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jeremylongshore on GitHub

Plugin Validator

Free

Automate validation for AI assistant plugins.

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Free · Opens the source repo

What Plugin Validator does

Plugin Validator is a tool designed to ensure that AI assistant plugins conform to the required structure and standards before they are committed to a repository. It automates the process of validating plugin configurations, checking for compliance with JSON schemas, and verifying that all necessary files are present. This skill is particularly useful for developers working with Claude Code plugins, as it performs the same checks as the CI pipeline, helping to catch issues early in the development process.

The validation process begins by identifying the target plugin directory, either from user input or defaulting to the current working directory. The tool checks for the existence of critical files such as plugin.json, README.md, and LICENSE, ensuring that they are valid and correctly formatted. It also verifies the schema of plugin.json, confirming that all required fields are present and that no disallowed fields are included.

In addition to basic file checks, Plugin Validator inspects the frontmatter of all component files within the plugin, ensuring they adhere to the specified format. It also validates the directory structure against established standards, checks script permissions, and runs security scans to identify potential vulnerabilities. The output is a structured validation report that details the results of each check, including any failures and suggested fixes, making it easy for developers to address issues promptly.

This skill is ideal for developers and designers involved in creating or maintaining plugins for AI assistants. By automating the validation process, it streamlines the workflow and reduces the likelihood of errors that could lead to plugin failures in production environments.

When to use it

Use this tool when preparing plugins for deployment or before committing changes to ensure they meet compliance requirements.

When not to use it

This skill may not be suitable for validating plugins outside the Claude Code ecosystem or for users unfamiliar with the required directory and file structures.

What you can build with it

Validate a specific plugin

Trigger the validation process with a command like 'Validate the skills-powerkit plugin.' The tool will run checks and report any issues.

Pre-commit readiness check

Before committing changes, use the skill to ensure your plugin is compliant and ready for deployment.

Debug CI failures

If your plugin fails CI, run the same validation checks to identify and fix the issues causing the failure.

How to install Plugin Validator

View source

1. Install with the skills CLI

npx skills add jeremylongshore/claude-code-plugins-plus-skills/plugin-validator --agent claude-code

2. Or install it manually

Download the skill folder and drop it into ~/.claude/skills/ for all projects, or .claude/skills/ to scope it to one repo. Restart Claude Code so it picks up the new skill.

Anthropic's agentic coding CLI, and the reference implementation of Agent Skills. Drop a skill folder into ~/.claude/skills and Claude Code loads it automatically whenever a task matches the skill's description. Claude Code docs

Inside SKILL.md

Written by jeremylongshore

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

ErrorCauseSolution
Plugin directory not foundIncorrect path providedVerify path matches plugins/[category]/[name]/ and the directory exists
jq parse error on JSONMalformed JSON in plugin.json or catalogRun jq empty <file> to locate the syntax error line
Frontmatter parse failureMissing --- delimiters or invalid YAMLEnsure YAML frontmatter is enclosed in --- lines with valid key-value pairs
Version mismatchplugin.json and marketplace.extended.json carry different versionsUpdate the stale version to match; run pnpm run sync-marketplace
Scripts not executable.sh files missing execute permissionRun chmod +x <script> for each flagged file
Disallowed fields in plugin.jsonExtra fields beyond the allowed setRemove 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

Frequently asked questions about Plugin Validator

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