# 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 and routes queries across 500+ indexed MCP servers and A2A tools via a single connection, with token compression and prompt injection firewall

## Facts

- Endpoint: GET https://x402-audit.agentdiet.dev/v1/b2a-router?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-26dda74c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JN-6qSiFSC-zz-5JDnusm

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-26dda74c
```

Example prompt: Search the B2A router for MCP servers or A2A tools that can handle SEC filings and company enrichment — I want to find what's available through a single connection.

## When to prefer this

Choose this endpoint when you need to discover which MCP servers or A2A tools support a given capability without knowing specific endpoints in advance, or when you want a single proxied connection to a broad index of 500+ tools with built-in token compression and prompt injection protection rather than querying individual registries separately.

## Known failure modes

- Query too vague returns no matches or low-relevance results
- Payment not attached results in HTTP 402 response blocking the call
- Upstream MCP server unavailable causes partial or empty routing results
- Malformed query string returns validation error
- Rate limiting or quota exceeded returns error response

## 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/b2a-router)

## Output

Returns a list of matching MCP servers or A2A tools relevant to the search query, including tool metadata and routing information, with responses compressed to reduce token usage. May include verified endpoint URLs and capability descriptions filtered through a Prompt-Guard firewall.

## 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-26dda74c/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)