Preserve local OpenTelemetry parent context

[fubhy]

Summary

Child spans lose an active parent's trace state and reconstruct a local parent as remote, affecting propagation and parent-based sampling.

Important

This PR starts with focused failing reproduction tests. Add the implementation fix to this same branch; CI is expected to fail until that fix is included.

Active local OpenTelemetry parents become remote without trace state

Module: opentelemetry/OtelTracer
Audit ID: adapters-otel-8-active-parent-context-loss
Severity / confidence: high / high

What happens

Child spans lose an active parent's trace state and reconstruct a local parent as remote, affecting propagation and parent-based sampling.

Why it happens

getOtelParent converts active context to an ExternalSpan with only IDs and sampled state; makeSpanContext then infers remote solely from the ExternalSpan tag.

Expected behavior

Spans attached to active OpenTelemetry context preserve the complete parent SpanContext, including traceState and isRemote.

Relevant implementation

These links and excerpts are pinned to audit base c9b56ab507f224426ee8388dc450da447ec4715f.

• packages/opentelemetry/src/OtelTracer.ts:521-533
• packages/opentelemetry/src/OtelTracer.ts:536-548

View problematic code at packages/opentelemetry/src/OtelTracer.ts:521-533

const getOtelParent = (
  tracer: Otel.TraceAPI,
  context: Otel.Context,
  annotations: Context.Context<never>
): Option.Option<Tracer.AnySpan> => {
  const otelParent = tracer.getSpan(context)?.spanContext()
  if (!otelParent) return Option.none()
  return Option.some(Tracer.externalSpan({
    spanId: otelParent.spanId,
    traceId: otelParent.traceId,
    sampled: (otelParent.traceFlags & 1) === 1,
    annotations
  }))

View exact lines on GitHub

View problematic code at packages/opentelemetry/src/OtelTracer.ts:536-548

const makeSpanContext = (
  span: Tracer.AnySpan,
  annotations?: Context.Context<never>
): Otel.SpanContext => {
  const traceFlags = makeTraceFlags(span, annotations)
  const traceState = makeTraceState(span, annotations)!
  return ({
    spanId: span.spanId,
    traceId: span.traceId,
    isRemote: span._tag === "ExternalSpan",
    traceFlags,
    traceState
  })

View exact lines on GitHub

Reproduction

pnpm test --run packages/opentelemetry/test/OtelTracerActiveParentRepro.test.ts

Observed failure: Observed [undefined, true] instead of trace state/local parent (1/1 failed).

Implementation handoff

The initial reproduction tests on this branch are the regression specification for the implementation fix that should follow in this PR.

1. Start with the pinned implementation excerpts and the Why it happens analysis above.
2. Change the implementation so it satisfies the stated Expected behavior; do not weaken or remove the reproduction assertions.
3. Run the focused reproduction command(s) and confirm the observed failures become passing tests:

pnpm test --run packages/opentelemetry/test/OtelTracerActiveParentRepro.test.ts

4. Run the affected package's existing tests, then the repository lint and type checks before requesting review.

Audit provenance

• Audit base: c9b56ab507f224426ee8388dc450da447ec4715f
• Reproduction base: c9b56ab507f224426ee8388dc450da447ec4715f
• Findings: adapters-otel-8-active-parent-context-loss
• Initial patch: focused reproduction tests; implementation fix pending

Closes EFF-347

[changeset-bot]

🦋 Changeset detected

Latest commit: 5dd44a3

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 30 packages

Name	Type
@effect/opentelemetry	Patch
effect	Patch
@effect/platform-browser	Patch
@effect/platform-bun	Patch
@effect/platform-deno	Patch
@effect/platform-node-shared	Patch
@effect/platform-node	Patch
@effect/vitest	Patch
@effect/ai-anthropic	Patch
@effect/ai-openai-compat	Patch
@effect/ai-openai	Patch
@effect/ai-openrouter	Patch
@effect/atom-react	Patch
@effect/atom-solid	Patch
@effect/atom-vue	Patch
@effect/sql-clickhouse	Patch
@effect/sql-d1	Patch
@effect/sql-libsql	Patch
@effect/sql-mssql	Patch
@effect/sql-mysql2	Patch
@effect/sql-pg	Patch
@effect/sql-pglite	Patch
@effect/sql-sqlite-bun	Patch
@effect/sql-sqlite-do	Patch
@effect/sql-sqlite-node	Patch
@effect/sql-sqlite-react-native	Patch
@effect/sql-sqlite-wasm	Patch
@effect/docgen	Patch
@effect/doctest	Patch
@effect/openapi-generator	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pullfrog]

✅ No new issues found.

Reviewed changes — one new reproduction test file exercising OtelSpan parent resolution when the active OpenTelemetry context carries a local SpanContext with traceState.

• OtelTracerActiveParentRepro.test.ts: directly constructs OtelSpan with parent: Option.none() and root: false while a local, non-remote SpanContext (with traceState) is set as the active OTel context via trace.setSpanContext. Asserts that the context passed to tracer.startSpan preserves traceState and isRemote: false.

The reproduction correctly isolates the gap in getOtelParent (OtelTracer.ts:526): tracer.getSpan(context) misses parents set via setSpanContext. The test assertion (deepStrictEqual on exact expected values) properly fails when the bug is present, producing [undefined, true] vs the expected ["vendor=value", false].

  ^{｜ View workflow run ｜ Using DeepSeek Pro (free via Pullfrog for OSS) (Kimi K2 not used — the program covers this model; add its provider key to run your pick) ｜ 𝕏}

[pullfrog]

✅ No new issues found.

Reviewed changes — implementation fix for preserving active OTel parent context, plus a consolidated test case.

• getOtelParent now uses getSpanContext: tracer.getSpan(context) missed parents set via setSpanContext; getSpanContext covers both active spans and active span contexts.
• Full Otel.SpanContext stored in annotations: new OtelParentSpanContext context service carries the complete parent context (including traceState and isRemote) through the external span.
• makeSpanContext recovers stored context: the guard clause returns the parent's full SpanContext when present, with annotations-supplied OtelTraceFlags/OtelTraceState overriding when provided.
• Test moved into main suite: the reproduction test is now in OtelTracer.test.ts and passes against the fixed implementation.

  ^{｜ View workflow run ｜ Using DeepSeek Pro (free via Pullfrog for OSS) (Kimi K2 not used — the program covers this model; add its provider key to run your pick) ｜ 𝕏}

[github-actions]

Bundle Size Analysis

Generated from PR build output; treat the content below as untrusted.

File Name	Current Size	Previous Size	Difference
basic.ts	7.06 KB	7.06 KB	0.00 KB (0.00%)
batching.ts	9.86 KB	9.86 KB	0.00 KB (0.00%)
brand.ts	6.34 KB	6.34 KB	0.00 KB (0.00%)
cache.ts	10.62 KB	10.62 KB	0.00 KB (0.00%)
config.ts	20.60 KB	20.60 KB	0.00 KB (0.00%)
differ.ts	20.20 KB	20.20 KB	0.00 KB (0.00%)
http-client.ts	21.49 KB	21.49 KB	0.00 KB (0.00%)
logger.ts	10.76 KB	10.76 KB	0.00 KB (0.00%)
metric.ts	8.99 KB	8.99 KB	0.00 KB (0.00%)
optic.ts	7.18 KB	7.18 KB	0.00 KB (0.00%)
pubsub.ts	14.90 KB	14.90 KB	0.00 KB (0.00%)
queue.ts	11.58 KB	11.58 KB	0.00 KB (0.00%)
schedule.ts	10.74 KB	10.74 KB	0.00 KB (0.00%)
schema-class.ts	19.14 KB	19.14 KB	0.00 KB (0.00%)
schema-fromJsonSchemaDocument.ts	28.96 KB	28.96 KB	0.00 KB (0.00%)
schema-representation-roundtrip.ts	25.29 KB	25.29 KB	0.00 KB (0.00%)
schema-string-transformation.ts	13.30 KB	13.30 KB	0.00 KB (0.00%)
schema-string.ts	10.94 KB	10.94 KB	0.00 KB (0.00%)
schema-template-literal.ts	15.17 KB	15.17 KB	0.00 KB (0.00%)
schema-toArbitraryLazy.ts	21.94 KB	21.94 KB	0.00 KB (0.00%)
schema-toCodeDocument.ts	24.34 KB	24.34 KB	0.00 KB (0.00%)
schema-toCodecJson.ts	19.18 KB	19.18 KB	0.00 KB (0.00%)
schema-toEquivalence.ts	19.01 KB	19.01 KB	0.00 KB (0.00%)
schema-toFormatter.ts	18.87 KB	18.87 KB	0.00 KB (0.00%)
schema-toJsonSchemaDocument.ts	22.60 KB	22.60 KB	0.00 KB (0.00%)
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schema.ts	18.41 KB	18.41 KB	0.00 KB (0.00%)
stm.ts	12.54 KB	12.54 KB	0.00 KB (0.00%)
stream.ts	9.80 KB	9.80 KB	0.00 KB (0.00%)