Fiddler AI

LLM tracing and evaluation with retrieval debugging.

Phoenix is Arize's observability platform — run locally in a notebook or as a hosted service. Especially strong for inspecting RAG pipelines, finding bad chunks, and tracking retrieval quality over time.

Evaluation and observability for GenAI apps and agents, with inline guardrails.

A platform for testing, monitoring, and guardrailing LLM and agent applications. It ships 20+ out-of-the-box evals for RAG, agents, and safety, lets teams author custom evaluators, and turns those offline evals into real-time production guardrails powered by its own Luna eval models.

Open-source LLM observability. Self-hostable, OpenTelemetry-native.

Tracing, evals, prompt management, and dataset tooling for LLM apps — self-host on your own infra or use Langfuse Cloud. The open-source default when you want full ownership of your observability stack.

Drop-in LLM proxy with logging, caching, and cost tracking.

One-line integration — change your OpenAI/Anthropic base URL and get a dashboard with every prompt, response, latency, and dollar tracked. Adds caching and rate-limit handling without code changes.