# 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 a meta-index of 500+ MCP servers and A2A tools by capability query, returning token-compressed results through a prompt-injection firewall

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/b2a-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-36ffeadf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_J1NroKpZPwN7-2joDvqJF

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-36ffeadf
```

Example prompt: Search your meta-index of 500+ MCP servers and A2A tools for anything that can do 'SEC filings' and return the top matches with compressed descriptions — also run it through the prompt-injection firewall before showing me results.

## When to prefer this

Use this endpoint when you need to dynamically discover, search, or verify MCP servers and A2A tools at runtime within an agent swarm, especially when you want a single connection point that aggregates 500+ sources, applies token compression to reduce LLM costs, and screens results through a prompt-injection firewall before surfacing them to your agent.

## Known failure modes

- Empty or too-generic query returns low-relevance or no matches
- Unknown or unindexed endpoint URL returns unverified/not-found status
- Payment not completed (HTTP 402) blocks result delivery
- Prompt-Guard firewall may flag and redact tool descriptions containing injection patterns
- Rate limiting if called too frequently without payment

## 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/b2a-router)

## Output

Returns a list of matching MCP servers or A2A tools for the given capability query, with token-compressed descriptions (up to 85% compression) and prompt-injection-screened metadata; or a verification result when an endpoint URL is supplied 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/preflight-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-36ffeadf/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)