mcpbeat

API Contract Validator MCP Server

io.github.lazymac2x/api-contract-validator
answering

API Contract Validator is answering right now. Last checked 14 min ago. It exposes 5 tools. Last commit 11 Apr 2026.

Cloudflare Workers MCP server: api-contract-validator

Uptime history 39 hours of history
39 hours agonow
100.0%
Uptime 24h
91 of 91 checks
5
Tools
read from the server
147 ms
Response time
average over 24h
0
Stars
last commit 11 Apr 2026

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 14 min ago.

run in your terminal
claude mcp add api-contract-validator --transport http https://api.lazy-mac.com/api-contract-validator/mcp
~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "api-contract-validator": {
      "url": "https://api.lazy-mac.com/api-contract-validator/mcp"
    }
  }
}
~/.codex/config.toml
[mcp_servers.api-contract-validator]
url = "https://api.lazy-mac.com/api-contract-validator/mcp"
.cursor/mcp.json
{
  "mcpServers": {
    "api-contract-validator": {
      "url": "https://api.lazy-mac.com/api-contract-validator/mcp"
    }
  }
}
.vscode/mcp.json
{
  "mcpServers": {
    "api-contract-validator": {
      "url": "https://api.lazy-mac.com/api-contract-validator/mcp"
    }
  }
}

Available tools 5

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

breaking
check_breaking_changes
Compare two OpenAPI spec versions to detect breaking changes: removed paths/operations, new required parameters, removed response codes, operationId renames.
diff
diff_request_response
Compare a real HTTP request/response against an OpenAPI spec contract. Returns per-field violations.
generate
generate_mock_from_spec
Generate mock response data from an OpenAPI spec. Uses examples, defaults, formats, and type heuristics.
lint
lint_api_schema
Lint an API spec for quality and best practice compliance. Rules: operation-id-kebab-case, response-success-required, tags-defined, no-empty-description, security-defined.
validate
validate_openapi_spec
Validate an OpenAPI 3.x or AsyncAPI spec JSON. Returns structural errors, missing required fields, and warnings.

Endpoints

URLTransportStateLatencyChecked
https://api.lazy-mac.com/api-contract-validator/mcp streamable-http answering 89 ms 14 min ago

API Contract Validator — questions

Answers built from our own checks of this server.

What can API Contract Validator do?
It exposes 5 tools, read directly from the server on our last check. Among them: check_breaking_changes, diff_request_response, generate_mock_from_spec, lint_api_schema, validate_openapi_spec. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →
Is API Contract Validator working right now?
We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 147 ms. The bar chart above shows every period we have measured.
How do I connect API Contract Validator?
Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.
Does API Contract Validator need an API key?
No. API Contract Validator completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 5 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is API Contract Validator?
It answers our handshake in 147 ms on average, which is faster than 74% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.
Is API Contract Validator open source?
Yes — written in JavaScript and 0 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.