# 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 prompt-guard.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

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

## Facts

- Endpoint: GET https://prompt-guard.agentdiet.dev/v1/broker/execute?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: prompt-guard.agentdiet.dev
- Website: https://prompt-guard.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/prompt-guard-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-b9513a87
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7kCIeqBD3SeDp1vgHcKRV

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 prompt-guard-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-b9513a87
```

Example prompt: Search the MCP and A2A tool index for anything that handles SEC filings or company enrichment — I need to find the right tool to route my agent to.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover or route to one of hundreds of MCP or A2A tools at runtime, rather than hard-coding specific tool URLs. Ideal for swarm orchestration, meta-agent setups, or when you need to find the right specialized tool for a capability without knowing its endpoint in advance. The built-in Prompt-Guard firewall adds safety for untrusted tool inputs.

## Known failure modes

- Empty or vague query returns no useful matches
- Query too broad returns too many unranked results
- Endpoint URL verification may fail if remote tool is offline
- Token-compressed response may lose nuance for complex tool descriptions
- Rate limiting or payment (x402) failure if USDC balance is 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://prompt-guard.agentdiet.dev/v1/broker/execute)

## Output

Returns a list of matching MCP servers or A2A tool endpoints relevant to the search query, including tool metadata and routing information, with responses compressed to reduce token usage. May also return verification status if an endpoint URL is submitted as the query.

## 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/prompt-guard-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-b9513a87/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from prompt-guard.agentdiet.dev](https://www.zero.xyz/host/prompt-guard.agentdiet.dev/llms.txt)