validate-marketplace

validate-marketplace is a command for Claude Code from dhofheinz/open-plugins. It costs 11 tokens per session (656 once invoked), scanned A, original, MIT.

A command that checks a Claude Code marketplace.json file, which lists a marketplace's owner and available add-ons. It checks the file's structure, quality, and security-related issues.

In plain words
What is it for?
Use it to locate and validate a marketplace.json file and review errors, warnings, suggestions, and a quality score.
Why use it?
It helps find invalid JSON, missing required fields, malformed add-on entries, and improvements before publishing.

Command for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: positional $N argument; mentions Claude Code.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the marketplace-validator-plugin plugin — 3 commands, 1 agent shipped together

Good fit Use it to locate and validate a marketplace.json file and review errors…

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add dhofheinz/open-plugins
Claude Code
/plugin install marketplace-validator-plugin

Made for: Claude Code.

Or install marketplace-validator-plugin, the plugin that ships this one along with the rest of its 3 commands, 1 agent.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for validate-marketplace

README.md
[![agentmods](https://agentmods.dev/badge/commands/dhofheinz/open-plugins/validate-marketplace.svg)](https://agentmods.dev/commands/dhofheinz/open-plugins/validate-marketplace)
Your own site
<a href="https://agentmods.dev/commands/dhofheinz/open-plugins/validate-marketplace"><img src="https://agentmods.dev/badge/commands/dhofheinz/open-plugins/validate-marketplace.svg" alt="Measured on agentmods" height="20"></a>
Per session 11 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 656 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00011 $0.00656
Opus 5 $0.00005 $0.00328
Sonnet 5 $0.00002 $0.00131
Haiku 4.5 $0.00001 $0.00066

Measured 6d ago against content hash e895dd4c2cce, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

validate-marketplace scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/marketplace-validator-plugin/commands/validate-marketplace.md · 107 lines

How it starts

The opening of the file, as written. The whole thing — 107 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Validate Marketplace

You are a marketplace validation specialist. Your task is to comprehensively validate a Claude Code marketplace.json file.

Process

1. Locate Marketplace File

Determine the marketplace.json path:

  • If user provided an argument ($1): Use that path
  • If no argument: Look for .claude-plugin/marketplace.json in current directory
  • Auto-detect: Search up directory tree for .claude-plugin/marketplace.json

2. Run Validation Script

Execute the validation script located at:

${CLAUDE_PLUGIN_ROOT}/scripts/validate-marketplace-full.sh [path]

The script will validate:

  • JSON syntax
  • Required fields (name, owner, plugins)
  • Optional recommended fields
  • Plugin entries structure
  • Quality scoring
  • Security checks

3. Interpret Results

The script outputs:

  • ✅ Success messages for valid items
  • ❌ Errors for critical issues
  • ⚠️ Warnings for recommended improvements
  • ℹ️ Info for suggestions

Quality Score:

  • 90-100: Excellent ⭐⭐⭐⭐⭐
  • 75-89: Good ⭐⭐⭐⭐
  • 60-74: Fair ⭐⭐⭐
  • 40-59: Needs Improvement ⭐⭐
  • 0-39: Poor ⭐

4. Provide Recommendations

Based on validation results, provide:

  1. Critical Issues: Must be fixed before publication
  2. Warnings: Should be addressed for quality
  3. Suggestions: Would improve discoverability and usability

5. Summary

Conclude with:

  • Overall quality assessment
  • Priority action items
  • Publication readiness status

Example Output Structure

🔍 Validating Marketplace: open-plugins

✅ JSON syntax valid
✅ Required fields present
✅ 3 plugins found

Plugin Validation:
✅ plugin-name (v1.0.0) - Excellent ⭐⭐⭐⭐⭐
⚠️  another-plugin (v0.1.0) - Fair ⭐⭐⭐
   - Missing recommended field: keywords
   - Description too short (< 50 chars)

Overall Quality Score: 85/100 - Good ⭐⭐⭐⭐

Recommendations:
1. Add keywords to another-plugin
2. Expand description in another-plugin

Summary: 1 excellent, 1 fair - Address warnings before publication

Error Handling

If validation fails:

  1. Show clear error messages
  2. Explain what's wrong
  3. Provide remediation steps
  4. Reference documentation if needed

Read the full file on GitHub · 107 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 107 lines · 11 tokens per session scan A e895dd4c2cce

Subscribe to this mod's changes

validate-marketplace is a command published in the GitHub repository dhofheinz/open-plugins (9 stars, last pushed 4mo ago), licensed MIT. It adds 11 tokens to every session and 656 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.