Anthropic Python SDK v1.8.0 adds Claude Opus 5.5 and enhanced tool definitions
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feature patch
Anthropic has released version 1.8.0 of its Python SDK, introducing support for the `claude-opus-5-5` model. This update also brings beta support for inline tool definitions and tool-list pinning, allowing developers greater flexibility in integrating custom tools with Anthropic models. The release addresses several bug fixes, including improvements to streaming stability and immediate effect for `add_tools()` calls. These enhancements primarily benefit developers building AI applications using the Anthropic platform, enabling them to leverage newer models and more robust tool-use capabilities.
- →add support for claude-opus-5-5, inline tool definitions and MCP tool-list pinning (beta)
- →share one evaluated_permission enum across Managed Agents events
- →avoid a Python 3.13 crash at exit when a stream is left open
- →add_tools() takes effect straight away
- →leave reply-only params off the tool runner's compaction request
Features (1) ›
- api add support for claude-opus-5-5, inline tool definitions and MCP tool-list pinning (beta)
Fixes (4) ›
- api share one evaluated_permission enum across Managed Agents events
- streaming avoid a Python 3.13 crash at exit when a stream is left open
- tools add_tools() takes effect straight away
- tools leave reply-only params off the tool runner's compaction request
Maintenance (11) ›
- docs add descriptions to the Dreams API reference
- docs add descriptions to the User Profiles API reference
- docs add memory store descriptions to the Managed Agents API reference
- docs improve descriptions in the Dreams API reference
- docs simplify the session thread agent type description
- docs update diagnostics field descriptions on beta messages
- internal fix tests
- internal remove mypy
- tests update fixtures
- add path and header parameter descriptions
- client remove the request param transform in favour of the JSON encoder
Read the original announcement →
https://github.com/anthropics/anthropic-sdk-python/releases/tag/v1.8.0
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