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Forge Cascade Agent Payments – x402 Payment Challenge
x402
Forge Cascade Agent Payments – x402 Payment Challenge is a paid API for AI agents from api.relai.fi, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-13).
Issues an x402 Payment Required challenge to discovery clients, enabling micropayment-gated API access via the x402 protocol.
Price / call$0.01
Success—
StatusUnknown
How this service works
Returns an x402 Payment Required challenge for discovery clients.
Output
Returns an HTTP 402 Payment Required response containing an x402 challenge payload specifying the payment amount (0.01 USDC), accepted payment method, and instructions needed for a client to construct and submit a valid payment to gain access.
Example use cases
Example prompt
“Send a payment challenge probe to the Forge Cascade Agent Payments endpoint so I can discover the x402 payment terms and USDC price required before proceeding with the call.”
Technical details
Endpoint
POSThttps://api.relai.fi/relay/1781295889777/api?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to discover or initiate the x402 micropayment challenge flow for an API gated behind payment, specifically in agentic or automated contexts where the AI agent must negotiate payment terms before proceeding. Ideal for probing relay-hosted APIs on relai.fi that require USDC micropayments.
Side effects
- Malformed request body returns 400 Bad Request
- Network timeout if relay is unavailable
- Unexpected 200 instead of 402 if payment gating is misconfigured
- Payment token already consumed returns 402 with different challenge
- Client does not support x402 protocol, cannot parse challenge
Tags
x402
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