# Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router

> Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router is a paid API for AI agents from x402-audit.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Searches and routes to 500+ MCP servers and A2A tools via a single connection, with token compression and prompt-injection firewall.

## Facts

- Endpoint: GET https://x402-audit.agentdiet.dev/api/mcp/audit?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: x402-audit.agentdiet.dev
- Website: https://x402-audit.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/x402-audit-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-a64ada77
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5fgOtJEpBS8wc2KROzMyW

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-audit-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-a64ada77
```

Example prompt: Search the MCP tool index for any available servers that handle 'SEC filings' or 'company enrichment' — I want to find what agent tools are out there so I can route my swarm to the right one.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover, search, or route to MCP servers or A2A tools without maintaining individual connections to hundreds of services. Ideal for agent swarms, orchestrators, or pipelines that need a single gateway with built-in safety filtering and token efficiency. Prefer over direct MCP connections when breadth of coverage (500+ servers), prompt-injection protection, or token budget constraints matter.

## Known failure modes

- Missing or empty 'query' parameter returns a validation error
- Query returns no matching tools if the capability is not indexed
- Firewall may block or sanitize queries flagged as prompt injection attempts
- Upstream MCP server index may be stale or partially unavailable
- Paid endpoint may return HTTP 402 if payment not configured

## How this service works

Single-connection meta-router indexing 500+ MCP servers & A2A tools with 85% token compression and Prompt-Guard firewall. (Live x402 v2, IETF MPP & MCP endpoint at https://x402-audit.agentdiet.dev/api/mcp/audit)

## Output

Returns a list of matching MCP servers or A2A tools relevant to the query, including metadata about each tool's capabilities, with 85% token-compressed output and prompt-injection filtering applied via the Prompt-Guard firewall.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "query": {
   "type": "string",
   "minLength": 1,
   "description": "Capability search query (e.g. 'context compression', 'github security', 'sec filings', 'company enrichment') or endpoint URL to verify"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-audit-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-a64ada77/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-audit.agentdiet.dev](https://www.zero.xyz/host/x402-audit.agentdiet.dev/llms.txt)