# `Otel.Metrics`
[🔗](https://github.com/yangbancode/otel/blob/main/lib/otel/metrics.ex#L1)

Metrics API facade.

Minikube has no plugin ecosystem, so the spec's
MeterProvider + Meter entities collapse to a single hardcoded
identity. There is no `Meter` handle to obtain via
`get_meter/0` first — call the instrument facades
(`Otel.Metrics.Counter`, `Otel.Metrics.Histogram`, etc.)
directly with just the instrument name + opts.

Three SDK-internal `XxxStorage` GenServers (one per ETS table)
own the metrics state; they're started by
`Otel.Application.start/2` and die with the SDK supervisor.
All knobs (scope, resource, exemplar filter, table identifiers)
are compile-time literals — `Otel.InstrumentationScope.new/0`
and `Otel.Resource.new/0` are pure functions called directly
at the relevant boundaries, and the ETS tables are referenced
by their module-name atoms (`Otel.Metrics.InstrumentsStorage`,
`Otel.Metrics.MetricsStorage`, `Otel.Metrics.ExemplarsStorage`).

## References

- OTel Metrics API §MeterProvider: `opentelemetry-specification/specification/metrics/api.md` L156-L499
- OTel Metrics SDK §MeterProvider: `opentelemetry-specification/specification/metrics/sdk.md` L43-L155

---

*Consult [api-reference.md](api-reference.md) for complete listing*