Finix API Reference

The Finix API is resource oriented, relying heavily on common REST principles. Our API uses JSON encoded requests and responses.

You will receive separate Sandbox and Live accounts, as well as corresponding API credentials to access the Finix API.

Authentication

To communicate with the Finix API, you must authenticate your requests via HTTP Basic Authentication with a username:password combination, which you can get from your Finix Dashboard. If you do not have a Dashboard yet, you can test our APIs with the Sandbox credentials below.

Request Format

curl "https://finix.sandbox-payments-api.com/" \
    -H "Content-Type: application/json" \
    -H "Finix-Version: 2022-02-01" \
    -u USsRhsHYZGBPnQw8CByJyEQW:8a14c2f9-d94b-4c72-8f5c-a62908e5b30e

Environments

Finix provides two environments with distinct base URLs to make API requests.

1. A Sandbox environment for developing and testing your integration.
2. A Live environment for processing payments.

These environments are entirely separate and do not share API Credentials.

Live Access

To get access to the Live environment, please reach out to your Finix point-of-contact.

HTTP Codes and Errors

Finix uses HTTP codes to communicate whether requests succeeded or failed. Requests to Finix's API return responses within less than one second.

However, communications between card networks and processors can increase response latency. Additionally, response latency for card-present devices can be higher depending on how quickly buyers complete the transaction on payment terminals.

Due of this, requests to the Finix API have a maximum timeout of 5 minutes.

For more details, see Error Codes.

Idempotent Requests

The Authorization and Transfer resources both have an idempotency_id field. Use this field to ensure the API Request is performed only once.

Why is this important? We've all experienced a checkout page that hangs on a request or payment, and feared that if we refresh or submit the payment again, we'd be charged twice.

Finix removes this ambiguity with the idempotency_id. You or the user can generate a unique ID that can be included as an idempotency_id with the usual request payload. If anyone attempts a request with the same idempotency_id, the response will raise an exception.

By passing an idempotency_id in the body of your requests, you can be rest assured that when you create an Authorization or Transfer, the user will be protected from potential network issues.

idempotency_id is available on the following three endpoints:

• /transfers
• /authorizations
• /transfers/{id}/reversals

idempotency_id scope

idempotency_id checks against previous requests made on the same endpoint.

Query Parameters

Every Finix resource (e.g., Authorizations, Transfers) can be listed and reviewed using GET requests. Additionally, every endpoint has query parameters available to help you filter the resources that are returned.

See the following example of how to query the Transfers endpoint for Transfer resources with type: DEBIT.

Query Parameter Example

curl "https://finix.sandbox-payments-api.com/transfers?type=DEBIT" \
    -H "Finix-Version: 2022-02-01" \
    -u USsRhsHYZGBPnQw8CByJyEQW:8a14c2f9-d94b-4c72-8f5c-a62908e5b30e

Tags

Many Finix resources (e.g., Authorization, Transfer) let you include tags to add key-value metadata to your Finix API resources. For example, when creating a Transfer, you might include customerId: Customer123 to tag the Transfer with your internal customer ID. You can update tags as many times as needed, as well as filter resources by tags.

Tags Example

{
    ...,
    "tags": {
        "card-type": "business card",
        "order_number": "H-1257",
        "customer_order_reference": "order1234",
        "item_type": "hardware",
        "vendor": "finix"
    }
}

The tags object accepts up to 50 key: value pairs to annotate resources with custom metadata.

• Maximum character length for individual keys is 40.
• Maximum character length for individual values is 500.

Special Characters

Finix does not allow special characters on tags (e.g., \, ,, ", ')

Versioning

As Finix improves our products and features, we will make changes to our APIs. When breaking changes are made to Finix's API, we may release a new dated API version.

The API version your requests use controls how API responses and webhooks behave (for example, the values you see in responses and the parameters you can include in requests). For more information, see Versioning.

Postman Collection

Finix has a Postman collection to help in your development. You can fork it using the button below.

Overview

URL https://finix.com

Finix support@finix.com

Languages

cURL

Servers

Sandbox server

https://finix.sandbox-payments-api.com