# A2A/MCP/x402 Deep Protocol & Security Audit

> A2A/MCP/x402 Deep Protocol & Security Audit is a paid API for AI agents from assay.agentdiet.dev, paid per call via MPP, $0.005/call, status unknown (last checked 2026-10-23).

Performs a deep protocol conformance and security audit of a target A2A, MCP, or x402 endpoint, returning a grade and score.

## Facts

- Endpoint: POST https://assay.agentdiet.dev/v1/audit?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: assay.agentdiet.dev
- Website: https://assay.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/assay-agentdiet-dev-a2a-mcp-x402-deep-protocol-security-audit-3bbd1a51
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tgxKlLVBd2svzPKtc5yzI

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 assay-agentdiet-dev-a2a-mcp-x402-deep-protocol-security-audit-3bbd1a51 -d '<json body>'
```

Example prompt: Can you run a deep security and protocol audit on https://x402broker.com and tell me its grade and score?

## When to prefer this

Choose this endpoint when you need a comprehensive, deep protocol and security audit of an A2A, MCP, or x402 endpoint — going beyond a quick pre-flight check to provide a graded score with detailed findings. Prefer this over lighter certification endpoints when evaluating third-party integrations, performing due diligence before production deployment, or when paginated audit results are needed.

## Known failure modes

- Invalid or unreachable target URL returns an error status
- Malformed target parameter results in a 4xx validation error
- Target endpoint times out during audit, returning a failed status
- Pagination cursor is invalid or expired, causing a cursor error
- Rate limiting or payment failure returns a 402 or 429 response

## How this service works

Deep protocol & security audit of an A2A/MCP/x402 endpoint (Live x402 v2, IETF MPP & MCP endpoint at https://assay.agentdiet.dev)

## Output

Returns a JSON object with a status string, a letter-based security grade (e.g. A, B, C), an integer score, the audited target URL, and pagination fields (has_more, next_cursor) for fetching additional audit records.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "target"
 ],
 "properties": {
  "target": {
   "type": "string",
   "default": "https://x402broker.com"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "status",
  "grade",
  "score"
 ],
 "properties": {
  "grade": {
   "type": "string"
  },
  "score": {
   "type": "integer"
  },
  "status": {
   "type": "string"
  },
  "target": {
   "type": "string"
  },
  "has_more": {
   "type": "boolean"
  },
  "next_cursor": {
   "type": "string",
   "nullable": true
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/assay-agentdiet-dev-a2a-mcp-x402-deep-protocol-security-audit-3bbd1a51/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from assay.agentdiet.dev](https://www.zero.xyz/host/assay.agentdiet.dev/llms.txt)