Show HN: Margin – a Markdown editor that runs /// commands while you write

Beta open now. The files are local and everything stays in your machine and limited context get sent to LLMs, you can read the security notes and threat model on the site. Commands API supports only anthropic for now. You can bring your own API key or use the demo key with limited usage. Plenty to get a feel for it.

A quick 30 second experiment to run:

1.Paste a small “Key Features” section

2.Type /// tabulate the features below into a recap table

3.Keep writing while it runs → output appears in preview → click “Insert into source” if you want it persisted

What Margin does today:

• /// commands that run asynchronously while you keep writing

• Generates structured artifacts (recap tables, Mermaid diagrams, charts)

• Clickable command status (running/done) + rerun/copy/insert/remove

• Export resolved markdown / copy rich HTML

I’d love feedback on: (1) does the “doc compiles into artifacts” mental model click? (2) what’s the first command you’d want as a writer?

Stack is react + tauri. Thanks!