Merchant direct integration

This is a direct full integration to FlexCharge

Data flow

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Step 1. Create a Sandbox account

If you don't already have a Sandbox account with the required credentials to start using our APIs, you can request one at [email protected]

Step 2. Authentication

All API requests are made over HTTPS. Requests without authentication will fail.

How to authenticate.

Step 3. Embed SenseJS

SenseJS is a JavaScript library for the browser that is used as a device fingerprint and to track simple page events like loading, pasting, resizing.

Your unique-key is your Mid ID, accessible in your Sandbox on the section Developers > SenseJS

How to embed SenseJS.

Step 4. Invoke SenseJS

Sense JS needs to be invoked with your order id for all of your payment transactions, as soon as possible in the payment flow, before you receive the response for your payment transaction from the PSP.

This allows to match the Sense JS data to a specific order.

How to invoke SenseJS.

Step 5. Embed UI Widget

The UI Widget manages all interactions with the consumer.

How to embed UI Widget.

Step 6. Transmit API

The Transmit API needs to receive a copy of each processed payment transaction (authorized or declined) related to any of your orders. The data sent the Transmit API is used to build customer profiles and DOES NOT activate the FlexCharge service.

Once transmitted, our API will respond with a transaction key.
This key can be used to update the order object, for example with its outcome.

How to implement /transmit.

Step 7. Evaluate API

PCI data needs to be tokenized for this step.

Payment Method tokenization

Your tokenization key can be found on the Developers > Tokenization section on the merchant portal.

How to /tokenize.


On declined/failed transactions, you will have to invoke FlexCharge's Evaluate API.

This ACTIVATES the FlexCharge service.

How to implement /evaluate

Step 8. Invoke UI Widget

Eligible transactions generate a response which needs to be sent to the InitUI function in order to initiate the user interaction required to complete the consumer flow.

How to invoke UI Widget

Step 9. Receive outcome

Receive updates on the transactions that were rescued by FlexCharge through a Webhook, and/or via the Outcome API.


Subscribe to webhooks for real-time updates and event-driven interactions.

How to manage webhooks

Outcome API

Invoke /outcome to retrieve information about orders that have been submitted through /evaluate.

The API response will make it easier to keep track of the order history and monitor the status of each order. The Outcome API endpoint can be integrated into your own application or used as a standalone tool to retrieve order information and track the progress of your orders.

How to implement /outcome.

Your integration is now done

You can now test transactions in your test environment.

Don't have a test environment? Ask us and we'll set up one for you.