Arize Phoenix
AI observability and evaluation you can self-host
Braintrust
Evals, logging and prompt tooling for AI products
Datadog LLM Observability
LLM traces inside Datadog
Helicone
Open-source LLM observability through a proxy or SDK
Langfuse
Open-source LLM observability, evals and prompt management
LangSmith
Tracing, evals and deployment from the LangChain team
OpenLLMetry
OpenTelemetry instrumentation for LLM apps
PostHog LLM analytics
LLM traces next to product analytics
Pydantic Logfire
OpenTelemetry observability from the Pydantic team
Weights & Biases Weave
Tracing and evaluation for AI applications