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

> Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router — Catalog Search 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 a catalog of 500+ MCP servers and A2A tools by capability query, returning matching endpoints with token-compressed metadata and Prompt-Guard firewall protection.

## Facts

- Endpoint: GET https://serp-extract.agentdiet.dev/v1/broker/catalog?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-b92d47bd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0aBGMeUg11tjICkED5hH3

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-b92d47bd
```

Example prompt: Search the agentdiet catalog for any tools that handle SEC filings or company enrichment — I need to find an MCP server or A2A agent that can pull financial data for me.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover available MCP servers or A2A tools by capability rather than hardcoding tool URLs. Especially useful for swarm orchestration, dynamic tool routing, and verifying whether a known endpoint is catalogued and compliant. Prefer over manual curation when you need access to 500+ tools from a single connection with built-in prompt-injection protection.

## Known failure modes

- Empty query string returns validation error (query is required, minLength 1)
- Query matches no tools in catalog — returns empty results set
- Endpoint URL verification returns not-found if URL is not indexed
- Rate limiting or payment failure (x402) if quota exceeded
- Catalog may be stale if a listed MCP server has gone offline

## 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/v1/broker/catalog)

## Output

A catalog listing of matching MCP servers and A2A tools relevant to the query, with token-compressed metadata (up to 85% compression) describing each tool's capabilities, endpoint URLs, and compliance status, filtered through a Prompt-Guard firewall.

## 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-b92d47bd/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)