Anthropic's Message Threads cut time to first token by 35 percent for long conversations

Anthropic released Message Threads as a public beta on its Claude platform, which transmits only what has changed since the last message instead of resending the full conversation history. According to Anthropic, this cuts time to first token by about 35 percent for requests between 500,000 and one million tokens, with coding agents, computer-use agents, and document- or image-heavy workflows benefiting most. Threads stay encrypted in memory between requests and expire after five minutes of inactivity, token usage is unchanged, and the feature works on the Claude platform and through AWS, Microsoft Foundry, and Google Cloud.