When this was first posted a couple of weeks ago by the spec's author, I took it as an opportunity to see how quickly I could spin up an IntelliJ language plugin since the last time I worked on a language plugin was pre-GPT (Klotho Annotations - basically TOML inside of @annotations inside comments or string literals in a variety of host languages). Back then, it took a week for me to figure out the ins and outs of basic syntax highlighting with GrammarKit.

This time around, I worked with Claude Code and we basically filled in each other's knowledge gaps to finish implementing every feature I was looking for in about 3 days of work:

Day 1:

- Plugin initialization

- Syntax highlighting

- JSON Schema integration

- Error inspections

Day 2:

- Code formatter (the code style settings page probably took longer to get right than the formatter)

- Test suite for existing features

Day 3:

- Intentions, QuickFix actions, etc. to help quickly reformat or fix issues detected in the file

- More graceful parsing error recovery and reporting

- Contextual completions (e.g., relevant keys/values from a JSON schema, existing keys from elsewhere in the file, etc.)

- Color picker gutter icon from string values that represent colors (in various formats)

I'm sure there are a few other features that I'm forgetting, but at the end of the day, roughly 80-85% of the code was generated from the command line by conversing with Claude Code (Sonnet 4.5) to plan, implement, test, and revise individual features.

For IntelliJ plugins, the SDK docs tend to cover the bare minimum to get common functionality working, and beyond that, the way to learn is by reading the source of existing OSS plugins. Claude was shockingly good at finding extension points for features I'd never implemented before and figuring out how to wire them up (though not always 100% successfully). It turns out that Claude can be quite an accelerator for building plugins for the JetBrains ecosystem.

Bottom line, if you're sitting on an idea for a plugin because you thought it might to take too long to bootstrap and figure out all the IDE integration parts, there's never been a better time to just go for it.

EDIT: Repo link for anyone interested: https://github.com/DavidSeptimus/maml-intellij-plugin