Preview Leffel Consulting Payments is in active development and migrating to Finix — the API isn't publicly live yet, and some examples still reflect the outgoing build. Request early access →

Guides

Testing

How to test your integration end to end before going live — test cards, ACH, and the coming sandbox console.

Test the full flow — onboarding, payment, webhook, fulfillment — before you take real money.

Test mode

In test mode, no real funds move and you use test credentials. You can exercise every endpoint exactly as in production.

Test cards

Use standard processor test cards in the Payment Element:

Card numberBehavior
4242 4242 4242 4242Succeeds.
4000 0000 0000 9995Declined (insufficient funds).
4000 0025 0000 3155Requires 3-D Secure authentication.

Use any future expiry, any CVC, and any postal code.

Testing ACH

ACH test payments move through processing → succeeded so you can verify your asynchronous handling. Make sure you only fulfill on succeeded, never on processing.

Testing webhooks

Point your callback URL at a tunnel (or a test endpoint) and confirm you:

  1. Verify the LC-Signature header.
  2. Deduplicate on LC-Event-Id.
  3. Respond 2xx quickly.

Interactive console — coming soon

An in-docs Try it console (log in, use a sandbox key, and call endpoints right from these pages) is on the way. For now, test with cURL or your server code against test credentials. Ask us for early access.

Go-live checklist

  • Onboarding reaches enabled for a real merchant.
  • A live payment reaches succeeded and your webhook fulfills the order.
  • Refunds and (if used) manual capture behave as expected.
  • Your callback endpoint verifies signatures and is idempotent.