Thinking blocks that Claude Sonnet 5.5 produces work only in the account that produced them, or in an account

UpdateSep 28, 20265d5 days ago·Unverified·Added Oct 2, 2026

Thinking blocks that Claude Sonnet 5.5 produces work only in the account that produced them, or in an account linked to it. When another account sends one of these blocks, the API drops the block before the model sees it, and the request succeeds. Blocks from earlier models aren't affected. See Preserved thinking.

Topics: LLMs, Developer tools