August 3, 2022

Reminder of Upcoming Breaking Changes

Following up on our March 18 email, we would like to remind users of a set of upcoming breaking changes to the Lithic API. These changes will make interacting with our API more intuitive and consistent.

Please take a moment to read through the changes and update your integrations accordingly. This Guide to Lithic API Changes is available for reference, in addition to the description of the changes below.

Change #1: Transaction Schema Update

What's Changing:

Events.amount — the amount field contained within the Events array, within the Transaction schema — will become a signed field in both the transactions endpoints and in transactions webhooks. Most notably, debits will appear as positive amounts and credits will appear as negative amounts.

Deploy Dates:

  • Sandbox Environment: Effective August 30, 2022 at 17:00 UTC
  • Production Environment: Effective September 27, 2022 at 17:00 UTC

Impacted Endpoints and Messages:

  • Sandbox and Production:
    • GET /transactions response schema
    • GET /transactions/{transaction_token} response schema
    • ASA messages
  • Sandbox — webhook payloads generated from these endpoints:
    • POST /simulate/authorize
    • POST /simulate/clearing
    • POST /simulate/return
    • POST /simulate/void

Action Needed:

Debit and credit values were previously all positive, so you will need to be ready to accept and interpret negative amounts. To defend against this, users can wrap an absolute value function around events.amount until they are ready to handle negative amounts in the schema.

Change #2: Simulating transactions

What’s Changing:

Simulated transactions that are declined will return a 200 response to indicate a “successful” decline. Previously, if a simulated transaction (created via the POST /simulate/authorize endpoint) was declined, a 422 response code would be returned.

Deploy Date:

  • Sandbox Environment: Effective September 27, 2022 at 17:00 UTC
  • Production Environment: N/A as this is a Sandbox-only change

Impacted Endpoints and Messages:

  • POST /simulate/authorize

Action Needed:

Update any integrations that expect a 422 response code to expect a 200 response code.


We appreciate your attention to these changes. If you have any questions, please contact our support team.