Agent Skills: Plugin Validator

Plugin Validator

Overview

Validates Claude Code plugin structure, JSON schemas, frontmatter format, security compliance, and marketplace catalog consistency. Runs the same checks as the CI pipeline to catch issues before committing.

Prerequisites

• Read access to the target plugin directory and repository-level .claude-plugin/marketplace.extended.json
• jq installed for JSON validation (jq empty <file>)
• grep and find available on PATH for pattern scanning
• ./scripts/validate-all-plugins.sh available at the repository root

Instructions

1. Identify the target plugin path from context or user request. Default to the current working directory if the path contains a .claude-plugin/ subdirectory.
2. Validate required files exist (see ${CLAUDE_SKILL_DIR}/references/validation-checks.md):
   • .claude-plugin/plugin.json present and valid JSON.
   • README.md present and non-empty.
   • LICENSE file present.
   • At least one component directory exists (commands/, agents/, skills/, hooks/, or mcp/).
3. Validate plugin.json schema:
   • Confirm all required fields: name (kebab-case), version (semver x.y.z), description, author.name, author.email, license, keywords (array, minimum 2).
   • Reject any fields not in the allowed set (name, version, description, author, repository, homepage, license, keywords).
4. Validate frontmatter in all component files:
   • Commands (commands/*.md): require name, description, model (one of sonnet, opus, haiku).
   • Agents (agents/*.md): require name, description, model.
   • Skills (skills/*/SKILL.md): require name, description; allowed-tools optional but validated against the allowed tools list if present.
5. Validate directory structure matches the expected hierarchy (see ${CLAUDE_SKILL_DIR}/references/validation-checks.md for the complete structure diagram).
6. Check script permissions: find all .sh files and verify they have execute permission. Report any that lack it with a fix command.
7. Run security scans: search for hardcoded secrets, AWS keys, private keys, dangerous commands, and suspicious URLs.
8. Validate marketplace compliance:
   • Confirm the plugin has an entry in marketplace.extended.json.
   • Verify version, name, category, and source path match between plugin.json and the catalog entry.
   • Check for duplicate plugin names.
9. Validate README content: confirm it contains installation, usage, and description sections.
10. Check hook path variables: verify hooks use ${CLAUDE_PLUGIN_ROOT} instead of hardcoded absolute paths (/home/, /Users/).
11. Compile results into a validation report following the format in ${CLAUDE_SKILL_DIR}/references/validation-report-format.md.

Output

A structured validation report containing:

• Total checks passed and failed (e.g., "8/10 PASSED")
• Per-check results with pass/fail status
• For each failure: the specific issue, file location, and a ready-to-run fix command
• Warnings for non-critical issues (e.g., missing optional README sections)
• Overall verdict: PASSED or FAILED with critical issue count

Error Handling

| Error | Cause | Solution | |---|---|---| | Plugin directory not found | Incorrect path provided | Verify path matches plugins/[category]/[name]/ and the directory exists | | jq parse error on JSON | Malformed JSON in plugin.json or catalog | Run jq empty <file> to locate the syntax error line | | Frontmatter parse failure | Missing --- delimiters or invalid YAML | Ensure YAML frontmatter is enclosed in --- lines with valid key-value pairs | | Version mismatch | plugin.json and marketplace.extended.json carry different versions | Update the stale version to match; run pnpm run sync-marketplace | | Scripts not executable | .sh files missing execute permission | Run chmod +x <script> for each flagged file | | Disallowed fields in plugin.json | Extra fields beyond the allowed set | Remove disallowed fields; only name, version, description, author, repository, homepage, license, keywords are permitted |

Examples

Validate a specific plugin: Trigger: "Validate the skills-powerkit plugin." Process: Run all 10 validation checks against plugins/community/skills-powerkit/. Identify 2 failures (script permissions, version mismatch). Provide fix commands: chmod +x scripts/*.sh and version update instruction. Report overall: FAILED (see ${CLAUDE_SKILL_DIR}/references/examples.md).

Pre-commit readiness check: Trigger: "Check if my plugin is ready to commit." Process: Detect the plugin from working directory context. Run comprehensive validation including marketplace compliance. Report PASSED or list blocking issues with fixes.

Debug CI failures: Trigger: "Why is my plugin failing CI?" Process: Run the same validation checks that CI executes (validate-all-plugins.sh). Identify the exact failure (e.g., disallowed field in plugin.json). Provide the fix command and verify the fix resolves the issue.

Resources

• ${CLAUDE_SKILL_DIR}/references/validation-checks.md -- complete list of all 10 validation categories with specific checks
• ${CLAUDE_SKILL_DIR}/references/validation-report-format.md -- report template with pass/fail formatting
• ${CLAUDE_SKILL_DIR}/references/examples.md -- validation scenario walkthroughs
• ${CLAUDE_SKILL_DIR}/references/errors.md -- error handling patterns