# Claude Code plugin eval: gate skills on delta before you merge

Claude Code now ships a first-party way to prove a plugin or skill actually helps. The command is `claude plugin eval`. It runs your suite with the plugin loaded and again without it, then reports `WITH`, `W/OUT`, and `Δ` — the lift the plugin contributed. That changes what production teams should do before they merge a skill into a kit repo or pin it in CI.

This is not another “write better prompts” essay. It is a builder workflow for Claude Code v2.1.269+: create cases under `evals/`, grade outcomes, and fail the build when the score drops. If you already ship agent docs in an owned monorepo, pair this with [Claude Code on an OTF kit: the CLAUDE.md and prompts that ship with the repo](/blog/claude-code-otf-kit-docs).

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*This is an excerpt. Read the full post at [otf-kit.dev/blog/claude-code-plugin-eval-ci](https://otf-kit.dev/blog/claude-code-plugin-eval-ci) — full-stack kits your AI coding agent can actually ship to production. [Browse the kits →](https://otf-kit.dev)*