anthropic Python SDK hits 1.0 — httpx2, Python 3.10+, Text Completions gone.
v1.0.0 published 20 Aug: HTTP layer moves from unmaintained httpx to Pydantic's httpx2 fork. Minimum Python rises from 3.9 to 3.10. Legacy Text Completions (client.completions.create, HUMAN_PROMPT / AI_PROMPT) are removed. .with_raw_response returns the same APIResponse / AsyncAPIResponse classes as streaming — async parse/read/text/json are coroutines; .text and .content are methods.12
Custom httpx clients, transports, and isinstance checks must switch to httpx2 (or httpx2.alias_httpx() at startup so tracers and mocks still see traffic). Bedrock clients now raise if no AWS region resolves instead of falling back to us-east-1. MIGRATION.md documents the rest; Claude Code can run /claude-api upgrade python.2
Pin anthropic>=1.0.0 only after you clear MIGRATION.md. If you construct HTTP clients or mock httpx, switch imports to httpx2 first. Drop any remaining Completions callers. Python <3.10 stays on 0.125.x.