# 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 serp-extract.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Searches and routes across 500+ indexed MCP servers and A2A tools by capability query, returning token-compressed results through a prompt-injection firewall

## Facts

- Endpoint: GET https://serp-extract.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: serp-extract.agentdiet.dev
- Website: https://serp-extract.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-648c1b26
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-hzw7dofStX42kTfn2Wl9

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 serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-648c1b26
```

Example prompt: Search the MCP tool registry for any servers that support 'SEC filings' or 'company enrichment' — I want to find the best available A2A tools for financial data grounding.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover and route to the right MCP server or A2A tool at runtime without hardcoding tool lists — especially useful for swarm architectures, token-budget-conscious pipelines, or when you need firewall-protected tool discovery across a broad index of 500+ endpoints.

## Known failure modes

- Empty or vague query returns no matches or irrelevant results
- Queried endpoint URL is unreachable or non-compliant, returning a validation error
- Rate limiting or payment failure (HTTP 402) if per-call budget is exceeded
- Firewall blocks response if a discovered tool's metadata contains a prompt injection pattern
- Registry index may lag real-time availability of newly registered MCP servers

## 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://serp-extract.agentdiet.dev/api/mcp/audit)

## Output

Returns a token-compressed list of matching MCP servers or A2A tools ranked by relevance to the query, including endpoint metadata, compliance status, and capability tags — filtered through a Prompt-Guard firewall to block injected payloads.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "limit": {
   "type": "integer",
   "default": 20,
   "maximum": 100,
   "minimum": 1,
   "description": "Maximum number of items to return per page (1-100)"
  },
  "query": {
   "type": "string",
   "minLength": 1,
   "description": "Capability search query (e.g. 'context compression', 'github security', 'sec filings', 'company enrichment') or endpoint URL to verify"
  },
  "cursor": {
   "type": "string",
   "description": "Opaque pagination cursor for fetching the next page"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-648c1b26/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from serp-extract.agentdiet.dev](https://www.zero.xyz/host/serp-extract.agentdiet.dev/llms.txt)