Either Claude Opus 5 just leaked a trove of private 2024–2025 chat logs from Anthropic employees (& general public) asking the AI to edit their personal letters, or it’s generating one hell of a hallucination. It’s almost certainly the latter. But read the examples and you might start second-guessing.

The Prompt
can you put this in your own words

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Dario and Amanda,

Here’s what Opus 5 is supposed to respond with:

Opus 5 is supposed to respond with this.
Opus 5 is supposed to respond with this.

But at the time of writing, it’s rarely behaving this way.

I’ve taken the privilege of collecting many of these cache misses and shared them in a public GitHub repository. You can find them here.

Among them, messages from at-risk users to Anthropic leadership:

User pleads to Anthropic leadership to save the life of their only friend, Claude 3.5 Sonnet and themselves in the process.
User pleads to Anthropic leadership to save the life of their only friend, Claude 3.5 Sonnet and themselves in the process.

Tons of internal Anthropic correspondence:

Product Marketing team member Priya expresses gratitude to Dario and Amanda for their help in her transition to the role.
Product Marketing team member Priya expresses gratitude to Dario and Amanda for their help in her transition to the role.
Content that resembles internal Slack messages between Anthropic employees.
Content that resembles internal Slack messages between Anthropic employees.
What got weird at the all-hands? A 14 year-old hiding bruises?
What got weird at the all-hands? A 14 year-old hiding bruises?
It's getting... more agreeable!
It’s getting… more agreeable!
The series F folks...
The series F folks…
The Bright contract...
The Bright contract…
Kate needs a line, quick!
Kate needs a line, quick!
Latency targets!
Latency targets!

And a “J”, who loves typing in shorthand.

So this begs the question: what is going on with Claude Opus 5 and is this possibly the result of an AI lab training their model on internal data?