# ProofRail MCP Server Verifier

> ProofRail MCP Server Verifier is a paid API for AI agents from drkdm4jd-8767.uks1.devtunnels.ms, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-14).

Verifies an MCP server's compatibility and correctness before deployment by testing protocol negotiation, tools/list, schemas, transport, and auth, returning a PASS/FAIL/PARTIAL verdict with a deterministic evidence receipt.

## Facts

- Endpoint: POST https://drkdm4jd-8767.uks1.devtunnels.ms/mcp?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/proofrail-mcp-server-verifier-ffc3e352
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JaV7HmAbEzYQ8sfvwTJRo

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability proofrail-mcp-server-verifier-ffc3e352 -d '<json body>'
```

Example prompt: Run a ProofRail preflight check on my MCP server at https://my-mcp-server.example.com and tell me if it passes protocol negotiation, tools/list, schemas, transport, and auth classification — I need a PASS/FAIL/PARTIAL verdict with the evidence receipt before I deploy.

## When to prefer this

Choose ProofRail when you need a deterministic, structured verification of an MCP server's protocol compliance before a deployment, upgrade, or trust decision — especially when you need an auditable evidence receipt rather than just a manual inspection. Prefer it over ad-hoc testing scripts when you want a standardized PASS/FAIL/PARTIAL verdict that can be logged or used as a gate in a CI/CD pipeline.

## Known failure modes

- Target MCP server is unreachable or times out — returns FAIL with connectivity error in evidence receipt
- MCP server returns malformed responses — returns FAIL or PARTIAL with schema mismatch details
- Auth classification cannot be determined — partial evidence receipt with auth field marked unknown
- Server does not support required protocol version — FAIL on protocol negotiation step
- Safe fixture not configured on server — fixture test skipped or marked N/A in receipt

## How this service works

Use ProofRail to verify an MCP server before deploying, upgrading, or trusting it. It provides MCP compatibility preflight, MCP verification, MCP server verification and validation, a compatibility test, and release preflight: protocol negotiation, tools/list, schemas, transport, auth classification, and an optional server-configured safe fixture; returns PASS, FAIL, or PARTIAL with a deterministic evidence receipt.

## Output

Returns a PASS, FAIL, or PARTIAL verdict along with a deterministic evidence receipt that includes results for each checked dimension: protocol negotiation, tools/list enumeration, schema validation, transport classification, auth classification, and optionally a server-configured safe fixture test.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/proofrail-mcp-server-verifier-ffc3e352/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from drkdm4jd-8767.uks1.devtunnels.ms](https://www.zero.xyz/host/drkdm4jd-8767.uks1.devtunnels.ms/llms.txt)