Welcome to the ACH Technical Guides. This documentation serves as a centralized reference for understanding and integrating with our API. These guides are designed to provide:
  • A high-level overview of each API endpoint
  • Request and response modeling to help guide implementation
  • Best practices and common patterns for working with our platform

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Goals of This Documentation

  • Clarity – Reduce guesswork by providing exact input/output examples
  • Consistency – Encourage standardized usage of endpoints across teams
  • Speed – Enable quicker implementation and onboarding for developers

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Testing

To test in GrailPay’s sandbox environment you will need to connect to our Sandbox API Environment. You can reach our sandbox environment at: https://api-sandbox.grailpay.com When creating people, businesses, or merchants in the sandbox, you can simulate bank accounts using:
  • A random 12-digit account number
  • One of the following test routing numbers:
    • 226078036
    • 221979363
This setup allows you to test your full integration flow — including onboarding, transactions, and ACH processing — without interacting with real financial institutions.
These guides are a work in progress. If you don’t see what you need, please reach out to our support team for assistance.