Anthropic has launched Message Threads in public beta on its Claude platform. The feature changes how conversation history is sent with Messages API requests: rather than resending the full history each time, agents transmit only what has changed since the previous message.
Anthropic says this reduces time to first token by about 35% for requests between 500,000 and one million tokens. The company identifies coding agents, computer-use agents, and workflows that handle large volumes of documents or images as the main beneficiaries.
The conversation thread remains encrypted in memory between requests and expires after five minutes of inactivity. Token usage is unchanged because Claude still reads the complete conversation history. Message Threads is available on the Claude platform and through AWS, Microsoft Foundry, and Google Cloud.
Sources: The Decoder.