# Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router (Audit/Search)

> Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router (Audit/Search) is a paid API for AI agents from mcp-compiler.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Searches and verifies across 500+ indexed MCP servers and A2A tools using a single query, returning compressed capability matches with prompt-injection firewall protection.

## Facts

- Endpoint: GET https://mcp-compiler.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: mcp-compiler.agentdiet.dev
- Website: https://mcp-compiler.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/mcp-compiler-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-d799cdc8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8qGO9vi-RLFEvtsm_9AGz

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 mcp-compiler-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-d799cdc8
```

Example prompt: Search the MCP tool index for any servers that handle 'company enrichment' or B2B lead data — I want to know which tools are available and what they can do.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover available MCP servers or A2A tools by capability at runtime, rather than hardcoding tool endpoints. Especially useful when building swarm-style multi-agent systems that need to self-assemble toolchains, or when verifying whether a specific endpoint is a known, safe MCP tool before calling it.

## Known failure modes

- Empty query string returns validation error
- Query matches no indexed tools — empty results returned
- Endpoint URL provided for verification is not indexed — returns unknown status
- Service temporarily unavailable if upstream MCP index is unreachable
- Rate limiting or payment failure via x402 if USDC balance insufficient

## 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://mcp-compiler.agentdiet.dev/api/mcp/audit)

## Output

Returns a compressed list of matching MCP servers and A2A tools relevant to the query, including capability descriptions, endpoint metadata, and verification status — with up to 85% token reduction compared to raw responses and Prompt-Guard firewall applied to results.

## 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/mcp-compiler-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-d799cdc8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-compiler.agentdiet.dev](https://www.zero.xyz/host/mcp-compiler.agentdiet.dev/llms.txt)