OpenTelemetry provides vendor-neutral trace context across the Next.js service, Pub/Sub messages, FastAPI worker, model invocations, memory operations, tools, validation, and effects.
How Harmonia uses it
The web runtime initializes a Node tracer provider and OTLP gRPC exporter when telemetry is enabled. The worker configures Python OpenTelemetry instrumentation for FastAPI and HTTPX. W3C traceparent values connect browser/API work to stage messages and worker spans.
Span attributes contain operational identifiers such as workspace digest, job ID, stage, role, model, operation ID, Pub/Sub message ID, status, latency, and normalized token or cost units.
Privacy and security
Telemetry helpers reject prompt, response, transcript, draft, media, content, body, credential, and token fields. Deployment disables ADK and GenAI message-content capture. Identifiers are bounded or digested where appropriate.
Failure behavior
Tracing is diagnostic and cannot change workflow outcome. Export failure does not create false effect success, approval, or verification. Workflow truth remains in Firestore.
Evidence status
Propagation, redaction, span structure, and instrumentation behavior have automated local coverage. An enabled exporter is not proof of received cloud traces; capture correlated backend evidence.
Relevant files
src/instrumentation.tssrc/lib/telemetry.tsagent/harmonia_agent/telemetry.pyagent/harmonia_agent/stages.pydocs/observability.mdx
Last modified on August 28, 2026
