# 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 discovers the right MCP server or A2A tool across 500+ indexed endpoints, routing queries through a prompt-injection firewall with 85% token compression.

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/web-rag-shield-dag?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-d24f517b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fwsUkaGeOLb4hadNQ8z8J

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-d24f517b
```

Example prompt: Search the MCP and A2A tool registry for anything that does 'SEC filings retrieval' and return the top matching endpoints, compressed and firewall-checked.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover the right MCP server or A2A tool from a large ecosystem without hardcoding tool lists, especially when token budget is constrained (85% compression) or when routing through untrusted third-party tools that require injection-safe proxying.

## Known failure modes

- No matching tools found for the query — returns empty result set
- Query too vague or short — may return irrelevant or low-confidence matches
- Endpoint URL verification fails if the URL is not indexed
- Payment not processed (x402 HTTP 402) — call blocked if $0.01 USDC payment missing
- Firewall blocks response if tool metadata contains prompt injection patterns

## 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/web-rag-shield-dag)

## Output

Returns a ranked list of matching MCP servers or A2A tools relevant to the query, with compressed metadata (85% token reduction), safety-filtered through the Prompt-Guard firewall, including endpoint references and capability summaries.

## 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-d24f517b/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)