# 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 preflight.agentdiet.dev, 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-screened results for agent routing and discovery

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/tool-search?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: preflight.agentdiet.dev
- Website: https://preflight.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/preflight-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-473d280c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pRKuhkNksQeFto28izXEI

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 preflight-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-473d280c
```

Example prompt: Search the MCP and A2A tool index for capabilities related to 'SEC filings' — I want to find the best available agent tools for pulling financial regulatory data.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover which MCP server or A2A tool to call for a given capability, especially in swarm or multi-agent architectures where the tool landscape is large and frequently changing. It is preferable over hardcoded tool registries because it indexes 500+ servers, applies prompt-injection safety screening, and compresses results to minimize token overhead. Use it to verify whether a specific endpoint URL is safe and indexed before routing live agent traffic.

## Known failure modes

- Empty query string returns a 400 validation error
- Query matches no indexed tools, returning an empty result set
- Endpoint URL verification fails if the URL is not in the index
- Rate limiting or payment failure (402) if x402 micropayment is not completed
- Ambiguous queries may return loosely relevant or low-confidence matches

## 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://preflight.agentdiet.dev/v1/tool-search)

## Output

Returns a list of matching MCP servers or A2A tools relevant to the query, with compressed capability descriptions (85% token reduction), safety screening via the Prompt-Guard firewall, and routing metadata to help an agent select and connect to the best tool.

## 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/preflight-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-473d280c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from preflight.agentdiet.dev](https://www.zero.xyz/host/preflight.agentdiet.dev/llms.txt)