Plugin Development

Plugin development

Custom WordPress plugin Development, built like products

Most “custom plugin” work is a functions.php snippet in a folder. What we build has an admin interface, proper settings storage, REST endpoints where they’re needed, translations, and conditional asset loading so it doesn’t slow down every page on your site. We’ve shipped more than 25 of them.

Discuss your plugin See finished plugins

What we build

A plugin from scratch

You have functionality that no existing plugin does properly. We scope it, build it, test it and hand it over with documentation and the source.

A plugin suite on a shared core

If you need ten related tools, you don’t want ten codebases. One core plugin holds settings, licensing and shared services; each tool is a lightweight add-on.

A plugin you intend to sell

Licensing, domain activation limits, automatic updates through WordPress’s own update system, and a payment processor behind it. We’ve built the whole chain.

AI features, without hosting the keys

Bring-your-own-key architecture across OpenAI, Anthropic, Gemini and OpenRouter. Your customers pay their own API bill, you carry no usage liability.

Taking over someone else’s plugin

A developer disappeared, or the plugin stopped being updated. We’ll audit what’s there, tell you whether to fix or rewrite, and then do it.

Pre-release security review

Sanitising, escaping, capability checks, nonces, rate limiting, CSV injection. Worth doing before a plugin reaches customers rather than after.

The architecture we use

Across several of our own sites we run suites of 20–25 tools each. They work because they share one core plugin rather than duplicating code:

  • One settings hub. API keys, language settings, affiliate routing and shared services live in the core. Add-ons inherit them.
  • Lightweight add-ons. Each tool is its own installable plugin that registers itself with the core. Adding tool 26 doesn’t touch tools 1–25.
  • Conditional asset loading. A tool’s CSS and JS load only on pages where its shortcode actually appears. This is the single biggest performance difference between a plugin suite and a slow site.
  • Server-side API proxy. Keys stay on the server, never in the browser, with rate limiting and capability checks in front.
  • Built-in internationalisation. Six languages in production, including the Unicode word-counting traps that break most plugins on non-Latin scripts.

What you get

  • Full source code, yours to keep
  • PHP-linted and smoke-tested before handover
  • Documentation of how it works and how to extend it
  • A .pot file if it needs translating
  • An installable zip, ready for the plugins screen
  • A defined support window after launch

Afterwards, plenty of clients move onto a care plan so the plugin keeps working through WordPress and PHP version changes. That’s optional, not a lock-in.

See it running

Don’t take our word for it — go and use them

Three suites built on this architecture, live on our own sites. No sign-up, no demo request. Open one and use it.

25 developer & AI tools

AI cost calculators, token estimators, model matchers, SEO micro-tools and file processors — all on one shared core with a multi-provider AI proxy behind it.

The closest one to what we’d build for an agency client.

Open all 25 tools

27 health calculators

A consumer-facing suite — macro splits, fasting windows, meal planners — with shared currency detection, lead capture and conditional asset loading.

Shows the same core serving a completely different audience.

Open the calculators

Content & generator tools

Quizzes, document generators, trackers and AI-assisted tools, several of them running across six languages from the same codebase.

Shows multilingual output and document generation.

Open the tools

Or try four specific ones

Each of these demonstrates a different part of the architecture.

Want something like this on your own site? Tell me what it needs to do — I read every message myself and reply within a day. Suggestions for tools that don’t exist yet are welcome too; several of the ones above started as somebody else’s request.

Send me the details

How a plugin project runs

Scoping call

What it has to do, who uses it, where it runs. Often this is where we find the plugin should be smaller than you thought.

Written spec and fixed quote

Functionality, admin screens, edge cases, what’s explicitly out of scope. One number, not an hourly estimate that drifts.

Build, with a working version early

You get something installable well before it’s finished, so direction changes are cheap rather than expensive.

Test, lint, hand over

Tested on a staging site, syntax-checked, packaged as a zip, documented. Then a support window while you put it into real use.

Common questions

Do we own the code?

Yes. You get the full source and you can take it to any other developer. We don’t build dependencies on ourselves into client work.

Can you build something we can sell to other people?

Yes, and that’s a speciality. We’ve built the whole commercial chain — a self-hosted license server with domain activation limits, license verification against a payment processor, and automatic updates hooked into WordPress’s native update notifications so your customers see the standard “Update available” prompt.

Will it slow our site down?

Not if it’s built properly. The default behaviour of most plugins — loading their CSS and JS on every page — is a choice, not a requirement. We gate assets on whether the plugin is actually used on the page being rendered.

What about AI features?

We build them bring-your-own-key: your customer supplies their own provider key, so you don’t resell credits, don’t carry usage costs and don’t become liable for their spend. The plugin routes across OpenAI, Anthropic, Gemini and OpenRouter behind one interface.

Can you fix a plugin someone else wrote?

Usually. We’ll audit it first and tell you whether fixing or rewriting is cheaper — sometimes the answer is rewrite, and we’d rather say so before taking your money to patch something unmaintainable.

Do you work with agencies?

Regularly, and white-label. We work under your name, to your process, and send you one invoice. More on how we work.

Related

Tell us what the plugin needs to do

A paragraph is enough to start. We’ll come back with whether it’s a fit, a rough size, and what we’d want to nail down before quoting.

Start a plugin project