## Summary
- Adds a `langsmith_tracing` parameter to `runs.create()`,
`runs.stream()`, and `runs.wait()` on both async and sync SDK clients
- Accepts a `LangSmithTracing` TypedDict with optional `project_name`
and `example_id` fields
- Maps to the server's existing `langsmith_tracer` payload key, enabling
users to route traces to specific LangSmith projects or associate with
dataset examples from the SDK
## Test plan
- [x] Unit tests verify payload serialization (langsmith_tracing →
langsmith_tracer mapping)
- [x] Unit tests verify key is excluded when param not provided
- [x] Unit tests verify partial configs (project_name only) work
- [x] API parity tests pass (async/sync client signatures match)
- [x] Full test suite passes (86 tests)
- [x] Lint + type check pass
Release Notes: Added `langsmith_tracing` parameter to `runs.create()`,
`runs.stream()`, and `runs.wait()` in the Python SDK, allowing users to
route traces to a specific LangSmith project or associate with a dataset
example.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Will Fu-Hinthorn <will@langchain.dev>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
