Flux
Couleur d'accent
Quoting Claude Opus 5 system prompt

Quoting Claude Opus 5 system prompt

Claude Fable 5 and Claude Mythos 5 were first released on June 9, 2026. On June 12, 2026, Anthropic suspended access to both models to comply with U.S. Department of Commerce export controls; the Department lifted those controls on June 30, 2026, and Anthropic restored access on July 1, 2026 (Anthropic's statement: https://www.anthropic.com/news/fable-mythos-access). These events are after Claude's training-data cutoff, so Claude knows about them only from this notice. If asked, Claude confirms…

Simon Willison's Weblog
Quoting Claude Opus 5 system prompt

Quoting Claude Opus 5 system prompt

Claude Fable 5 and Claude Mythos 5 were first released on June 9, 2026. On June 12, 2026, Anthropic suspended access to both models to comply with U.S. Department of Commerce export controls; the Department lifted those controls on June 30, 2026, and Anthropic restored access on July 1, 2026 (Anthropic's statement: https://www.anthropic.com/news/fable-mythos-access). These events are after Claude's training-data cutoff, so Claude knows about them only from this notice. If asked, Claude confirms…

Simon Willison's Weblog
GitHub Models is now retired

GitHub Models is now retired

GitHub Models is now retired I missed this news until today, when the GitHub Actions run for my simonw/research repository failed with this error message: GitHub Models is temporarily unavailable as part of a scheduled retirement brownout. That message is already stale, because the retirement has been completed. GitHub Models was an odd-shaped duck. GitHub provided a model playground tool and a unified API across a bunch of different LLM providers, with the biggest benefit being that code…

Simon Willison's Weblog
GitHub Models is now retired

GitHub Models is now retired

GitHub Models is now retired I missed this news until today, when the GitHub Actions run for my simonw/research repository failed with this error message: GitHub Models is temporarily unavailable as part of a scheduled retirement brownout. That message is already stale, because the retirement has been completed. GitHub Models was an odd-shaped duck. GitHub provided a model playground tool and a unified API across a bunch of different LLM providers, with the biggest benefit being that code…

Simon Willison's Weblog
SQLite compressed text-history prototypes

SQLite compressed text-history prototypes

Research: SQLite compressed text-history prototypes I'm perennially interested in options for storing revision histories in relational databases. While out on a dog walk I had a new idea: how about taking the full text of every prior version in a big JSON array of strings and then applying zlib or zstd compression to the whole thing? Surely that would compress really well due to all of the repeated strings. The new GPT‑Live voice mode in the ChatGPT iPhone app has got really good, so I…

Simon Willison's Weblog
SQLite compressed text-history prototypes

SQLite compressed text-history prototypes

Research: SQLite compressed text-history prototypes I'm perennially interested in options for storing revision histories in relational databases. While out on a dog walk I had a new idea: how about taking the full text of every prior version in a big JSON array of strings and then applying zlib or zstd compression to the whole thing? Surely that would compress really well due to all of the repeated strings. The new GPT‑Live voice mode in the ChatGPT iPhone app has got really good, so I…

Simon Willison's Weblog
Auto mode is now the default in Claude Code for Pro, Max, and Team plans

Auto mode is now the default in Claude Code for Pro, Max, and Team plans

Auto mode is now the default in Claude Code for Pro, Max, and Team plans Anthropic are really confident in Claude Code's auto mode, to the point that they are making it the default setting for new sessions in most Claude Code plans starting on August 14th. This was one of the topics discussed in our Fireside Chat with Cat Wu and Thariq Shihipar at the AI Engineer World’s Fair last month. I asked them how they run Claude Code safely within Anthropic (given the threat of prompt injection) and…

Simon Willison's Weblog
Auto mode is now the default in Claude Code for Pro, Max, and Team plans

Auto mode is now the default in Claude Code for Pro, Max, and Team plans

Auto mode is now the default in Claude Code for Pro, Max, and Team plans Anthropic are really confident in Claude Code's auto mode, to the point that they are making it the default setting for new sessions in most Claude Code plans starting on August 14th. This was one of the topics discussed in our Fireside Chat with Cat Wu and Thariq Shihipar at the AI Engineer World’s Fair last month. I asked them how they run Claude Code safely within Anthropic (given the threat of prompt injection) and…

Simon Willison's Weblog
Now we have a timeline of the OpenAI accidental attack against Hugging Face

Now we have a timeline of the OpenAI accidental attack against Hugging Face

My comment on Now we have a timeline of the OpenAI accidental attack against Hugging Face — Hacker News.I think one of the most interesting details here might be tucked away in that first bulletin point: May 7: OpenAI starts a new training run for an experimental, unreleased model. (Do they mean an evaluation run? They say training run in the video, and later mention a “reward signal to judge how well they’re doing”, so I guess this really was about training a model, not evaluating one…

Simon Willison's Weblog
Now we have a timeline of the OpenAI accidental attack against Hugging Face

Now we have a timeline of the OpenAI accidental attack against Hugging Face

My comment on Now we have a timeline of the OpenAI accidental attack against Hugging Face — Hacker News.I think one of the most interesting details here might be tucked away in that first bulletin point: May 7: OpenAI starts a new training run for an experimental, unreleased model. (Do they mean an evaluation run? They say training run in the video, and later mention a “reward signal to judge how well they’re doing”, so I guess this really was about training a model, not evaluating one…

Simon Willison's Weblog
Quoting John Gruber

Quoting John Gruber

Me, I try to get into the mindset of playing live music, not recording a studio album. Except when I’m writing a piece where I really want it to be an album. Those aren’t rare, per se, but they’re occasional. If I tried to make every post a hall-of-famer I’d never get anything out. I’m aiming for professionalism. I’m performing live in front of an audience — not just jamming in my garage or bedroom, fucking around. So I’m careful and concentrate. I want to hit every note, in time. But at my…

Simon Willison's Weblog
Quoting John Gruber

Quoting John Gruber

Me, I try to get into the mindset of playing live music, not recording a studio album. Except when I’m writing a piece where I really want it to be an album. Those aren’t rare, per se, but they’re occasional. If I tried to make every post a hall-of-famer I’d never get anything out. I’m aiming for professionalism. I’m performing live in front of an audience — not just jamming in my garage or bedroom, fucking around. So I’m careful and concentrate. I want to hit every note, in time. But at my…

Simon Willison's Weblog
Now we have a timeline of the OpenAI accidental attack against Hugging Face

Now we have a timeline of the OpenAI accidental attack against Hugging Face

OpenAI gave a last-minute presentation at the Black Hat security on Wednesday about "the Hugging Face Incident" (previously on this blog). The video was published yesterday. It's short and information dense and well worth watching, in particular because it provides full details of what happened and how things played out inside OpenAI. I've used the video to construct the timeline below. Here's the timeline. My favourite detail is at the end: OpenAI found out that they were responsible for the…

Simon Willison's Weblog
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