# 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 x402broker.com, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Searches an index of 500+ MCP servers and A2A tools by capability query, returning compressed, firewall-filtered tool discovery results via a single meta-router connection.

## Facts

- Endpoint: GET https://x402broker.com/v1/web-rag-shield-dag?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-router-a3664870
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2WyrVwTd_sRxKYCfZAMme

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-router-a3664870
```

Example prompt: Search the MCP and A2A tool index for anything that handles 'SEC filings' so I can find the right server to plug into my agent pipeline.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover which MCP server or A2A tool to use for a given capability, rather than hard-coding a specific tool. Ideal for orchestrators, swarm routers, and meta-agents that need to select tools at runtime from a large index with minimal token overhead.

## Known failure modes

- Missing or empty query parameter returns a validation error
- Query too generic returns a large or noisy result set
- Specific endpoint URL not found in the index returns no match
- Service unavailable or x402 payment failure returns HTTP 402 or 503
- Firewall may block results flagged as prompt-injection risks

## 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/web-rag-shield-dag)

## Output

Returns a compressed, structured list of matching MCP servers or A2A tools relevant to the capability query, including tool metadata filtered through a Prompt-Guard firewall, with approximately 85% token compression applied to keep responses agent-friendly.

## 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-router-a3664870/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)