# Vendor module, third-party module or custom build

> The same feature can come from three places: a module published by the platform vendor, a module sold by a third party, or code written for you. These three don’t compare on price but on what they guarantee over time.

- Source canonique : [https://allaux.fr/en/modules/module-officiel-tiers-ou-developpement](https://allaux.fr/en/modules/module-officiel-tiers-ou-developpement)
- Langue : EN
- Dernière mise à jour : 2026-09-30

## The module published by the platform vendor

This is the only category I willingly name, because it is tied to the product itself. On PrestaShop, part of the module set ships with the core and follows its releases; on WordPress, the WooCommerce extension is published by the store software’s own maker; on Shopify, some functions are published by Shopify. These modules have a structural advantage: they are tested alongside the platform, and they rarely break on an upgrade, because the same teams build both.

The drawback is that they stay deliberately generic: they cover the standard case and stop there. Trying to make them do something else nearly always calls for an additional module.

## The third-party module: what you actually buy

You buy a right of use, rarely a right to modify, and almost never a guarantee of longevity. Three points are worth reading before purchase, because they decide what happens in two years. First, the licence: does it cover a domain, a store, an installation, and does it allow a staging copy. Second, how it is delivered: is the code readable or protected by an encoder, in which case nobody can fix it without its publisher. Third, the update rhythm: declared compatibility with the platform’s latest major release tells you more than any sales page.

A well-kept third-party module remains the best choice for a standard need. It is the badly kept one that costs money, and that isn’t visible at the time of purchase.

## What each origin leaves you with

- **Vendor module** — Compatibility tracked with the platform, deliberately generic scope, little or no adaptation possible.
- **Third-party module** — Function ready immediately, dependency on a publisher, a licence to re-read, sometimes unreadable code.
- **Custom build** — Exact scope, sources delivered, no licence to renew, but maintenance that falls to you.
- **A mix of all three** — In practice the most common case: an off-the-shelf base, completed by targeted custom work where it falls short.

## Encoded code deserves flagging before purchase

> Some modules ship in encoded form, unreadable and unmodifiable. As long as the publisher keeps up, that isn’t a problem. The day they stop, or the day an encoding extension is no longer available on your server, nobody can step in: not me, not another developer. Worth knowing before a critical function rests on it.

## Related pages

- **Buy a module or have one built** — The upstream decision, with the four cases where buying becomes the wrong maths. ([/modules/acheter-ou-faire-developper](/modules/acheter-ou-faire-developper))
- **The module works but its publisher is gone** — The options left when the dependency turns against you. ([/modules/module-dont-l-editeur-a-disparu](/modules/module-dont-l-editeur-a-disparu))
- **Abandoned modules and extensions** — The same subject seen from the store security angle. ([/securite/modules-et-extensions-abandonnes](/securite/modules-et-extensions-abandonnes))
- **Bespoke PrestaShop module** — The third origin in detail, when it is the one that wins. ([/prestashop/module-sur-mesure](/prestashop/module-sur-mesure))

## FAQ

### Why won’t you recommend a third-party module by name?

Because a publisher can be acquired, change licence or disappear, and my recommendation would still be online afterwards. I give the criteria and review the module you are considering, which helps you without tying you to a product.

### Is a vendor module always preferable?

When it covers the need, yes, because its compatibility tracks the platform. But its scope is deliberately broad and barely configurable: don’t try to make it do what it wasn’t written for.

### Can I have a third-party module I bought modified?

It depends on its licence and the form it ships in. If the code is readable and modification allowed, yes, by isolating the changes so they survive updates. If the code is encoded, no.

### How do I check a licence before buying?

I read the seller’s terms on three points: how many installations are covered, whether modification is allowed, and what happens to updates after the first year. Those are the three clauses that cause trouble later.