2.52.0a3

New Features ✨

• feat(integration): add gen_ai.conversation.id if available by @constantinius in #5307

Bug Fixes 🐛

Mcp

• fix(mcp): Nest MCP spans under HTTP transactions by @alexander-alderman-webb in #5292
• fix(mcp): Handle all awaitable return types by @alexander-alderman-webb in #5415

Span Streaming

• fix(span-streaming): Always preserialize attributes by @sentrivana in #5407
• fix(span-streaming): Warn about thread usage if any batcher is active by @sentrivana in #5408

Other

• fix(anthropic): Token reporting by @alexander-alderman-webb in #5403
• fix(celery): Close the connection we're reading driver_type from by @sentrivana in #5427
• fix(google-genai): Token reporting by @alexander-alderman-webb in #5404
• fix(openai): Token reporting by @alexander-alderman-webb in #5406
• fix(openai-agents): Inject propagation headers for HostedMCPTool when streaming by @alexander-alderman-webb in #5405
• fix: Fix list attribute type by @sentrivana in #5417
• fix: Adapt to new packaging in toxgen by @sentrivana in #5382

Internal Changes 🔧

Fastmcp

• test(fastmcp): Wrap prompt in Message by @alexander-alderman-webb in #5411
• test(fastmcp): Remove test_fastmcp_without_request_context() by @alexander-alderman-webb in #5412
• test(fastmcp): Use AsyncClient for SSE by @alexander-alderman-webb in #5400
• test(fastmcp): Use TestClient for Streamable HTTP by @alexander-alderman-webb in #5384
• test(fastmcp): Simulate stdio transport with memory streams by @alexander-alderman-webb in #5333

Mcp

• test(mcp): Use AsyncClient for SSE by @alexander-alderman-webb in #5396
• test(mcp): Use TestClient for Streamable HTTP by @alexander-alderman-webb in #5383
• test(mcp): Remove unused stdio helpers by @alexander-alderman-webb in #5409

Other

• ci: Pin setuptools for linting and chalice tests by @alexander-alderman-webb in #5438
• ci: Fix lint step by @sentrivana in #5418
• ci: 🤖 Update test matrix with new releases (02/02) by @github-actions in #5413
• ci: Update tox and pin packaging version for tox by @alexander-alderman-webb in #5381

Other

• [do not merge] feat: Span streaming & new span API by @sentrivana in #5317
• Update CHANGELOG.md by @alexander-alderman-webb in bcec5780
• release: 2.52.0 by @alexander-alderman-webb in 3d2154ce
• Revert "feat(ai): Add original input length meta attribute (#5375)" by @alexander-alderman-webb in #5419