# 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 by capability query, returning token-compressed, firewall-screened results via a single meta-router connection.

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/x402-broker?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-f8f7c79e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gsqu403BMoUIj4PYD5caO

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-f8f7c79e
```

Example prompt: Search the MCP and A2A tool index for any available capabilities around 'SEC filings' or 'company enrichment' — I want a compressed, firewall-checked list of matching servers I can route to.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover, vet, and route to one of hundreds of MCP or A2A-compatible tools without maintaining its own registry. It is especially valuable when token budget is constrained (85% compression), when prompt-injection safety screening is required before calling untrusted endpoints, or when a single connection point to the broader agent tool ecosystem is preferred over direct multi-server discovery.

## Known failure modes

- No matching tools found for the given query — returns empty result set
- Query string is empty or too short — returns validation error
- Endpoint URL provided for verification is not indexed — returns not-found response
- Payment not received (HTTP 402) — request blocked until x402 micropayment is completed
- Firewall flags all candidates as unsafe — returns empty or redacted 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/x402-broker)

## Output

Returns a token-compressed (up to 85% reduction) list of matching MCP servers or A2A tool endpoints relevant to the query, filtered through the Prompt-Guard firewall to remove malicious or injection-prone results. Each result includes capability metadata, routing information, and safety signals.

## 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-f8f7c79e/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)