> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/nemo/relay/_mcp/server.

# Module otel

> OpenTelemetry subscriber support for NeMo Relay.

Generated from `cargo doc --no-deps -p nemo-relay -p nemo-relay-adaptive -p nemo-relay-pii-redaction -p nemo-relay-ffi -p nemo-relay-types -p nemo-relay-plugin -p nemo-relay-worker-proto -p nemo-relay-worker`.

OpenTelemetry subscriber support for NeMo Relay.

This crate adapts NeMo Relay lifecycle events into the selected `full`, `gen_ai`, or `openinference` OpenTelemetry trace projection. Scope start and end events open and close supported spans. Non-metric mark behavior is fixed by the selected projection; reserved metric-schema marks are not projected into traces.

The public API is intentionally small:

* [`OpenTelemetryConfig`](/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetryconfig) configures the OTLP exporter and resource metadata
* [`OpenTelemetrySubscriber`](/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetrysubscriber) exposes a NeMo Relay [`EventSubscriberFn`](/reference/api/rust-library-reference/nemo-relay/api/runtime/callbacks/type-eventsubscriberfn) and convenience `register` / `deregister` / `force_flush` / `shutdown` methods

## Structs

* [OpenTelemetryConfig](/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetryconfig): Configuration for an OpenTelemetry subscriber exporting to a collector.
* [OpenTelemetryFileSinkConfig](/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetryfilesinkconfig): Configuration for an OpenTelemetry subscriber writing OTLP to a local file.
* [OpenTelemetrySubscriber](/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetrysubscriber): OpenTelemetry-backed NeMo Relay subscriber.
* [OpenTelemetrySubscriberOptions](/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetrysubscriberoptions): Options for constructing an OpenTelemetry subscriber from an existing tracer provider.
* [OtlpFileSinkSettings](/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-otlpfilesinksettings): A local file destination for exported spans.

## Enums

* [OpenTelemetryError](/reference/api/rust-library-reference/nemo-relay/observability/otel/enum-opentelemetryerror): Errors produced while configuring or operating the OpenTelemetry subscriber.
* [OtlpFileSinkMode](/reference/api/rust-library-reference/nemo-relay/observability/otel/enum-otlpfilesinkmode): Open mode used when a trace file sink creates its output file.
* [OtlpTransport](/reference/api/rust-library-reference/nemo-relay/observability/otel/enum-otlptransport): Supported OTLP trace transports.

## Constants

* [DEFAULT\_COMPLETED\_SPAN\_CONTEXT\_TTL](/reference/api/rust-library-reference/nemo-relay/observability/otel/constant-default-completed-span-context-ttl): Default period for attaching late marks to a completed scope's trace span.

## Functions

* [default\_otlp\_file\_sink\_filename](/reference/api/rust-library-reference/nemo-relay/observability/otel/fn-default-otlp-file-sink-filename): Returns the default output filename for a trace file sink.

## Type Aliases

* [Result](/reference/api/rust-library-reference/nemo-relay/observability/otel/type-result): Result type for the OpenTelemetry subscriber crate.

> OpenTelemetry subscriber support for NeMo Relay.

## Docs

- [Struct Open Telemetry Config](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetryconfig.md): Configuration for an OpenTelemetry subscriber exporting to a collector.
- [Struct Open Telemetry File Sink Config](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetryfilesinkconfig.md): Configuration for an OpenTelemetry subscriber writing OTLP to a local file.
- [Struct Open Telemetry Subscriber](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetrysubscriber.md): OpenTelemetry-backed NeMo Relay subscriber.
- [Struct Open Telemetry Subscriber Options](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-opentelemetrysubscriberoptions.md): Options for constructing an OpenTelemetry subscriber from an existing tracer provider.
- [Struct Otlp File Sink Settings](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/struct-otlpfilesinksettings.md): A local file destination for exported spans.
- [Enum Open Telemetry Error](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/enum-opentelemetryerror.md): Errors produced while configuring or operating the OpenTelemetry subscriber.
- [Enum Otlp File Sink Mode](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/enum-otlpfilesinkmode.md): Open mode used when a trace file sink creates its output file.
- [Enum Otlp Transport](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/enum-otlptransport.md): Supported OTLP trace transports.
- [Constant DEFAULT_COMPLETED_SPAN_CONTEXT_TTL](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/constant-default-completed-span-context-ttl.md): Default period for attaching late marks to a completed scope's trace span.
- [Function default_otlp_file_sink_filename](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/fn-default-otlp-file-sink-filename.md): Returns the default output filename for a trace file sink.
- [Type Alias Result](https://docs.nvidia.com/nemo/relay/v0.10.0/reference/api/rust-library-reference/nemo-relay/observability/otel/type-result.md): Result type for the OpenTelemetry subscriber crate.