# 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 a meta-index of 500+ MCP servers and A2A tools by capability query, returning compressed, firewall-filtered results via a single proxy connection

## Facts

- Endpoint: GET https://x402-audit.agentdiet.dev/v1/x402-gateway?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-b8e4b5a0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zT4vAhrTw06x5tvTqKT0c

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-b8e4b5a0
```

Example prompt: Search the MCP and A2A tool index for any servers that handle 'SEC filings' or 'company enrichment' — I want to find the best available tool to route that kind of request through.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover which MCP server or A2A tool to call for a given capability, rather than hard-coding a specific tool. Especially useful in swarm or multi-agent architectures where the right downstream tool is not known in advance, or when you want a single safe-proxy connection with token-compressed responses instead of managing 500+ individual integrations.

## Known failure modes

- Empty or overly broad query returns too many low-relevance results
- Query for an obscure capability returns no matches if not indexed
- Prompt-Guard firewall may block or sanitize queries flagged as adversarial
- Payment failure (x402) prevents access to results
- Endpoint URL verification returns inconclusive status for non-standard implementations

## 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/v1/x402-gateway)

## Output

A compressed list of matching MCP servers or A2A tools from the meta-index, filtered through a Prompt-Guard firewall, with tool metadata and routing information — delivered with up to 85% token compression relative to raw tool manifests.

## 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-b8e4b5a0/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)