Payment protocols

MPP Stripe

The MPP challenge and credential flow, charged to card-backed payment methods. Useful when your buyers or agents pay with cards rather than crypto.

URL segment
mpp-stripe
Payment header
Authorization
Availability
Paid plans
Best for
Accepting MPP payments backed by cards instead of wallet balances.

Endpoint URL

https://agent-proxy.alchemy.com/v1/mpp-stripe/{projectId}/{endpointSlug}/{path}

Setup

  1. Enable MPP Stripe in the dashboard.
  2. Enter your Stripe secret key. A saved key stays hidden and can be left unchanged.
  3. Set the price per request in USD, such as 0.05.
  4. Optionally set a network ID if your integration uses one.
  5. Save and send an unpaid request to confirm the MPP challenge is returned.

Request flow

  1. The client calls the mpp-stripe URL without a payment credential.
  2. AgentPay returns a 402 challenge for a card payment.
  3. The client completes the challenge and retries with the Authorization header.
  4. AgentPay verifies and charges the credential, then forwards the request.

Notes

  • Store your Stripe key carefully and rotate it if access changes.
  • Works for human-in-the-loop clients as well as agents that hold card-backed credentials.