Simon Willison’s Weblog

A minor bugfix release. Fixes a bug with INSERT ... RETURNING queries via the new /db/-/execute-write endpoint and a bunch of base_url issues which showed up when I was experimenting with Service Workers yesterday.

Another significant alpha release, with two new headline features.

Datasette now offers users with the necessary permissions the ability to both execute write queries against their database and to save stored queries (renamed from "canned queries") both privately and for use by other members of their Datasette instance.

There's more detail in SQL write queries and stored queries in Datasette 1.0a31 on the Datasette blog, which now has three posts introducing new features since the blog launched two weeks ago.

Here's an animated demo from the blog post showing how the new execute query interface lets people get started with templated insert/update/delete queries from tables they have permission to edit:

• New model: Claude Opus 4.8 (claude-opus-4.8).
• New -o fast 1 option for fast mode, for organizations with that feature enabled on their account.
• Default max_tokens for each model now defaults to that model's maximum output rather than 8,192. #72

See also my notes on Opus 4.8 - I used this new release of llm-anthropic to generate the pelicans.

The big new feature in this alpha is a new customizable "Jump to..." menu, described in detail in The extensible "Jump to" menu in Datasette 1.0a30 on the Datasette blog. You can try it out by hitting / on latest.datasette.io - it looks like this:

The new jump_items_sql() plugin hook allows plugins to add their own items to the set that's searched by the plugin.

Taking advantage of the new makeJumpSections() JavaScript plugin hook added in Datasette 1.0a30, datasette-agent now presents this "Start a new agent chat" interface as part of the Jump to menu, any time you hit /:

You can try this out by signing into agent.datasette.io using your GitHub account.

One of the smaller features in Datasette 1.0a30 is this:

New documented datasette.fixtures.populate_fixture_database(conn) helper for creating the fixture database tables used by Datasette's own tests, intended for plugin test suites.

This new plugin takes advantage of that API. You can try it out using uvx without even installing Datasette like this:

uvx --prerelease=allow \
  --with datasette-fixtures datasette \
  --get /fixtures/roadside_attractions.json

Which outputs:

{
  "ok": true,
  "next": null,
  "rows": [
    {"pk": 1, "name": "The Mystery Spot", "address": "465 Mystery Spot Road, Santa Cruz, CA 95065", "url": "https://www.mysteryspot.com/", "latitude": 37.0167, "longitude": -122.0024},
    {"pk": 2, "name": "Winchester Mystery House", "address": "525 South Winchester Boulevard, San Jose, CA 95128", "url": "https://winchestermysteryhouse.com/", "latitude": 37.3184, "longitude": -121.9511},
    {"pk": 3, "name": "Burlingame Museum of PEZ Memorabilia", "address": "214 California Drive, Burlingame, CA 94010", "url": null, "latitude": 37.5793, "longitude": -122.3442},
    {"pk": 4, "name": "Bigfoot Discovery Museum", "address": "5497 Highway 9, Felton, CA 95018", "url": "https://www.bigfootdiscoveryproject.com/", "latitude": 37.0414, "longitude": -122.0725}
  ],
  "truncated": false
}

• Improved design of the /-/llm-limits page, now using the base template. #2
• Now shown in application menu for users with the datasette-llm-limits-view permission.

A Datasette Agent plugin for running commands in a Fly Sprites sandbox.

• "View SQL query" buttons below rendered charts.

• "View SQL query" buttons for both visible tables and collapsed SQL result tool calls.
• Don't display empty reasoning chunks
• Improved handling of truncated responses - table still displays to the user even if the SQL results were truncated when showing the agent.

See Datasette Agent, an extensible AI assistant for Datasette.

• More color! Bar and waffle charts without a color column are shaded by magnitude with a sequential color scheme; color columns holding text values use the observable10 categorical scheme. #2
• Now checks execute-sql permission before running the query to find the column names.
• Charts now display interactive tooltips.
• Fixed a bug where waffleY charts were not described to the agent.

• New model gemini-3.5-flash for Gemini 3.5 Flash.

See also my notes on Gemini 3.5 Flash, and the pelican I drew using this upgrade to the plugin.

• Fixed bug tracking chains of responses. Refs datasette-llm#7

• Compatible with llm>=0.32a0 alpha - adds the ability to stream reasoning tokens.

• Fix for bug where llm_prompt_context() hook did not fully collect chains of responses. #7

Part of the infrastructure I use for publishing my iNaturalist sightings on my blog. I've been running this in production for a few weeks now, inspiring some iterations on how it works, so I decided to ship a 0.1 release.

You can see an example of the output in this JSON file.

This plugin works in conjunction with datasette-llm and datasette-llm-accountant to let you configure a per-user (or global) spending limit for LLM usage inside of Datasette. Configuration looks something like this:

plugins:
  datasette-llm-limits:
    limits:
      per-user-daily:
        scope: actor
        window: rolling-24h
        amount_usd: 1.00

• Tool availability can now be attached to a required_permission. The default background agent tools now require the new datasette-agent-background permission. #10

• Now uses the execute-sql permission when deciding which tables to list to the user. #8

The datasette.io site was being hammered by poorly-behaved crawlers, so I had Codex (GPT-5.5 xhigh) build a configurable rate limiting plugin to block IPs that were hammering specific areas of the site too quickly.

Here's the production configuration I'm using on that site for the new plugin:

  datasette-ip-rate-limit:
    header: Fly-Client-IP
    max_keys: 10000
    exempt_paths:
    - "/static/*"
    - "/-/turnstile*"
    rules:
    - name: demo-databases
      paths:
      - "/global-power-plants/*"
      - "/legislators/*"
      window_seconds: 60
      max_requests: 60
      block_seconds: 20

• New TokenRestrictions.abbreviated(datasette) utility method for creating "_r" dictionaries. #2695
• Table headers and column options are now visible even if a table contains zero rows. #2701
• Fixed bug with display of column actions dialog on Mobile Safari. #2708
• Fixed bug where tests could crash with a segfault due to a race condition between Datasette.close() and Database.close(). #2709

That segfault bug was gnarly. I added a mechanism to Datasette recently that would automatically close connections at the end of each test, but it turned out that introduced a race condition where an in-flight query could sometimes be executing in a thread against a connection while it was being closed. I ended up solving that by having Codex CLI (with GPT-5.5 xhigh) create a minimal Dockerfile that recreated the bug.

• Initial (silent) alpha release.

A bunch of useful stuff in this LLM alpha, but the most important detail is this one:

Most reasoning-capable OpenAI models now use the /v1/responses endpoint instead of /v1/chat/completions. This enables interleaved reasoning across tool calls for GPT-5 class models. #1435

This means you can now see the summarized reasoning tokens when you run prompts against an OpenAI model, displayed in a different color to standard error. Use the -R or --hide-reasoning flags if you don't want to see that.

• gemini-3.1-flash-lite is no longer a preview.

Here's my write-up of the Gemini 3.1 Flash-Lite Preview model back in March. I don't believe this new non-preview model has changed since then.

The OpenStreetMap tiles on the Datasette global-power-plants demo weren't displaying correctly. This turned out to be caused by two bugs.

The first is that the CAPTCHA I added to that site a few weeks ago was triggering for the .json fetch requests used by the map plugin, and since those weren't HTML the user was not being asked to solve them. Here's the fix.

The second was that OpenStreetMap quite reasonably block tile requests from sites that use a Referrer-Policy: no-referrer header.

Datasette does this by default, and I didn't want to change that default on people without warning - so I had Codex + GPT-5.5 build me a new plugin to help set that header to another value.

• Mechanism for configuring default options for specific models.

Part of Datasette's evolving support mechanism for plugins that use LLMs. It's now possible to configure a model with default options, e.g. to say all enrichment operations should use a specific model with temperature set to 0.5.

• New -o thinking 1 option to help test against LLM 0.32a0 and higher.

This plugin provides a fake model called "echo" for LLM which doesn't run an LLM at all - it's useful for writing automated tests. You can now do this:

uvx --with llm==0.32a1 --with llm-echo==0.5a0 llm -m echo hi -o thinking 1

This will fake a reasoning block to standard error before returning JSON echoing the prompt.

• Fixed a bug in 0.32a0 where tool-calling conversations were not correctly reinflated from SQLite. #1426