OpenTelemetry

Zen Router can automatically set span attributes on the active OpenTelemetry span when a route matches. This gives you per-route observability with a single config option.

Zen Router has no dependency on @opentelemetry/api itself. You provide the getActiveSpan function, so the coupling is entirely in your code.

Setup

Pass an otel config with a getActiveSpan function:

import { trace } from "@opentelemetry/api";

const zen = new ZenRouter({
  authorize,
  otel: {
    getActiveSpan: () => trace.getActiveSpan(),
  },
});

Span attributes

When a route matches, Zen Router sets these attributes on the active span:

These attributes are set early in the request lifecycle, so they are recorded even if the request later fails due to auth or validation errors.