Crate rustlavel_otel 

rustlavel-otel: OpenTelemetry traces and metrics, over OTLP.

App::new()?
    .routes(routes::web::routes)
    .plugin(OpenTelemetry::default())
    .serve()
    .await

Nothing is instrumented twice. Every package in the framework already reports what it does on rustlavel_core::events; this listens, the way Telescope and the Prometheus exporter do, and turns what it hears into OTLP. Adding a span to a new package therefore means dispatching an event, not reaching for this crate.

What it produces

• A server span per request, named for the route pattern, carrying the method, path, status and route. Everything the request awaits — a query, a model call, an MCP tool, an outbound request — becomes a child span.
• Logs, when asked for, with the trace and span they were written inside (logs).
• Metrics for the same work: request, query, model and job durations as histograms, token usage and job outcomes as counters, and the exporter’s own queue depth and drop count so a broken telemetry pipeline is visible from inside the telemetry.

Propagation

W3C traceparent is read from the request and written to the response, so a trace that began upstream continues here instead of starting again. For an outbound call, attach trace::traceparent to carry it onwards.

Encoding

Protobuf by default, because every collector must accept application/x-protobuf while JSON is optional. The encoder is written here rather than generated (protobuf), which rule one asks for and which the narrow, fixed schema makes reasonable. application/json is a configuration switch away when a payload needs to be readable in a proxy log.

Failure

Telemetry must not be able to take down what it observes. Recording a span is a mutex and a push; the queue is bounded and drops with a counter and a log line; an unreachable collector costs spans and never a request. See exporter for the drop and retry policy in full.

Re-exports

pub use exporter::Exporter;

pub use exporter::Protocol;

pub use exporter::Settings;

pub use logs::LogRecord;

pub use logs::LogSettings;

pub use metrics::Instrument;

pub use metrics::Meter;

pub use plugin::OpenTelemetry;

pub use protobuf::Encoder;

pub use resource::Resource;

pub use resource::Value;

pub use trace::Span;

pub use trace::SpanContext;

pub use trace::SpanId;

pub use trace::SpanKind;

pub use trace::SpanStatus;

pub use trace::TraceId;

pub use trace::in_span;

pub use trace::traceparent;

Modules

exporter

Batching and shipping, over OTLP/HTTP.

logs

OTLP logs: the third signal.

metrics

Counters, gauges and histograms, aggregated in process and shipped as OTLP.

plugin

Turning OpenTelemetry on.

protobuf

Just enough protobuf to write OTLP.

resource

The vocabulary both signals share: attribute values, the resource that says who is reporting, and the scope that says which library reported.

trace

Spans: identity, W3C propagation, and the OTLP ResourceSpans payload.