Install

macOS users can brew install:

  brew install agent-ecosystem/tap/skillxp

For other install options, including npm, PyPI, go install, and prebuilt binaries, refer to Installation.

See what each harness does with skills

To see where each supported harness discovers project-level skills, and whether its transcripts record injected context, use the harnesses command:

  $ skillxp harnesses
antigravity    project skills: .agents/skills   does NOT record injected context (evidence is inference)
claude-code    project skills: .claude/skills   records injected context
codex          project skills: .codex/skills    records injected context

Observe a skill invocation

To stage a skill in a fresh fixture, activate it, and trace how two phrases reached the model, use observe:

  skillxp observe -harness claude-code -install ./my-skill \
  -prompt "Activate the my-skill skill and follow its instructions." \
  -activation -trace "PHRASE-IN-BODY-1234,PHRASE-IN-REFERENCE-5678" \
  -out out/

The bundle written to out/ contains observation.json (run metadata and the trace report), session.json (the normalized transcript), and the archived native transcript(s) that evidence line numbers point into. See CLI for the trace report’s classifications and the one rule about choosing phrases.