@reactive-agents/observe

OpenInference-compliant OpenTelemetry tracing for reactive-agents — maps AgentEvent stream to semantic spans

Zero-config OpenTelemetry tracing for AI agents. This package subscribes to the Reactive Agents EventBus and emits OpenInference-attributed spans (AGENT, LLM, TOOL) so your agent runs show up in any OTLP backend — Phoenix, Arize, Jaeger, Grafana Tempo, Honeycomb, and more. Drop-in LLM observability with model names, token counts, tool parameters, and inputs/outputs already on the spans.

Install

bun add @reactive-agents/observe
# or: npm install @reactive-agents/observe

Usage

Wire the OTLP exporter once at process start, then provide the tracer layer to your agent runtime so events become spans.

import { setupOpenInferenceExporter, OpenInferenceTracerLayer } from "@reactive-agents/observe";

// 1. Start the exporter (sends spans over OTLP/HTTP).
const handle = setupOpenInferenceExporter({
  serviceName: "my-agent",
  endpoint: "http://localhost:4318", // defaults to OTEL_EXPORTER_OTLP_ENDPOINT
});

// 2. Provide OpenInferenceTracerLayer to your agent's Effect runtime
//    (it subscribes to the EventBus and records AGENT / LLM / TOOL spans).
//    ... run your agents ...

// 3. Flush + shut down before exit.
await handle.shutdown();

Already exporting OTel elsewhere? Use autoConfigureExporter() — it's a no-op unless OTEL_EXPORTER_OTLP_ENDPOINT is set.

API

• OpenInferenceTracerLayer — Effect Layer that subscribes to the EventBus and emits OpenInference spans. Requires EventBus.
• setupOpenInferenceExporter(config?) — register an OTLP/HTTP exporter and global tracer provider; returns an ExporterHandle.
• autoConfigureExporter(config?) — set up the exporter only if OTEL_EXPORTER_OTLP_ENDPOINT is present; otherwise a no-op handle.
• OpenInferenceExporterConfig — { endpoint?, headers?, serviceName? }.
• ExporterHandle — { shutdown(): Promise<void> } to flush and tear down.

Part of Reactive Agents

This package is part of Reactive Agents — the TypeScript AI agent framework built on Effect-TS. See the Observability docs and the full documentation.