OpenInference

OpenInference is a fixed projection of the unified OpenTelemetry exporter. It is always available and no longer has a separate configuration section, subscriber class, or Cargo feature.

Plugin Configuration

Select openinference on an endpoint in the opentelemetry section:

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[components.config]
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version = 4
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[components.config.opentelemetry]
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enabled = true
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[[components.config.opentelemetry.endpoints]]
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type = "openinference"
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endpoint = "http://localhost:6006/v1/traces"
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transport = "http_binary"
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service_name = "agent-service"
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instrumentation_scope = "opentelemetry"
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timeout_millis = 3000
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[components.config.opentelemetry.endpoints.header_env]
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authorization = "OTEL_AUTHORIZATION"
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[components.config.opentelemetry.endpoints.resource_attributes]
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"deployment.environment" = "dev"

The endpoint emits the existing OpenInference scope, tool, LLM, and mark projection. It supports the mark_projection, mark_exclude_names, and attribute_mappings controls on the typed endpoint, retaining the legacy behavior.

Normalized tool results emit one llm.input_messages entry per result with message.role = "tool", message.tool_call_id, and message.content. Anthropic user messages that contain only tool_result blocks expand into separate entries so parallel tool results retain their original order and correlation IDs.

Set OTEL_AUTHORIZATION to the complete authorization header value before activation. NeMo Relay snapshots the value when the plugin activates. The variable must be set and nonblank. A header name cannot appear in both headers and header_env, including names that differ only by ASCII case. The resolved value cannot have surrounding whitespace.

For the complete endpoint field table, multi-endpoint behavior, and version-2 migration, refer to OpenTelemetry.

Direct Subscriber

Use OpenTelemetrySubscriber with the OpenInference discriminator:

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from nemo_relay import OpenTelemetryConfig, OpenTelemetrySubscriber
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config = OpenTelemetryConfig(
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    "openinference",
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    "http://localhost:6006/v1/traces",
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)
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config.service_name = "agent-service"
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config.header_env = {"authorization": "OTEL_AUTHORIZATION"}
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subscriber = OpenTelemetrySubscriber(config)

Direct OpenInference subscribers use the shared header_env construction, validation, and secret-handling behavior. Set OTEL_AUTHORIZATION to the complete, nonblank authorization header value before constructing OpenTelemetrySubscriber. Subscriber construction fails if the environment variable is missing or invalid.

Register the subscriber before instrumented work. During graceful teardown, deregister it, flush it, and then shut it down.