Overview

APIsage is an intelligent MCP server designed to help developers analyze, debug, and optimize API endpoints faster.

Instead of manually inspecting responses, APIsage performs end-to-end analysis—covering health checks, failure diagnosis, framework detection, security auditing, performance insights, and test generation.

The flagship analyze-endpoint tool acts as a smart orchestrator. It automatically adapts its workflow: running diagnosis on failures and deeper audits on successful endpoints.

🔗 Testing Local APIs (Using Cloudflare Tunnel / ngrok)

To test local backend APIs, you need to expose your local server to the internet so APIsage can reach it. You can use any tunneling tool that suits your workflow.

🚀 Recommended: Cloudflare Tunnel

Cloudflare Tunnel is a great primary choice because it provides free, stable HTTPS tunnels without strict session limits.

Install cloudflared:
- Windows: Download from Cloudflare Releases
- macOS: brew install cloudflared
- Linux: sudo apt install cloudflared
Start the tunnel:
```
cloudflared tunnel --url http://localhost:8000
```
Replace 8000 with your local port.

⚡ Alternative: ngrok

ngrok is a very popular alternative, though the free tier has some limitations (like mandatory signup and occasional interstitial pages).

Start ngrok:
```
ngrok http 8000
```

🛠️ Other Tools

You can use any tool that provides a public HTTPS bridge to your local environment, such as:

LocalTunnel: npx localtunnel --port 8000
Tailscale Funnel: For users already in the Tailscale ecosystem.
Bore / Playit.gg: Great for specific networking needs.

🔗 Use the URL in APIsage

Once your tunnel is running, copy the Public URL (e.g., https://random-name.trycloudflare.com) and use it in place of localhost:

Before (Local)	After (Public Tunnel)
http://localhost:8000/api/health	https://random-name.trycloudflare.com/api/health
http://127.0.0.1:3000/api/users	https://abc123.ngrok-free.app/api/users

Key Capabilities

Endpoint Intelligence
Use check-endpoint to inspect status codes, latency, headers, and response previews instantly.
Smart Failure Diagnosis
diagnose-failure identifies root causes (authentication errors, validation issues, server faults) with confidence scores and suggested fixes.
Framework Detection
detect-framework infers backend technologies like Express.js, Django, or FastAPI from response patterns.
Security Audit
security-audit detects vulnerabilities such as insecure CORS, missing HTTPS, token exposure, and weak authentication.
Performance Analysis
performance-analysis evaluates latency and response size, providing optimization insights and performance scoring.
Auto Documentation
infer-docs generates API schemas, field descriptions, and example payloads directly from responses.
Test Case Generation
generate-test-cases creates ready-to-use curl, Postman, Jest, and Pytest tests with optional live validation.
Endpoint Comparison
compare-endpoints highlights schema differences and performance changes between API versions.

Use Cases

Pre-deployment Validation
Run analyze-endpoint to verify endpoint health, performance, and security before release.
Debugging API Failures
Use diagnose-failure to quickly identify and fix issues in failing endpoints.
Automated Testing
Generate and validate test cases instantly without manual setup.
Version Comparison
Compare endpoints across versions to detect breaking changes and regressions.

Who This Is For

Backend developers building and debugging APIs
Full-stack developers integrating APIs
Teams needing fast validation, testing, and documentation workflows