MCP Release Check

Know what changed.
Before your AI client does.

Compare two MCP tool catalogs. Get a clear review of renamed tools, schema changes and shifting behavior hints—without installing a test runner.

Start here: get your two catalog files

A catalog is the JSON returned by your MCP server’s tools/list request. It contains tool definitions—not server configuration or tool-call results.

Before your change: save the approved release’s complete catalog as baseline.json.
After your change: export the candidate release’s catalog as current.json, using the same permissions and configuration.
Choose both files below. For your own report, verify your purchase email. You can explore the free synthetic sample without purchasing.

Download example baseline Download example current Download full export guide

The example changes get_order → order_id from a string to an integer. Expected finding: /inputSchema/properties/order_id/type.

How do I export my server’s catalog?

Use MCP Inspector to connect to your server and inspect its Tools tab. Save the full tools/list response as JSON; if the UI does not expose the complete response, use the CLI export command below.

npx @modelcontextprotocol/inspector --cli node path/to/server/index.js --method tools/list --format json > baseline.json

Replace the entry point with your actual server command. Repeat for the candidate release and save current.json. For remote HTTP servers, authentication, and format troubleshooting, read the downloadable guide. Inspector requires Node.js; first use may download it from npm.

What if my server returns multiple pages?

Follow each nextCursor with your MCP client until all pages have been retrieved. Combine their complete tools arrays into one {"tools":[...]} file for each release. Remove the cursor only after collecting every page. A partial catalog can hide removed tools.

Maximum 50 tools per file; keep both files below 60 KB combined. Remove credentials and personal data before upload. No old baseline? Export the previous server version in a test environment; this service cannot recover an earlier catalog.

Contract comparison console

Server-side analysis

01 / APPROVED CONTRACT

Your baseline

The complete tools/list catalog you previously approved.

Choose baseline JSONNo file selected

02 / PROPOSED CONTRACT

Your current release

The complete catalog you want to compare against it.

Choose current JSONNo file selected

Maximum 50 tools per catalog; 64 KiB for the combined request. Only upload catalogs you are authorized to share. Files are sent to this service for analysis and are not stored. We retain a hashed license and comparison fingerprint, plus encrypted purchase credentials and hashed email/session identifiers for passwordless access. No MCP tools are executed.

Useful evidence, with a defined scope.

We compare tool presence, descriptions, input schemas, output schemas and annotations. Basic metadata lint highlights missing descriptions, invalid schema containers and conflicting hints.

Every change deserves a review. A finding does not automatically mean your server is broken. An unchanged catalog does not prove that runtime behavior stayed the same.

Which catalogs can I upload?

A JSON object containing a tools array, or a JSON-RPC response containing result.tools. Combine all pagination pages first. This service does not connect to a server, require a particular live transport, or perform protocol-version conformance checks.

What does €29 include?

One distinct baseline/current pair and downloadable HTML/JSON findings. Re-uploading the same catalog content with the same key regenerates that report. A different comparison needs a new purchase. No source code, hosted monitoring, AI-model evaluation or consulting is included.

How are files and keys handled?

Your catalogs are processed in memory and are not stored. Your license key is verified with Payhip, our checkout provider. Purchase access requires a one-time email link and a secure 30-day browser cookie. We retain encrypted purchase credentials, hashed email/session identifiers, a comparison fingerprint and redemption time. Sign-in links expire in 15 minutes, are single-use, and must be opened in the requesting browser. Your purchase email and sign-in link are sent to our email provider; catalogs are not. Expired authentication records are removed by scheduled cleanup. No analytics, third-party scripts or AI model calls are used by this app. Do not upload credentials or sensitive data inside catalogs. Reports remain in your browser until cleared or downloaded.

What is outside the scope?

Tool execution, full JSON Schema validation, runtime testing, prompt-injection scanning, security certification, MCP conformance certification and AI-agent evaluation. Only the tracked advertised contract is compared.