CDON Marketplace Connector for OpenCart

Overview

Integrates OpenCart 4.1 with the CDON marketplace in Sweden, Denmark, Finland and Norway. Your products become CDON articles with a price per market in SEK, DKK, EUR or NOK, stock and prices stay in sync, and CDON orders arrive as real OpenCart orders that you fulfil with a tracking number from OpenCart. It uses the new CDON merchant API (the platform that replaced CDON Connect in 2026) with your own CDON seller account. OpenCart 4, events only, no OCMOD, no core file changed.

What it does

• Articles per market. Lists mapped products on CDON with titles and descriptions in every CDON language your store has (CDON translates the rest), images, brand, GTIN, properties, condition, delivery type and the GPSR manufacturer block.
• Four markets, four currencies. Tick SE, DK, FI and NO; prices are converted from your default currency with your own rate or the OpenCart currency table, then your markup and price endings run in each market currency. Delivery time per market.
• Net prices handled. OpenCart stores prices without tax. Products with a tax class get the market VAT (25 / 25 / 25.5 / 25 %, editable) added before they are sent, because CDON prices include VAT: VAT-exclusive prices are never listed too cheap.
• Stock and price sync. A sale, a cancellation or an edit in OpenCart reaches CDON with the next sync (every 15 minutes by default), with a stock buffer and minimum.
• Orders. New CDON orders become OpenCart orders once (never twice, also with overlapping cron runs), with the buyer address, the market, the CDON order number, the amount converted to your default currency (the order shows the CDON currency when your store has it) and the fulfilment deadline. VAT-inclusive and VAT-exclusive order amounts are told apart per order. Optional acceptance at CDON.
• Fulfilment with tracking. When the order reaches Shipped (or Complete), the CDON order is fulfilled with the tracking number from the order history ("Tracking: ABC123 Carrier: PostNord"). With "Wait for a tracking number", orders without one wait at the end of the line and never hold up the others.
• States only move forward. A late or stale answer from CDON never reopens a cancelled order or moves a completed one back; an order you moved yourself keeps your status (a cancellation at CDON always follows).
• Per item results. CDON processes articles in batches; the extension reads the result per article and market and shows refusals (for example "DK: permission_denied") on the Listings page.
• Safe operation. Token stored encrypted, sandbox and production, rate limits respected (the job waits for the CDON reset window), a refused login pauses the account, job queue with retries, log with CSV export, data kept on uninstall.

What it does not do

• Returns: the CDON merchant API has no return endpoints; returns stay in the CDON merchant portal.
• Product variations are listed as separate articles (no CDON product grouping).
• OpenCart 3.0 is not supported (OpenCart 4.1.0.0 to 4.1.x).

Compatibility

• OpenCart 4.1.0.0 to 4.1.x (tested on 4.1.0.4), PHP 8.1 to 8.3 as OpenCart 4.1 requires.
• A CDON seller account with API access (merchant ID and API token from CDON).
• The OpenCart cron, or a secret web address called every 5 to 15 minutes.

Next steps

CDON is a trademark of its owner. This extension integrates with the CDON merchant API; it is not made, endorsed or certified by CDON.

Installation and setup

Requirements

• OpenCart 4.1.0.0 or later 4.1.x, administrator access.
• A CDON seller account for the markets you sell in (Sweden, Denmark, Finland, Norway) and API access to the CDON merchant API.
• Your merchant ID and API token. CDON issues them; ask CDON merchant support for API credentials and, for testing, for sandbox credentials (CDON gives them on request). Sandbox and production credentials are separate; CDON and Fyndiq credentials are not interchangeable.
• The OpenCart cron or a cron job of your host (step 9).

Install the extension

1. Download kv_cdon.ocmod.zip from your Kavio Labs or opencart.com account.
2. Extensions > Installer, upload the file, then click Install (green +) in the list of installed packages.
3. Extensions > Extensions, choose Modules, find CDON Marketplace Connector and click Install, then Edit.
4. Enter your licence key and click Check now. Without a key the extension works for 14 days; the admin pages always stay open.

Connect CDON

1. Open CDON in the admin menu (or the gear on the settings page) > Connection. Choose Sandbox, enter the sandbox merchant ID and API token and click Save and test. "Connected" confirms that CDON accepted them.
2. Open Rules. Tick your markets, check the exchange rate of each market currency (enter your own rate, or add the currency under System > Localisation > Currencies; it may stay disabled for the storefront), check the VAT per market, set the delivery time per market, your markup and price endings, the default brand and the manufacturer (GPSR) details. Save.
3. Open Categories, search the CDON category tree and map your OpenCart categories (optionally with a markup and a brand). Optionally map properties (colour, size, material, weight ...) on Attributes.
4. On Listings, add products (one by one or a whole category) and click Sync now. After a few minutes the Listings page shows each article as live, or the reason CDON gave per market.
5. Make sure the queue runs: the extension adds the OpenCart cron task "CDON: sync queue", due every minute (System > Maintenance > Cron Jobs; OpenCart's cron needs php <store>/cron.php in your host's crontab, every minute). Without it, call the secret web address shown on the Jobs page every 5 to 15 minutes.
6. Test an order with the CDON sandbox ("Create a test order" call, sandbox only); the next sync imports it. Set the OpenCart order to Shipped with a history comment such as Tracking: 00370712345678901234 Carrier: PostNord and check that the CDON order is fulfilled.
7. Go live: switch the Connection page to Production, enter the production merchant ID and token and click Save and test.

Updating and uninstalling

OpenCart 4 updates an extension by uninstalling and installing it again, so uninstall keeps your data: the links between CDON orders and OpenCart orders and between products and CDON articles, the connection, the rules, the settings and the licence state. A reinstall or an update continues where it stopped and never imports an order or creates an article twice. The imported OpenCart orders always stay. To remove everything for good, drop the kv_cdon_* tables after uninstalling.

Configuration

Extension settings (Extensions > Modules > CDON Marketplace Connector > Edit)

Connection page

If CDON refuses the credentials (HTTP 401) the account is paused: nothing is sent to CDON until you save the credentials again or a connection test passes. This avoids repeated failed logins.

Rules page

Net and gross prices

OpenCart stores every product price without tax; the tax class adds it at checkout. CDON prices always include VAT. The extension therefore adds the VAT of the market to every product that has a tax class with a percentage rate (for example "Taxable Goods"). A product without a tax class is sent at its price as it is. Example: 100.00 EUR net, rate 11.5, Sweden 25 % = 1437.50 SEK on CDON.

Tracking numbers

OpenCart has no shipment records. When an imported order reaches the status mapped to Fulfilled (default: Shipped), also when you move it on to Complete before the next sync or set it straight to Complete, the extension reads the newest history comments of the order for Tracking: <number> (also "Tracking number", "Tracking no.") and optionally Carrier: <name>, and sends them to CDON. The number must contain a digit and follow "Tracking:" (or "Tracking number" / "Tracking no."), so a comment such as "Tracking number will follow" never fulfils an order. With Wait for a tracking number on, the order waits until such a comment exists; waiting orders go to the end of the line, so they never hold up the others.

Categories and Attributes

• Categories: search the CDON category tree (by name) and map it to an OpenCart category, optionally with a markup and a brand. "Refresh reference data" reloads the tree.
• Attributes: CDON properties are the same for every category: free text (colour, size, material ...; up to 36 characters), pre-defined lists (size S/M/L, colour, connection type ...) and numbers (weight, volume, sizes). Map an OpenCart attribute, the manufacturer, model or SKU, or a fixed value.

Cron

The extension registers the OpenCart cron task "CDON: sync queue", due every minute (runs with php <store>/cron.php in your crontab, every minute); the queue itself starts the order import, the sync and the fulfilment every "Sync interval" minutes (default 15). Alternatively call the secret web address shown on the Jobs page every 5 to 15 minutes. Overlapping runs are prevented.

Usage

Listings

CDON > Listings shows every mapped product: its SKU and CDON article id, the state (not listed yet, waiting for CDON, live on CDON), what is synchronised (stock, price), the last values pushed and CDON's last answer.

• Add mapping: a product id and optionally its SKU on CDON (default: the product SKU or model). Tick "Already on CDON" for articles you created on CDON before: they are linked, not created again.
• Add all products of this category: maps every product of an OpenCart category.
• Sync now: queues an order import, a product sync and the fulfilment push at once.
• A product that cannot be listed (no image, title shorter than 5 characters, no rate for any market ...) shows the reason and is not sent.
• CDON checks each article per market. "Partly listed: DK: permission_denied" means the article is live in the other markets and your account may not sell in Denmark.

Product edits in OpenCart (name, description, images, status) are sent as an article update, and so are changes of the markets, delivery times and article data on the Rules page; stock and prices go out with every sync.

Orders

CDON > Orders lists the imported CDON orders with the CDON order number and id, the CDON state (new, accepted, fulfilled, cancelled), the OpenCart order and what was sent back.

• Each CDON order (one article with a quantity) becomes one OpenCart order with a guest customer (CDON sends no e-mail address; a placeholder channel-<number>@channel.invalid is used and no e-mail is sent). The comment holds the CDON order number, the market, the total in the market currency with VAT and the fulfilment deadline. The order page has a CDON panel.
• Fulfilment: set the order to Shipped (or Complete) with a history comment Tracking: <number> Carrier: <name>. The next sync fulfils the CDON order with that tracking. With "Wait for a tracking number" off, Shipped alone fulfils the order; with it on, the order shows "Waiting for a tracking number" until the comment is there. A refused fulfilment (for example past the deadline) shows Send fulfilment again.
• Cancel at CDON: for a new order you cannot ship (for example out of stock). CDON cancels it and refunds the customer; the OpenCart order gets the status mapped to "cancelled" and the stock comes back. An accepted order can no longer be cancelled through the API.
• Retry: a CDON order that could not be imported (for example an SKU that is not mapped) shows the reason; fix it and press Retry.
• An order cancelled at CDON is followed in OpenCart within about 30 minutes. Orders you moved on yourself keep your status.

Log and Jobs

Log lists every call and event (filters, CSV export); secrets are masked. Jobs shows the queue (waiting, running, waiting to retry, done, gave up) with Retry and Remove, the cron command and the secret web address.

CDON Marketplace Connector: developer notes

CDON is a trademark of its owner. This extension integrates with the CDON merchant API; it is not made, endorsed or certified by CDON.

OpenCart 4.1 port of the CS-Cart add-on kv_cdon 1.0.0 (same API client, mapper, driver and hub logic, with every fix of its release audit). Extension code kv_cdon (package kv_cdon.ocmod.zip, licence id kv_oc_cdon), PHP namespace KavioLabs\KvCdon in extension/kv_cdon/system/library/ (autoloaded by bootstrap.php). Built on the Kavio Marketplace Hub (Hub\*, channel independent) with one channel driver: Client\Api (HTTP), Drivers\CDON\Mapper (pure translation, unit tested), Drivers\CDON\Driver (Hub\DriverInterface), plus Markets (markets, currencies, exchange rates). OpenCart glue: Store (products, orders, statuses, tracking), compat.php (small db_* helpers over the OpenCart DB object), Keep (data kept across uninstall + install).

Sources (read 2026-11-08)

Only the documentation of the NEW CDON merchant API is used. The legacy CDON Connect API (and the old ma-docs pages on Read the Docs) closed in Q1 2026 and is not called anywhere.

Every page is also available as Markdown with its OpenAPI 3.1 block (<page>.md); the request and response examples of those blocks are the unit test samples in tests/samples/ (copied unchanged).

Hosts, authentication, format

Test override: the setting module_kv_cdon_base_url (e.g. http://127.0.0.1:11893/api) replaces the base URL (mock server, tests/mock-server/server.js). tests/e2e.js refuses to run unless it points at 127.0.0.1 / localhost.

Endpoints used

GET /v1/articles/sku/{sku} is implemented (Api::articleBySku) but not needed by the sync: a second create of an existing SKU is answered with sku_already_exists (status error_code), which the extension adopts (below).

Not used: v1 single-article write endpoints (deprecated, Fyndiq only), shipping configurations, payment reports, settlement notes, receipts, delete_article (an unmapped product stays on CDON; set it to 0 stock or delete it in the CDON portal).

Article mapping (Mapper::article, Mapper::content)

Variations (parent_sku, variational_properties) are not sent: each OpenCart product is its own article (options are not split).

Never twice

• Articles. One bulk create per run. When the answer is lost (timeout, 5xx) the row stays "not listed" and the next run sends the create again; CDON refuses the duplicate SKU (sku_already_exists, at once in failed or later in the batch status), and the extension treats that as "already there": the row is linked and its content goes out once as update_article. Unit and e2e tested (504 after save -> one article).
• Orders. The order map row is written BEFORE the order is created (INSERT IGNORE, unique key company + CDON order id), the import of one CDON order runs under GET_LOCK (Idempotency::lock), a placing_at marker and a comment marker [kv_cdon:<account>:<order id>] (written in the same INSERT that creates the order) let a later run adopt an order that an interrupted run created. Store::createOrder removes a half-written order before it rethrows. Parallel cron runs import once (e2e: three cron calls at once).
• Fulfilment / acceptance. Rows are claimed with UPDATE ... WHERE state = old (N -> R); a repeat answered 403 "Order row already has fulfilled as state" counts as done. Refusals of this request (400/403/404/409/422, e.g. past the deadline or cancelled) are final ("E", with a "Send fulfilment again" button); network errors, 429 and 5xx retry.

Orders

• One CDON order = one SKU with a quantity (Introduction, "The order lifecycle"); the extension creates one OpenCart order per CDON order directly in the order tables (Store::createOrder: no cart, no checkout events, no e-mail), payment and shipping method "CDON". customer_order_id (shown as the CDON order number) is kept in the comment.
• price / total_price = the price of the whole quantity; the line price is amount / quantity. Whether amount includes VAT is decided per order (Mapper::gross, see Unverified 1). Amounts are converted from the market currency to the default currency with the same rate as the article prices (Markets::rate: own rate on the Rules page, else the OpenCart currency value, also of a disabled currency). The order carries the CDON currency (when the store has it) with that rate as currency_value, so OpenCart shows the amounts as sold; otherwise the default currency.
• Delivery country = the market code (shipping_address.country is a name such as "Sweden"). B2B orders have no first / last name: the full_name is used as company and first name. The API has no customer e-mail: a placeholder channel-<number>@channel.invalid is used.
• New orders are read with state=CREATED and state=ACCEPTED; the order map skips known ones. CDON states only move forward (CREATED < ACCEPTED < FULFILLED / NOT_FULFILLED, terminal): a stale read right after an asynchronous accept / cancel (202) is ignored. An OpenCart order follows a CDON state only while its status still equals the status mapped for the previous state (the merchant has not moved it); a cancellation at CDON always follows. Store::setStatus writes the history and moves stock like OpenCart (subtract when entering a processing / complete status, restore when leaving).
• Fulfilment: an imported order at the status mapped to "fulfilled" (default Shipped) is sent; the tracking number and carrier come from the newest history comments (Tracking: <number>, Carrier: <name>, Store::parseTracking). With "Wait for a tracking number" the query only takes orders with a "track" comment and an order still without a parsable number is moved to the end (push_waiting_at), so waiting orders never block the queue (unit: 50 waiting rows rotated, none claimed). Rows are claimed N -> R (push_claimed_at); a claim left by a process that died during the call is released after 15 minutes (a repeat is answered "already fulfilled" = done).
• Order date = created_at (UTC) shown in the shop time zone; the comment shows date and "fulfil by" (fulfillment_deadline).
• States: CREATED -> new, ACCEPTED -> accepted, FULFILLED -> fulfilled, NOT_FULFILLED -> cancelled (OpenCart statuses on the Rules page; defaults Processing, Processing, Shipped, Canceled). Imported orders still CREATED / ACCEPTED are read back every 30 minutes.
• Returns: the CDON merchant API has no return or claim endpoints (documentation index, 2026-11-08); returns stay in the CDON portal.

OpenCart integration

• Events (no OCMOD): admin/view/common/column_left/before (menu), admin/view/sale/order_info/after (CDON panel on the order page), admin/model/catalog/product.editProduct/after (content and stock -> next sync), admin/model/catalog/product.deleteProduct/after (mapping removed), catalog/model/checkout/order.addHistory/after (stock of ordered products -> next sync), admin/controller/common/header/before (licence check). Nothing is printed on storefront pages.
• Cron: OpenCart cron task extension/kv_cdon/channel/cdon.cron (OpenCart passes 5 arguments) or the secret web address (func_num_args() < 4 -> the key must match the stored cron key, compared with hash_equals).
• Licence: kv_oc_cdon, 14-day trial; when the licence is not valid no new sync work starts; the admin pages are never blocked.
• Data: tables kv_cdon_accounts, _log, _jobs, _product_map, _order_map, _options, _category_map, _attr_map, _cache, _batches. Uninstall keeps all of them (OpenCart 4 updates are uninstall + install; the maps are the guard against duplicate orders and articles); settings and licence state are restored on install (Keep).

Bulk calls refused as a whole (400 / 422) are split in halves down to single articles / SKUs, so one bad article cannot stop the others; the product sync runs its phases (batch results, stock and prices, creates, content updates) independently. Batch statuses are read one batch per call (the endpoint takes a list; fewer calls are a possible optimisation).

Tests

• php81 tests/unit.php / php83 tests/unit.php: CDON samples from the documentation, mapper, driver, HTTP (Basic auth, 403 texts, 429 waits, 401 pause), hub rules, OpenCart glue (language codes, currency value, net prices, fulfilment queue rotation, forward-only states, order creation with the CDON rate, marker adoption) and tests/defects.php (recurring defect checklist).
• node tests/e2e.js: full flow on an OpenCart 4.1 pool store against the mock (59 checks).

Unverified (the documentation does not say, or contradicts itself)

1. Whether order price.amount includes VAT. The two documented examples disagree (299 with VAT 59.80 at 25 % = VAT included; 23.20 with VAT 5.80 at 25 % = VAT excluded). The extension decides per order (Mapper::gross): vat_amount = amount x rate -> net, VAT is added; otherwise the amount is taken as VAT included. Check one real sandbox order.
2. Order vat_rate is a fraction (0.25) in the order examples and a percent (25) in article prices; the extension accepts both.
3. How long batch statuses are kept: not documented; the extension gives up after 24 hours and sends the create again (adopted if it exists).
4. The 401 error body shape: not documented; any 401 pauses the account.
5. Whether the immediate failed text for a duplicate SKU contains "already exists": only the status error_code sku_already_exists is documented; both are handled.
6. Accept availability: documented as "not available by default"; a 403 "not available" marks the order as not accepted and fulfilment works as usual.
7. Rate-limit figures (9 000 / min, 270 000 / h) "may be adjusted": the extension follows the response headers.

Troubleshooting

Debug log (settings page) records every call with masked credentials. PHP errors go to system/storage/logs/error.log.

FAQ

Do I need a CDON account?

Yes, a CDON seller account with API access. The extension uses your own merchant ID and API token.

Does it use the old CDON Connect API?

No. CDON Connect closed in 2026; the extension uses the new CDON merchant API only.

Which markets and currencies?

Sweden (SEK), Denmark (DKK), Finland (EUR) and Norway (NOK). Your OpenCart default currency can be any currency; you give a rate per market currency or use the OpenCart currency table.

My OpenCart prices are without tax. Will CDON show the right price?

Yes. Products with a tax class get the market VAT added, because CDON prices include VAT.

Can an order be imported twice?

No. Each CDON order is recorded before the OpenCart order is created, under a lock, and an interrupted import is adopted instead of repeated.

Does it handle returns?

The CDON merchant API has no return endpoints; handle returns in the CDON merchant portal.

Is OCMOD used or is core changed?

No. Events only; no OCMOD, no core file changed.

What happens on update or uninstall?

Your data stays (links, rules, connection, licence state), so updates continue where they stopped.

Does it send e-mails to buyers?

No. CDON has the buyer contact; imported orders use a placeholder address and notify nobody.

OpenCart 3?

Not supported; OpenCart 4.1.x only.

CDON is a trademark of its owner. This extension integrates with the CDON merchant API; it is not made, endorsed or certified by CDON.