What problem does it solve?
Phoenix solves the lack of visibility into LLM-powered applications by collecting detailed traces, evaluations, and dataset-backed experiments so teams can debug, measure quality, and monitor performance over time.
Core Features & Use Cases
- Tracing: Capture OpenTelemetry traces and spans from OpenAI, LangChain, LlamaIndex, Anthropic, and other instrumented clients to diagnose request flows and failures.
- Evaluation: Run built-in and custom LLM evaluators (hallucination, relevance, toxicity) and log evaluation results back to projects for regression testing.
- Datasets & Experiments: Version datasets, run experiments to compare prompts and models, and aggregate metrics for A/B comparisons and CI checks.
- Monitoring & Deployment: Self-host with PostgreSQL or SQLite, expose REST/gRPC endpoints, and support Docker/Kubernetes production deployments for real-time dashboards and alerts.
- Use Case: Debug a production chatbot by tracing a failed conversation, running automated evaluations on recent spans, and rolling back to a safer prompt variant based on experiment results.
Quick Start
Start a Phoenix server locally and configure your LLM client to send OpenTelemetry traces to http://localhost:6006/v1/traces so you can inspect spans and run evaluations immediately.