Quick Start
Make your first API call in minutes with step-by-step guidance
Authentication
Set up OAuth2 credentials and learn how to obtain access tokens
Guides
Step-by-step walkthroughs for onboarding users and initiating payments
API Reference
Full reference for every endpoint, parameter, and response field
How Diameter Works
Diameter connects your platform to partner banks through a unified API. Once you obtain OAuth2 credentials, you can start onboarding end users and processing payments in a few steps:1
Obtain credentials
Contact support@diameterpay.com to receive your
client_id and client_secret for sandbox or production.2
Get an access token
Use the OAuth2 Client Credentials flow to exchange your credentials for a short-lived Bearer token.
3
Onboard an end user
Create an individual or organization end user. Diameter handles compliance checks and bank onboarding automatically.
4
Initiate a payment
Once the end user is active and has a virtual account, create a counterparty and initiate a domestic wire, international wire, or internal transfer.
Explore by Topic
End Users
Manage individuals and organizations on the platform
Payments
Domestic wires, international wires, and internal transfers
Webhooks
Real-time event notifications for payments and user lifecycle
Accounts
Virtual accounts automatically created during onboarding
Counterparties
Register payment recipients to speed up wire processing
Sandbox Testing
Simulate inbound wires and test your integration end-to-end
Environments
Diameter provides separate sandbox and production environments. All sandbox operations are isolated and use test data.Contact support@diameterpay.com to request sandbox or production credentials.