Knowledge catalogue
Notes (and a Pelican) on Claude Sonnet 5 - the new tokenizer makes it ~1.4x more expensive for English, ~1.33x more expensive for Spanish but roughly the same price for Simplified Mandarin https://sim
We’ve received notice that the Department of Commerce has lifted export controls on Claude Fable 5 and Mythos 5. We'll begin restoring access tomorrow, and will share an update soon. We’re grateful to
Is it just me, or are today's LLMs less likely to default to building everything in React than they were last year? I used to have to say 'don't use React' in almost all of my frontend web dev prompts
Not sure if that's a change in default preferences from the models or just that I'm often prompting inside existing projects and the models know full well not to introduce React to a project that isn'
This statement is a critical analogy about dismissing learning curves in technology or professional contexts. Simon Willison uses the comparison to highlight how unrealistic expectations—assuming empl
Also not a great advertisement for a sandboxing product: @daytonaio effectively saying they don't trust the security of their product enough to expose the source code When the competition for sandboxe
Update: it's fixed! @simonw @ClaudeDevs @claudeai This is fixed — the egress proxy was incorrectly blocking git/gh reads to public repos that weren't attached to the session. Clones/fetches work again
Claude Code for web just started saying 'GitHub is blocked by egress policy', which is a big problem for me because most of my prompts there start with things like 'clone simonw/sqlite-utils to /tmp t
This entry references a Claude.ai coding session shared by Simon Willison, a well-known technology writer and open source developer, likely demonstrating a practical example of using Claude's code int
... and now you can buy your own! https://happy-pelicans.printify.me/product/29480311 Proceeds go to http://birdrescue.org, a local non-profit that rescues pelicans (among other birds) I printed a cus
Pamela rocks https://x.com/pamelafox/status/2069183465501921605 By popular demand, here's a lil store where you can buy your own: https://happy-pelicans.printify.me/product/29480311 I will donate proc
This post highlights an interactive web-based demo of the Moebius model, which users can test directly in their browser with approximately 1.3GB of model data downloaded locally. The tool appears to b
Pamela Fox created a custom t-shirt design referencing Simon Willison's Pelican benchmark, a technical tool or metric in web development or performance testing. She posted about it on X (formerly Twit
My parallel agent side-project today was having Claude Code port the new Moebius image pinpointing model to ONNX in order to run it entirely in the browser https://simonwillison.net/2026/Jun/22/portin
I just released the first release candidate for sqlite-utils v4, adding a migrations system (previously released independently as sqlite-migrate) and support for nested transactions: https://simonwill
Don't miss the exact text though: 'We’re changing Fable 5’s safeguards for frontier LLM development to make them visible' - make them visible means they're undoing the truly egregious (dare I say 'una
Simon Willison demonstrated Fable's pelican illustrations generated at different Claude API thinking effort levels, showcasing how increased computational investment affects output quality and cost. T
Wrote up my initial impressions of Claude Fable 5 - it has a big model smell: slow, expensive and capable of crunching through pretty much everything I threw at it https://simonwillison.net/2026/Jun/9
A TIL on using http://agentsview.io to calculate token spending with Claude Fable 5 despite that model not yet being included in the AgentsView pricing database https://til.simonwillison.net/llms/agen
BREAKING: Anthropic just dropped Claude Fable 5—this is Mythos, made safe for public release. It is the best coding model in the world. We've been testing it internally @every for the last week or so
I've had access to Fable for a bit. A genuine jump in capability, I could feed it a 15 page design document for a project and it would work for 9+ hours and deliver terrific results. But working with
That's both OpenAI and Anthropic with confidential S-1s filed with the SEC - Anthropic filed theirs on June 1st We recently submitted a confidential S-1. We expect it to leak so we’re just announcing
I may have finally found the Python-in-a-sandbox solution I've been looking for... here's my latest experiment, this time running MicroPython in WebAssembly inside my Python applications https://simon
This post demonstrates how to run MicroPython compiled to WebAssembly using the `uvx` tool with a simple command-line example that prints 'Hello world'. It showcases the ease of executing MicroPython
Uber reportedly now caps coding agents at $1,500/month per employee per tool - seems sensible to me, but it's also an interesting hint at the value Uber thinks these tools are providing https://simonw
Simon Willison reports that after updating Codex desktop, a previously unavailable feature or functionality has been restored, expressing gratitude to Philipps Spiess. This likely refers to a bug fix
Every month I publish the now-a-month-old previous newsletter so people can see what they're missing out on. Here's what you would have got a month ago covering what happened in LLMs in April: https:/
Simon Willison announced the release of a May edition of his sponsors-only newsletter, which is designed for supporters who prefer a curated summary format instead of following his daily blog posts. T
Excellent news, this was a mistake, it's coming back! https://x.com/PhilippSpiess/status/2061189796689494339 @simonw Sorry about this! The button was unintentionally removed during some recent menu re
This post discusses concerns about automatic updates to Codex Desktop and the risk of losing important features in newer versions, reflecting broader anxieties among users about software upgrades remo
@simonw Sorry about this! The button was unintentionally removed during some recent menu restructurings. It'll be back with the next hotfix release. You can bind a custom keyboard shortcut to the 'Cop
Anthropic's self-reported run-rate revenue growth is wild - Axios @JimVandeHei said he could not find 'any company — in any industry, in any era — that has scaled organic revenue this quickly at this
Here's an extended edit of the quote that includes a following fragment where Andrew Macdonald called the trade 'harder to justify' - full, unedited transcript is here: https://gist.github.com/simonw/
Simon Willison expresses skepticism about reports claiming Uber overspent on AI and was disappointed with the results, indicating he investigated the story and found issues with its accuracy or framin
Simon Willison comments on the relative scarcity of well-documented AI product failure stories, suggesting that despite widespread predictions of AI disappointment, there are surprisingly few detailed
Given the recent burst of activity around enterprise pricing and contracts, I think April 2026 was the month when both OpenAI and Anthropic found product-market fit https://simonwillison.net/2026/May/
PICARD: Data, shields up DATA: Brilliant! Shields can reduce damage we sustain. Not immunity. Not hubris. Just prudence. It's not precaution—it's strategy. [camera shakes] WORF: HULL BREACHES ON NINE
... plus a bonus section of transcript from the Oxide and Friends 2026 predictions episode in January where, bizarrely, we predicted that something like this would happen - listen here: https://oxide-
When I woke up this morning I didn't think I'd be spending a bunch of time today getting familiar with Catholic theology, but here we are. Notes on Pope Leo XIV's encyclical on AI. https://simonwillis
Simon Willison discusses whether coding agents should automatically generate tests alongside the code they produce, addressing a key quality assurance consideration in AI-assisted development. This li
Fun new feature in Datasette 1.0a30 - a 'jump to' menu, also available by the '/' keyboard shortcut, which lets you type to jump to a database, table or canned query. It offers a hook so plugins can e
Given how much of the original 'bottle of water per generated email' water estimate came from guesses at the architecture of GPT-4, it would be very much in @OpenAI's interest to publish the architect
Simon Willison reflects on the disconcerting experience of unknowingly reading AI-written emails presented as human-authored, comparing it to deliberate deception. The post raises concerns about authe
(I'm firmly on team red/green TDD for agent code, I like having a test suite that protects against them breaking old features when they make new changes - https://simonwillison.net/guides/agentic-engi
Datasette, an open-source tool for exploring and publishing data, released a blog post detailing a new jump menu feature for 2026. The jump menu likely provides improved navigation and quick access to
Plugins can also affect the empty state of the new menu - the latest datasette-agent adds a form for kicking off a new agent conversation - live demo (if you sign in with GitHub) on https://agent.data
Simon Willison shared an article from his blog dated September 2, 2024, discussing Facebook's relationship with CMG (likely a media or publishing organization). The post appears to examine a significa
I was VERY suspicious of this 'active listening' story when it first started circulating. Turns out it was a scam, they weren't targeting ads by listening through microphones at all FTC to require Cox
Here's more about Datasette Agent on my blog: https://simonwillison.net/2026/May/21/datasette-agent/ - and the announcement on the new Datasette project blog too: https://datasette.io/blog/2026/datase
I released the first alpha of Datasette Agent - a conversational AI assistant for Datasette that can answer questions about data in SQLite databases, and can be extended with plugins to add extra tool
Simon Willison announced an interactive demo for an AI agent built with Datasette, available at https://agent.datasette.io/. The demo allows users to experience hands-on functionality of the Datasette
Anyone understand what Google mean by 'Gemini Spark runs on Gemini 3.5 and uses the Antigravity harness' - is 'Antigravity' a generic term they're using for their agent harnesses now or is their Claw-
I don't have much to say about this year's Google I/O because I prefer to write about products that have shipped, not just 'coming soon' announcements - but here are some notes on Gemini Spark and Ant
it’s in gemini, just create it in ai studio. oh, that’s for your personal google one account. for workspace you need gemini business. no, not gemini advanced, that’s ai pro now. unless you need ai ult
Google's Gemini 3.5 Flash model costs approximately 3x more than Gemini 3 Flash, despite being a newer version. Google plans to integrate Gemini 3.5 Flash into many of their own products, suggesting t
Also a great example of positive contribution to open source by wanderingmeow - you don't need to contribute code to have a positive impact, just providing detailed feedback and confirmation that some
Simon Willison shares notes and script related to OpenClaw names on his website, discussing naming conventions or identifiers associated with OpenClaw systems. The post likely covers technical details
To prepare for my #PyConUS lightning talk this afternoon I decided to track down ALL of the names that @openclaw has used since November, using a script against its GitHub repo Warelay → CLAWDIS → CLA
First talk in our AI track at #PyConUS is coming up at 11am Today at 11:00 AM I’ll be speaking at PyCon US in Grand Ballroom A at the Long Beach Convention Center about AI-assisted contributions and t
Doing this is a great way to make a bonfire of your reputation A person I know (and who is? was? a good professional al) left an AI-generated comment under my LinkedIn post. Full-on AI slop. I asked: