The below steps and set of credentials allow you to test linking a merchant account, syncing a cart, checking out a cart, and retrieving post-purchase transaction data.
Please note that you cannot perform multiple operations on the same merchant account simultaneously, so you must wait to receive a webhook event to confirm the operation is complete before proceeding with any additional requests.

For testing purposes, you can also use a different external_user_id when beginning a new round of testing to ensure you link a new merchant account.
1

Create a session

Call Create Session with type: link and a dummy external_user_id that you will use in subsequent API requests.
2

Invoke the SDK

Use the session to invoke the SDK. In KnotConfiguration, pass the session in sessionId and a merchantId for a merchant of your choosing. In your implementation, merchants are retrieved via List Merchants by passing type: shopping. For testing purposes, you can likely hardcode a single merchantId for a merchant.
3

Login to a merchant account

Once you’ve invoked the SDK, you can link a merchant account by logging in to the merchant using the credentials user_good/ pass_good. Once your merchant account is successfully linked, you will receive the AUTHENTICATED webhook event.
4

Add a product to the cart

Upon receiving the AUTHENTICATED webhook event, make a request to Sync Cart with the same external_user_id & merchant_id as you used in prior steps and a dummy products.external_id. Optionally, pass a delivery_location as well in the request.Optionally, send simulate: failed in the request to simulate receiving a SYNC_CART_FAILED webhook event.
5

Receive SYNC_CART_SUCCEEDED webhook

Receive the SYNC_CART_SUCCEEDED webhook event.Optionally, make another request to Sync Cart with the fullfillment.id of an alternative fulfillment option received in the webhook.
6

Checkout

Upon receiving the SYNC_CART_SUCCEEDED webhook, make a request to Checkout with the same external_user_id & merchant_id as you used in prior steps and optionally a payment_method object.Optionally, send simulate: failed in the request to simulate receiving a CHECKOUT_FAILED webhook event.
7

Receive CHECKOUT_SUCCEEDED webhook

Receive the CHECKOUT_SUCCEEDED webhook event.
8

Retrieve the transaction information

Extract the transactions.id value(s) from the CHECKOUT_SUCCEEDED webhook event and make a request to Get Transaction By ID for each transaction to retrieve the transaction information.Most merchants generate a single transaction for a purchase, but some generate multiple.