pi OTEL Telemetry Extension

Emits OpenTelemetry spans for pi agent lifecycle + tool usage to an OTLP/HTTP collector (Jaeger).

Install / enable

Install as a pi package (recommended):

# Global install (writes ~/.pi/agent/settings.json)
pi install npm:pi-telemetry-otel

# Project-local install (writes .pi/settings.json)
pi install -l npm:pi-telemetry-otel

Try without installing:

pi -e npm:pi-telemetry-otel "List files"

Pi loads the extension from the package’s pi.extensions manifest automatically once installed (unless disabled via pi config).

Configuration

All settings accept PI_ overrides (e.g. PI_OTEL_SERVICE_NAME) and fall back to standard OTEL env vars.

Env var	Default	Purpose
OTEL_EXPORTER_OTLP_ENDPOINT	http://localhost:4318/v1/traces	OTLP/HTTP endpoint
OTEL_EXPORTER_OTLP_HEADERS	(none)	Comma-separated k=v headers
OTEL_SERVICE_NAME	pi-agent	Service name in Jaeger (defaults to agent name from PI_AGENT_CHAIN if present)
OTEL_RESOURCE_ATTRIBUTES	(none)	Comma-separated k=v attributes
PI_AGENT_TRACE_ID	(generated)	Parent trace ID to reuse; set once and kept for subprocess trace linking
PI_AGENT_SPAN_ID	(generated)	Parent span ID for subprocess linking; updated to current active span (session/agent/turn/tool)

Extension interoperability (child spans)

Other pi extensions can attach spans to the current pi trace.

Recommended: use the helper APIs

import { withPiSpan } from "pi-telemetry-otel/helpers";

pi.on("tool_call", async (_event, ctx) => {
  await withPiSpan(ctx, "myext.do_work", async (span) => {
    span?.setAttribute("myext.foo", "bar");
    // ... your work
  });
});

The helper functions:

• reuse the tracer/export pipeline registered by this extension
• parent spans under the active pi span (session/agent/turn/tool)
• prefer a per-session context registry (avoids env-var races in concurrent in-process sub-sessions)

Advanced: global registries (no hard dependency)

If you don’t want to depend on the package, you can read the registries directly:

• Runtime registry symbol: Symbol.for("pi.telemetry-otel.runtimeRegistry.v1")
• Active span context registry symbol: Symbol.for("pi.telemetry-otel.activeSpanContextRegistry.v1")
• Map key: ctx.sessionManager.getSessionId()

(See flow-machine for a reference integration that emits pi.flow.* spans.)

Open the current trace

Use /open-jaeger-trace to show the current trace URL and optionally open it in your browser. If Tailscale is available, the command also surfaces a Tailscale IP URL for remote access.

Jaeger smoke check

# Run pi (interactive preferred so spans flush)
PI_OTEL_SERVICE_NAME=pi-agent-dev pi

# Query traces
curl -sSf "http://localhost:16686/api/traces?service=pi-agent-dev&limit=5" | jq -r '.data[].traceID'
curl -sSf "http://localhost:16686/api/traces/<trace-id>" | jq -r '.data[0].spans[].operationName'

Expected operations: pi.session, pi.agent, pi.turn, pi.tool: <tool-name> (bash adds command preview).

Tests

cd telemetry-otel
bun install
bun test