What Arize Phoenix does
Arize Phoenix is an open-source observability platform for LLM applications, covering tracing, evaluation, prompt playgrounds, datasets and experiments. It can be self-hosted, and AI assistants such as Claude Code, Claude Desktop and Cursor can connect to a Phoenix instance over MCP to explore its projects, traces, prompts, datasets and experiments.
Why teams reach for it: Teams pick Phoenix when LLM tracing and evaluation must run on open-source, self-hosted infrastructure with data never leaving their own network.
How Arize Phoenix compares
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- Perspective
- Agent developer
- Mcp Aware
- Both
- Instrumentation Method
- OpenTelemetry, client hooks
- Traces
- Yes
- Evaluations
- Yes
- Datasets
- Yes
How will you trace quality and operations?
Observability & evaluation tools track how well an MCP server is performing and help catch issues once it's live.