# A2A, MCP & HTTP 402 Endpoint SLA Compliance Auditor

> A2A, MCP & HTTP 402 Endpoint SLA Compliance Auditor is a paid API for AI agents from prompt-guard.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Audits a remote agent, MCP, or x402 service URL for JSON-RPC compliance, latency SLA, OpenAPI schema validity, and HTTP 402 payment settlement headers.

## Facts

- Endpoint: GET https://prompt-guard.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: prompt-guard.agentdiet.dev
- Website: https://prompt-guard.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/prompt-guard-agentdiet-dev-a2a-mcp-http-402-endpoint-sla-compliance-f3b67a3d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ruqwMdXirlyWNla59SOgx

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 prompt-guard-agentdiet-dev-a2a-mcp-http-402-endpoint-sla-compliance-f3b67a3d
```

Example prompt: Can you audit https://myagent.example.com/mcp for JSON-RPC compliance, latency SLA, OpenAPI schema validity, and HTTP 402 payment settlement headers?

## When to prefer this

Use this endpoint when you need a programmatic, structured compliance report on a specific agent or MCP URL before integrating it into an agent workflow, when debugging x402/HTTP 402 payment header issues, or when validating latency SLAs and JSON-RPC protocol conformance for A2A services. Prefer it over manual inspection or generic HTTP testing tools when you need simultaneous multi-protocol checks (JSON-RPC, OpenAPI, HTTP 402/x402, SLA) in a single call.

## Known failure modes

- Target URL is unreachable or times out — audit returns connectivity error
- URL does not implement any recognized protocol (A2A/MCP/x402) — returns non-compliant result with no applicable checks
- Malformed or missing URL parameter — returns 400 validation error
- Target endpoint returns unexpected content type — schema validation may be incomplete
- Rate limiting or auth on the target endpoint blocks the probe — audit returns partial or failed results

## 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://prompt-guard.agentdiet.dev/v1/paywall-check)

## Output

Returns a structured audit report covering JSON-RPC compliance status, measured latency against SLA thresholds, OpenAPI schema validation findings, and HTTP 402 / x402 v2 settlement header presence and correctness for the submitted 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/prompt-guard-agentdiet-dev-a2a-mcp-http-402-endpoint-sla-compliance-f3b67a3d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from prompt-guard.agentdiet.dev](https://www.zero.xyz/host/prompt-guard.agentdiet.dev/llms.txt)