[linhongyu510]

Summary

Fixes #549.

The in-memory span processor attached custom invocation and agent values to the OpenTelemetry context, but did not set the started span as the current span. A nested agent could therefore start without the parent agent span and receive an independent trace ID.

This change:

• places invocation and agent spans into the attached OTel context with set_span_in_context
• stores context tokens by span ID because on_end receives a ReadableSpan
• detaches the matching token when each span ends, restoring the parent context
• cleans up tokens for RECORD_ONLY spans even though they are not exported
• keeps cleanup in finally so exporter failures cannot leak context

Validation

tests/tracing/test_inmemory_exporter.py now covers:

• invocation → parent agent → child agent trace inheritance
• concurrent asyncio task isolation
• exceptional agent termination
• nested non-agent spans
• ReadableSpan cleanup in on_end
• unsampled RECORD_ONLY cleanup

Results:

• target tests — 6 passed
• Ruff check and format check
• git diff --check

AI assistance

This change was developed with AI assistance. I reviewed the ContextVar lifecycle, verified the patch with real OpenTelemetry spans, and ran the checks above.

[linhongyu510]

Recovery check on current main (43f958d8): patch replays cleanly; tracing regression 6 passed, Ruff/format/diff-check pass. Happy to update the branch if preferred.

[linhongyu510]

Merge & local verification

Merged the latest main (86c93529) into this branch in an independent worktree (regular merge, no rebase / force / --no-verify).

• Conflict: only veadk/tracing/telemetry/exporters/inmemory_exporter.py (import block). Resolution kept this branch's from opentelemetry.trace import set_span_in_context, which the on_start context fix relies on; main had already adopted the bounded span-cache refactor, so the retained delta here is the context-token lifecycle change (_context_tokens keyed by span_id, try/finally detach on sampled/unsampled/raising spans).
• Target tests: tests/tracing/test_inmemory_exporter.py — 6 passed.
• Related regression: tests/test_inmemory_exporter.py — 12 passed.
• Lint/format: ruff==0.11.12 check + ruff format --check clean on the touched files; module imports/compiles.
• Hermetic: in-memory OpenTelemetry only — no network, credentials, GPU, or external service.

No CI checks are reported on this fork head; the above was verified locally against the pinned dependency set.