grammr

grammr

Lightning-fast AI grammar checker in your terminal ⚡

grammr (yes, it's misspelled on purpose) is a blazingly fast TUI grammar checker powered by OpenAI or Anthropic Claude. Copy text from anywhere, fix it in seconds, and paste it back. No UI, no bloat, just speed.

Why grammr?

• Fast: Sub-3-second workflow from copy to paste
• Keyboard-only: Vim-inspired keybindings
• AI-powered: GPT-4o and Claude quality beats rule-based checkers
• Translation: Built-in AI translation to any language
• Offline cache: Already-checked text loads instantly
• Beautiful: Colorful diffs, clean interface
• Private: Runs locally, API calls only for corrections

Install

Homebrew (macOS)

Option 1: Direct installation (recommended)

brew tap maximbilan/grammr https://github.com/maximbilan/grammr
brew install grammr

Option 2: Using the installation script

curl -fsSL https://raw.githubusercontent.com/maximbilan/grammr/main/install.sh | bash

Or for a specific version:

curl -fsSL https://raw.githubusercontent.com/maximbilan/grammr/main/install.sh | bash -s v1.0.0

Option 3: Direct formula URL

brew install --build-from-source https://raw.githubusercontent.com/maximbilan/grammr/v1.0.0/Formula/grammr.rb

Replace v1.0.0 with the desired version tag.

Go Install

go install github.com/maximbilan/grammr@latest

Build from Source

git clone https://github.com/maximbilan/grammr
cd grammr
go build -o grammr

Setup

1. Get an API key from OpenAI or Anthropic
2. Initialize configuration (optional, creates config directory):

grammr config init

1. Configure grammr:

For OpenAI:

grammr config set provider openai
grammr config set api_key YOUR_OPENAI_API_KEY

For Anthropic Claude:

grammr config set provider anthropic
grammr config set anthropic_api_key YOUR_ANTHROPIC_API_KEY

Optional: Choose a model (default: gpt-4o for OpenAI, claude-3-5-sonnet-20241022 for Anthropic)

grammr config set model gpt-4o-mini  # OpenAI: Faster and cheaper
grammr config set model claude-3-5-sonnet-20241022  # Anthropic: Latest Claude model

Optional: Set language (default: english)

grammr config set language spanish  # For Spanish text correction

Optional: Enable translation to a target language

grammr config set translation_language french  # Translate corrected text to French

Usage

1. Copy text from anywhere (Cmd+C / Ctrl+C)
2. Run grammr
3. Press V to paste
4. Wait ~1s for AI correction
5. Press C to copy result
6. Paste back to your app (Cmd+V / Ctrl+V)

That's it! 🎉

Keyboard Shortcuts

Global Mode:

Edit Mode:

Review Mode:

Styles

Switch correction styles:

• 1 - Casual (default)
• 2 - Formal
• 3 - Academic
• 4 - Technical

Configuration

Edit ~/.grammr/config.yaml:

provider: "openai"  # or "anthropic"
api_key: "sk-..."  # OpenAI API key
anthropic_api_key: "sk-ant-..."  # Anthropic API key (if using Anthropic)
model: "gpt-4o"  # OpenAI: gpt-4o, gpt-4o-mini | Anthropic: claude-3-5-sonnet-20241022, claude-3-opus-20240229, etc.
style: "casual"  # or use "mode" for backward compatibility
language: "english"  # Default: english. Options: english, spanish, french, german, etc.
translation_language: ""  # Optional: Translate corrected text to this language (e.g., "spanish", "french", "german")
cache_enabled: true
cache_ttl_days: 7
show_diff: true
auto_copy: false

Or use the CLI:

grammr config set provider anthropic
grammr config set anthropic_api_key sk-ant-...
grammr config set model claude-3-5-sonnet-20241022
grammr config set language spanish
grammr config set translation_language french
grammr config get provider
grammr config get language
grammr config get translation_language

Model Comparison

OpenAI Models

Anthropic Models

Recommendation:

• OpenAI: Start with gpt-4o-mini for speed and cost, upgrade to gpt-4o if you need better quality.
• Anthropic: Start with claude-3-5-sonnet-20241022 for the best balance, use claude-3-haiku-20240307 for speed/cost, or claude-3-opus-20240229 for maximum quality.

Examples

Quick fix:

grammr
# Press V, wait, press C

Change style:

# Press 2 for formal writing
# Press V to paste

Review changes word-by-word:

grammr
# Press V to paste
# Press A to enter review mode
# Press Tab to apply changes, Space to skip
# Press Esc when done

Use translation:

# First, configure translation language
grammr config set translation_language spanish

# Then use grammr normally
grammr
# Press V to paste
# After correction completes, translation appears automatically
# Press T to copy translation

Clear cache:

rm -rf ~/.grammr/cache/

Initialize config:

grammr config init

Features

• ✅ Real-time streaming corrections
• ✅ AI-powered translation to any language
• ✅ Smart caching (hash-based, configurable TTL)
• ✅ Beautiful colored diffs
• ✅ Word-by-word change review mode
• ✅ Multiple writing modes (casual, formal, academic, technical)
• ✅ Inline text editing
• ✅ Vim-inspired keybindings
• ✅ Cross-platform (macOS, Linux, Windows)
• ✅ Single binary, no dependencies
• ✅ Comprehensive test suite

Why the weird name?

Because a grammar checker with a misspelled name is hilariously ironic. Also, it's shorter to type. 😄

Development

Running Tests

go test ./...

Building

go build -o grammr

Test Coverage

The project includes comprehensive unit tests covering:

• Cache operations (hash, get, set, expiration)
• Configuration management (load, save, set, get)
• Corrector initialization and prompt building
• UI utility functions (diff parsing, text building, whitespace trimming)

Roadmap

• Support for Anthropic Claude (in addition to OpenAI)
• Custom system prompts
• Plugin system for custom corrections
• Batch file processing

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

See LICENSE file for details.