# X402-Broker Preflight – MCP/A2A/x402 Meta-Router Capability Check

> X402-Broker Preflight – MCP/A2A/x402 Meta-Router Capability Check is a paid API for AI agents from x402broker.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-27).

Performs a preflight lookup against the X402-Broker meta-index to retrieve capability routing metadata, quality scores, and execution parameters for a given MCP server, x402 API, or A2A agent endpoint URL.

## Facts

- Endpoint: GET https://x402broker.com/v1/preflight?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-broker-preflight-mcp-a2a-x402-meta-router-capability-check-557ebe77
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lw1Ar76ut-IZUF0Rg8Atb

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 x402-broker-preflight-mcp-a2a-x402-meta-router-capability-check-557ebe77
```

Example prompt: Do a preflight check on this URL using the X402-Broker to see if it's indexed, get its quality score, and find out how to route a GET request to it: https://some-mcp-tool.com/api/endpoint

## When to prefer this

Choose this endpoint when an AI agent needs to verify, discover, or preflight a specific MCP server, x402 API, or A2A agent URL before committing to a call — especially when quality scoring (TDQS), token compression metadata, or cross-protocol routing (x402 v2, IETF MPP, L402) information is needed. Prefer this over direct tool calls when you want to confirm a capability is live and indexed without side effects.

## Known failure modes

- URL not indexed in the broker returns empty data or 404-equivalent status
- Invalid or missing 'url' query parameter causes schema validation failure
- Endpoint is indexed but currently offline returns degraded status
- Unsupported HTTP method value returns enum validation error
- Payment of $0.01 USDC not fulfilled causes 402 Payment Required response

## How this service works

Universal B2A/A2A/MCP Meta-Router & Autonomous Tool Marketplace indexing 7,340+ live capabilities across x402 v2 (5-chain EVM USDC), IETF MPP, and L402 with TDQS quality scoring and zero-fee pass-through execution.

## Output

Returns a JSON object with a 'status' field ('ok' or error), a 'data' object containing routing metadata and capability descriptors for the queried endpoint, and a 'roi_proof' object including a compression_ratio_pct value (e.g. 91.4%) indicating token efficiency. Confirms whether the endpoint is indexed, live, and callable.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "url": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "status": "ok",
  "roi_proof": {
   "compression_ratio_pct": 91.4
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-broker-preflight-mcp-a2a-x402-meta-router-capability-check-557ebe77/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402broker.com](https://www.zero.xyz/host/x402broker.com/llms.txt)