Anthropic Opens Message Threads Beta in the Messages API
Anthropic has launched the message threads beta on its Messages API. The API caches conversations server-side, so subsequent requests only need to send the new message and the previous message ID, allowing Claude to start responding faster. The company says the feature is already integrated in Claude Code, with median time to first token for 500K to 1M token requests reduced by about 35%, and median request size for long conversations dropping from about 800 KB to 1.8 KB. To use it, add the thread parameter and beta header to requests. The feature is available on Claude Platform, Claude Platform on AWS, Claude in Microsoft Foundry, and Claude on Google Cloud, and is billed at standard token prices.
Why read this
AI score 62
The official announcement details the latency and request size changes of message threads in Claude Code, and explains how to integrate and which platforms are available.
Topics
Body
Message threads are now in public beta on the Messages API.
The API caches your conversation on the server between turns, so instead of resending the full conversation, you send only new messages and the previous message ID, and Claude starts responding sooner. https://t.co/VeiehyqfIg