Grammarly, but you pay OpenAI by the token
A Bob plugin that pipes your prose through ChatGPT for polishing and grammar fixes on macOS.

What it does
This is a plugin for Bob, a macOS translation/OCR app. You highlight text, and the plugin sends it to OpenAI’s API for grammar correction and style polishing. The author claims it “perfectly replaces Grammarly” — your mileage and API bill may vary.
The interesting bit
The real architecture here is Bob + PopClip + OpenAI. The plugin itself is a thin adapter; the cleverness is in the integration. Bob handles the UI and text capture, PopClip triggers it from any selection, and ChatGPT does the actual heavy lifting. It’s a nice example of gluing together existing tools to solve a workflow problem.
Key highlights
- Requires macOS, Bob ≥ 1.8.0, and an OpenAI API key
- Supports streaming output (needs Bob ≥ 1.8.0, plugin ≥ 1.0.0)
- Non-macOS users are directed to the author’s browser extension, openai-translator
- Licensed CC BY-NC-SA 4.0 — commercial use is a no-go
- The author is admirably honest: “I am just a small Bob plugin; the powerful one is Bob itself”
Caveats
- No mention of which model it uses, token costs, or rate limits
- CC BY-NC-SA 4.0 license is unusual for developer tools and may block workplace adoption
- “Effect is outstanding” is the author’s claim, not a benchmark
Verdict
Grab it if you’re already a Bob user on macOS and have an OpenAI API key burning a hole in your pocket. Skip it if you need cross-platform support, predictable costs, or a license your employer can stomach.