Simon Willison's Weblog: TILs

Using LLM in the shebang line of a script

2026-05-11T18:48:57+00:00

Using LLM in the shebang line of a script

This comment on Hacker News inspired me to investigate patterns for using my LLM CLI tool in a shebang line:

SQL functions in Google Sheets to fetch data from Datasette

2026-04-20T02:33:58+00:00

SQL functions in Google Sheets to fetch data from Datasette

I've been experimenting with ways to fetch data from Datasette and display it in Google Sheets.

Running OpenClaw in Docker

2026-02-01T23:59:07+00:00

Running OpenClaw in Docker

I'm not brave enough to run [OpenClaw](https://openclaw.ai/) (aka Clawdbot aka Moltbot) directly on my Mac, so I decided to try running it in a Docker instead container.

Cloudflare response header transform rules

2026-01-23T15:08:25+00:00

Cloudflare response header transform rules

I serve Python files from my `tools.simonwillison.net` subdomain, which is a GitHub Pages site that's served via Cloudflare. For example:

Previewing Claude Code for web branches with GitHub Pages

2026-01-22T16:43:41+00:00

Previewing Claude Code for web branches with GitHub Pages

I'm a big user of [Claude Code on the web](https://code.claude.com/docs/en/claude-code-on-the-web), Anthropic's poorly named cloud-based version of Claude Code which can be driven via the web or their native mobile and desktop applications.

Taking Neon I at the Crucible

2026-01-11T17:34:29+00:00

Taking Neon I at the Crucible

I took the Neon I intensive week-long evening class at [the Crucible](https://www.thecrucible.org/) in Oakland, with teachers Dan Kuppe and Kat. I learned to make a neon sign! It's still awaiting final infusion of gas, but I'll share photos here once it's finished.

Downloading archived Git repositories from archive.softwareheritage.org

2025-12-30T23:43:48+00:00

Downloading archived Git repositories from archive.softwareheritage.org

Last February I [blogged about](https://simonwillison.net/2025/Feb/7/sqlite-s3vfs/) a neat script called `sqlite-s3vfs` which was released as MIT licensed open source by the UK government's Department for Business and Trade.

Subtests in pytest 9.0.0+

2025-12-05T05:44:04+00:00

Subtests in pytest 9.0.0+

[pytest 9.0.0](https://pypi.org/project/pytest/9.0.0/) was released on November 8th 2025. I just got around to looking at the [release notes](https://docs.pytest.org/en/stable/changelog.html#pytest-9-0-0-2025-11-05) and the biggest new feature is **subtests**, previously available as the separate [pytest-subtests](https://pypi.org/project/pytest-subtests/) plugin.

Dependency groups and uv run

2025-12-03T04:55:17+00:00

Dependency groups and uv run

I've adopted a new (to me) pattern for my Python projects to make them easier to hack on using `uv run`. I'm using a [PEP 735 dependency group](https://peps.python.org/pep-0735/) called `dev` to declare my development dependencies - in particular `pytest` - such that running `uv run pytest` executes the tests for my project without me having to even think about setting up a virtual environment first.

Using Codex CLI with gpt-oss:120b on an NVIDIA DGX Spark via Tailscale

2025-11-07T07:16:55+00:00

Using Codex CLI with gpt-oss:120b on an NVIDIA DGX Spark via Tailscale

I've written about the [DGX Spark](https://simonwillison.net/2025/Oct/14/nvidia-dgx-spark/) before. Here's how I got OpenAI's Codex CLI to run on my Mac against a gpt-oss:120b model running on the DGX Spark via a Tailscale network.

Exploring OpenAI's deep research API model o4-mini-deep-research

2025-10-18T18:46:03+00:00

Exploring OpenAI's deep research API model o4-mini-deep-research

I was reviewing some older PRs and landed [this one](https://github.com/simonw/llm-prices/pull/9) by Manuel Solorzano adding pricing for [o4-mini-deep-research](https://platform.openai.com/docs/models/o4-mini-deep-research) and [o3-deep-research](https://platform.openai.com/docs/models/o3-deep-research) to my [llm-prices.com](https://www.llm-prices.com/) site. I realized I hadn't tried those models yet so I decided to give one of them a go.

Testing different Python versions with uv with-editable and uv-test

2025-10-09T02:47:48+00:00

Testing different Python versions with uv with-editable and uv-test

A quick `uv` recipe I figured out today, for running the tests for a project against multiple Python versions.

Testing different Python versions with uv with-editable and uv-test

2025-10-09T02:47:48+00:00

Testing different Python versions with uv with-editable and uv-test

A quick `uv` recipe I figured out today, for running the tests for a project against multiple Python versions.

Error 153 Video player configuration error on YouTube embeds

2025-09-30T17:07:00+00:00

Error 153 Video player configuration error on YouTube embeds

I recently noticed that almost every YouTube video on [my blog](https://simonwillison.net/) was displaying the same mysterious error message:

Running a gpt-oss eval suite against LM Studio on a Mac

2025-08-17T03:38:16+00:00

Running a gpt-oss eval suite against LM Studio on a Mac

OpenAI's [gpt-oss models](https://github.com/openai/gpt-oss/) come with an eval suite, which is described in their [Verifying gpt-oss implementations](https://cookbook.openai.com/articles/gpt-oss/verifying-implementations) cookbook. I figured out how to run it on my Mac against their `gpt-oss-20b` model hosted locally using LM Studio, using [uv](https://github.com/astral-sh/uv).