Evaluation and observability

Open sourceApache 2.0Updated November 2026

OpenTelemetry

Open standard and ecosystem for traces, metrics, and logs increasingly used in LLM app observability.

Advanced · Language-specific SDK packages (opentelemetry-sdk, @opentelemetry/sdk-node) that can export straight to a backend, or through an optional OpenTelemetry Collector deployed as a sidecar or centralized gateway service

Editorial details

EditorCJ ZwartLast updatedNovember 2026SourcesOpenTelemetry

Tool categories, pricing, source status, deployment options, and product claims can change quickly. Verify the official source before production or commercial use.

About OpenTelemetry

Open standard and ecosystem for traces, metrics, and logs increasingly used in LLM app observability.

Best for: Engineering teams that want LLM application traces, metrics, and logs to flow into existing observability infrastructure (Datadog, Grafana, Jaeger, Honeycomb, or any OTLP-compatible backend) using the same instrumentation standard as the rest of the service stack.

Deployment: Language-specific SDK packages (opentelemetry-sdk, @opentelemetry/sdk-node) that can export straight to a backend, or through an optional OpenTelemetry Collector deployed as a sidecar or centralized gateway service

Skill level: Advanced

Tradeoffs

OpenTelemetry is an instrumentation and export standard, not an LLM-specific evaluation or debugging product, so a backend (Datadog, Honeycomb, Grafana, etc.) is required to visualize and query the exported data. LLM-specific features like prompt management, RAG evaluation, and dataset comparison require additional tooling like Phoenix or Langfuse layered on top.

Related guides and resources

Explore step-by-step setup guides, comparisons, and stack recipes for this tool category.

Best for

Engineering teams that want LLM application traces, metrics, and logs to flow into existing observability infrastructure (Datadog, Grafana, Jaeger, Honeycomb, or any OTLP-compatible backend) using the same instrumentation standard as the rest of the service stack.

Why use it

OpenTelemetry is the emerging standard for AI application observability through its GenAI semantic conventions (still marked Development), which define how to represent LLM spans (model, prompt, completion, token counts, latency) in vendor-neutral OTLP format. Teams already operating OTel infrastructure can add LLM traces to existing dashboards and alerts without adopting a separate AI-specific platform.

Key features

  • Vendor-neutral OTLP trace, metric, and log export to any OpenTelemetry-compatible backend, directly or via the OpenTelemetry Collector pipeline
  • GenAI semantic conventions for LLM span attributes such as the model and token counts. Their status is still Development, so names can change. OpenLLMetry is a separate Traceloop project that builds on OpenTelemetry
  • Collector pipeline for trace sampling, batching, attribute transformation, and fan-out export to multiple observability backends simultaneously
  • Language SDKs for Python, JavaScript/TypeScript, Go, Java, .NET, and Rust (traces in Beta). Zero-code instrumentation is available for Python, JavaScript, Go, Java and .NET, but is not listed for Rust

Tradeoffs

OpenTelemetry is an instrumentation and export standard, not an LLM-specific evaluation or debugging product, so a backend (Datadog, Honeycomb, Grafana, etc.) is required to visualize and query the exported data. LLM-specific features like prompt management, RAG evaluation, and dataset comparison require additional tooling like Phoenix or Langfuse layered on top.

Alternatives

  • Langfuse
  • Phoenix
  • Ragas

Official verification sources

Direct official links used to verify pricing, features, security claims, and product packaging.

CategoryEvaluation and observabilityLicenseApache 2.0DeploymentLanguage-specific SDK packages (opentelemetry-sdk, @opentelemetry/sdk-node) that can export straight to a backend, or through an optional OpenTelemetry Collector deployed as a sidecar or centralized gateway serviceModeOpen standard
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