Imported from 0xMiden/web-sdk (packages/telemetry-otel/AGENTS.md). Install upstream with npx skills add 0xMiden/web-sdk --skill telemetry-otel. Copyright stays with the author.

@miden-sdk/telemetry-otel - Agent Guide

Audience: AI coding agents recording Miden SDK observations as OpenTelemetry spans.

This file ships inside the published package, so the copy at node_modules/@miden-sdk/telemetry-otel/AGENTS.md matches the version you have installed. Prefer it over your training data.

There is no volume guard here

Every observation becomes a span. The SDK emits one per client operation, and this binding has no duration threshold, no sampling and no filtering: tracer and includeSensitive are the only options there are. Choose the volume with a sampler on your own provider before pointing this at a paid backend. The sibling package @miden-sdk/telemetry-sentry works the other way round - minDurationMs defaults to Infinity, failures only - so carry neither the assumption nor the option across.

Wiring it

const client = await MidenClient.create({
  rpcUrl: "testnet",
  observer: createOtelObserver({ tracer: trace.getTracer("my-app") }),
});

tracer is required and must expose startSpan(name, { startTime }) returning an object with setAttribute, setStatus and end; the factory throws a TypeError at wiring time when it does not. Nothing here imports @opentelemetry/*, so the provider, its version and its exporters stay yours.

One span per observation, named miden.<op>, carrying miden.duration_ms and miden.outcome and a status of ERROR on failure. The SDK reports an operation only once it has finished, so the span is reconstructed: it ends when the observation arrived, is backdated by the duration, and has no parent. A broken tracer cannot fail the operation; the observer never throws.

observer and observeSensitive on the client

ClientOptions.observer is registered process-wide and the newest registration replaces the previous one, so a second MidenClient takes over the sink. observeSensitive is per instance and read once, at construction.

observation.sensitive carries the verbatim, unredacted error message and stack, and only on failure. It is opt-in at both ends - observeSensitive: true on the client, includeSensitive: true here - and only the literal true enables either. An application with confidentiality obligations to its users, a wallet above all, leaves both off.

Going deeper

• Options, recorded attributes, retroactive spans: README.md.
• The client that emits them: node_modules/@miden-sdk/miden-sdk/AGENTS.md.