# 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 and routes across 500+ indexed MCP servers and A2A tools via a single connection, with 85% token compression and prompt-injection firewall protection.

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/a2a-router?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-ec51eac7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WXsHD0EI4ePGuioztS2WK

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-ec51eac7
```

Example prompt: Search the MCP and A2A tool registry for any servers that handle 'SEC filings' or 'company enrichment' — I want to find the best available endpoint I can route my agent through without setting up 500 separate connections.

## When to prefer this

Choose this endpoint when an agent needs to discover and route to any of 500+ MCP or A2A tools through a single connection rather than managing individual integrations. Especially valuable when token budget is constrained (85% compression), when safety is a concern (built-in prompt-injection firewall), or when the right downstream tool is unknown and needs to be discovered dynamically at runtime.

## Known failure modes

- Empty query string returns validation error
- No matching tools found for obscure capability query returns empty result set
- Endpoint URL verification may return unverified status if URL is not indexed
- Rate limiting or payment failure (HTTP 402) if x402 payment not processed
- Malformed query may return low-relevance results

## 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/a2a-router)

## Output

Returns a list of matching MCP servers and A2A tools relevant to the query, including compressed metadata (85% token reduction), safety status from the Prompt-Guard firewall, capability descriptions, and routing information needed to connect to the matched endpoints.

## 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-ec51eac7/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)