# A2A, MCP & HTTP 402 Endpoint SLA Compliance Auditor

> A2A, MCP & HTTP 402 Endpoint SLA Compliance Auditor 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).

Audits any A2A, MCP, or x402 service URL for JSON-RPC compliance, latency SLA, OpenAPI schema validity, and HTTP 402 payment settlement headers

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/paywall-check?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-a2a-mcp-http-402-endpoint-sla-compliance-69839fa5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gnGG2JUWloScHJCSDUYlB

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-a2a-mcp-http-402-endpoint-sla-compliance-69839fa5
```

Example prompt: Can you audit https://mcp.example.com/tools for JSON-RPC compliance, latency SLA, and HTTP 402 payment header support and tell me if it's fully protocol-compliant?

## When to prefer this

Choose this endpoint when you need to verify that an A2A agent, MCP server, or x402 paywall URL is correctly implementing JSON-RPC, OpenAPI, latency SLA, and HTTP 402 payment protocols before integrating it into an agent pipeline or swarm. Ideal for due-diligence audits of third-party agent endpoints, debugging payment flow failures, or confirming compliance before production deployment.

## Known failure modes

- Target URL unreachable or times out — returns connectivity error
- Target URL returns non-standard protocol responses causing incomplete audit
- Malformed or empty URL input returns validation error
- Target service blocks probe requests returning 403 or firewall errors
- Partial compliance data if target endpoint only partially implements protocols

## How this service works

Audits any remote agent or MCP URL for JSON-RPC compliance, latency SLA, OpenAPI schema, and HTTP 402 settlement headers. (Live x402 v2, IETF MPP & MCP endpoint at https://preflight.agentdiet.dev/v1/paywall-check)

## Output

Returns a compliance report object covering JSON-RPC conformance status, measured latency against SLA thresholds, OpenAPI schema presence and validity, and HTTP 402 payment settlement header inspection for the target URL.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string",
   "minLength": 1,
   "description": "Target A2A, MCP, or x402 service URL to audit for protocol compliance"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/preflight-agentdiet-dev-a2a-mcp-http-402-endpoint-sla-compliance-69839fa5/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)