🤖 AI Products · $12/mo

Can I vibe code Grammarly?

Real-time grammar, spelling, and writing suggestions everywhere you type.

🔴Not reallyest. a weekend (for the paste box, not the ubiquity)

A paste-your-text-and-fix-it tool is easy — send the text to an LLM, ask for corrections, show a diff — and for occasional editing that genuinely works. But that is not what Grammarly is. Grammarly is a fast, dedicated writing model that runs in real time inside every text field you touch, across the browser and native apps, with sub-second inline suggestions and years of tuning on tone, clarity, and correctness. The product is that ubiquitous, low-latency integration plus a purpose-built model, and neither the everywhere-integration nor the tuned model is something you vibe-code. You can build the paste box; you cannot build the thing that quietly fixes your writing everywhere.

The one-shot prompt
Build a personal writing-assistant web app that checks and improves my text with an LLM. Provide a large editor where, as I stop typing, the app sends the text to the Claude API and returns suggestions grouped as grammar, clarity, and tone, each shown inline as an accept/reject change with a short explanation. Add a readability score, a one-click fix-everything apply, and tone presets (formal, friendly, concise). Debounce requests and cache results to control cost. Use Next.js App Router with the key server-side, and be honest in the README that Grammarly's real product is a fast dedicated model running inline across every app — this paste-in tool covers only the simplest slice.
Paste into Claude Code, Codex, or your agent of choice — then steer. Learn the moves in Prompt Engineering.
What you build

A paste-in editor that sends your text to an LLM and shows suggested grammar, clarity, and tone fixes as an accept/reject diff.

What you give up
  • Real-time inline checking inside every app and browser field
  • A dedicated low-latency model instead of a slower general LLM round-trip
  • Tone, clarity, and consistency scoring tuned over years
  • The browser extension and native integrations that make it ubiquitous
Why people still pay

The value is that Grammarly is always on, everywhere, correcting you as you type without a single copy-paste. That real-time ubiquity plus a purpose-built model is the moat — an LLM can fix a pasted paragraph, but it cannot become an invisible layer over your entire operating system.

modelintegration
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Actually build it

A prompt is the first move, not the whole game. Course 01 teaches you to take a prompt like this one to a shipped, working app — reviewing, correcting, and steering the agent the whole way.

Start Course 01 →