Plugin development and custom extensions
Plugin development means adding one precise feature to software you already use, without replacing it. In Bastia we build plugins and custom extensions, as well as templates and digital resources. Some are for your own staff. Others are made to be sold to other users.
Plugin or extension, what is it?
A plugin, also called an extension, is a module that attaches to existing software to give it a new feature. The host might be a website, a browser, an office suite, a piece of professional software, even a development environment. It provides the frame. The extension brings what you were missing.
Templates and digital resources are ready-to-use pieces. Think document or page templates, interface components, rule sets, reusable code libraries. They save time for whoever uses them, and they can become a product in their own right.
The sums are simple. Your staff keep the tool they know, and you only pay to develop the feature that really counts for you.
Example extensions, by tool and by sector
- 01
Websites and online shops
A booking module, extra order fields, a link to your management software. Or shipping costs worked out by your own rules, including for a parcel leaving Corsica for the mainland.
- 02
Browser
An extension that grabs details from the page you are looking at and sends them to your customer file. Or one that adds shortcuts to the online tool you keep open all day.
- 03
Office suite and email
A module that fills in a document from your data, sorts certain emails, or adds a button that opens your business software.
- 04
Professional software
An extension for design, management or accounting software, where its publisher has made room for one.
- 05
Development and AI tools
Feature Workflow, one of our projects, is a plugin for an AI coding agent. It holds the agent to a structured development workflow, with feature definition, analysis, planning and implementation, then review, testing and documentation.
- 06
Local authorities and networks
Document and page templates shared between several organisations, for instance the municipalities of one area of Haute-Corse. Communications line up, and nobody redrafts the same letter on their own.
Making and selling plugins or digital resources
An extension or a template can also bring in money. When you know a trade well, you know what the tools in that sector are missing. That know-how can be sold as a digital product.
There are several commercial models. One-off sale, first of all. The licence, in other words permission to use under conditions (number of sites, duration, whether updates are included). Then subscription, or pay-per-use. It all depends on your audience and on what the product will cost to maintain. We design the product with its activation and update system. Then we help you get it ready for your own online shop or for marketplaces, those online catalogues where users of a piece of software go looking for extensions.
The stages of plugin development
- 01
Understand
The host software and its version, the feature you expect, the people who will use it. Your budget and your calendar. For a commercial product, we also talk about the target audience and the sales model.
- 02
Design
We study what the host allows, and what it forbids. Interface mock-ups are approved before development, and the architecture limits the knock-on effect of future host updates.
- 03
Build
Development and testing on the relevant versions of the host. A trial version then goes into your environment, so you can approve it in real conditions.
- 04
Launch and support
Installation or publication, documentation. After that, we keep an eye on compatibility with each new host version and keep improving the extension.
Compatibility and security of an extension
- 01
Dependence on the host software
An extension lives at the pace of its host. After each major update someone has to check it still works, and it is better to have planned for that from the beginning.
- 02
Security
A badly written extension can open a hole in a whole website or application. It should ask for as few permissions as possible and check the data it receives. It also has to be kept up to date.
- 03
Data
If the extension reads or sends data, personal data in particular, you need to know which data, where it goes and how it is protected. GDPR applies here like anywhere else.
- 04
Marketplace rules
Extension catalogues set their own conditions. A review before publication, payment rules, perhaps a commission.
- 05
Intellectual property
For a product you sell, the quote states who owns the code and under which licence it is distributed.
What sets the price of a plugin or extension
No price without knowing what you need. Your quote takes each of these factors in turn, in simple terms.
- 01
The feature itself
A small addition to one page, or a full module with its own settings screens.
- 02
The host software
How good its documentation is. What its extension system allows, and what it makes awkward.
- 03
Connections
The data to exchange with your other tools or with online services.
- 04
Versions to support
One version of the host, the one running in your company. Or every version your future customers might use.
- 05
Commercial release
Licensing and activation, automatic updates, documentation. Not forgetting support for users.
Looking after an extension once it is out
With an extension, the real work often begins after release. We follow new versions of the host software and fix the faults people report. Security patches go first, then the features users ask for. For a commercial product, we can also host the licensing and update system, and help you answer your users' questions.
Technologies and methods
- TypeScript
- JavaScript
- Browser extensions
- Website modules
- APIs
- Licensing and activation
Frequently asked questions
Will an extension slow down my website?
Very little, if it is well designed. It loads only what it needs, and only on the pages where it is used. We measure performance before and after installing it.
What happens when the host software is updated?
Usually nothing. Major versions, on the other hand, may need an adjustment. As part of maintenance, we test the extension on new versions and adapt it if needed.
Can you modify an existing extension?
Yes, if its licence allows it and the code is available. Sometimes it is safer to write a complementary extension. Change someone else's, and your edits vanish with their next update.
Will I be able to sell the extension you build for me?
Yes, if the ownership terms in the quote give you that right. We agree them together before starting. We can also prepare the publication, the licensing system and the documentation.
Do I need an extension or a complete piece of software?
If your current tool suits your staff and lacks just one feature, an extension is often the cheapest answer. If you spend your days working around the tool, business software built for you is probably the better fit. We will help you decide.