Fondy — card payments for OpenCart 2.3, 3.x and 4.x

Fondy for OpenCart is a payment module that connects Fondy (Flitt) acquiring to OpenCart 3.x and 4.x. The customer pays by Visa or Mastercard on a secure Fondy page, and everything after that is automatic: Fondy sends a signed server callback, the extension verifies the SHA1 signature and sets the order to the right status itself. You don’t have to reconcile the Fondy account against your order list every morning.

The basic version is free. Download it from the official OpenCart marketplace: opencart.com/…/extension_id=48712. The Pro licence adds a payment log with status reconciliation, two-step payment (preauth hold + capture) and partial and repeat refunds from the admin.

What the admin gets

How it works, step by step

1. At checkout, the customer chooses “Card payment (Fondy)” and confirms the order.
2. The module builds a signed request and redirects the customer to the Fondy payment page.
3. After payment, Fondy sends a server callback — the module checks the SHA1 signature and moves the order to the configured status.
4. When the customer returns to the shop, the transaction status is additionally verified via the Fondy API, so the order is only closed as paid on a genuine payment.
5. With Pro: in two-step mode, funds are first held and captured when you move the order to a completed status; refunds are made from the payment log without logging into the Fondy account.

How much it costs

1,490 UAH — one-off purchase. The licence is perpetual: you pay once, updates and technical support are included in the price. One key covers one domain and its subdomains.

Moving the shop to another domain — deactivate the licence on the old one and activate it on the new one yourself in the account.

The licence is perpetual — nothing expires or switches off. One key — one domain; moving the shop, deactivate the licence on the old domain and activate it on the new one yourself.

One key — one domain. Moving the shop, deactivate the licence on the old domain and activate it on the new one yourself, without contacting support.

Trial first, then payment. A fresh install is the free version: Pro doesn’t switch itself on, and nothing expires after a week. When you want to see Pro — click “Try Pro” in the module’s settings, enter your email and get a 7-day key (also sent by email). So you get to check the payment log, preauth/capture and refunds on your own shop before you buy — that’s exactly why refunds after purchase aren’t offered.

Technical requirements

• OpenCart 4.0.2 – 4.1.x (native build) or a separate build for OpenCart 3.0.2 – 3.0.5.0
• PHP 8.0+
• Merchant ID and secret key from the Fondy (Flitt) account; not needed for test mode

Under the hood

• A native build for OpenCart 4.x — the standard extension structure (admin/catalog/system), installed via the built-in Installer; a separate port for OpenCart 3.0.x.
• The secret key is stored encrypted in the database — a database dump doesn’t expose the key in the clear.
• Two lines of defence for payment verification: the server callback’s SHA1 signature plus a status reconciliation via the Fondy API on the customer’s return.
• Works out of the box on the public test merchant — the full payment cycle can be tested before signing an agreement with Fondy.

How to install

1. Upload fondy.ocmod.zip via “Extensions → Installer” in your admin. For OpenCart 3.0.x use the fondy-oc3.ocmod.zip build.
2. Open “Extensions → Extensions → Payments”, find Fondy, click “Install”, then “Edit”.
3. Leave test mode on for testing — the module works right away on the public Fondy test merchant.
4. For live mode, enter the Merchant ID and secret key from the Fondy account, choose the order statuses, enable the module.
5. For Pro, enter the licence key from the email after payment → “Activate licence”.

Version history

1.0.8 — 13 August 2026

Fixed multi-store setups: the payment description and the Fondy account used to receive the main store’s domain, because it was taken from a constant shared across the whole install — it’s now the domain of the store the order was actually placed in. The OpenCart 3.x and 2.3 builds were bumped to 1.1.1 with the same fix.

1.0.7 — 2 August 2026

Fixed underpayment: a callback for an amount lower than the order is no longer stored as a successful payment — the order stays unpaid with an underpayment note, and the next callback for the full amount correctly moves it to “Paid”. The licence now survives catcode.com.ua being unreachable: a network error is no longer treated as an “invalid key” response, so Pro doesn’t switch off during an outage (the 14-day grace period finally works).

1.0.6 — 1 August 2026

Admin refunds no longer fail with an error (a missing catalog model was being loaded), partial refunds are now tracked cumulatively, and API errors are visible right in the log. Removed a duplicate “payment received” entry in the order history. The trial only starts on your click, and a fresh install is a plain free version.

1.0.2 — 23 July 2026

Fixed a conflict at checkout on OpenCart 4.0.2.x: the geo-zone check no longer loads a catalog model missing in this version and no longer blocks choosing a payment or shipping method.

1.0.0 — July 2026

First public release: card payment via the Fondy page, a signed server callback with SHA1 verification, status reconciliation on return, a test merchant out of the box, builds for OpenCart 4.0.2 – 4.1.x and 3.0.2 – 3.0.5.0. Pro: payment log, two-step payment (preauth/capture), full and partial refunds.