Independent AI researcher, creator of datasette.io and llm.datasette.io, building open source tools for data journalism, writing about a lot of stuff at https://simonwillison.net/https://bsky.app/profile/simonwillison.nethttps://bsky.app/profile/simonwillison.net/post/3mjkfkgva5c2dThe example prompt for Google's new Gemini Flash TTS text-to-speed model is a lot https://simonwillison.net/2026/Apr/15/gemini-31-flash-tts/15 Apr 2026 17:16 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mjkfkgva5c2dhttps://bsky.app/profile/simonwillison.net/post/3mizg7apj6c2zPelicans for Meta's new Muse Spark models - plus I did a bit of a deep dive into the Code Interpreter and fascinating "container.visual_grounding" tools in their meta.ai chat UI https://simonwillison.net/2026/Apr/8/muse-spark/08 Apr 2026 23:12 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mizg7apj6c2zhttps://bsky.app/profile/simonwillison.net/post/3miwpxjyqa22cWrote up some thoughts on Anthropic's Project Glassing, where their latest Opus-beating model is available to partnered security research organizations only. Given the recent alarm bells raised by credible security voices I think this is a justified decision. https://simonwillison.net/2026/Apr/7/project-glasswing/07 Apr 2026 21:29 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3miwpxjyqa22chttps://bsky.app/profile/simonwillison.net/post/3miwpsrjsas2cI'm a big fan of the pelican GLM-5.1 drew me today, it even animated it! https://simonwillison.net/2026/Apr/7/glm-51/07 Apr 2026 21:26 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3miwpsrjsas2chttps://bsky.app/profile/simonwillison.net/post/3mirqhe5e2s2gThis is excellent, one of my favorite long-form pieces on agentic engineering - includes several non-obvious ways in which leaning on coding agents can catch you out [contains quote post or other embedded content]05 Apr 2026 21:55 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mirqhe5e2s2ghttps://bsky.app/profile/simonwillison.net/post/3mipvfya3w22qI built a new Python CLI tool for scanning folders for secret strings, useful if you want to share a bunch of log files but first want to check they didn't accidentally leak API keys or similar. Run this command to learn more: uvx scan-for-secrets --help Blog: https://simonwillison.net/2026/Apr/5/scan-for-secrets-3/05 Apr 2026 04:18 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mipvfya3w22qhttps://bsky.app/profile/simonwillison.net/post/3mimwjkjn7c23Started a new tag on my blog to track stories about AI-powered security research, which is very much having a moment right now - 11 posts so far already https://simonwillison.net/tags/ai-security-research/04 Apr 2026 00:00 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mimwjkjn7c23https://bsky.app/profile/simonwillison.net/post/3mily2qmwgc2iWarning to open source maintainers: the Axios supply chain attack started with some very sophisticated social engineering targeted at one of their developers https://simonwillison.net/2026/Apr/3/supply-chain-social-engineering/03 Apr 2026 14:55 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mily2qmwgc2ihttps://bsky.app/profile/simonwillison.net/post/3mik2zk4p222sI was a guest on @lennysan's podcast! We talked about agentic engineering and all sorts of other LLM-related topics for 1h39m(!), plus a little bit about kākāpō parrots - here's my selection of highlights from our conversation https://simonwillison.net/2026/Apr/2/lennys-podcast/02 Apr 2026 20:43 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mik2zk4p222shttps://bsky.app/profile/simonwillison.net/post/3mijufekjhk2yPelicans for Gemma 4 E2B, E4B, 26B-A4B and 31B - the first three generated on my laptop via LM Studio, the 31B was broken on my laptop so I ran it via the Gemini API instead https://simonwillison.net/2026/Apr/2/gemma-4/02 Apr 2026 18:44 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mijufekjhk2yhttps://bsky.app/profile/simonwillison.net/post/3mibuu2skjc2pMr. Chatterbox is a really fun project. It's not great to talk to but it's a fun demo of what you can build using entirely out-of-copyright training data It's a 2GB nanochat model - I released a new llm-mrchatterbox plugin that can run it on my Mac https://simonwillison.net/2026/Mar/30/mr-chatterbox/ [contains quote post or other embedded content]30 Mar 2026 14:31 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mibuu2skjc2phttps://bsky.app/profile/simonwillison.net/post/3mi2zaqvlmc2wI've been vibe coding SwiftUI menu bar apps for my new Mac, turns out Claude Opus 4.6 and GPT-5.4 are both competent at Swift programming, no need to even open Xcode! https://simonwillison.net/2026/Mar/27/vibe-coding-swiftui/27 Mar 2026 21:01 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mi2zaqvlmc2whttps://bsky.app/profile/simonwillison.net/post/3mhtftauemc2uGiven today's LiteLLM supply chain attack, what are people's preferred development environment sandboxes on MacOS these days? I think it's time I started running my development environments somewhere where rogue code can't steal all my ~/... credential files24 Mar 2026 20:25 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhtftauemc2uhttps://bsky.app/profile/simonwillison.net/post/3mhormu6cys2vStarlette 1.0 is out! I used this as an opportunity to experiment with Claude Skills, since Claude isn't yet familiar with the (minor) breaking changes in the 1.0 release compared to 0.x https://simonwillison.net/2026/Mar/22/starlette/23 Mar 2026 00:12 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhormu6cys2vhttps://bsky.app/profile/simonwillison.net/post/3mhmb5wj4x22sNew surveillance dystopia prompt: try running "Profile this user" against 1,000 comments by someone on Hacker News to see what an LLM can figure out https://simonwillison.net/2026/Mar/21/profiling-hacker-news-users/22 Mar 2026 00:12 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhmb5wj4x22shttps://bsky.app/profile/simonwillison.net/post/3mhm5u53fb22sI can't find an option in the Gmail iPhone app to view raw email headers, which is deeply frustrating when I am trying to evaluate a suspicious email to figure out if it's a phishing attack or not21 Mar 2026 23:13 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhm5u53fb22shttps://bsky.app/profile/simonwillison.net/post/3mhm2xt7yac2sStill a work in progress, but I've published the first draft of a new chapter on "Using Git with coding agents" https://simonwillison.net/guides/agentic-engineering-patterns/using-git-with-coding-agents/21 Mar 2026 22:22 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhm2xt7yac2shttps://bsky.app/profile/simonwillison.net/post/3mhgy5yznek2lHas there ever been a better acquisition in terms of ongoing product quality than Microsoft's of Minecraft? The deal closed in 2014, and was followed by more than a decade of excellent upgrades all very much in the spirit of what people loved about the original https://en.wikipedia.org/wiki/Minecraft#Java_Edition19 Mar 2026 21:48 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhgy5yznek2lhttps://bsky.app/profile/simonwillison.net/post/3mhglt6qlj222I thought this was a newer feature but it turns out str.removeprefix() and str.removesuffix() were added in Python 3.9! [contains quote post or other embedded content]19 Mar 2026 18:07 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhglt6qlj222https://bsky.app/profile/simonwillison.net/post/3mhghamcoms2nThoughts on OpenAI acquiring Astral and uv/ruff/ty https://simonwillison.net/2026/Mar/19/openai-acquiring-astral/19 Mar 2026 16:45 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhghamcoms2nhttps://bsky.app/profile/simonwillison.net/post/3mhbq2yvuyc26Notes and pelicans for today's GPT-5.4 mini and nano releases - the nano model looks like it could describe every image in my 76,000 photo library for $52 total https://simonwillison.net/2026/Mar/17/mini-and-nano/17 Mar 2026 19:40 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mhbq2yvuyc26https://bsky.app/profile/simonwillison.net/post/3mh6myiuavc2eNew chapter for Agentic Engineering Patterns: I tried to distill key details of how coding agents work under the hood that are most useful to understand in order to use them effectively https://simonwillison.net/guides/agentic-engineering-patterns/how-coding-agents-work/16 Mar 2026 14:07 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mh6myiuavc2ehttps://bsky.app/profile/simonwillison.net/post/3mh54pwsyak2pNew on Niche Museums: the John M. Mossman Lock Collection, available to view by appointment only at The General Society of Mechanics and Tradesmen of the City of New York www.niche-museums.com/118 https://www.niche-museums.com/11815 Mar 2026 23:43 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mh54pwsyak2phttps://bsky.app/profile/simonwillison.net/post/3mh4zh4vvvk2qJust added the 12th chapter to my Agentic Engineering Patterns guide, but it's the first one in the sequence: I figured it was time to try and answer the obvious question, "What is agentic engineering?" https://simonwillison.net/guides/agentic-engineering-patterns/what-is-agentic-engineering/15 Mar 2026 22:45 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mh4zh4vvvk2qhttps://bsky.app/profile/simonwillison.net/post/3mh22dmg2uc2gI spoke about agentic engineering at the Pragmatic Summit last month, in a fireside chat hosted by Eric Lui - here's the half hour video plus highlight quotes and extra notes from our conversation https://simonwillison.net/2026/Mar/14/pragmatic-summit/14 Mar 2026 18:22 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mh22dmg2uc2ghttps://bsky.app/profile/simonwillison.net/post/3mgqg75kqgk2gAI should help us produce better code https://simonwillison.net/guides/agentic-engineering-patterns/better-code/10 Mar 2026 22:28 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mgqg75kqgk2ghttps://bsky.app/profile/simonwillison.net/post/3mgn6ln4er22rGot excited about a brand new PostgreSQL 18 feature (for simulating production query plan statistics locally), posted about it on the SQLite forum... and got a reply from D. Richard Hipp within minutes that SQLite has had the same ability for years https://simonwillison.net/2026/Mar/9/production-query-plans-without-production-data/09 Mar 2026 15:34 +0000at://did:plc:kft6lu4trxowqmter2b6vg6z/app.bsky.feed.post/3mgn6ln4er22r