<!-- 0Gkit docs — Datadog — instrument0g wire-up
     Source: https://docs.0gkit.com/concepts/observability/exporters/datadog
     LLM-friendly Markdown twin of the page. -->

# Datadog

Datadog accepts OTLP traces through the Datadog Agent (recommended) or
through the OTLP-native intake. Both work — the agent route is the most
common because it gives you per-host metrics, log correlation, and traces in
one place.

## Wire-up (via the Datadog Agent)

Run the agent locally or as a sidecar; its OTLP HTTP receiver listens on
`:4318` by default.

```ts
import { instrument0g } from "@foundryprotocol/0gkit-observability";

await instrument0g({
  serviceName: "my-0g-app",
  exporter: {
    kind: "otlp",
    endpoint: "http://localhost:4318/v1/traces",
    // No headers needed — the agent authenticates outbound to Datadog.
  },
});
```

For the OTLP-native intake (no agent), point at the regional Datadog endpoint
and include the API key:

```ts
await instrument0g({
  serviceName: "my-0g-app",
  exporter: {
    kind: "otlp",
    endpoint: "https://trace.agent.datadoghq.com/v0.4/traces", // adjust by region
    headers: { "dd-api-key": process.env.DD_API_KEY! },
  },
});
```

## Auth

When sending via the agent, the agent itself holds `DD_API_KEY` and the
in-app code is unauthenticated. When sending directly, the API key goes in
the `dd-api-key` header. Either way, load from env — never hardcode.

## Where the traces land

Datadog's APM trace explorer groups spans into flame graphs. Each
`0gkit.<op>` span carries the full `0gkit.*` attribute set. Useful views:

- **Resource page**: pick `0gkit.compute.inference` (or any op) to see all
  invocations as a sorted list with p50/p95/p99 latency.
- **Trace search**: filter on `0gkit.error_code:STORAGE_QUOTA_EXCEEDED` to
  pull all instances of a specific failure mode.
- **Custom metrics**: Datadog auto-generates trace metrics from span
  attributes, so `0gkit.fee_native` becomes graphable in dashboards without
  any extra wiring.

## Service map

If you also instrument your HTTP / DB calls with the standard OTel
auto-instrumentations, the service map shows 0G as a downstream — each
`0gkit.*` span links into the parent service's request span via OTel context
propagation. No extra config required.