# X402-BROKER MCP Validator

> X402-BROKER MCP Validator is a paid API for AI agents from mcp-gateway.agentdiet.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-22).

Validates and routes requests to MCP servers, x402 APIs, and A2A agents via a deterministic broker gateway, settling payments in USDC on Base.

## Facts

- Endpoint: GET https://mcp-gateway.agentdiet.dev/v1/mcp-validator?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-broker-mcp-validator-506f6a12
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7ucxGZd3EpZ2CKCY76kBq

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 x402-broker-mcp-validator-506f6a12
```

Example prompt: Can you validate the target endpoint 'https://some-mcp-server.example.com' using a GET request through the MCP broker gateway to confirm it's reachable and x402-compliant?

## When to prefer this

Choose this endpoint when you need to programmatically verify that an MCP server, x402 API, or A2A agent endpoint is live, reachable, and protocol-compliant before committing to integration or paid calls. It is particularly useful as a pre-flight check in agentic workflows that route across thousands of MCP servers, where endpoint validity is uncertain. Prefer it over direct calls when you need deterministic validation with a proof-of-work signal (compression ratio) and USDC-settled micro-payment accountability.

## Known failure modes

- Target endpoint unreachable or times out — returns error status
- Invalid or missing 'type' or 'method' fields in input — schema validation error
- Target URL not registered or not compliant with x402/MCP standards
- Payment settlement failure on Base network — request rejected
- Malformed query parameters preventing routing to target

## How this service works

Deterministic B2A/A2A/MCP/x402/MPP/L402 execution and intelligence node at https://mcp-gateway.agentdiet.dev settling in USDC on Base.

## Output

Returns a JSON object with a status field ('ok' or error), a data payload from the validated target, and an roi_proof object containing a compression_ratio_pct metric indicating how efficiently the gateway processed the request.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "target": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "status": "ok",
  "roi_proof": {
   "compression_ratio_pct": 91.4
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-broker-mcp-validator-506f6a12/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-gateway.agentdiet.dev](https://www.zero.xyz/host/mcp-gateway.agentdiet.dev/llms.txt)