# Anthropic Python SDK (anthropic) - AgentBreakWatch Reference

> TL;DR Verdict: Anthropic Python SDK (`anthropic`) is currently at v2.3.0 on PYPI (published 2026-10-23), with a 90-day Stability Score of 78/100 (B) and MEDIUM schema drift risk across 30 releases in the last 90 days. v2.x drops Python 3.9 support, requires typed thinking blocks on multi-turn tool loops, and updates streaming citation events.

## Live Telemetry Metadata
- Canonical Page: https://agentbreakwatch.vercel.app/p/anthropic-python
- Category Hub: https://agentbreakwatch.vercel.app/c/agent-sdks (AI Agent SDKs & Frameworks Breaking-Change Index)
- Package Name: `anthropic`
- Registry: PYPI (https://pypi.org/project/anthropic/)
- GitHub Repository: https://github.com/anthropics/anthropic-sdk-python
- Vendor: Anthropic
- Latest Live Version: v2.3.0
- Published Date: 2026-10-23T23:18:45.779480Z
- 90-Day Release Count: 30
- Direct Dependencies: 17
- License: Apache-2.0
- Stability Score: 78/100 (Grade B)
- Schema Drift Risk: MEDIUM
- Recommended Exact Pin Command: `pip install "anthropic==2.3.0"`
- Watched Symbols / MCP Tools: Anthropic, AsyncAnthropic, messages.stream
- Snapshot Timestamp: 2026-10-24T12:11:27.697Z

## Breaking Change & Schema Drift Summary
v2.x drops Python 3.9 support, requires typed thinking blocks on multi-turn tool loops, and updates streaming citation events.

## Migration Diff: Before (Deprecated / Unpinned Pattern)
```
client.beta.prompt_caching.messages.create(model="claude-3-5-sonnet-20241022", messages=msgs)
```

## Migration Diff: After (Verified v2.3.0 Pattern)
```
client.messages.create(model="claude-sonnet-4-5", max_tokens=4096, messages=msgs)
```

## Recent Verified Releases
- v2.3.0 (published 2026-10-23) [LATEST]
- v2.2.0 (published 2026-10-23)
- v2.1.0 (published 2026-10-21)
- v2.0.0 (published 2026-10-21)
- v1.17.0 (published 2026-10-20)
- v1.16.0 (published 2026-10-20)