{"version":"2.1.274","anchor":"new-built-in-claude-test-plugin-for-browser-based-spec-tes","canonical_anchor":"new-built-in-claude-test-plugin-for-browser-based-spec-tes","heading":"New built-in 'diff' and 'claude-test' plugins added","tier":"use","area":"Testing","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.274\/e\/new-built-in-claude-test-plugin-for-browser-based-spec-tes","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.274","markdown":"### New built-in 'diff' and 'claude-test' plugins added\n\nClaude Code now ships built-in 'diff' and 'claude-test' plugins, loaded through a new lazy plugin-loading mechanism\n\n**Unclear.** Whether the tengu_mellow_hollerith gate is switched on for any account is unread, so nothing can be said about its status.\n\n**What**\n\n- Two new built-in plugin bundles, named `diff` and `claude-test`, are now loaded alongside the existing built-in plugins (`sec-default`, `agents-md`, `plugin-authoring`, `tips`).\n\n- The `claude-test` plugin adds skills (`claude-test`, `claude-test-execute`, `claude-test-draft`), agents (`explorer`, `author`, `runner`), and a browser automation server so Claude Code can run plain-language specs from `.claude-test\/specs\/` against your local dev server in a real headless browser and report pass\/fail results with screenshots, via a new `\/claude-test` command.\n\n- Built-in plugin registration itself was refactored from immediate registration calls into a named, lazy-loading pattern.\n\n**Why** This adds a ready-to-use way to write and run browser-based tests for your app directly from Claude Code, without installing a separate plugin.\n\n- Area: Testing\n- Names: `\/claude-test`\n- Tier: Use it now\n- Useful: 5\/5\n- Signal: 4\/5"}