for this instance of Datasette. T
 .. code-block:: json
 
     {
+        "ok": true,
         "settings": {
             "template_debug": true,
             "trace_debug": true,
@@ -129,20 +139,47 @@ Any keys that include the one of the following substrings in their names will be
 /-/databases
 ------------
 
-Shows currently attached databases. `Databases example <https://latest.datasette.io/-/databases>`_:
+Shows currently attached databases that the current actor is allowed to view, based on the ``view-database`` permission. `Databases example <https://latest.datasette.io/-/databases>`_:
 
 .. code-block:: json
 
-    [
-        {
-            "hash": null,
-            "is_memory": false,
-            "is_mutable": true,
-            "name": "fixtures",
-            "path": "fixtures.db",
-            "size": 225280
-        }
-    ]
+    {
+        "ok": true,
+        "databases": [
+            {
+                "hash": null,
+                "is_memory": false,
+                "is_mutable": true,
+                "name": "fixtures",
+                "path": "fixtures.db",
+                "size": 225280
+            }
+        ]
+    }
+
+.. _JsonDataView_actions:
+
+/-/actions
+----------
+
+Shows all actions registered with the permission system, including those added by plugins. Requires the ``permissions-debug`` permission.
+
+.. code-block:: json
+
+    {
+        "ok": true,
+        "actions": [
+            {
+                "name": "view-instance",
+                "abbr": "vi",
+                "description": "View Datasette instance",
+                "takes_parent": false,
+                "takes_child": false,
+                "resource_class": null,
+                "also_requires": null
+            }
+        ]
+    }
 
 .. _JumpView:
 
@@ -160,6 +197,7 @@ The endpoint supports a ``?q=`` query parameter for filtering items by name.
 .. code-block:: json
 
     {
+        "ok": true,
         "matches": [
             {
                 "name": "fixtures",
@@ -188,6 +226,7 @@ Search example with ``?q=facet`` returns only items matching ``.*facet.*``:
 .. code-block:: json
 
     {
+        "ok": true,
         "matches": [
             {
                 "name": "fixtures: facetable",
@@ -215,11 +254,12 @@ Without those query string arguments, the page lists up to five tables with dete
 /-/threads
 ----------
 
-Shows details of threads and ``asyncio`` tasks. `Threads example <https://latest.datasette.io/-/threads>`_:
+Shows details of threads and ``asyncio`` tasks. This endpoint requires the ``permissions-debug`` permission, since it exposes runtime internals. `Threads example <https://latest.datasette.io/-/threads>`_:
 
 .. code-block:: json
 
     {
+        "ok": true,
         "num_threads": 2,
         "threads": [
             {
@@ -251,6 +291,7 @@ Shows the currently authenticated actor. Useful for debugging Datasette authenti
 .. code-block:: json
 
     {
+        "ok": true,
         "actor": {
             "id": 1,
             "username": "some-user"

docs/json_api.rst

@@ -9,6 +9,53 @@ through the Datasette user interface can also be accessed as JSON via the API.
 To access the API for a page, either click on the ``.json`` link on that page or
 edit the URL and add a ``.json`` extension to it.
 
+.. _json_api_stability:
+
+API stability
+-------------
+
+Datasette 1.0 makes a stability promise for its JSON API: the endpoints,
+parameters and response keys documented here and on the pages this
+documentation links to will not change in backwards-incompatible ways for
+the duration of the 1.x release series.
+
+Stability means:
+
+- Documented endpoints will keep their URLs, methods, parameters and
+  permission requirements.
+- Documented response keys will keep their names and types. New keys may be
+  **added** in any release - clients should ignore keys they do not
+  recognize.
+- The documented ``?_extra=`` names, ``?_shape=`` values and
+  :ref:`column filter operators <table_arguments>` are stable.
+- Pagination tokens - the ``"next"`` key and ``?_next=`` parameter - are
+  **opaque strings**. Pass them back exactly as you received them; their
+  internal structure is not part of the API and can change at any time.
+- The :ref:`standard error format <json_api_errors>` and the
+  :ref:`API token format and restriction semantics <CreateTokenView>` are
+  stable, including the action abbreviations stored inside signed tokens.
+
+Some JSON endpoints are **exempt** from this promise:
+
+- Endpoints that are not documented include this marker key in their
+  responses and can change at any time::
+
+      "unstable": "This API is not part of Datasette's stable interface and may change at any time"
+
+  This currently covers the instance homepage (``/.json``), the stored
+  query ``analyze``/``store``/``definition`` endpoints, ``/-/query/parameters``,
+  ``/-/execute-write/analyze`` and the JSON returned by the ``/-/permissions``
+  debug playground.
+- Debug and support endpoints are documented so you can use them, but their
+  JSON shapes are not frozen: :ref:`/-/threads <JsonDataView_threads>`,
+  :ref:`/-/actions <JsonDataView_actions>`,
+  the :ref:`permission debug endpoints <PermissionsDebugView>`
+  (``/-/allowed``, ``/-/rules``, ``/-/check``) and the
+  :ref:`table autocomplete endpoint <TableAutocompleteView>`.
+- Response keys explicitly labeled as unstable in this documentation, such
+  as the ``"analysis"`` block returned by :ref:`execute-write <ExecuteWriteView>`
+  and the ``debug`` and ``request`` extras.
+
 .. _json_api_default:
 
 Default representation
@@ -42,13 +89,49 @@ looks like this:
       "truncated": false
     }
 
-``"ok"`` is always ``true`` if an error did not occur.
+``"ok"`` is always ``true`` if an error did not occur. Every Datasette JSON endpoint that returns an object includes this key on success.
 
 The ``"rows"`` key is a list of objects, each one representing a row.
 
 The ``"truncated"`` key lets you know if the query was truncated. This can happen if a SQL query returns more than 1,000 results (or the :ref:`setting_max_returned_rows` setting).
 
-For table pages, an additional key ``"next"`` may be present. This indicates that the next page in the pagination set can be retrieved using ``?_next=VALUE``.
+For table pages, two additional keys are present: ``"next"``, an opaque token that can be used to retrieve the next page using ``?_next=TOKEN``, and ``"next_url"``, the full URL of that next page. Both are ``null`` on the final page. See :ref:`json_api_pagination`.
+
+.. _json_api_errors:
+
+Error responses
+---------------
+
+Every JSON error response from Datasette uses the same format:
+
+.. code-block:: json
+
+    {
+        "ok": false,
+        "error": "Table not found",
+        "errors": [
+            "Table not found"
+        ],
+        "status": 404
+    }
+
+- ``"ok"`` is always ``false`` for an error.
+- ``"errors"`` is a list of one or more error message strings. Endpoints that
+  validate multiple things at once - such as the :ref:`insert API <TableInsertView>` -
+  may return several messages here.
+- ``"error"`` is all of those messages joined with ``"; "``, for
+  convenience when displaying a single string.
+- ``"status"`` matches the HTTP status code of the response.
+
+Some endpoints add extra context keys. For example, a SQL error from a
+:ref:`custom query <json_api_custom_sql>` also includes the empty
+``"rows"`` and ``"truncated"`` keys of the response it was unable to
+produce.
+
+Permission errors use the same format: a request that fails a permission
+check receives a ``403`` with this JSON error body when the URL ends in
+``.json`` or the request sends an ``Accept: application/json`` or
+``Content-Type: application/json`` header.
 
 .. _json_api_custom_sql:
 
@@ -92,6 +175,7 @@ options:
     {
       "ok": true,
       "next": null,
+      "next_url": null,
       "rows": [
         [3, "Detroit"],
         [2, "Los Angeles"],
@@ -192,6 +276,10 @@ Here is an example Python function built using `requests <https://requests.readt
 Special JSON arguments
 ----------------------
 
+Boolean query string arguments - such as ``?_labels=`` and
+``?_json_infinity=`` - accept ``on``, ``true`` or ``1`` for true and
+``off``, ``false`` or ``0`` for false.
+
 Every Datasette endpoint that can return JSON also accepts the following
 query string arguments:
 
@@ -245,7 +333,9 @@ These can be repeated or comma-separated:
 
 ::
 
-    ?_extra=columns&_extra=count,next_url
+    ?_extra=columns&_extra=count,count_sql
+
+Requesting an ``_extra`` name that does not exist returns a ``400`` error in the :ref:`standard error format <json_api_errors>`, for example ``{"ok": false, "error": "Unknown _extra: nope", ...}``.
 
 .. [[[cog
     from json_api_doc import table_extras
@@ -266,6 +356,15 @@ The available table extras are listed below.
 
         15
 
+``count_truncated``
+    True if the count hit Datasette's counting limit, meaning the real number of matching rows is at least the reported count. (May execute additional queries.)
+
+    ``GET /fixtures/facetable.json?_extra=count,count_truncated``
+
+    .. code-block:: json
+
+        false
+
 ``count_sql``
     SQL query string used to calculate the total count for the current table view, including active filters.
 
@@ -338,17 +437,6 @@ The available table extras are listed below.
 
         "where state = \"CA\" sorted by pk"
 
-``next_url``
-    Full URL for the next page of results
-
-    ``GET /fixtures/facetable.json?_size=1&_extra=next_url``
-
-    ``null`` if there are no more pages of results. See :ref:`json_api_pagination`.
-
-    .. code-block:: json
-
-        "http://localhost/fixtures/facetable.json?_size=1&_extra=next_url&_next=1"
-
 ``columns``
     List of column names returned by this table, row or query.
 
@@ -1175,7 +1263,6 @@ The following extras are available for arbitrary SQL query responses and stored,
           "description_html": null,
           "hide_sql": false,
           "fragment": null,
-          "params": [],
           "parameters": [],
           "is_write": false,
           "is_private": false,
@@ -1570,6 +1657,8 @@ The JSON write API
 
 Datasette provides a write API for JSON data. This is a POST-only API that requires an authenticated API token, see :ref:`CreateTokenView`. The token will need to have the specified :ref:`authentication_permissions`.
 
+The request body is always parsed as JSON, regardless of the request's ``Content-Type`` header - a body that is not valid JSON returns a ``400`` error. Cross-site request forgery is prevented by Datasette's ``Origin`` and ``Sec-Fetch-Site`` header checks rather than by content type requirements.
+
 The row-based write APIs can write :ref:`binary values in JSON <binary_json_format>` using Datasette's Base64 representation for BLOB data.
 
 .. _ExecuteWriteView:
@@ -1605,7 +1694,7 @@ Unsupported SQL operations are rejected by default. ``VACUUM`` is not allowed in
 A successful response includes a message, the SQLite ``rowcount``, a ``"rows"``
 list, a ``"truncated"`` flag and a summary of the operations that were executed:
 
-The shape of the ``"analysis"`` block is not yet considered a stable API and may change in future Datasette releases.
+The shape of the ``"analysis"`` block is not part of the :ref:`stable API <json_api_stability>` and may change in future Datasette releases.
 
 .. code-block:: json
 
@@ -1665,15 +1754,17 @@ the execute-write returning row limit, which defaults to 10:
         ]
     }
 
-Errors use the standard Datasette error format:
+Errors use the :ref:`standard Datasette error format <json_api_errors>`:
 
 .. code-block:: json
 
     {
         "ok": false,
+        "error": "Permission denied: need execute-write-sql",
         "errors": [
             "Permission denied: need execute-write-sql"
-        ]
+        ],
+        "status": 403
     }
 
 .. _TableInsertView:
@@ -1769,9 +1860,11 @@ If any of your rows have a primary key that is already in use, you will get an e
 
     {
         "ok": false,
+        "error": "UNIQUE constraint failed: new_table.id",
         "errors": [
             "UNIQUE constraint failed: new_table.id"
-        ]
+        ],
+        "status": 400
     }
 
 Pass ``"ignore": true`` to ignore these errors and insert the other rows:
@@ -1846,7 +1939,7 @@ The above example will:
 
 Similar to ``/-/insert``, a ``row`` key with an object can be used instead of a ``rows`` array to upsert a single row.
 
-If successful, this will return a ``200`` status code and a ``{"ok": true}`` response body.
+If successful, this will return a ``200`` status code and a ``{"ok": true}`` response body. This is deliberately different from the ``201`` returned by :ref:`insert <TableInsertView>`: an upsert may update existing rows without creating anything, so it does not claim resource creation.
 
 Add ``"return": true`` to the request body to return full copies of the affected rows after they have been inserted or updated:
 
@@ -1903,9 +1996,11 @@ When using upsert you must provide the primary key column (or columns if the tab
 
     {
         "ok": false,
+        "error": "Row 0 is missing primary key column(s): \"id\"",
         "errors": [
             "Row 0 is missing primary key column(s): \"id\""
-        ]
+        ],
+        "status": 400
     }
 
 If your table does not have an explicit primary key you should pass the SQLite ``rowid`` key instead.
@@ -1960,14 +2055,16 @@ The returned JSON will look like this:
 
     {
         "ok": true,
-        "row": {
-            "id": 1,
-            "title": "New title",
-            "other_column": "Will be present here too"
-        }
+        "rows": [
+            {
+                "id": 1,
+                "title": "New title",
+                "other_column": "Will be present here too"
+            }
+        ]
     }
 
-Any errors will return ``{"errors": ["... descriptive message ..."], "ok": false}``, and a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
+Any errors will use the :ref:`standard error format <json_api_errors>`, with a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
 
 Pass ``"alter: true`` to automatically add any missing columns to the table. This requires the :ref:`actions_alter_table` permission.
 
@@ -1988,7 +2085,7 @@ To delete a row, make a ``POST`` to ``/<database>/<table>/<row-pks>/-/delete``.
 
 If successful, this will return a ``200`` status code and a ``{"ok": true}`` response body.
 
-Any errors will return ``{"errors": ["... descriptive message ..."], "ok": false}``, and a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
+Any errors will use the :ref:`standard error format <json_api_errors>`, with a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
 
 .. _TableCreateView:
 
@@ -2170,9 +2267,11 @@ If you pass a row to the create endpoint with a primary key that already exists
 
     {
         "ok": false,
+        "error": "UNIQUE constraint failed: creatures.id",
         "errors": [
             "UNIQUE constraint failed: creatures.id"
-        ]
+        ],
+        "status": 400
     }
 
 You can avoid this error by passing the same ``"ignore": true`` or ``"replace": true`` options to the create endpoint as you can to the :ref:`insert endpoint <TableInsertView>`.
@@ -2408,7 +2507,7 @@ A successful response returns the new schema and the previous schema. If the req
         "operations_applied": 11
     }
 
-Any errors will return ``{"errors": ["... descriptive message ..."], "ok": false}``, and a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
+Any errors will use the :ref:`standard error format <json_api_errors>`, with a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
 
 .. _TableSetColumnTypeView:
 
@@ -2472,7 +2571,7 @@ To clear an existing column type assignment, set ``column_type`` to ``null``:
 
 This API stores the assignment in Datasette's internal database, so it can be used with immutable databases as well as mutable ones.
 
-Any errors will return ``{"errors": ["... descriptive message ..."], "ok": false}``, and a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
+Any errors will use the :ref:`standard error format <json_api_errors>`, with a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
 
 .. _TableDropView:
 
@@ -2509,4 +2608,4 @@ If you pass the following POST body:
 
 Then the table will be dropped and a status ``200`` response of ``{"ok": true}`` will be returned.
 
-Any errors will return ``{"errors": ["... descriptive message ..."], "ok": false}``, and a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.
+Any errors will use the :ref:`standard error format <json_api_errors>`, with a ``400`` status code for a bad input or a ``403`` status code for an authentication or permission error.

docs/pages.rst

@@ -95,7 +95,7 @@ Use the :ref:`ExecuteWriteView` JSON API to execute writable SQL programmaticall
 Stored query browsers
 ---------------------
 
-The ``/-/queries`` page lists stored queries across every database visible to the current actor. The ``/database-name/-/queries`` page lists stored queries for a single database.
+The ``/-/queries`` page lists stored queries across every database visible to the current actor. The ``/database-name/-/queries`` page lists stored queries for a single database. The JSON versions accept ``?_size=`` (default 50, ``max`` for the :ref:`setting_max_returned_rows` limit) and a ``?_next=`` pagination token.
 
 These pages support search, pagination and filters for read-only or writable queries and private or public queries. Adding a ``.json`` extension to either URL returns the same list as JSON.
 
@@ -169,11 +169,13 @@ Use ``/-/schema.json`` to get the same information as JSON, which looks like thi
 .. code-block:: json
 
     {
+      "ok": true,
       "schemas": [
         {
           "database": "content",
           "schema": "create table posts ..."
         }
+      ]
     }
 
 .. _DatabaseSchemaView:
@@ -181,11 +183,11 @@ Use ``/-/schema.json`` to get the same information as JSON, which looks like thi
 Database schema
 ---------------
 
-Use ``/database-name/-/schema`` to see the complete schema for a specific database. The ``.md`` and ``.json`` extensions work here too. The JSON returns an object with ``"database"`` and ``"schema"`` keys.
+Use ``/database-name/-/schema`` to see the complete schema for a specific database. The ``.md`` and ``.json`` extensions work here too. The JSON returns an object with ``"ok"``, ``"database"`` and ``"schema"`` keys.
 
 .. _TableSchemaView:
 
 Table schema
 ------------
 
-Use ``/database-name/table-name/-/schema`` to see the schema for a specific table. The ``.md`` and ``.json`` extensions work here too. The JSON returns an object with ``"database"``, ``"table"``, and ``"schema"`` keys.
+Use ``/database-name/table-name/-/schema`` to see the schema for a specific table. The ``.md`` and ``.json`` extensions work here too. The JSON returns an object with ``"ok"``, ``"database"``, ``"table"``, and ``"schema"`` keys.

docs/plugin_hooks.rst

@@ -1685,6 +1685,8 @@ forbidden(datasette, request, message)
 
 Plugins can use this to customize how Datasette responds when a 403 Forbidden error occurs - usually because a page failed a permission check, see :ref:`authentication_permissions`.
 
+Datasette's default behavior returns the :ref:`standard JSON error format <json_api_errors>` with a 403 status when the request path ends in ``.json`` or the request has an ``Accept: application/json`` or ``Content-Type: application/json`` header; other requests get an HTML error page.
+
 If a plugin hook wishes to react to the error, it should return a :ref:`Response object <internals_response>`.
 
 This example returns a redirect to a ``/-/login`` page:
@@ -2544,6 +2546,10 @@ The default ``SignedTokenHandler`` uses itsdangerous signed tokens (``dstok_`` p
 
         async def verify_token(self, datasette, token):
             # Look up token in database, return actor dict or None
+            # if this handler does not recognize the token. Raise
+            # datasette.TokenInvalid for a token this handler
+            # recognizes but rejects (revoked, expired) - Datasette
+            # will respond with a 401 error.
             ...
 
 

docs/plugins.rst

@@ -459,6 +459,8 @@ Secret configuration values
 
 Some plugins may need configuration that should stay secret - API keys for example. There are two ways in which you can store secret configuration values.
 
+The :ref:`/-/config <JsonDataView_config>` introspection endpoint redacts the values of any configuration keys whose names contain one of these substrings: ``secret``, ``key``, ``password``, ``token``, ``hash`` or ``dsn``. Name your plugin's secret configuration keys accordingly - for example ``api_key`` or ``client_secret`` - so they are automatically redacted there.
+
 **As environment variables**. If your secret lives in an environment variable that is available to the Datasette process, you can indicate that the configuration value should be read from that environment variable like so:
 
 .. [[[cog

docs/sql_queries.rst

@@ -657,7 +657,7 @@ There are three options for specifying that you would like the response to your
 - Include ``?_json=1`` in the URL that you POST to
 - Include ``"_json": 1`` in your JSON body, or ``&_json=1`` in your form encoded body
 
-The JSON response will look like this:
+A successful JSON response will look like this:
 
 .. code-block:: json
 
@@ -667,7 +667,21 @@ The JSON response will look like this:
         "redirect": "/data/add_name"
     }
 
-The ``"message"`` and ``"redirect"`` values here will take into account ``on_success_message``, ``on_success_message_sql``,  ``on_success_redirect``, ``on_error_message`` and ``on_error_redirect``, if they have been set.
+If the SQL fails to execute - for example a constraint violation - the response uses the :ref:`standard error format <json_api_errors>` with a ``400`` status, plus the ``"redirect"`` key from the query configuration:
+
+.. code-block:: json
+
+    {
+        "ok": false,
+        "error": "UNIQUE constraint failed: docs.id",
+        "errors": [
+            "UNIQUE constraint failed: docs.id"
+        ],
+        "status": 400,
+        "redirect": null
+    }
+
+The ``"message"``, ``"error"`` and ``"redirect"`` values here take into account ``on_success_message``, ``on_success_message_sql``, ``on_success_redirect``, ``on_error_message`` and ``on_error_redirect``, if they have been set.
 
 .. _pagination:
 

docs/template_context.rst

@@ -329,7 +329,7 @@ Many of these keys are shared with the :ref:`JSON API <json_api>` for this page.
     Pagination token for the next page, or None
 
 ``next_url`` - ``str``
-    Full URL for the next page of results
+    Full URL for the next page of results, or None if there are no more pages. See :ref:`json_api_pagination`.
 
 ``ok`` - ``bool``
     True if the data for this page was retrieved without errors

tests/test_api.py

@@ -1,5 +1,6 @@
 from datasette.app import Datasette
 from datasette.plugins import DEFAULT_PLUGINS
+from datasette.utils import UNSTABLE_API_MESSAGE
 from datasette.utils.sqlite import sqlite_version
 from datasette.version import __version__
 from .fixtures import make_app_client, EXPECTED_PLUGINS
@@ -26,8 +27,9 @@ async def test_homepage(ds_client):
         "title",
     ]
     databases = data.get("databases")
-    assert databases.keys() == {"fixtures": 0}.keys()
-    d = databases["fixtures"]
+    assert isinstance(databases, list)
+    assert [d["name"] for d in databases] == ["fixtures"]
+    d = databases[0]
     assert d["name"] == "fixtures"
     assert isinstance(d["tables_count"], int)
     assert isinstance(len(d["tables_and_views_truncated"]), int)
@@ -42,8 +44,7 @@ async def test_homepage_sort_by_relationships(ds_client):
     response = await ds_client.get("/.json?_sort=relationships")
     assert response.status_code == 200
     tables = [
-        t["name"]
-        for t in response.json()["databases"]["fixtures"]["tables_and_views_truncated"]
+        t["name"] for t in response.json()["databases"][0]["tables_and_views_truncated"]
     ]
     assert tables == [
         "simple_primary_key",
@@ -250,8 +251,10 @@ def test_no_files_uses_memory_database(app_client_no_files):
     response = app_client_no_files.get("/.json")
     assert response.status == 200
     assert {
-        "databases": {
-            "_memory": {
+        "ok": True,
+        "unstable": UNSTABLE_API_MESSAGE,
+        "databases": [
+            {
                 "name": "_memory",
                 "hash": None,
                 "color": "a6c7b9",
@@ -266,7 +269,7 @@ def test_no_files_uses_memory_database(app_client_no_files):
                 "views_count": 0,
                 "private": False,
             },
-        },
+        ],
         "metadata": {},
     } == response.json
     # Try that SQL query
@@ -323,20 +326,15 @@ def test_sql_time_limit(app_client_shorter_time_limit):
         "/fixtures/-/query.json?sql=select+sleep(0.5)",
     )
     assert 400 == response.status
+    expected_message = (
+        "SQL query took too long. The time limit is"
+        " controlled by the sql_time_limit_ms setting."
+    )
     assert response.json == {
         "ok": False,
-        "error": (
-            "<p>SQL query took too long. The time limit is controlled by the\n"
-            '<a href="https://docs.datasette.io/en/stable/settings.html#sql-time-limit-ms">sql_time_limit_ms</a>\n'
-            "configuration option.</p>\n"
-            '<textarea style="width: 90%">select sleep(0.5)</textarea>\n'
-            "<script>\n"
-            'let ta = document.querySelector("textarea");\n'
-            'ta.style.height = ta.scrollHeight + "px";\n'
-            "</script>"
-        ),
+        "error": expected_message,
+        "errors": [expected_message],
         "status": 400,
-        "title": "SQL Interrupted",
     }
 
 
@@ -350,7 +348,7 @@ async def test_custom_sql_time_limit(ds_client):
         "/fixtures/-/query.json?sql=select+sleep(0.01)&_timelimit=5",
     )
     assert response.status_code == 400
-    assert response.json()["title"] == "SQL Interrupted"
+    assert response.json()["error"].startswith("SQL query took too long.")
 
 
 @pytest.mark.asyncio
@@ -546,7 +544,7 @@ async def test_row_extra_render_cell():
 
 def test_databases_json(app_client_two_attached_databases_one_immutable):
     response = app_client_two_attached_databases_one_immutable.get("/-/databases.json")
-    databases = response.json
+    databases = response.json["databases"]
     assert 2 == len(databases)
     extra_database, fixtures_database = databases
     assert "extra database" == extra_database["name"]
@@ -562,8 +560,12 @@ def test_databases_json(app_client_two_attached_databases_one_immutable):
 
 @pytest.mark.asyncio
 async def test_threads_json(ds_client):
-    response = await ds_client.get("/-/threads.json")
-    expected_keys = {"threads", "num_threads"}
+    ds_client.ds.root_enabled = True
+    try:
+        response = await ds_client.get("/-/threads.json", actor={"id": "root"})
+    finally:
+        ds_client.ds.root_enabled = False
+    expected_keys = {"ok", "threads", "num_threads"}
     if sys.version_info >= (3, 7, 0):
         expected_keys.update({"tasks", "num_tasks"})
     data = response.json()
@@ -578,13 +580,13 @@ async def test_plugins_json(ds_client):
     response = await ds_client.get("/-/plugins.json")
     # Filter out TrackEventPlugin
     actual_plugins = sorted(
-        [p for p in response.json() if p["name"] != "TrackEventPlugin"],
+        [p for p in response.json()["plugins"] if p["name"] != "TrackEventPlugin"],
         key=lambda p: p["name"],
     )
     assert EXPECTED_PLUGINS == actual_plugins
     # Try with ?all=1
     response = await ds_client.get("/-/plugins.json?all=1")
-    names = {p["name"] for p in response.json()}
+    names = {p["name"] for p in response.json()["plugins"]}
     assert names.issuperset(p["name"] for p in EXPECTED_PLUGINS)
     assert names.issuperset(DEFAULT_PLUGINS)
 
@@ -616,7 +618,7 @@ async def test_actions_json(ds_client):
     try:
         ds_client.ds.root_enabled = True
         response = await ds_client.get("/-/actions.json", actor={"id": "root"})
-        data = response.json()
+        data = response.json()["actions"]
     finally:
         ds_client.ds.root_enabled = original_root_enabled
     assert isinstance(data, list)
@@ -648,6 +650,7 @@ async def test_actions_json(ds_client):
 async def test_settings_json(ds_client):
     response = await ds_client.get("/-/settings.json")
     assert response.json() == {
+        "ok": True,
         "default_page_size": 50,
         "default_facet_size": 30,
         "default_allow_sql": True,
@@ -717,7 +720,7 @@ def test_config_cache_size(app_client_larger_cache_size):
 def test_config_force_https_urls():
     with make_app_client(settings={"force_https_urls": True}) as client:
         response = client.get(
-            "/fixtures/facetable.json?_size=3&_facet=state&_extra=next_url,suggested_facets"
+            "/fixtures/facetable.json?_size=3&_facet=state&_extra=suggested_facets"
         )
         assert response.json["next_url"].startswith("https://")
         assert response.json["facet_results"]["results"]["state"]["results"][0][
@@ -812,7 +815,9 @@ def test_common_prefix_database_names(app_client_conflicting_database_names):
     # https://github.com/simonw/datasette/issues/597
     assert ["foo-bar", "foo", "fixtures"] == [
         d["name"]
-        for d in app_client_conflicting_database_names.get("/-/databases.json").json
+        for d in app_client_conflicting_database_names.get("/-/databases.json").json[
+            "databases"
+        ]
     ]
     for db_name, path in (("foo", "/foo.json"), ("foo-bar", "/foo-bar.json")):
         data = app_client_conflicting_database_names.get(path).json
@@ -883,8 +888,9 @@ async def test_tilde_encoded_database_names(db_name):
     ds = Datasette()
     ds.add_memory_database(db_name)
     response = await ds.client.get("/.json")
-    assert db_name in response.json()["databases"].keys()
-    path = response.json()["databases"][db_name]["path"]
+    databases_by_name = {d["name"]: d for d in response.json()["databases"]}
+    assert db_name in databases_by_name
+    path = databases_by_name[db_name]["path"]
     # And the JSON for that database
     response2 = await ds.client.get(path + ".json")
     assert response2.status_code == 200
@@ -923,7 +929,7 @@ async def test_config_json(config, expected):
     "/-/config.json should return redacted configuration"
     ds = Datasette(config=config)
     response = await ds.client.get("/-/config.json")
-    assert response.json() == expected
+    assert response.json() == {"ok": True, **expected}
 
 
 @pytest.mark.asyncio
@@ -1019,7 +1025,7 @@ async def test_config_json(config, expected):
 async def test_upgrade_metadata(metadata, expected_config, expected_metadata):
     ds = Datasette(metadata=metadata)
     response = await ds.client.get("/-/config.json")
-    assert response.json() == expected_config
+    assert response.json() == {"ok": True, **expected_config}
     response2 = await ds.client.get("/-/metadata.json")
     assert response2.json() == expected_metadata
 

tests/test_api_write.py

@@ -1,6 +1,6 @@
 from datasette.app import Datasette
 from datasette.events import RenameTableEvent
-from datasette.utils import escape_sqlite, sqlite3
+from datasette.utils import error_body, escape_sqlite, sqlite3
 from .utils import last_event
 import pytest
 import re
@@ -169,7 +169,10 @@ async def test_base64_write_api_insert_upsert_update_decode_blobs(ds_write):
         headers=_headers(token),
     )
     assert update_response.status_code == 200
-    assert update_response.json()["row"]["data"] == {"$base64": True, "encoded": "/wAB"}
+    assert update_response.json()["rows"][0]["data"] == {
+        "$base64": True,
+        "encoded": "/wAB",
+    }
 
     rows = (await db.execute("""
             select
@@ -344,10 +347,9 @@ async def test_insert_rows_post_body_too_large(tmp_path_factory):
         headers=_headers(token),
     )
     assert response.status_code == 413
-    assert response.json() == {
-        "ok": False,
-        "errors": ["Request body exceeded maximum size of 100 bytes"],
-    }
+    assert response.json() == error_body(
+        ["Request body exceeded maximum size of 100 bytes"], 413
+    )
     # A small body should still work
     response2 = await ds.client.post(
         "/data/docs/-/insert",
@@ -380,8 +382,8 @@ async def test_insert_rows_post_body_too_large(tmp_path_factory):
             "/data/docs/-/insert",
             {"rows": [{"title": "Test"} for i in range(10)]},
             "bad_token",
-            403,
-            ["Permission denied"],
+            401,
+            ["Invalid token signature"],
         ),
         (
             "/data/docs/-/insert",
@@ -392,13 +394,6 @@ async def test_insert_rows_post_body_too_large(tmp_path_factory):
                 "Invalid JSON: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)"
             ],
         ),
-        (
-            "/data/docs/-/insert",
-            {},
-            "invalid_content_type",
-            400,
-            ["Invalid content-type, must be application/json"],
-        ),
         (
             "/data/docs/-/insert",
             [],
@@ -580,20 +575,17 @@ async def test_insert_or_upsert_row_errors(
         json=input,
         headers={
             "Authorization": "Bearer {}".format(token),
-            "Content-Type": (
-                "text/plain"
-                if special_case == "invalid_content_type"
-                else "application/json"
-            ),
+            "Content-Type": "application/json",
         },
     )
 
-    actor_response = (
-        await ds_write.client.get("/-/actor.json", headers=kwargs["headers"])
-    ).json()
-    assert set((actor_response["actor"] or {}).get("_r", {}).get("a") or []) == set(
-        token_permissions
-    )
+    if special_case != "bad_token":
+        actor_response = (
+            await ds_write.client.get("/-/actor.json", headers=kwargs["headers"])
+        ).json()
+        assert set((actor_response["actor"] or {}).get("_r", {}).get("a") or []) == set(
+            token_permissions
+        )
 
     if special_case == "invalid_json":
         del kwargs["json"]
@@ -966,7 +958,12 @@ async def test_update_row_invalid_key(ds_write):
         headers=_headers(token),
     )
     assert response.status_code == 400
-    assert response.json() == {"ok": False, "errors": ["Invalid keys: bad_key"]}
+    assert response.json() == {
+        "ok": False,
+        "error": "Invalid keys: bad_key",
+        "errors": ["Invalid keys: bad_key"],
+        "status": 400,
+    }
 
 
 @pytest.mark.asyncio
@@ -1285,10 +1282,9 @@ async def test_alter_table_foreign_key_requires_fk_table_for_fk_column(ds_write)
         headers=_headers(write_token(ds_write, permissions=["at"])),
     )
     assert response.status_code == 400
-    assert response.json() == {
-        "ok": False,
-        "errors": ["operations.0.add_foreign_key.args: fk_column requires fk_table"],
-    }
+    assert response.json() == error_body(
+        ["operations.0.add_foreign_key.args: fk_column requires fk_table"], 400
+    )
 
 
 @pytest.mark.asyncio
@@ -1312,10 +1308,9 @@ async def test_alter_table_foreign_key_without_fk_column_requires_single_pk(ds_w
         headers=_headers(token),
     )
     assert response.status_code == 400
-    assert response.json() == {
-        "ok": False,
-        "errors": ["Could not detect single primary key for table 'accounts'"],
-    }
+    assert response.json() == error_body(
+        ["Could not detect single primary key for table 'accounts'"], 400
+    )
 
 
 @pytest.mark.asyncio
@@ -1381,10 +1376,7 @@ async def test_foreign_key_suggestions_permission_denied(ds_write):
         headers=_headers(token),
     )
     assert response.status_code == 403
-    assert response.json() == {
-        "ok": False,
-        "errors": ["Permission denied: need alter-table"],
-    }
+    assert response.json() == error_body(["Permission denied: need alter-table"], 403)
 
 
 @pytest.mark.asyncio
@@ -1495,10 +1487,7 @@ async def test_foreign_key_targets_permission_denied(ds_write):
         headers=_headers(token),
     )
     assert response.status_code == 403
-    assert response.json() == {
-        "ok": False,
-        "errors": ["Permission denied: need create-table"],
-    }
+    assert response.json() == error_body(["Permission denied: need create-table"], 403)
 
 
 @pytest.mark.asyncio
@@ -1521,10 +1510,7 @@ async def test_alter_table_permission_denied(ds_write):
         headers=_headers(token),
     )
     assert response.status_code == 403
-    assert response.json() == {
-        "ok": False,
-        "errors": ["Permission denied: need alter-table"],
-    }
+    assert response.json() == error_body(["Permission denied: need alter-table"], 403)
 
 
 @pytest.mark.asyncio
@@ -1668,9 +1654,9 @@ async def test_update_row(ds_write, input, expected_errors, use_return):
 
     assert response.json()["ok"] is True
     if not use_return:
-        assert "row" not in response.json()
+        assert "rows" not in response.json()
     else:
-        returned_row = response.json()["row"]
+        returned_row = response.json()["rows"][0]
         assert returned_row["id"] == pk
         for k, v in input.items():
             assert returned_row[k] == v
@@ -2203,6 +2189,9 @@ async def test_create_table(
     )
     assert response.status_code == expected_status
     data = response.json()
+    if expected_response.get("ok") is False:
+        # Error expectations list their messages; derive the canonical envelope
+        expected_response = error_body(expected_response["errors"], expected_status)
     if isinstance(expected_response, dict) and "schema" in expected_response:
         assert data.get("schema") in schema_variants(expected_response["schema"])
         expected_response = dict(expected_response, schema=data.get("schema"))
@@ -2405,13 +2394,12 @@ async def test_create_table_column_validation(ds_write, column, expected_error):
     )
     if expected_error:
         assert response.status_code == 400
-        assert response.json() == {"ok": False, "errors": [expected_error]}
+        assert response.json() == error_body([expected_error], 400)
     else:
         assert response.status_code == 400
-        assert response.json() == {
-            "ok": False,
-            "errors": ["Could not detect single primary key for table 'owners'"],
-        }
+        assert response.json() == error_body(
+            ["Could not detect single primary key for table 'owners'"], 400
+        )
 
 
 @pytest.mark.asyncio
@@ -2449,10 +2437,9 @@ async def test_create_table_foreign_key_without_fk_column_requires_single_pk(ds_
         headers=_headers(token),
     )
     assert response.status_code == 400
-    assert response.json() == {
-        "ok": False,
-        "errors": ["Could not detect single primary key for table 'accounts'"],
-    }
+    assert response.json() == error_body(
+        ["Could not detect single primary key for table 'accounts'"], 400
+    )
 
 
 @pytest.mark.asyncio
@@ -2602,10 +2589,9 @@ async def test_create_table_error_if_pk_changed(ds_write):
         headers=_headers(token),
     )
     assert second_response.status_code == 400
-    assert second_response.json() == {
-        "ok": False,
-        "errors": ["pk cannot be changed for existing table"],
-    }
+    assert second_response.json() == error_body(
+        ["pk cannot be changed for existing table"], 400
+    )
 
 
 @pytest.mark.asyncio
@@ -2629,10 +2615,9 @@ async def test_create_table_error_rows_twice_with_duplicates(ds_write):
         headers=_headers(token),
     )
     assert second_response.status_code == 400
-    assert second_response.json() == {
-        "ok": False,
-        "errors": ["UNIQUE constraint failed: test_create_twice.id"],
-    }
+    assert second_response.json() == error_body(
+        ["UNIQUE constraint failed: test_create_twice.id"], 400
+    )
 
 
 @pytest.mark.asyncio
@@ -2655,6 +2640,8 @@ async def test_method_not_allowed(ds_write, path):
     assert response.json() == {
         "ok": False,
         "error": "Method not allowed",
+        "errors": ["Method not allowed"],
+        "status": 405,
     }
 
 
@@ -2722,10 +2709,9 @@ async def test_create_using_alter_against_existing_table(
     )
     if not has_alter_permission:
         assert response2.status_code == 403
-        assert response2.json() == {
-            "ok": False,
-            "errors": ["Permission denied: need alter-table"],
-        }
+        assert response2.json() == error_body(
+            ["Permission denied: need alter-table"], 403
+        )
     else:
         assert response2.status_code == 201
 

tests/test_auth.py

@@ -236,7 +236,9 @@ def test_auth_create_token(
 
 @pytest.mark.asyncio
 async def test_auth_create_token_not_allowed_for_tokens(ds_client):
-    ds_tok = ds_client.ds.sign({"a": "test", "token": "dstok"}, "token")
+    ds_tok = ds_client.ds.sign(
+        {"a": "test", "token": "dstok", "t": int(time.time())}, "token"
+    )
     response = await ds_client.get(
         "/-/create-token",
         headers={"Authorization": "Bearer dstok_{}".format(ds_tok)},
@@ -294,7 +296,7 @@ async def test_auth_with_dstok_token(ds_client, scenario, should_work):
     try:
         if should_work:
             data = response.json()
-            assert data.keys() == {"actor"}
+            assert data.keys() == {"ok", "actor"}
             actor = data["actor"]
             expected_keys = {"id", "token"}
             if scenario != "valid_unlimited_token":
@@ -304,8 +306,16 @@ async def test_auth_with_dstok_token(ds_client, scenario, should_work):
             assert actor["token"] == "dstok"
             if scenario != "valid_unlimited_token":
                 assert isinstance(actor["token_expires"], int)
+        elif scenario == "no_token":
+            # No credentials presented - request proceeds as anonymous
+            assert response.json() == {"ok": True, "actor": None}
         else:
-            assert response.json() == {"actor": None}
+            # Invalid credentials presented - hard 401
+            assert response.status_code == 401
+            data = response.json()
+            assert data["ok"] is False
+            assert data["status"] == 401
+            assert response.headers["www-authenticate"].startswith("Bearer")
     finally:
         ds_client.ds._settings["allow_signed_tokens"] = True
 
@@ -337,10 +347,11 @@ def test_cli_create_token(app_client, expires):
         }
         if expires and expires > 0:
             expected_actor["token_expires"] = details["t"] + expires
-        assert response.json == {"actor": expected_actor}
+        assert response.json == {"ok": True, "actor": expected_actor}
     else:
-        expected_actor = None
-    assert response.json == {"actor": expected_actor}
+        # Expired token - hard 401
+        assert response.status == 401
+        assert response.json["ok"] is False
 
 
 @pytest.mark.asyncio

tests/test_autocomplete.py

@@ -25,13 +25,14 @@ async def test_autocomplete_single_pk_exact_match_and_label_order():
 
     assert response.status_code == 200
     assert response.json() == {
+        "ok": True,
         "rows": [
             {"pks": {"id": 2}, "label": "Longer non-label pk match"},
             {"pks": {"id": 20}, "label": "2"},
             {"pks": {"id": 21}, "label": "22"},
             {"pks": {"id": 3}, "label": "A label containing 2"},
             {"pks": {"id": 200}, "label": "A"},
-        ]
+        ],
     }
 
 
@@ -52,12 +53,12 @@ async def test_autocomplete_blank_q_returns_no_results():
     response = await ds.client.get("/autocomplete_blank/people/-/autocomplete?q=")
 
     assert response.status_code == 200
-    assert response.json() == {"rows": []}
+    assert response.json() == {"ok": True, "rows": []}
 
     response = await ds.client.get("/autocomplete_blank/people/-/autocomplete")
 
     assert response.status_code == 200
-    assert response.json() == {"rows": []}
+    assert response.json() == {"ok": True, "rows": []}
 
 
 @pytest.mark.asyncio
@@ -81,11 +82,12 @@ async def test_autocomplete_initial_returns_latest_rows():
 
     assert response.status_code == 200
     assert response.json() == {
+        "ok": True,
         "rows": [
             {"pks": {"id": 3}, "label": "Cleo"},
             {"pks": {"id": 2}, "label": "Bob"},
             {"pks": {"id": 1}, "label": "Alice"},
-        ]
+        ],
     }
 
     response = await ds.client.get(
@@ -94,11 +96,12 @@ async def test_autocomplete_initial_returns_latest_rows():
 
     assert response.status_code == 200
     assert response.json() == {
+        "ok": True,
         "rows": [
             {"pks": {"id": 3}, "label": "Cleo"},
             {"pks": {"id": 2}, "label": "Bob"},
             {"pks": {"id": 1}, "label": "Alice"},
-        ]
+        ],
     }
 
 
@@ -121,9 +124,10 @@ async def test_autocomplete_escapes_like_characters():
 
     assert response.status_code == 200
     assert response.json() == {
+        "ok": True,
         "rows": [
             {"pks": {"id": 1}, "label": "100% real"},
-        ]
+        ],
     }
 
 
@@ -149,11 +153,12 @@ async def test_autocomplete_compound_pk_searches_all_pk_columns():
 
     assert response.status_code == 200
     assert response.json() == {
+        "ok": True,
         "rows": [
             {"pks": {"country": "mx", "code": "ca"}, "label": "Campeche"},
             {"pks": {"country": "us", "code": "ca"}, "label": "California"},
             {"pks": {"country": "ca", "code": "bc"}, "label": "British Columbia"},
-        ]
+        ],
     }
 
 
@@ -184,9 +189,10 @@ async def test_autocomplete_primary_key_called_label():
 
     assert response.status_code == 200
     assert response.json() == {
+        "ok": True,
         "rows": [
             {"pks": {"label": "abc"}, "label": "Display value"},
-        ]
+        ],
     }
 
 
@@ -246,8 +252,9 @@ async def test_autocomplete_timeout_uses_prefix_fallback(monkeypatch):
     assert timeout_was_simulated
     data = response.json()
     assert data == {
+        "ok": True,
         "rows": [
             {"pks": {"id": f"item-1999{i:02d}"}, "label": f"name 1999{i:02d}"}
             for i in range(10)
-        ]
+        ],
     }

tests/test_base_view.py

@@ -53,6 +53,8 @@ async def test_get_view():
     assert json.loads(post_json_response.body) == {
         "ok": False,
         "error": "Method not allowed",
+        "errors": ["Method not allowed"],
+        "status": 405,
     }
     assert post_json_response.status == 405
 

tests/test_cli.py

@@ -385,7 +385,9 @@ def test_setting_boolean_validation_false_values(value):
     )
     # Should be forbidden (setting is false)
     assert result.exit_code == 1, result.output
-    assert "Forbidden" in result.output
+    error = json.loads(result.output)
+    assert error["ok"] is False
+    assert error["status"] == 403
 
 
 @pytest.mark.parametrize("value", ("on", "true", "1"))
@@ -425,8 +427,9 @@ def test_setting_default_allow_sql(default_allow_sql):
         assert json.loads(result.output)["rows"][0] == {"21": 21}
     else:
         assert result.exit_code == 1, result.output
-        # This isn't JSON at the moment, maybe it should be though
-        assert "Forbidden" in result.output
+        error = json.loads(result.output)
+        assert error["ok"] is False
+        assert error["status"] == 403
 
 
 def test_sql_errors_logged_to_stderr():
@@ -444,7 +447,7 @@ def test_serve_create(tmpdir):
         cli, [str(db_path), "--create", "--get", "/-/databases.json"]
     )
     assert result.exit_code == 0, result.output
-    databases = json.loads(result.output)
+    databases = json.loads(result.output)["databases"]
     assert {
         "name": "does_not_exist_yet",
         "is_mutable": True,
@@ -493,7 +496,7 @@ def test_serve_duplicate_database_names(tmpdir):
         conn.close()
     result = runner.invoke(cli, [db_1_path, db_2_path, "--get", "/-/databases.json"])
     assert result.exit_code == 0, result.output
-    databases = json.loads(result.output)
+    databases = json.loads(result.output)["databases"]
     assert {db["name"] for db in databases} == {"db", "db_2"}
 
 
@@ -585,7 +588,7 @@ def test_duplicate_database_files_error(tmpdir):
         cli, ["serve", other_db_path, str(config_dir), "--get", "/-/databases.json"]
     )
     assert result4.exit_code == 0
-    databases = json.loads(result4.output)
+    databases = json.loads(result4.output)["databases"]
     assert {db["name"] for db in databases} == {"other", "data"}
 
     # Test that multiple directories raise an error

tests/test_cli_serve_get.py

@@ -95,7 +95,10 @@ def test_serve_with_get_and_token():
         ],
     )
     assert 0 == result2.exit_code, result2.output
-    assert json.loads(result2.output) == {"actor": {"id": "root", "token": "dstok"}}
+    assert json.loads(result2.output) == {
+        "ok": True,
+        "actor": {"id": "root", "token": "dstok"},
+    }
 
 
 def test_serve_with_get_exit_code_for_error():
@@ -130,8 +133,9 @@ def test_serve_get_actor():
     )
     assert result.exit_code == 0
     assert json.loads(result.output) == {
+        "ok": True,
         "actor": {
             "id": "root",
             "extra": "x",
-        }
+        },
     }

tests/test_column_types.py

@@ -9,7 +9,7 @@ from datasette.column_types import (
 )
 from datasette.hookspecs import hookimpl
 from datasette.plugins import pm
-from datasette.utils import sqlite3
+from datasette.utils import error_body, sqlite3
 from datasette.utils import StartupError
 import markupsafe
 import pytest
@@ -322,12 +322,6 @@ async def test_clear_column_type_api(ds_ct):
                 "Invalid JSON: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)"
             ],
         ),
-        (
-            {"column": "title", "column_type": {"type": "email"}},
-            "invalid_content_type",
-            400,
-            ["Invalid content-type, must be application/json"],
-        ),
         (
             [],
             None,
@@ -413,11 +407,7 @@ async def test_set_column_type_api_errors(
     kwargs = {
         "headers": {
             "Authorization": f"Bearer {token}",
-            "Content-Type": (
-                "text/plain"
-                if special_case == "invalid_content_type"
-                else "application/json"
-            ),
+            "Content-Type": "application/json",
         }
     }
     if special_case == "invalid_json":
@@ -426,7 +416,7 @@ async def test_set_column_type_api_errors(
         kwargs["json"] = body
     response = await ds_ct.client.post("/data/posts/-/set-column-type", **kwargs)
     assert response.status_code == expected_status
-    assert response.json() == {"ok": False, "errors": expected_errors}
+    assert response.json() == error_body(expected_errors, expected_status)
 
 
 @pytest.mark.asyncio

tests/test_config_dir.py

@@ -109,9 +109,10 @@ def test_settings(config_dir_client):
 def test_plugins(config_dir_client):
     response = config_dir_client.get("/-/plugins.json")
     assert 200 == response.status
-    assert "hooray.py" in {p["name"] for p in response.json}
-    assert "non_py_file.txt" not in {p["name"] for p in response.json}
-    assert "mypy_cache" not in {p["name"] for p in response.json}
+    plugins = response.json["plugins"]
+    assert "hooray.py" in {p["name"] for p in plugins}
+    assert "non_py_file.txt" not in {p["name"] for p in plugins}
+    assert "mypy_cache" not in {p["name"] for p in plugins}
 
 
 def test_templates_and_plugin(config_dir_client):
@@ -136,7 +137,7 @@ def test_static_directory_browsing_not_allowed(config_dir_client):
 def test_databases(config_dir_client):
     response = config_dir_client.get("/-/databases.json")
     assert 200 == response.status
-    databases = response.json
+    databases = response.json["databases"]
     assert 4 == len(databases)
     databases.sort(key=lambda d: d["name"])
     for db, expected_name in zip(databases, ("demo", "immutable", "j", "k")):

tests/test_docs.py

@@ -248,7 +248,7 @@ async def test_homepage():
 async def test_actor_is_null():
     ds = Datasette(memory=True)
     response = await ds.client.get("/-/actor.json")
-    assert response.json() == {"actor": None}
+    assert response.json() == {"ok": True, "actor": None}
 # -- end test_actor_is_null --
 
 
@@ -258,5 +258,5 @@ async def test_signed_cookie_actor():
     ds = Datasette(memory=True)
     cookies = {"ds_actor": ds.client.actor_cookie({"id": "root"})}
     response = await ds.client.get("/-/actor.json", cookies=cookies)
-    assert response.json() == {"actor": {"id": "root"}}
+    assert response.json() == {"ok": True, "actor": {"id": "root"}}
 # -- end test_signed_cookie_actor --

tests/test_error_shape.py

@@ -0,0 +1,749 @@
+"""
+Tests for the canonical JSON error shape.
+
+Every JSON error response from Datasette should use one shape:
+
+    {
+        "ok": false,
+        "error": "<all messages joined with '; '>",
+        "errors": ["<message>", ...],
+        "status": <int matching the HTTP status code>
+    }
+
+Additional context keys (for example "rows" and "truncated" on SQL errors)
+are permitted, but "ok", "error", "errors" and "status" must always be
+present and the legacy "title" key must not be.
+
+https://github.com/simonw/datasette/issues - 1.0 API consistency
+"""
+
+import pytest
+import time
+from datasette.app import Datasette
+from datasette.utils import sqlite3
+
+
+def assert_canonical_error(response, expected_status):
+    assert response.status_code == expected_status
+    data = response.json()
+    assert data["ok"] is False
+    assert isinstance(data["error"], str)
+    assert data["error"]
+    assert isinstance(data["errors"], list)
+    assert data["errors"]
+    assert all(isinstance(message, str) for message in data["errors"])
+    assert data["error"] == "; ".join(data["errors"])
+    assert data["status"] == expected_status
+    assert "title" not in data
+    return data
+
+
+@pytest.fixture
+def ds_error_shape(tmp_path_factory):
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "data.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.execute("create table docs (id integer primary key, title text)")
+    conn.close()
+    ds = Datasette([db_path])
+    ds.root_enabled = True
+    yield ds
+    ds.close()
+
+
+# Shape 1: the exception handler (handle_exception.py)
+
+
+@pytest.mark.asyncio
+async def test_not_found_error_shape(ds_client):
+    response = await ds_client.get("/fixtures/no_such_table.json")
+    assert_canonical_error(response, 404)
+
+
+@pytest.mark.asyncio
+async def test_datasette_error_with_title_omits_title_key(ds_client):
+    # DatasetteError(title="Invalid SQL") previously leaked a "title" key
+    response = await ds_client.get(
+        "/fixtures/-/query.json?sql=update+facetable+set+state+=+1"
+    )
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["Statement must be a SELECT"]
+
+
+# Shape 2: the _error() helper (views/base.py) - write API and friends
+
+
+@pytest.mark.asyncio
+async def test_write_api_validation_error_shape(ds_error_shape):
+    token = "dstok_{}".format(
+        ds_error_shape.sign(
+            {"a": "root", "token": "dstok", "t": 0},
+            namespace="token",
+        )
+    )
+    response = await ds_error_shape.client.post(
+        "/data/docs/-/insert",
+        json={"rows": [{"nope": 1}, {"also_nope": 2}]},
+        headers={
+            "Authorization": "Bearer {}".format(token),
+            "Content-Type": "application/json",
+        },
+    )
+    data = assert_canonical_error(response, 400)
+    # Multiple messages: errors keeps them all, error joins them
+    assert len(data["errors"]) == 2
+    assert data["errors"][0].startswith("Row 0")
+    assert data["errors"][1].startswith("Row 1")
+
+
+@pytest.mark.asyncio
+async def test_write_api_permission_denied_shape(ds_error_shape):
+    response = await ds_error_shape.client.post(
+        "/data/docs/-/insert",
+        json={"rows": [{"title": "hello"}]},
+        headers={"Content-Type": "application/json"},
+    )
+    assert_canonical_error(response, 403)
+
+
+# Shape 3: the JSON renderer (renderer.py)
+
+
+@pytest.mark.asyncio
+async def test_sql_error_shape_keeps_context_keys(ds_client):
+    response = await ds_client.get(
+        "/fixtures/-/query.json?sql=select+*+from+no_such_table"
+    )
+    data = assert_canonical_error(response, 400)
+    # Renderer errors keep their context keys
+    assert data["rows"] == []
+    assert "truncated" in data
+
+
+@pytest.mark.asyncio
+async def test_invalid_shape_error_shape(ds_client):
+    response = await ds_client.get("/fixtures/-/query.json?sql=select+1&_shape=bananas")
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["Invalid _shape: bananas"]
+
+
+@pytest.mark.asyncio
+async def test_shape_object_on_query_is_a_400_error(ds_client):
+    # Previously returned HTTP 200 with an ok: false body
+    response = await ds_client.get("/fixtures/-/query.json?sql=select+1&_shape=object")
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["_shape=object is only available on tables"]
+
+
+# Shape 4: bare {"error": ...} from the permission debug endpoints
+
+
+@pytest.mark.asyncio
+async def test_allowed_missing_action_error_shape(ds_client):
+    response = await ds_client.get("/-/allowed.json")
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["action parameter is required"]
+
+
+@pytest.mark.asyncio
+async def test_allowed_unknown_action_error_shape(ds_client):
+    response = await ds_client.get("/-/allowed.json?action=no_such_action")
+    assert_canonical_error(response, 404)
+
+
+@pytest.mark.asyncio
+async def test_check_unknown_action_error_shape(ds_error_shape):
+    response = await ds_error_shape.client.get(
+        "/-/check.json?action=no_such_action",
+        actor={"id": "root"},
+    )
+    assert_canonical_error(response, 404)
+
+
+@pytest.mark.asyncio
+async def test_rules_missing_action_error_shape(ds_error_shape):
+    response = await ds_error_shape.client.get(
+        "/-/rules.json",
+        actor={"id": "root"},
+    )
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["action parameter is required"]
+
+
+# Other stragglers
+
+
+@pytest.mark.asyncio
+async def test_method_not_allowed_error_shape(ds_client):
+    response = await ds_client.post("/fixtures.json")
+    assert_canonical_error(response, 405)
+
+
+@pytest.mark.asyncio
+async def test_schema_unknown_database_error_shape(ds_client):
+    response = await ds_client.get("/no_such_db/-/schema.json")
+    assert_canonical_error(response, 404)
+
+
+# Forbidden responses (the default forbidden() hook)
+
+
+@pytest.fixture
+def ds_forbidden(tmp_path_factory):
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "data.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.execute("create table docs (id integer primary key, title text)")
+    conn.close()
+    ds = Datasette(
+        [db_path],
+        config={"databases": {"data": {"tables": {"docs": {"allow": {"id": "root"}}}}}},
+    )
+    ds.root_enabled = True
+    yield ds
+    ds.close()
+
+
+@pytest.mark.asyncio
+async def test_forbidden_json_path_returns_canonical_json(ds_forbidden):
+    response = await ds_forbidden.client.get("/data/docs.json")
+    data = assert_canonical_error(response, 403)
+    assert "permission" in data["error"].lower()
+
+
+@pytest.mark.asyncio
+async def test_forbidden_accept_json_returns_canonical_json(ds_forbidden):
+    response = await ds_forbidden.client.get(
+        "/data/docs", headers={"Accept": "application/json"}
+    )
+    assert_canonical_error(response, 403)
+
+
+@pytest.mark.asyncio
+async def test_forbidden_html_path_still_returns_html(ds_forbidden):
+    response = await ds_forbidden.client.get("/data/docs")
+    assert response.status_code == 403
+    assert response.headers["content-type"].startswith("text/html")
+
+
+@pytest.mark.asyncio
+async def test_forbidden_json_path_allowed_actor_still_works(ds_forbidden):
+    response = await ds_forbidden.client.get("/data/docs.json", actor={"id": "root"})
+    assert response.status_code == 200
+    assert response.json()["ok"] is True
+
+
+# Write canned queries: SQL failures must not return HTTP 200
+
+
+@pytest.fixture
+def ds_write_query(tmp_path_factory):
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "data.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.execute("create table docs (id integer primary key, title text)")
+    conn.close()
+    ds = Datasette(
+        [db_path],
+        config={
+            "databases": {
+                "data": {
+                    "queries": {
+                        "add_doc": {
+                            "sql": (
+                                "insert into docs (id, title)" " values (:id, :title)"
+                            ),
+                            "write": True,
+                        },
+                        "add_doc_custom_error": {
+                            "sql": (
+                                "insert into docs (id, title)" " values (:id, :title)"
+                            ),
+                            "write": True,
+                            "on_error_message": "Custom error message",
+                            "on_error_redirect": "/data",
+                        },
+                    }
+                }
+            }
+        },
+    )
+    yield ds
+    ds.close()
+
+
+@pytest.mark.asyncio
+async def test_write_query_success_returns_200(ds_write_query):
+    response = await ds_write_query.client.post(
+        "/data/add_doc",
+        json={"id": 1, "title": "One"},
+        headers={"Accept": "application/json"},
+    )
+    assert response.status_code == 200
+    data = response.json()
+    assert data["ok"] is True
+    assert data["message"] == "Query executed, 1 row affected"
+    assert data["redirect"] is None
+
+
+@pytest.mark.asyncio
+async def test_write_query_sql_failure_returns_400(ds_write_query):
+    for _ in range(2):
+        response = await ds_write_query.client.post(
+            "/data/add_doc",
+            json={"id": 1, "title": "One"},
+            headers={"Accept": "application/json"},
+        )
+    data = assert_canonical_error(response, 400)
+    assert "UNIQUE constraint failed" in data["error"]
+    # The redirect context key from the canned query flow is preserved
+    assert data["redirect"] is None
+
+
+@pytest.mark.asyncio
+async def test_write_query_failure_uses_on_error_message_and_redirect(
+    ds_write_query,
+):
+    for _ in range(2):
+        response = await ds_write_query.client.post(
+            "/data/add_doc_custom_error",
+            json={"id": 1, "title": "One"},
+            headers={"Accept": "application/json"},
+        )
+    data = assert_canonical_error(response, 400)
+    assert data["error"] == "Custom error message"
+    assert data["redirect"] == "/data"
+
+
+@pytest.mark.asyncio
+async def test_write_query_forbidden_is_canonical_403(ds_write_query):
+    # An untrusted write query run by an actor without execute-write-sql
+    # raises Forbidden, handled by the forbidden() hook
+    await ds_write_query.invoke_startup()
+    await ds_write_query.add_query(
+        "data",
+        name="untrusted_add",
+        sql="insert into docs (id, title) values (:id, :title)",
+        is_write=True,
+        is_trusted=False,
+        source="user",
+        owner_id="someone",
+    )
+    response = await ds_write_query.client.post(
+        "/data/untrusted_add",
+        json={"id": 5, "title": "Five"},
+        headers={"Accept": "application/json"},
+        actor={"id": "someone"},
+    )
+    assert_canonical_error(response, 403)
+
+
+@pytest.mark.asyncio
+async def test_write_query_rejected_operation_is_canonical_403(ds_write_query):
+    # A rejected operation (VACUUM) raises QueryWriteRejected, handled by
+    # the dedicated branch in QueryView.post - root has execute-write-sql
+    ds_write_query.root_enabled = True
+    await ds_write_query.invoke_startup()
+    await ds_write_query.add_query(
+        "data",
+        name="vacuum_it",
+        sql="vacuum",
+        is_write=True,
+        is_trusted=False,
+        source="user",
+        owner_id="root",
+    )
+    response = await ds_write_query.client.post(
+        "/data/vacuum_it",
+        json={},
+        headers={"Accept": "application/json"},
+        actor={"id": "root"},
+    )
+    data = assert_canonical_error(response, 403)
+    assert data["redirect"] is None
+
+
+# Row delete write failures must be 400, matching row update
+
+
+@pytest.mark.asyncio
+async def test_row_delete_write_failure_is_400(tmp_path_factory):
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "data.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.execute("create table docs (id integer primary key, title text)")
+    conn.execute("insert into docs (id, title) values (1, 'One')")
+    conn.execute(
+        "create trigger no_delete before delete on docs "
+        "begin select raise(abort, 'deletes are blocked'); end"
+    )
+    conn.commit()
+    conn.close()
+    ds = Datasette([db_path])
+    ds.root_enabled = True
+    try:
+        response = await ds.client.post(
+            "/data/docs/1/-/delete",
+            json={},
+            headers={"Content-Type": "application/json"},
+            actor={"id": "root"},
+        )
+        data = assert_canonical_error(response, 400)
+        assert "deletes are blocked" in data["error"]
+    finally:
+        ds.close()
+
+
+# Invalid bearer tokens must produce 401, not silent anonymous access
+
+
+@pytest.mark.asyncio
+async def test_expired_token_returns_401(ds_error_shape):
+    token = "dstok_{}".format(
+        ds_error_shape.sign(
+            {"a": "root", "t": int(time.time()) - 2000, "d": 1000},
+            namespace="token",
+        )
+    )
+    response = await ds_error_shape.client.get(
+        "/-/actor.json", headers={"Authorization": "Bearer {}".format(token)}
+    )
+    data = assert_canonical_error(response, 401)
+    assert "expired" in data["error"].lower()
+    assert response.headers["www-authenticate"].startswith("Bearer")
+
+
+@pytest.mark.asyncio
+async def test_bad_signature_token_returns_401(ds_error_shape):
+    response = await ds_error_shape.client.get(
+        "/-/actor.json", headers={"Authorization": "Bearer dstok_garbage"}
+    )
+    assert_canonical_error(response, 401)
+    assert response.headers["www-authenticate"].startswith("Bearer")
+
+
+@pytest.mark.asyncio
+async def test_unrecognized_token_prefix_stays_anonymous(ds_error_shape):
+    # No registered handler claims this token - it might belong to a
+    # plugin's actor_from_request hook, so it must not hard-fail
+    response = await ds_error_shape.client.get(
+        "/-/actor.json", headers={"Authorization": "Bearer sometoken_abc"}
+    )
+    assert response.status_code == 200
+    assert response.json() == {"ok": True, "actor": None}
+
+
+@pytest.mark.asyncio
+async def test_valid_token_still_authenticates(ds_error_shape):
+    token = "dstok_{}".format(
+        ds_error_shape.sign(
+            {"a": "root", "t": int(time.time())},
+            namespace="token",
+        )
+    )
+    response = await ds_error_shape.client.get(
+        "/-/actor.json", headers={"Authorization": "Bearer {}".format(token)}
+    )
+    assert response.status_code == 200
+    assert response.json()["actor"]["id"] == "root"
+
+
+@pytest.mark.asyncio
+async def test_bad_token_beats_valid_cookie(ds_error_shape):
+    # A malformed Authorization header is a hard error even if a valid
+    # ds_actor cookie is also present
+    response = await ds_error_shape.client.get(
+        "/-/actor.json",
+        headers={"Authorization": "Bearer dstok_garbage"},
+        cookies={"ds_actor": ds_error_shape.client.actor_cookie({"id": "root"})},
+    )
+    assert_canonical_error(response, 401)
+
+
+@pytest.mark.asyncio
+async def test_token_when_signed_tokens_disabled_returns_401(tmp_path_factory):
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "data.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.close()
+    ds = Datasette([db_path], settings={"allow_signed_tokens": False})
+    try:
+        token = "dstok_{}".format(
+            ds.sign({"a": "root", "t": int(time.time())}, namespace="token")
+        )
+        response = await ds.client.get(
+            "/-/actor.json", headers={"Authorization": "Bearer {}".format(token)}
+        )
+        data = assert_canonical_error(response, 401)
+        assert "not enabled" in data["error"]
+    finally:
+        ds.close()
+
+
+# GET /db/-/query without SQL: 400 for data formats, HTML editor stays 200
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "path",
+    (
+        "/fixtures/-/query.json",
+        "/fixtures/-/query.json?sql=",
+    ),
+)
+async def test_query_json_without_sql_is_400(ds_client, path):
+    response = await ds_client.get(path)
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["?sql= is required"]
+
+
+@pytest.mark.asyncio
+async def test_query_html_without_sql_is_still_the_editor(ds_client):
+    response = await ds_client.get("/fixtures/-/query")
+    assert response.status_code == 200
+    assert response.headers["content-type"].startswith("text/html")
+
+
+# Write API return:true responses use "rows" consistently
+
+
+@pytest.mark.asyncio
+async def test_row_update_return_uses_rows_list(ds_error_shape):
+    await ds_error_shape.client.post(
+        "/data/docs/-/insert",
+        json={"row": {"id": 1, "title": "One"}},
+        headers={"Content-Type": "application/json"},
+        actor={"id": "root"},
+    )
+    response = await ds_error_shape.client.post(
+        "/data/docs/1/-/update",
+        json={"update": {"title": "Updated"}, "return": True},
+        headers={"Content-Type": "application/json"},
+        actor={"id": "root"},
+    )
+    assert response.status_code == 200
+    data = response.json()
+    assert data["ok"] is True
+    assert "row" not in data
+    assert data["rows"] == [{"id": 1, "title": "Updated"}]
+
+
+# Schema endpoints: no existence oracle, no 500 on unknown database
+
+
+@pytest.mark.asyncio
+async def test_schema_endpoints_no_existence_oracle(tmp_path_factory):
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "data.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.execute("create table docs (id integer primary key)")
+    conn.close()
+    ds = Datasette([db_path], default_deny=True)
+    ds.root_enabled = True
+    try:
+        # An actor without view-database cannot distinguish an existing
+        # database from a missing one
+        denied_existing = await ds.client.get("/data/-/schema.json")
+        denied_missing = await ds.client.get("/nope/-/schema.json")
+        assert denied_existing.status_code == denied_missing.status_code == 403
+
+        # An authorized actor sees the real thing
+        root_existing = await ds.client.get("/data/-/schema.json", actor={"id": "root"})
+        assert root_existing.status_code == 200
+        root_missing = await ds.client.get("/nope/-/schema.json", actor={"id": "root"})
+        assert root_missing.status_code == 404
+    finally:
+        ds.close()
+
+
+@pytest.mark.asyncio
+async def test_table_schema_unknown_database_is_404_not_500(ds_client):
+    response = await ds_client.get("/no_such_db/some_table/-/schema.json")
+    assert_canonical_error(response, 404)
+
+
+# Unknown _extra names are a 400, not silently ignored
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "path",
+    (
+        "/fixtures/facetable.json?_extra=nope",
+        "/fixtures/facetable.json?_extra=count,nope",
+        "/fixtures/simple_primary_key/1.json?_extra=nope",
+        "/fixtures/-/query.json?sql=select+1&_extra=nope",
+    ),
+)
+async def test_unknown_extra_is_400(ds_client, path):
+    response = await ds_client.get(path)
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["Unknown _extra: nope"]
+
+
+@pytest.mark.asyncio
+async def test_html_only_extra_via_json_is_400(ds_client):
+    # display_rows exists for the HTML view but is not part of the JSON API
+    response = await ds_client.get("/fixtures/facetable.json?_extra=display_rows")
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["Unknown _extra: display_rows"]
+
+
+@pytest.mark.asyncio
+async def test_unknown_extra_ignored_on_html_pages(ds_client):
+    response = await ds_client.get("/fixtures/facetable?_extra=nope")
+    assert response.status_code == 200
+    assert response.headers["content-type"].startswith("text/html")
+
+
+# /-/threads exposes runtime internals and requires permissions-debug
+
+
+@pytest.mark.asyncio
+async def test_threads_requires_permissions_debug(ds_error_shape):
+    denied = await ds_error_shape.client.get("/-/threads.json")
+    assert_canonical_error(denied, 403)
+    allowed = await ds_error_shape.client.get("/-/threads.json", actor={"id": "root"})
+    assert allowed.status_code == 200
+    assert allowed.json()["ok"] is True
+
+
+# _size is the one page-size parameter, with uniform validation
+
+
+@pytest.mark.asyncio
+async def test_query_list_size_supports_max_keyword(ds_client):
+    response = await ds_client.get("/fixtures/-/queries.json?_size=max")
+    assert response.status_code == 200
+    # ds_client runs with max_returned_rows=100
+    assert response.json()["limit"] == 100
+
+
+@pytest.mark.asyncio
+async def test_query_list_size_rejects_out_of_range(ds_client):
+    response = await ds_client.get("/fixtures/-/queries.json?_size=5000")
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["_size must be <= 100"]
+
+
+@pytest.mark.asyncio
+async def test_query_list_size_rejects_non_integer(ds_client):
+    response = await ds_client.get("/fixtures/-/queries.json?_size=bananas")
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["_size must be a positive integer"]
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("endpoint", ("allowed", "rules"))
+async def test_debug_endpoints_use_size_and_page_parameters(ds_error_shape, endpoint):
+    base = "/-/{}.json?action=view-instance".format(endpoint)
+    ok = await ds_error_shape.client.get(
+        base + "&_size=1&_page=1", actor={"id": "root"}
+    )
+    assert ok.status_code == 200
+    assert ok.json()["page_size"] == 1
+
+    max_size = await ds_error_shape.client.get(
+        base + "&_size=max", actor={"id": "root"}
+    )
+    assert max_size.status_code == 200
+    assert max_size.json()["page_size"] == 200
+
+    too_big = await ds_error_shape.client.get(base + "&_size=500", actor={"id": "root"})
+    data = assert_canonical_error(too_big, 400)
+    assert data["errors"] == ["_size must be <= 200"]
+
+    bad_page = await ds_error_shape.client.get(base + "&_page=0", actor={"id": "root"})
+    data = assert_canonical_error(bad_page, 400)
+    assert data["errors"] == ["_page must be a positive integer"]
+
+
+# Write endpoints parse the body as JSON regardless of Content-Type
+
+
+@pytest.mark.asyncio
+async def test_insert_works_without_content_type_header(ds_error_shape):
+    # Previously a 500 AttributeError
+    response = await ds_error_shape.client.post(
+        "/data/docs/-/insert",
+        content='{"row": {"id": 1, "title": "One"}}',
+        actor={"id": "root"},
+    )
+    assert response.status_code == 201
+    assert response.json()["rows"][0]["title"] == "One"
+
+
+@pytest.mark.asyncio
+async def test_insert_works_with_form_content_type(ds_error_shape):
+    # Previously 400 "Invalid content-type, must be application/json"
+    response = await ds_error_shape.client.post(
+        "/data/docs/-/insert",
+        content='{"row": {"id": 2, "title": "Two"}}',
+        headers={"Content-Type": "application/x-www-form-urlencoded"},
+        actor={"id": "root"},
+    )
+    assert response.status_code == 201
+
+
+@pytest.mark.asyncio
+async def test_insert_form_encoded_body_is_invalid_json(ds_error_shape):
+    response = await ds_error_shape.client.post(
+        "/data/docs/-/insert",
+        content="title=Three",
+        headers={"Content-Type": "application/x-www-form-urlencoded"},
+        actor={"id": "root"},
+    )
+    data = assert_canonical_error(response, 400)
+    assert data["errors"][0].startswith("Invalid JSON:")
+
+
+@pytest.mark.asyncio
+async def test_alter_and_set_column_type_ignore_content_type(ds_error_shape):
+    alter = await ds_error_shape.client.post(
+        "/data/docs/-/alter",
+        content='{"operations": [{"op": "add_column", "args": {"name": "extra"}}]}',
+        actor={"id": "root"},
+    )
+    assert alter.status_code == 200, alter.text
+    sct = await ds_error_shape.client.post(
+        "/data/docs/-/set-column-type",
+        content='{"column": "title", "column_type": {"type": "textarea"}}',
+        actor={"id": "root"},
+    )
+    assert sct.status_code == 200, sct.text
+
+
+# SQL Interrupted errors carry plain text in JSON, not an HTML fragment
+
+
+@pytest.mark.asyncio
+async def test_sql_interrupted_json_error_is_plain_text(ds_client):
+    response = await ds_client.get(
+        "/fixtures/-/query.json?sql=select+sleep(0.01)&_timelimit=5"
+    )
+    data = assert_canonical_error(response, 400)
+    assert "<" not in data["error"]
+    assert data["error"].startswith("SQL query took too long.")
+
+
+@pytest.mark.asyncio
+async def test_sql_interrupted_html_page_keeps_rich_error(ds_client):
+    response = await ds_client.get(
+        "/fixtures/-/query?sql=select+sleep(0.01)&_timelimit=5"
+    )
+    assert response.status_code == 400
+    assert "<textarea" in response.text
+
+
+@pytest.mark.asyncio
+async def test_next_url_extra_no_longer_exists(ds_client):
+    # next_url is always present in table JSON; the extra was removed
+    response = await ds_client.get("/fixtures/facetable.json?_extra=next_url")
+    data = assert_canonical_error(response, 400)
+    assert data["errors"] == ["Unknown _extra: next_url"]

tests/test_html.py

@@ -1363,12 +1363,12 @@ async def test_permission_debug_tabs_with_query_string(ds_client):
 
         # Test /-/allowed with query string
         response = await ds_client.get(
-            "/-/allowed?action=view-table&page_size=50", actor=actor
+            "/-/allowed?action=view-table&_size=50", actor=actor
         )
         assert response.status_code == 200
         # Check that Rules and Check tabs have the query string
-        assert 'href="/-/rules?action=view-table&page_size=50"' in response.text
-        assert 'href="/-/check?action=view-table&page_size=50"' in response.text
+        assert 'href="/-/rules?action=view-table&_size=50"' in response.text
+        assert 'href="/-/check?action=view-table&_size=50"' in response.text
         # Playground and Actions should not have query string
         assert 'href="/-/permissions"' in response.text
         assert 'href="/-/actions"' in response.text

tests/test_internals_datasette.py

@@ -167,7 +167,7 @@ def test_static_rejects_path_traversal(tmp_path, monkeypatch):
 @pytest.mark.asyncio
 async def test_datasette_constructor():
     ds = Datasette()
-    databases = (await ds.client.get("/-/databases.json")).json()
+    databases = (await ds.client.get("/-/databases.json")).json()["databases"]
     assert databases == [
         {
             "name": "_memory",
@@ -184,11 +184,12 @@ async def test_datasette_constructor():
 @pytest.mark.asyncio
 async def test_num_sql_threads_zero():
     ds = Datasette([], memory=True, settings={"num_sql_threads": 0})
+    ds.root_enabled = True
     db = ds.add_database(Database(ds, memory_name="test_num_sql_threads_zero"))
     await db.execute_write("create table t(id integer primary key)")
     await db.execute_write("insert into t (id) values (1)")
-    response = await ds.client.get("/-/threads.json")
-    assert response.json() == {"num_threads": 0, "threads": []}
+    response = await ds.client.get("/-/threads.json", actor={"id": "root"})
+    assert response.json() == {"ok": True, "num_threads": 0, "threads": []}
     response2 = await ds.client.get("/test_num_sql_threads_zero/t.json?_shape=array")
     assert response2.json() == [{"id": 1}]
 

tests/test_internals_datasette_client.py

@@ -318,7 +318,7 @@ async def test_actor_parameter_sets_cookie(datasette):
     """Passing actor= should sign a ds_actor cookie and authenticate the request."""
     response = await datasette.client.get("/-/actor.json", actor={"id": "root"})
     assert response.status_code == 200
-    assert response.json() == {"actor": {"id": "root"}}
+    assert response.json() == {"ok": True, "actor": {"id": "root"}}
 
 
 @pytest.mark.asyncio
@@ -327,7 +327,7 @@ async def test_actor_parameter_works_with_request_method(datasette):
         "GET", "/-/actor.json", actor={"id": "root"}
     )
     assert response.status_code == 200
-    assert response.json() == {"actor": {"id": "root"}}
+    assert response.json() == {"ok": True, "actor": {"id": "root"}}
 
 
 @pytest.mark.asyncio
@@ -362,7 +362,7 @@ async def test_actor_parameter_merges_with_other_cookies(datasette):
         cookies={"unrelated": "value"},
     )
     assert response.status_code == 200
-    assert response.json() == {"actor": {"id": "root"}}
+    assert response.json() == {"ok": True, "actor": {"id": "root"}}
 
 
 @pytest.mark.asyncio

tests/test_internals_response.py

@@ -1,4 +1,5 @@
 from datasette.utils.asgi import Response
+import json
 import pytest
 
 
@@ -52,3 +53,26 @@ async def test_response_set_cookie():
         },
         {"type": "http.response.body", "body": b""},
     ] == events
+
+
+def test_response_error_single_message():
+    response = Response.error("Method not allowed", 405)
+    assert response.status == 405
+    assert response.content_type == "application/json; charset=utf-8"
+    assert json.loads(response.body) == {
+        "ok": False,
+        "error": "Method not allowed",
+        "errors": ["Method not allowed"],
+        "status": 405,
+    }
+
+
+def test_response_error_message_list_and_default_status():
+    response = Response.error(["First problem", "Second problem"])
+    assert response.status == 400
+    assert json.loads(response.body) == {
+        "ok": False,
+        "error": "First problem; Second problem",
+        "errors": ["First problem", "Second problem"],
+        "status": 400,
+    }

tests/test_permission_endpoints.py

@@ -137,9 +137,7 @@ async def test_allowed_json_pagination():
     await ds.refresh_schemas()
 
     # Test page 1
-    response = await ds.client.get(
-        "/-/allowed.json?action=view-table&page_size=10&page=1"
-    )
+    response = await ds.client.get("/-/allowed.json?action=view-table&_size=10&_page=1")
     assert response.status_code == 200
     data = response.json()
     assert data["page"] == 1
@@ -147,9 +145,7 @@ async def test_allowed_json_pagination():
     assert len(data["items"]) == 10
 
     # Test page 2
-    response = await ds.client.get(
-        "/-/allowed.json?action=view-table&page_size=10&page=2"
-    )
+    response = await ds.client.get("/-/allowed.json?action=view-table&_size=10&_page=2")
     assert response.status_code == 200
     data = response.json()
     assert data["page"] == 2
@@ -157,10 +153,10 @@ async def test_allowed_json_pagination():
 
     # Verify items are different between pages
     response1 = await ds.client.get(
-        "/-/allowed.json?action=view-table&page_size=10&page=1"
+        "/-/allowed.json?action=view-table&_size=10&_page=1"
     )
     response2 = await ds.client.get(
-        "/-/allowed.json?action=view-table&page_size=10&page=2"
+        "/-/allowed.json?action=view-table&_size=10&_page=2"
     )
     items1 = {(item["parent"], item["child"]) for item in response1.json()["items"]}
     items2 = {(item["parent"], item["child"]) for item in response2.json()["items"]}
@@ -323,7 +319,7 @@ async def test_rules_json_pagination():
 
     # Test basic pagination structure - just verify it returns paginated results
     response = await ds.client.get(
-        "/-/rules.json?action=view-table&page_size=2&page=1",
+        "/-/rules.json?action=view-table&_size=2&_page=1",
         actor={"id": "root"},
     )
     assert response.status_code == 200

tests/test_permissions.py

@@ -3,6 +3,7 @@ from asgiref.sync import async_to_sync
 from datasette.app import Datasette
 from datasette.cli import cli
 from datasette.default_permissions import restrictions_allow_action
+from datasette.utils import UNSTABLE_API_MESSAGE
 from .fixtures import assert_permissions_checked, make_app_client
 from click.testing import CliRunner
 from bs4 import BeautifulSoup as Soup
@@ -739,6 +740,8 @@ async def test_actor_restricted_permissions(
         "path": expected_path,
     }
     expected = {
+        "ok": True,
+        "unstable": UNSTABLE_API_MESSAGE,
         "action": permission,
         "allowed": expected_result,
         "resource": expected_resource,
@@ -1115,7 +1118,7 @@ def test_cli_create_token(options, expected):
         ],
     )
     assert 0 == result2.exit_code, result2.output
-    assert json.loads(result2.output) == {"actor": expected}
+    assert json.loads(result2.output) == {"ok": True, "actor": expected}
 
 
 _visible_tables_re = re.compile(r">\/((\w+)\/(\w+))\.json<\/a> - Get rows for")
@@ -1799,3 +1802,35 @@ async def test_root_allow_block_with_table_restricted_actor():
         actor=admin_actor,
     )
     assert result is True
+
+
+@pytest.mark.asyncio
+async def test_databases_json_respects_view_database(tmp_path_factory):
+    # https://github.com/simonw/datasette - /-/databases should not list
+    # databases the actor is not allowed to view
+    db_directory = tmp_path_factory.mktemp("dbs")
+    from datasette.utils import sqlite3 as _sqlite3
+
+    paths = []
+    for name in ("public", "private"):
+        path = str(db_directory / "{}.db".format(name))
+        conn = _sqlite3.connect(path)
+        conn.execute("vacuum")
+        conn.close()
+        paths.append(path)
+    ds = Datasette(
+        paths,
+        config={"databases": {"private": {"allow": {"id": "root"}}}},
+    )
+    ds.root_enabled = True
+    await ds.invoke_startup()
+    try:
+        anon_response = await ds.client.get("/-/databases.json")
+        assert anon_response.status_code == 200
+        anon_names = {db["name"] for db in anon_response.json()["databases"]}
+        assert anon_names == {"public"}
+        root_response = await ds.client.get("/-/databases.json", actor={"id": "root"})
+        root_names = {db["name"] for db in root_response.json()["databases"]}
+        assert root_names == {"public", "private"}
+    finally:
+        ds.close()

tests/test_plugins.py

@@ -783,9 +783,13 @@ async def test_hook_permission_resources_sql():
 
 @pytest.mark.asyncio
 async def test_actor_json(ds_client):
-    assert (await ds_client.get("/-/actor.json")).json() == {"actor": None}
+    assert (await ds_client.get("/-/actor.json")).json() == {
+        "ok": True,
+        "actor": None,
+    }
     assert (await ds_client.get("/-/actor.json?_bot2=1")).json() == {
-        "actor": {"id": "bot2", "1+1": 2}
+        "ok": True,
+        "actor": {"id": "bot2", "1+1": 2},
     }
 
 
@@ -1478,7 +1482,7 @@ async def test_plugin_is_installed():
         datasette.pm.register(DummyPlugin(), name="DummyPlugin")
         response = await datasette.client.get("/-/plugins.json")
         assert response.status_code == 200
-        installed_plugins = {p["name"] for p in response.json()}
+        installed_plugins = {p["name"] for p in response.json()["plugins"]}
         assert "DummyPlugin" in installed_plugins
 
     finally:

tests/test_queries.py

@@ -8,6 +8,7 @@ from bs4 import BeautifulSoup as Soup
 from datasette.app import Datasette
 from datasette.resources import DatabaseResource, QueryResource
 from datasette.stored_queries import StoredQuery, StoredQueryPage
+from datasette.utils import UNSTABLE_API_MESSAGE
 from datasette.utils.asgi import Forbidden
 from datasette.utils.sqlite import sqlite3, supports_returning
 
@@ -879,7 +880,7 @@ async def test_query_list_html_defaults_to_twenty_and_shows_pagination():
     assert response.text.count('aria-label="Query pagination"') == 1
     assert "Demo query 20" in response.text
     assert "Demo query 21" not in response.text
-    assert 'href="/data/-/queries?_next=' in response.text
+    assert 'href="http://localhost/data/-/queries?_next=' in response.text
     assert len(json_response.json()["queries"]) == 25
 
 
@@ -1125,6 +1126,47 @@ async def test_query_update_api_rejects_config_only_fields():
     assert query.on_success_message_sql is None
 
 
+@pytest.mark.asyncio
+async def test_query_api_rejects_params_alias():
+    # "params" is a datasette.yaml configuration key, not an API input -
+    # the API only accepts "parameters"
+    ds = Datasette(memory=True, default_deny=True)
+    ds.root_enabled = True
+    db = ds.add_memory_database("query_params_alias", name="data")
+    await db.execute_write("create table dogs (id integer primary key, name text)")
+    await ds.invoke_startup()
+
+    store_response = await ds.client.post(
+        "/data/-/queries/store",
+        actor={"id": "root"},
+        json={
+            "query": {
+                "name": "by_name",
+                "sql": "select * from dogs where name = :name",
+                "params": ["name"],
+            }
+        },
+    )
+    assert store_response.status_code == 400
+    assert store_response.json()["errors"] == ["Invalid keys: params"]
+    assert await ds.get_query("data", "by_name") is None
+
+    await ds.add_query(
+        "data",
+        "editable",
+        "select * from dogs where name = :name",
+        source="user",
+        owner_id="root",
+    )
+    update_response = await ds.client.post(
+        "/data/editable/-/update",
+        actor={"id": "root"},
+        json={"update": {"params": ["name"]}},
+    )
+    assert update_response.status_code == 400
+    assert update_response.json()["errors"] == ["Invalid keys: params"]
+
+
 @pytest.mark.asyncio
 async def test_query_update_api_rejects_trusted_queries_but_internal_update_allowed():
     ds = Datasette(
@@ -2140,7 +2182,11 @@ async def test_query_parameters_endpoint_uses_get_sql_only():
     )
 
     assert response.status_code == 200
-    assert response.json() == {"ok": True, "parameters": ["name", "id"]}
+    assert response.json() == {
+        "ok": True,
+        "unstable": UNSTABLE_API_MESSAGE,
+        "parameters": ["name", "id"],
+    }
     assert permission_denied_response.status_code == 403
     assert permission_denied_response.json()["errors"] == [
         "Permission denied: need execute-sql"
@@ -3093,9 +3139,9 @@ async def test_untrusted_stored_write_query_rejects_virtual_table_control_insert
     )
 
     assert denied_response.status_code == 403
-    assert denied_response.json()["message"] == (
+    assert denied_response.json()["errors"] == [
         "Writes to virtual tables are not allowed in user-supplied SQL"
-    )
+    ]
     assert (
         await db.execute("select count(*) from docs where docs match 'hello'")
     ).first()[0] == 1
@@ -3742,3 +3788,81 @@ async def test_stored_write_query_with_truncated_returning_message():
     assert response.status_code == 200
     assert response.json()["ok"] is True
     assert response.json()["message"] == "Query executed"
+
+
+@pytest.mark.asyncio
+async def test_query_delete_api_rejects_trusted_queries():
+    ds = Datasette(
+        memory=True,
+        default_deny=True,
+        config={
+            "databases": {
+                "data": {
+                    "permissions": {
+                        "view-query": {"id": "editor"},
+                        "delete-query": {"id": "editor"},
+                    },
+                    "queries": {
+                        "trusted_report": {
+                            "sql": "select 1 as one",
+                        },
+                    },
+                }
+            }
+        },
+    )
+    ds.add_memory_database("query_delete_trusted_api", name="data")
+    await ds.invoke_startup()
+
+    response = await ds.client.post(
+        "/data/trusted_report/-/delete",
+        actor={"id": "editor"},
+        json={},
+    )
+    assert response.status_code == 403
+    assert response.json()["errors"] == [
+        "Trusted queries cannot be deleted using the API"
+    ]
+    # The query must still exist
+    assert await ds.get_query("data", "trusted_report") is not None
+
+    # The HTML confirmation page refuses too
+    get_response = await ds.client.get(
+        "/data/trusted_report/-/delete",
+        actor={"id": "editor"},
+    )
+    assert get_response.status_code == 403
+
+    # datasette.remove_query() remains available for internal use
+    await ds.remove_query("data", "trusted_report")
+    assert await ds.get_query("data", "trusted_report") is None
+
+
+@pytest.mark.asyncio
+async def test_stored_query_json_uses_parameters_not_params():
+    ds = Datasette(
+        memory=True,
+        config={
+            "databases": {
+                "data": {
+                    "queries": {
+                        "with_params": {
+                            "sql": "select :name as name, :age as age",
+                            "params": ["name", "age"],
+                        },
+                    },
+                }
+            }
+        },
+    )
+    ds.add_memory_database("query_parameters_key", name="data")
+    await ds.invoke_startup()
+
+    definition = (await ds.client.get("/data/with_params/-/definition")).json()
+    assert definition["query"]["parameters"] == ["name", "age"]
+    assert "params" not in definition["query"]
+
+    listing = (await ds.client.get("/data/-/queries.json")).json()
+    query = [q for q in listing["queries"] if q["name"] == "with_params"][0]
+    assert query["parameters"] == ["name", "age"]
+    assert "params" not in query

tests/test_routes.py

@@ -73,7 +73,7 @@ async def ds_with_route():
 @pytest.mark.asyncio
 async def test_db_with_route_databases(ds_with_route):
     response = await ds_with_route.client.get("/-/databases.json")
-    assert response.json()[0] == {
+    assert response.json()["databases"][0] == {
         "name": "original-name",
         "route": "custom-route-name",
         "path": None,

tests/test_success_envelope.py

@@ -0,0 +1,170 @@
+"""
+Tests for the canonical JSON success envelope.
+
+Every JSON object returned by a Datasette endpoint on success should include
+"ok": true. (Endpoints that return a top-level array are being converted to
+objects separately - see /-/plugins, /-/databases, /-/actions.)
+"""
+
+import pytest
+from datasette.app import Datasette
+from datasette.utils import sqlite3, UNSTABLE_API_MESSAGE
+
+
+@pytest.fixture
+def ds_envelope(tmp_path_factory):
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "data.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.execute("create table docs (id integer primary key, title text)")
+    conn.close()
+    ds = Datasette([db_path])
+    ds.root_enabled = True
+    yield ds
+    ds.close()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "path",
+    (
+        "/.json",
+        "/-/.json",
+        "/-/versions.json",
+        "/-/settings.json",
+        "/-/config.json",
+        "/-/actor.json",
+        "/-/jump.json",
+        "/-/schema.json",
+        "/fixtures/-/schema.json",
+        "/fixtures/facetable/-/schema.json",
+        "/-/allowed.json?action=view-instance",
+        "/fixtures/facet_cities/-/autocomplete?_initial=1",
+    ),
+)
+async def test_success_object_has_ok_true(ds_client, path):
+    response = await ds_client.get(path)
+    assert response.status_code == 200
+    data = response.json()
+    assert isinstance(data, dict)
+    assert data["ok"] is True
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "path",
+    (
+        "/-/rules.json?action=view-instance",
+        "/-/check.json?action=view-instance",
+        "/-/threads.json",
+    ),
+)
+async def test_permission_debug_success_has_ok_true(ds_envelope, path):
+    response = await ds_envelope.client.get(path, actor={"id": "root"})
+    assert response.status_code == 200
+    data = response.json()
+    assert data["ok"] is True
+
+
+@pytest.mark.asyncio
+async def test_permissions_post_success_has_ok_true(ds_envelope):
+    response = await ds_envelope.client.post(
+        "/-/permissions",
+        data={"actor": '{"id": "root"}', "permission": "view-instance"},
+        actor={"id": "root"},
+    )
+    assert response.status_code == 200
+    assert response.json()["ok"] is True
+
+
+@pytest.mark.asyncio
+async def test_plugins_json_is_object(ds_client):
+    response = await ds_client.get("/-/plugins.json")
+    assert response.status_code == 200
+    data = response.json()
+    assert set(data.keys()) == {"ok", "plugins"}
+    assert data["ok"] is True
+    assert isinstance(data["plugins"], list)
+    # ?all=1 should include Datasette's default plugins in the same shape
+    response_all = await ds_client.get("/-/plugins.json?all=1")
+    all_plugins = response_all.json()["plugins"]
+    assert len(all_plugins) > len(data["plugins"])
+
+
+@pytest.mark.asyncio
+async def test_databases_json_is_object(ds_client):
+    response = await ds_client.get("/-/databases.json")
+    assert response.status_code == 200
+    data = response.json()
+    assert set(data.keys()) == {"ok", "databases"}
+    assert data["ok"] is True
+    assert isinstance(data["databases"], list)
+    assert "fixtures" in {db["name"] for db in data["databases"]}
+
+
+@pytest.mark.asyncio
+async def test_actions_json_is_object(ds_envelope):
+    response = await ds_envelope.client.get("/-/actions.json", actor={"id": "root"})
+    assert response.status_code == 200
+    data = response.json()
+    assert set(data.keys()) == {"ok", "actions"}
+    assert data["ok"] is True
+    assert isinstance(data["actions"], list)
+    assert "view-instance" in {action["name"] for action in data["actions"]}
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "path",
+    (
+        "/.json",
+        "/-/.json",
+        "/fixtures/-/queries/analyze?sql=select+1",
+        "/fixtures/-/query/parameters?sql=select+:name",
+        "/fixtures/-/execute-write/analyze?sql=delete+from+facetable",
+    ),
+)
+async def test_undocumented_endpoints_report_unstable(ds_client, path):
+    ds_client.ds.root_enabled = True
+    try:
+        response = await ds_client.get(path, actor={"id": "root"})
+    finally:
+        ds_client.ds.root_enabled = False
+    assert response.status_code == 200
+    assert response.json()["unstable"] == UNSTABLE_API_MESSAGE
+
+
+@pytest.mark.asyncio
+async def test_query_store_and_definition_report_unstable(ds_envelope):
+    store = await ds_envelope.client.post(
+        "/data/-/queries/store",
+        json={"query": {"name": "unstable_check", "sql": "select 1"}},
+        actor={"id": "root"},
+    )
+    assert store.status_code == 201
+    assert store.json()["unstable"] == UNSTABLE_API_MESSAGE
+    definition = await ds_envelope.client.get(
+        "/data/unstable_check/-/definition", actor={"id": "root"}
+    )
+    assert definition.status_code == 200
+    assert definition.json()["unstable"] == UNSTABLE_API_MESSAGE
+
+
+@pytest.mark.asyncio
+async def test_permissions_post_reports_unstable(ds_envelope):
+    response = await ds_envelope.client.post(
+        "/-/permissions",
+        data={"actor": '{"id": "root"}', "permission": "view-instance"},
+        actor={"id": "root"},
+    )
+    assert response.status_code == 200
+    assert response.json()["unstable"] == UNSTABLE_API_MESSAGE
+
+
+@pytest.mark.asyncio
+async def test_documented_endpoints_do_not_report_unstable(ds_client):
+    for path in ("/-/versions.json", "/fixtures.json", "/fixtures/facetable.json"):
+        response = await ds_client.get(path)
+        assert response.status_code == 200
+        assert "unstable" not in response.json()

tests/test_table_api.py

@@ -31,8 +31,8 @@ async def test_table_not_exists_json(ds_client):
     assert (await ds_client.get("/fixtures/blah.json")).json() == {
         "ok": False,
         "error": "Table not found",
+        "errors": ["Table not found"],
         "status": 404,
-        "title": None,
     }
 
 
@@ -123,8 +123,8 @@ async def test_html_only_extras_are_not_available_via_json(ds_client, extra):
     # These extras exist for the HTML view; their values are not JSON
     # serializable so they are internal, not part of the JSON API
     response = await ds_client.get(f"/fixtures/facetable.json?_extra={extra}")
-    assert response.status_code == 200
-    assert extra not in response.json()
+    assert response.status_code == 400
+    assert response.json()["errors"] == [f"Unknown _extra: {extra}"]
 
 
 @pytest.mark.asyncio
@@ -180,9 +180,11 @@ def test_query_extra_query_reports_bound_params():
         assert response.json["query"]["params"] == {}
 
 
-def test_query_extra_query_does_not_echo_querystring_without_sql():
+def test_query_extra_query_does_not_echo_querystring():
     with make_app_client() as client:
-        response = client.get("/fixtures/-/query.json?_extra=query&foo=bar")
+        response = client.get(
+            "/fixtures/-/query.json?sql=select+1&_extra=query&foo=bar"
+        )
         assert response.status == 200
         assert response.json["query"]["params"] == {}
 
@@ -242,8 +244,8 @@ async def test_table_shape_invalid(ds_client):
     assert response.json() == {
         "ok": False,
         "error": "Invalid _shape: invalid",
+        "errors": ["Invalid _shape: invalid"],
         "status": 400,
-        "title": None,
     }
 
 
@@ -321,10 +323,6 @@ async def test_paginate_tables_and_views(
     fetched = []
     count = 0
     while path:
-        if "?" in path:
-            path += "&_extra=next_url"
-        else:
-            path += "?_extra=next_url"
         response = await ds_client.get(path)
         assert response.status_code == 200
         count += 1
@@ -357,9 +355,7 @@ async def test_validate_page_size(ds_client, path, expected_error):
 @pytest.mark.asyncio
 async def test_page_size_zero(ds_client):
     """For _size=0 we return the counts, empty rows and no continuation token"""
-    response = await ds_client.get(
-        "/fixtures/no_primary_key.json?_size=0&_extra=count,next_url"
-    )
+    response = await ds_client.get("/fixtures/no_primary_key.json?_size=0&_extra=count")
     assert response.status_code == 200
     assert [] == response.json()["rows"]
     assert 202 == response.json()["count"]
@@ -370,7 +366,7 @@ async def test_page_size_zero(ds_client):
 @pytest.mark.asyncio
 async def test_paginate_compound_keys(ds_client):
     fetched = []
-    path = "/fixtures/compound_three_primary_keys.json?_shape=objects&_extra=next_url"
+    path = "/fixtures/compound_three_primary_keys.json?_shape=objects"
     page = 0
     while path:
         page += 1
@@ -391,7 +387,9 @@ async def test_paginate_compound_keys(ds_client):
 @pytest.mark.asyncio
 async def test_paginate_compound_keys_with_extra_filters(ds_client):
     fetched = []
-    path = "/fixtures/compound_three_primary_keys.json?content__contains=d&_shape=objects&_extra=next_url"
+    path = (
+        "/fixtures/compound_three_primary_keys.json?content__contains=d&_shape=objects"
+    )
     page = 0
     while path:
         page += 1
@@ -444,7 +442,7 @@ async def test_paginate_compound_keys_with_extra_filters(ds_client):
     ],
 )
 async def test_sortable(ds_client, query_string, sort_key, human_description_en):
-    path = f"/fixtures/sortable.json?_shape=objects&_extra=human_description_en,next_url&{query_string}"
+    path = f"/fixtures/sortable.json?_shape=objects&_extra=human_description_en&{query_string}"
     fetched = []
     page = 0
     while path:
@@ -635,8 +633,8 @@ async def test_searchable_invalid_column(ds_client):
     assert response.json() == {
         "ok": False,
         "error": "Cannot search by that column",
+        "errors": ["Cannot search by that column"],
         "status": 400,
-        "title": None,
     }
 
 
@@ -775,7 +773,7 @@ async def test_table_filter_extra_where_invalid(ds_client):
         "/fixtures/facetable.json?_where=_neighborhood=Dogpatch'"
     )
     assert response.status_code == 400
-    assert "Invalid SQL" == response.json()["title"]
+    assert "unrecognized token" in response.json()["error"]
 
 
 def test_table_filter_extra_where_disabled_if_no_sql_allowed():
@@ -848,7 +846,7 @@ def test_page_size_matching_max_returned_rows(
     app_client_returned_rows_matches_page_size,
 ):
     fetched = []
-    path = "/fixtures/no_primary_key.json?_extra=next_url"
+    path = "/fixtures/no_primary_key.json"
     while path:
         response = app_client_returned_rows_matches_page_size.get(path)
         fetched.extend(response.json["rows"])
@@ -1592,6 +1590,7 @@ async def test_col_nocol_errors(ds_client, path, expected_error):
             {
                 "ok": True,
                 "next": None,
+                "next_url": None,
                 "columns": ["id", "content", "content2"],
                 "rows": [{"id": "1", "content": "hey", "content2": "world"}],
                 "truncated": False,
@@ -1602,9 +1601,11 @@ async def test_col_nocol_errors(ds_client, path, expected_error):
             {
                 "ok": True,
                 "next": None,
+                "next_url": None,
                 "rows": [{"id": "1", "content": "hey", "content2": "world"}],
                 "truncated": False,
                 "count": 1,
+                "count_truncated": False,
             },
         ),
     ),
@@ -1691,3 +1692,58 @@ async def test_extra_render_cell():
 
     finally:
         ds.pm.unregister(name="TestRenderCellPlugin")
+
+
+@pytest.mark.asyncio
+async def test_count_truncated_included_with_count_extra(tmp_path_factory):
+    from datasette.app import Datasette
+    from datasette.utils import sqlite3
+
+    db_directory = tmp_path_factory.mktemp("dbs")
+    db_path = str(db_directory / "counts.db")
+    conn = sqlite3.connect(db_path)
+    conn.execute("vacuum")
+    conn.execute("create table big (id integer primary key)")
+    conn.execute("create table small (id integer primary key)")
+    conn.executemany("insert into big (id) values (?)", [(i,) for i in range(10)])
+    conn.executemany("insert into small (id) values (?)", [(i,) for i in range(3)])
+    conn.commit()
+    conn.close()
+    ds = Datasette([db_path])
+    ds.get_database("counts").count_limit = 5
+    try:
+        response = await ds.client.get("/counts/big.json?_extra=count")
+        data = response.json()
+        # Count is capped at count_limit + 1 and flagged as truncated
+        assert data["count"] == 6
+        assert data["count_truncated"] is True
+
+        response = await ds.client.get("/counts/small.json?_extra=count")
+        data = response.json()
+        assert data["count"] == 3
+        assert data["count_truncated"] is False
+
+        # count_truncated can also be requested on its own
+        response = await ds.client.get("/counts/big.json?_extra=count_truncated")
+        assert response.json()["count_truncated"] is True
+    finally:
+        ds.close()
+
+
+@pytest.mark.asyncio
+async def test_next_url_included_by_default(ds_client):
+    response = await ds_client.get("/fixtures/compound_three_primary_keys.json")
+    data = response.json()
+    assert data["next"] is not None
+    assert data["next_url"].endswith(
+        "/fixtures/compound_three_primary_keys.json?_next="
+        + urllib.parse.quote(data["next"], safe="")
+    )
+    # Follow to the last page - next and next_url are both null there
+    while data["next"]:
+        response = await ds_client.get(
+            "/fixtures/compound_three_primary_keys.json?_next=" + data["next"]
+        )
+        data = response.json()
+    assert data["next"] is None
+    assert data["next_url"] is None

tests/test_table_html.py

@@ -1665,7 +1665,7 @@ async def test_row_update_sets_message():
             json={"update": {"name": long_name}, "return": True},
         )
         assert response.status_code == 200
-        assert response.json()["row"]["name"] == long_name
+        assert response.json()["rows"][0]["name"] == long_name
         assert ds.unsign(response.cookies["ds_messages"], "messages") == [
             ["Updated row 1 ({})".format(truncated_name), ds.INFO]
         ]
@@ -2015,8 +2015,8 @@ async def test_sort_errors(ds_client, json, params, error):
         assert response.json() == {
             "ok": False,
             "error": error,
+            "errors": [error],
             "status": 400,
-            "title": None,
         }
     else:
         assert error in response.text
@@ -2349,6 +2349,7 @@ async def test_foreign_key_labels_obey_permissions(config):
     assert root_b.json() == {
         "ok": True,
         "next": None,
+        "next_url": None,
         "rows": [{"id": 1, "name": "world", "a_id": {"value": 1, "label": "hello"}}],
         "truncated": False,
     }
@@ -2356,6 +2357,7 @@ async def test_foreign_key_labels_obey_permissions(config):
     assert anon_b.json() == {
         "ok": True,
         "next": None,
+        "next_url": None,
         "rows": [{"id": 1, "name": "world", "a_id": 1}],
         "truncated": False,
     }

tests/test_token_handler.py

@@ -5,7 +5,12 @@ Tests for the register_token_handler plugin hook.
 from datasette.app import Datasette
 from datasette.hookspecs import hookimpl
 from datasette.plugins import pm
-from datasette.tokens import TokenHandler, TokenRestrictions, SignedTokenHandler
+from datasette.tokens import (
+    TokenHandler,
+    TokenInvalid,
+    TokenRestrictions,
+    SignedTokenHandler,
+)
 import pytest
 
 
@@ -66,10 +71,10 @@ async def test_verify_token_unknown_returns_none(datasette):
 
 
 @pytest.mark.asyncio
-async def test_verify_token_bad_signature_returns_none(datasette):
-    """verify_token() should return None for tokens with bad signatures."""
-    result = await datasette.verify_token("dstok_tampered_data_here")
-    assert result is None
+async def test_verify_token_bad_signature_raises(datasette):
+    """verify_token() should raise TokenInvalid for tokens with bad signatures."""
+    with pytest.raises(TokenInvalid):
+        await datasette.verify_token("dstok_tampered_data_here")
 
 
 @pytest.mark.asyncio
@@ -334,5 +339,6 @@ async def test_signed_tokens_disabled():
     ds = Datasette(settings={"allow_signed_tokens": False})
     with pytest.raises(ValueError, match="Signed tokens are not enabled"):
         await ds.create_token("test_actor", handler="signed")
-    # verify_token should return None rather than raising
-    assert await ds.verify_token("dstok_anything") is None
+    # verify_token should raise TokenInvalid for a dstok_ token
+    with pytest.raises(TokenInvalid, match="not enabled"):
+        await ds.verify_token("dstok_anything")