# Finix Core API Collection This Postman Collection includes the following collections: - [Getting Started Guide](https://developers.finixpayments.com/#getting-started) - [Onboard a merchant](https://developers.finixpayments.com/#step-1-create-an-identity-for-a-merchant) - [Create a card sale](https://developers.finixpayments.com/#step-4-create-an-identity-for-a-buyer) - [Subscription Billing](https://finix.admin.payments-docs.com/#subscription-billing) Use the __Finix Core API Environment__ to set the appropriate credentials. If you are facing any issues with the credentials, you can reach out to your Sales Engineer or use the credentials available [here](https://developers.finixpayments.com/#authentication). For Subscription Billing, you will require __ROLE_PLATFORM__ credentials. You can use the ones that are available in the Environment Variables file or use the credentials provided in the Curl command for Subscription Billing [here](https://finix.admin.payments-docs.com/#subscription-billing).

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