From c01e95f3bde22e43eb0cc293caff0757e61b5f90 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Tue, 8 Sep 2026 21:12:33 -0700
Subject: [PATCH] Filter foreign-key helper targets by view permission

---
 datasette/views/table_create_alter.py | 41 +++++++++++++++++++++++++++
 tests/test_api_write.py               |  6 ++--
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/datasette/views/table_create_alter.py b/datasette/views/table_create_alter.py
index f8f8c31e..47a2a39e 100644
--- a/datasette/views/table_create_alter.py
+++ b/datasette/views/table_create_alter.py
@@ -27,6 +27,11 @@ from datasette.utils import (
     table_column_details,
 )
 from datasette.utils.asgi import NotFound, PayloadTooLarge, Response
+from datasette.utils.permissions import (
+    SKIP_PERMISSION_CHECKS,
+    gather_permission_sql_from_hooks,
+    resolve_permissions_with_candidates,
+)
 from datasette.utils.sqlite import sqlite_hidden_table_names
 
 from .base import BaseView
@@ -122,6 +127,30 @@ def _public_foreign_key_target(target):
     }
 
 
+async def _filter_visible_foreign_key_targets(datasette, actor, database_name, targets):
+    if not targets:
+        return []
+
+    permission_sqls = await gather_permission_sql_from_hooks(
+        datasette=datasette,
+        actor=actor,
+        action="view-table",
+    )
+    if permission_sqls is SKIP_PERMISSION_CHECKS:
+        return targets
+
+    candidate_tables = list(dict.fromkeys(target["fk_table"] for target in targets))
+    permission_rows = await resolve_permissions_with_candidates(
+        datasette.get_internal_database(),
+        actor,
+        permission_sqls,
+        [(database_name, table_name) for table_name in candidate_tables],
+        "view-table",
+    )
+    visible_tables = {row["child"] for row in permission_rows if bool(row["allow"])}
+    return [target for target in targets if target["fk_table"] in visible_tables]
+
+
 def _singular(name):
     if name.endswith("ies") and len(name) > 3:
         return name[:-3] + "y"
@@ -1014,6 +1043,9 @@ class DatabaseForeignKeyTargetsView(BaseView):
             for target in (await db.execute(FOREIGN_KEY_TARGETS_SQL)).dicts()
             if target["fk_table"] not in hidden_tables
         ]
+        targets = await _filter_visible_foreign_key_targets(
+            self.ds, request.actor, database_name, targets
+        )
         return Response.json(
             {
                 "ok": True,
@@ -1052,6 +1084,15 @@ class TableForeignKeySuggestionsView(BaseView):
         source_columns, targets, current_by_column = await db.execute_fn(
             lambda conn: _foreign_key_suggestion_metadata(conn, table_name)
         )
+        targets = await _filter_visible_foreign_key_targets(
+            self.ds, request.actor, database_name, targets
+        )
+        visible_target_tables = {target["fk_table"] for target in targets}
+        current_by_column = {
+            column: current
+            for column, current in current_by_column.items()
+            if current["fk_table"] in visible_target_tables
+        }
 
         columns = []
         options_by_column = {}
diff --git a/tests/test_api_write.py b/tests/test_api_write.py
index 1c560cf5..839a50bc 100644
--- a/tests/test_api_write.py
+++ b/tests/test_api_write.py
@@ -1296,7 +1296,7 @@ async def test_alter_table_foreign_key_without_fk_column_requires_single_pk(ds_w
 
 @pytest.mark.asyncio
 async def test_foreign_key_suggestions(ds_write):
-    token = write_token(ds_write, permissions=["at"])
+    token = write_token(ds_write, permissions=["alter-table", "view-table"])
     db = ds_write.get_database("data")
     await db.execute_write("create table owners (id integer primary key)")
     await db.execute_write("insert into owners (id) values (1), (2), (3)")
@@ -1362,7 +1362,7 @@ async def test_foreign_key_suggestions_permission_denied(ds_write):
 
 @pytest.mark.asyncio
 async def test_foreign_key_suggestions_fail_open(ds_write, monkeypatch):
-    token = write_token(ds_write, permissions=["at"])
+    token = write_token(ds_write, permissions=["alter-table", "view-table"])
     db = ds_write.get_database("data")
     await db.execute_write("create table owners (id integer primary key)")
 
@@ -1393,7 +1393,7 @@ async def test_foreign_key_suggestions_fail_open(ds_write, monkeypatch):
 
 @pytest.mark.asyncio
 async def test_foreign_key_targets(ds_write):
-    token = write_token(ds_write, permissions=["ct"])
+    token = write_token(ds_write, permissions=["create-table", "view-table"])
     db = ds_write.get_database("data")
     await db.execute_write("create table owners (id integer primary key)")
     await db.execute_write("create table categories (slug varchar(30) primary key)")