Skills

Teach your coding agent Phoenix’s conventions for the CLI, tracing, and evals, so it gets them right the first time.

A skill is a set of instructions your coding agent loads when a task matches it, such as debugging with px or writing an evaluator. Phoenix ships five, in the Phoenix repository.

Install

npx -y @arizeai/phoenix-cli setup skills

Installs all five into your agent’s skills directory, such as .claude/skills/. To pick specific ones, npx skills add Arize-ai/phoenix --skill <name>.

The Claude Code plugin installs phoenix-cli, phoenix-evals, and phoenix-tracing and keeps them updated. setup skills is a one-time copy; rerun it to pick up changes.

What your agent can do with them

phoenix-cli

Debug LLM apps using Phoenix CLI for traces, experiments, datasets, and prompts. Recommended.

phoenix-error-analysis

Read sampled traces, write free-form notes, then group them into a failure taxonomy that picks eval targets and fix priorities.

phoenix-evals

Build and run evaluators for AI/LLM apps across code-based and LLM-as-judge workflows.

phoenix-tracing

Implement OpenInference tracing conventions and instrumentation in Python and TypeScript.

phoenix-harbor

Configure Harbor agent evaluations and interpret their Phoenix experiments, scores, and ATIF traces.

Example prompt, with phoenix-error-analysis installed:

Review the last 50 traces in my support-agent project and tell me what categories of failures we have

Learn more

• Connect Your Coding Agent installs skills alongside the CLI and MCP server.
• Phoenix CLI is what the phoenix-cli skill teaches an agent to use.
• Agent Skills specification is the format these follow.

Add your own skills

Set PHOENIX_SKILLS_PATHS on the Phoenix server to one or more directories of your own Agent Skills; the MCP server serves them alongside the built-in ones:

PHOENIX_SKILLS_PATHS=/opt/skills/team-analysis,/srv/agents/skills

Each skill is a directory named after the name in its SKILL.md frontmatter, which also needs a description.