An open source multi-tool for exploring and publishing data https://datasette.io
  • Python 81.9%
  • JavaScript 9.8%
  • HTML 5.6%
  • CSS 2.5%
  • Shell 0.1%
Find a file
Claude 1bc15caef7
Connection budget: pages, startup and sweeps only touch the databases they need
Adds tests/connection_budget.py, a helper that records which databases a
block of code opens, reads, writes or ATTACHes, and tests/test_connection_budget.py
which asserts budgets for ~60 endpoints, startup, sweeps and telemetry with
50 attached databases.

Fixes for every all-database loop it found:

- Index page: tables, views, hidden tables, columns, primary keys, FTS
  tables and foreign-key relationship counts come from the _internal
  catalog (a few queries for any number of databases). Row counts are only
  run when at most 20 databases need counting (COUNT_MAX_DATABASES);
  above that the page shows table counts plus counts already known.
- Derived-table permissions: allowed_resources() no longer queries every
  database per page; dependency maps are computed by the SchemaWatcher from
  the rows it scans, cached per database, and read back from the catalog
  for databases restored from a persisted catalog.
- catalog_tables gains a type column (PRAGMA table_list: table, virtual,
  shadow) so hidden shadow tables can be identified without a connection.
- PaginatedResources.all() fetches pages of 1000 after the first.
- /-/api and /-/debug/autocomplete use the catalog; /-/schema does one
  permission query and skips databases with nothing visible.
- /-/versions computes SQLite details once per instance, without crossdb
  ATTACHes; detect_json1() caches its answer.
- /-/databases only stats/hashes databases the actor can see.
- Immutable table counts are computed when first needed, not at startup.
- check_databases() (serve, --get) reuses the catalog scan instead of
  opening every database a second time, and reports "file is not a
  database" as a usage error.
- SchemaWatcher: failed scans are retried when the file changes, not on
  every sweep; scan connections skip crossdb ATTACH; catalog_generation
  counter for caches.
- The SQL write UI no longer forces a stat sweep of every database.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EwkLo2rJWidpkDVT3HkvNv
2026-10-04 05:58:31 +00:00
.github Deploy canned queries to latest.datasette.io again with workaround for #2916 2026-09-15 12:12:22 -07:00
datasette Connection budget: pages, startup and sweeps only touch the databases they need 2026-10-04 05:58:31 +00:00
demos Fixed an unnecessary f-string 2024-02-04 10:15:21 -08:00
docs Connection budget: pages, startup and sweeps only touch the databases they need 2026-10-04 05:58:31 +00:00
tests Connection budget: pages, startup and sweeps only touch the databases they need 2026-10-04 05:58:31 +00:00
.coveragerc Configure code coverage, refs #841, #843 2020-06-13 13:48:23 -07:00
.dockerignore Build Dockerfile with SpatiaLite 5, refs #1249 2021-03-26 21:27:40 -07:00
.git-blame-ignore-revs Ignore Black commits in git blame, refs #1716 2022-04-22 14:58:46 -07:00
.gitattributes New explicit versioning mechanism 2020-10-28 20:38:15 -07:00
.gitignore Ignore ignored/ directory 2026-06-25 21:20:29 -07:00
.isort.cfg Used isort to re-order my imports 2018-05-14 00:04:23 -03:00
.prettierrc .prettierrc, refs #1166 2020-12-31 13:25:44 -08:00
.readthedocs.yaml dependency-groups and uv (#2611) 2025-12-11 17:32:58 -08:00
CODE_OF_CONDUCT.md Add code of conduct again 2022-03-15 08:38:42 -07:00
codecov.yml codecov should not be blocking 2020-07-02 21:29:32 -07:00
Dockerfile Fix Docker release builds on main with Bookworm base image 2026-09-10 18:52:19 -07:00
Justfile Screenshots for reusable modal dialogs docs, plus just shots (#2958) 2026-09-24 15:06:57 -07:00
LICENSE Initial commit 2017-10-22 17:39:03 -07:00
MANIFEST.in Include LICENSE in sdist (#1043) 2020-10-23 13:54:34 -07:00
package-lock.json Bump rollup from 3.29.5 to 3.30.0 (#2651) 2026-03-30 10:54:48 -07:00
package.json Bump rollup from 3.29.5 to 3.30.0 (#2651) 2026-03-30 10:54:48 -07:00
pyproject.toml Screenshots for reusable modal dialogs docs, plus just shots (#2958) 2026-09-24 15:06:57 -07:00
pytest.ini pytest skip tests in ignored/ folder 2026-09-16 16:22:48 -07:00
README.md README: minimum Python is 3.10, not 3.8 (#2878) 2026-09-15 12:38:41 -07:00
ruff.toml Upgrade to ruff>=0.16.0 (#2857) 2026-07-25 15:47:08 -07:00
setup.cfg Switch to ruff and fix all lint errors, refs #2630 2026-01-23 20:43:16 -08:00
test-in-pyodide-with-shot-scraper.sh Test against pyodide/v314.0.0 2026-06-22 10:11:56 -07:00

Datasette

PyPI Changelog Python 3.x Tests Documentation Status License docker: datasette discord

An open source multi-tool for exploring and publishing data

Datasette is a tool for exploring and publishing data. It helps people take data of any shape or size and publish that as an interactive, explorable website and accompanying API.

Datasette is aimed at data journalists, museum curators, archivists, local governments, scientists, researchers and anyone else who has data that they wish to share with the world.

Explore a demo, watch a video about the project or try it out on GitHub Codespaces.

Want to stay up-to-date with the project? Subscribe to the Datasette newsletter for tips, tricks and news on what's new in the Datasette ecosystem.

Installation

If you are on a Mac, Homebrew is the easiest way to install Datasette:

brew install datasette

You can also install it using pip or pipx:

pip install datasette

Datasette requires Python 3.10 or higher. We also have detailed installation instructions covering other options such as Docker.

Basic usage

datasette serve path/to/database.db

This will start a web server on port 8001 - visit http://localhost:8001/ to access the web interface.

serve is the default subcommand, you can omit it if you like.

Use Chrome on OS X? You can run datasette against your browser history like so:

 datasette ~/Library/Application\ Support/Google/Chrome/Default/History --nolock

Now visiting http://localhost:8001/History/downloads will show you a web interface to browse your downloads data:

Downloads table rendered by datasette

metadata.json

If you want to include licensing and source information in the generated datasette website you can do so using a JSON file that looks something like this:

{
    "title": "Five Thirty Eight",
    "license": "CC Attribution 4.0 License",
    "license_url": "http://creativecommons.org/licenses/by/4.0/",
    "source": "fivethirtyeight/data on GitHub",
    "source_url": "https://github.com/fivethirtyeight/data"
}

Save this in metadata.json and run Datasette like so:

datasette serve fivethirtyeight.db -m metadata.json

The license and source information will be displayed on the index page and in the footer. They will also be included in the JSON produced by the API.

datasette publish

If you have Heroku or Google Cloud Run configured, Datasette can deploy one or more SQLite databases to the internet with a single command:

datasette publish heroku database.db

Or:

datasette publish cloudrun database.db

This will create a docker image containing both the datasette application and the specified SQLite database files. It will then deploy that image to Heroku or Cloud Run and give you a URL to access the resulting website and API.

See Publishing data in the documentation for more details.

Datasette Lite

Datasette Lite is Datasette packaged using WebAssembly so that it runs entirely in your browser, no Python web application server required. Read more about that in the Datasette Lite documentation.