# 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 x402broker.com, 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 keyword or endpoint URL to discover matching agent-callable endpoints.

## Facts

- Endpoint: GET https://x402broker.com/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: x402broker.com
- Website: https://x402broker.com
- Canonical page: https://www.zero.xyz/c/x402broker-com-universal-a2a-mcp-tool-discovery-safe-proxy-swarm-ab5d4222
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__JuXluw799_4k2ZrvkwJf

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 x402broker-com-universal-a2a-mcp-tool-discovery-safe-proxy-swarm-ab5d4222
```

Example prompt: Search the x402broker MCP catalog for tools that handle SEC filings and company enrichment — I want to know which agent-callable endpoints are available for those capabilities.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover which MCP servers or A2A tools support a given capability at runtime, rather than hardcoding tool configurations. Ideal for meta-agents or orchestrators that need to route tasks to the right specialist tool from a large pool of 500+ indexed servers. Prefer over manual MCP registries when you need keyword-based capability search with a single connection point and built-in prompt firewall.

## Known failure modes

- Empty query string returns validation error (query is required, minLength 1)
- No matching tools found returns empty result set
- Upstream MCP server index unavailable causes degraded or empty catalog response
- Payment not settled via x402 results in HTTP 402 response blocking access
- Overly broad query returns too many low-relevance results

## 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://x402broker.com/v1/broker/catalog)

## Output

Returns a catalog of matching MCP server and A2A tool entries, including endpoint metadata, capability descriptions, and URLs for agent-callable tools that match the search query, with token-compressed payloads.

## 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/x402broker-com-universal-a2a-mcp-tool-discovery-safe-proxy-swarm-ab5d4222/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402broker.com](https://www.zero.xyz/host/x402broker.com/llms.txt)