Metadata

Metadata is arbitrary structured data (string keys, JSON-serializable values) attached to traces. It helps you filter and understand production traffic in the Noryen UI.

Per-event metadata

Pass metadata on each track() call:

noryen.track({
  model: "gpt-4o-mini",
  prompt: "Hello",
  response: "Hi!",
  metadata: {
    userId: "usr_123",
    feature: "chat",
    deployment: "eu-west",
  },
});

Good candidates: internal user or tenant ids (non-PII where possible), feature flags, request route names, environment names, and correlation ids.

Global context with setContext

This is default metadata, not the RAG TrackContext field on individual traces.

noryen.setContext(metadata) merges into a client-wide map. Every subsequent track() (including wrapper emissions) merges: global context first, then per-event metadata, so per-event keys override globals on conflict.

noryen.setContext({
  service: "billing-worker",
  version: process.env.APP_VERSION,
});

// Later events merge global context with per-event metadata
noryen.track({
  model: "gpt-4o-mini",
  prompt: "…",
  response: "…",
  metadata: { step: "invoice_summary" },
});
// Effective metadata includes service, version, and step

Wrapper-level metadata

When using wrappers, you can pass metadata in WrapOptions so every wrapped call includes the same fields:

const client = noryen.wrapOpenAI(openai, {
  metadata: { route: "api/chat" },
});