mrc-audit · v0.1 · open source

Stateless audit for MCP servers & API endpoints.
30 seconds, no signup.

Runs Spectral-style metadata checks, security posture probes, and CORS abuse detection against any URL. Catches leaked backend subdomains (workers.dev, herokuapp.com, vercel.app, netlify.app) in your published agent-card.json and openapi.json — the exact class of bug we caught on our own production.

$ npx mrc-audit scan https://your-mcp.example.com
Zero install. Zero dependencies. Works on any MCP server, OpenAPI API, or A2A agent.
Live scan

Try it right now — paste any URL.

Runs the same 9 checks the CLI does. No signup. Rate-limited to 5 scans per hour per IP.

Example targets: https://api.meacheal.ai · https://smithery.ai · any MCP server URL
What it catches

Nine checks, zero noise.

Metadata
Backend URL leaks
Detects when your agent-card.json, openapi.json, or ai-plugin.json exposes *.workers.dev, *.herokuapp.com, *.vercel.app, or *.netlify.app — a real bug we caught on our own production.
Metadata
Semantic field validation
Validates servers[0].url, api.url, url fields against public host allowlists. Spectral-style rules applied to MCP / OpenAPI / A2A spec documents.
Security
CORS abuse probe
Sends Origin: https://evil.example.com and checks if the server reflects it or returns ACAO: * with credentials — OWASP ZAP 40040 misconfiguration.
Security
Security-header depth
HSTS, CSP, X-Frame-Options, X-Content-Type-Options + X-Powered-By/version leaks in Server headers.
Contract
Latency measurement
First-byte latency per endpoint. Upgrade to full audit for p50/p95/p99 tracking over 30 days.
Protocol
MCP / A2A / OpenAPI / ai-plugin awareness
Knows what /.well-known/agent-card.json, /mcp, and /.well-known/ai-plugin.json are supposed to contain. Generic uptime monitors don't.
How we compare

Not another MCP security scanner. An aggregator.

Most MCP audit tools focus on tool-action MCPs (Slack, Jira). We focus on data-type MCPs — the ones that claim verified data — and we plug other scanners in.

mrc-audit Runlayer ScanMCP Datadog Synth.
MCP protocol awareness
Self-hosted (no gateway proxy)
Spectral-style metadata rules partial partial
Data observability (Monte Carlo 5 pillars)
Compliance map (ASVS / SOC2 / ISO / OpenSSF) SOC2 partial
Aggregates other scanners (OpenSSF, Cisco, Snyk)
Free tier includes CLI
Pricing

Free CLI forever. Upgrade for history & compliance.

The public scan is always free. Sign up to unlock drift detection, SLA uptime, compliance PDF export, and BYO rules.

Free
$0
Public CLI
  • npx mrc-audit scan
  • 9 stateless checks
  • 5 scans/hour
  • No signup
Pro — soon
$49 / mo
Solo devs
  • All 135+ checks
  • Drift detection
  • SLA uptime %, p95/p99
  • Compliance PDF
Team — soon
$199 / mo
Growing company
  • + BYO rules
  • + Alert webhooks
  • + 3rd-party scanners
  • + Error-budget reports
Enterprise
Contact
Vertical MCP ops
  • + RBAC / SSO
  • + Self-hosted worker
  • + Terraform provider
  • + SLA & support
Built by

The team running MRC Data.

MRC Data is an MCP server for the Chinese apparel supply chain. We use mrc-audit every day to manage 3,000+ verified supplier records, 350+ lab-tested fabrics, and 170+ industrial clusters — 135 checks passing on every daily audit.

Learn more about MRC Data →