Merit Systems Staging Echo Payment Link

Use this endpoint when you specifically need to retrieve a payment link from the Merit Systems staging echo service and are operating in a staging/test environment. Prefer this when testing x402 micropayment-gated content access flows with Merit Systems infrastructure.

• Payment not authorized or x402 header missing — 402 Payment Required
• Invalid or expired payment token — 401 Unauthorized
• Staging service unavailable — 503 Service Unavailable
• Rate limit exceeded — 429 Too Many Requests
• Endpoint not found if staging environment is down — 404 Not Found