`instrumentLangGraph` does not instrument `stream()`, only `invoke()`

[priscilawebdev]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/browser

SDK Version

^10.40.0

Framework Version

No response

Link to Sentry event

https://pri-dogfooding-ai.sentry.io/insights/ai-agents/?project=4510951776059472&statsPeriod=30d&query=trace:[990f076070fd4e64b8d9032e10f0f27c,34466beafe8a4f39a4ba82da51559827]

Reproduction Example/SDK Setup

No response

Steps to Reproduce

const graph = new StateGraph(MyAnnotation)
  .addNode("step1", stepFn)
  .addEdge(START, "step1")
  .addEdge("step1", END);

Sentry.instrumentLangGraph(graph, { recordInputs: true, recordOutputs: true });
const compiled = graph.compile({ name: "my_agent" });

// Using invoke() — works, produces invoke_agent span
const result = await compiled.invoke({ input: "test" });

// Using stream() — no invoke_agent span created
const stream = await compiled.stream({ input: "test" });
for await (const chunk of stream) { /* ... */ }

Expected Result

Both invoke() and stream() should produce a parent span wrapping the graph execution.

Actual Result

Method	create_agent span	Agent execution span
invoke()	Yes (0.5ms)	Yes — gen_ai.invoke_agent (wraps full execution)
stream()	Yes (0.5ms)	None

With stream(), only the create_agent span (from compile()) appears. The actual graph execution has no parent span. If createLangChainCallbackHandler is also used, its child spans become orphaned root transactions instead of nesting under a parent.

Note: The SDK currently defines only gen_ai.invoke_agent as the agent-level operation (via GEN_AI_INVOKE_AGENT_OPERATION_ATTRIBUTE). There is no stream_agent equivalent. Whether stream() should reuse invoke_agent or get its own operation name is a design decision.

Additional Context

instrumentStateGraphCompile only patches invoke():

const originalInvoke = compiledGraph.invoke;
if (originalInvoke && typeof originalInvoke === 'function') {
  compiledGraph.invoke = instrumentCompiledGraphInvoke(...);
}
// stream() is never patched

Priority

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[linear]

JS-1858