Anthropic shipped the official Python SDK v1.8.0 on 2026-09-22 (PyPI anthropic 1.8.0). Versus 1.7.0 it adds `claude-opus-5-5`, inline tool definitions, and MCP tool-list pinning (beta) into client types/runners; fixes a shared `evaluated_permission` enum across Managed Agents events, a Python 3.13 crash when a stream is left open at exit, immediate `add_tools()` effect, and stripping reply-only params from the tool runner compaction request. For stacks already on Opus 5.5 and MCP-managed tools, this is the typed client surface that matches the server features.

Key Takeaways

  • ✓Shipped: v1.8.0 / PyPI anthropic 1.8.0
  • ✓Model id: claude-opus-5-5 on the typed client surface
  • ✓Tools/MCP: inline tool definitions + MCP tool-list pinning (beta)
  • ✓Stability: add_tools() applies immediately; Py3.13 open-stream exit fix; compaction omits reply-only params
  • ✓Install: pip install anthropic==1.8.0; see Client SDKs docs
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Project Links & Resources

Direct Access
Direct access to official project resources and documentation
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GitHub Release anthropic-sdk-python v1.8.0
github.com/anthropics/anthropic-sdk-python/releases/tag/v1.8.0
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PyPI anthropic 1.8.0
pypi.org/project/anthropic/1.8.0/
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Anthropic Client SDKs
docs.anthropic.com/en/api/client-sdks
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Claude Models Docs
docs.anthropic.com/en/docs/about-claude/models
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Anthropic MCP Docs
docs.anthropic.com/en/docs/agents-and-tools/mcp
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Tool use overview
docs.anthropic.com/en/docs/agents-and-tools/tool-use/overview
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SDK README
github.com/anthropics/anthropic-sdk-python/blob/main/README.md
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#874
github.com/anthropics/anthropic-sdk-python/issues/874
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#871
github.com/anthropics/anthropic-sdk-python/issues/871
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In-Depth Technical Analysis

Core Background & Industry Pain Points Opus 5.5 is live on the API, but production agents need the official SDK to expose model IDs, inline tool schemas, and MCP list controls in typed runners. Without them, stacks hand-roll JSON and hit compaction, streaming-exit, and permission-event bugs. 1.7.x lacked inline tool definitions and MCP tool-list pinning (beta). ### Architecture Highlights & Internals v1.8.0 codegen wires claude-opus-5-5, inline tools, and MCP tool-list pinning (beta) into types and lib/tools. See Models, MCP, and Tool use. Fixes: shared evaluated_permission enum, Py3.13 open-stream exit crash, immediate add_tools() (#874), compaction without reply-only params (#871). ### Authoritative Benchmarks & Measured Scores SDK release—no official latency/SWE-bench numbers attached. Validate typed claude-opus-5-5, server acceptance of inline tools, MCP pin behavior, and clean 3.13 exits. ### Developer Hands-on Guide pip install 'anthropic==1.8.0'; see README and Client SDKs. Point agents at claude-opus-5-5, tighten tools via inline defs or MCP pinning, re-run tool-runner/compaction tests. Package: PyPI 1.8.0.