- We've lowered the price of prompt cache reads on Claude Sonnet 5.5 from $0.20 USD to $0.10 USD per million tokens: 0.05x the base input price instead of 0.1x. Cache writes and all other prices are unchanged. See Prompt caching pricing.
- We've launched Claude Haiku 5.5 (
claude-haiku-5-5), our most capable model tuned for high-volume and latency-sensitive work. It has a 1M token context window, 128k max output tokens, and adaptive thinking with the effort parameter. It's available on the Claude API, Claude in Amazon Bedrock, Claude Platform on AWS, Claude on Google Cloud, and Claude in Microsoft Foundry. See What's new in Claude Haiku 5.5.
- Code written for Claude Haiku 4.5 can break on Claude Haiku 5.5. Manual extended thinking (
budget_tokens), the sampling parameters temperature, top_p, and top_k, and assistant message prefill can each return a 400 error. computer_20250124 also returns a 400 error: use the computer_toolset_20260801 toolset on the Claude API and Google Cloud, or computer_20251124 on Amazon Bedrock. A request that sends thinking blocks back after a change to system, tools, or earlier turns can also return a 400 error. On Amazon Bedrock, structured outputs aren't available for Claude Haiku 5.5. Adaptive thinking is on by default, so a response can begin with thinking blocks, and their text is omitted unless you set thinking.display to "summarized". The same text also counts as more tokens. See the migration guide for each change. For model-specific prompting patterns, see Prompting Claude Haiku 5.5.
- The Python and TypeScript SDKs now include classes, in beta, for the browser use tool and the computer use tool. You subclass one and write one method per tool against your own browser or desktop automation. The SDK runs the tool loop, the URL and file policies you set for the browser, and your approval callback. See Browser and computer use with the SDK toolsets.
- Claude Max and Team plans now include monthly API credits. To learn how to claim them, see API credits for Max and Team plans.
- In Claude Managed Agents, a cloud environment with
limited networking now also applies its allowed_hosts to the web_search and web_fetch tools. A web_fetch call for a URL on a host that allowed_hosts does not match returns a url_not_allowed error result to the agent. web_search omits results from such hosts. When allowed_hosts lists no hosts, neither tool returns a page or a search result. allow_package_managers and allow_mcp_servers add no hosts for these tools. To let the tools reach a host, add it to allowed_hosts, which also opens it to the sandbox. unrestricted networking and self-hosted environments do not limit these tools. See Environment networking.
- With
limited networking, creating a session fails with a 400 error when an enabled web tool's allowed_domains has an entry not within allowed_hosts. So does a session update that adds such an entry. An allowed_hosts entry matches one exact host unless it starts with *., so docs.example.com is not within ["example.com"]. To fix the error, add the host to allowed_hosts or remove the entry from allowed_domains. See Restrict web search and web fetch domains.
- In Claude Managed Agents, the
web_fetch tool now fetches only URLs that have already appeared in the session, for example in the text of a user message, in a web_search result, or in a page that web_fetch returned earlier. This reduces the risk of data exfiltration. A URL that appears only in Claude's own output, the agent's system prompt, an attached document, or the output of a tool such as bash, read, or an MCP tool does not count: a web_fetch call for it returns a url_not_in_prior_context error result to the agent. To let the agent fetch a URL, send it in the text of a user.message event.