Jack Damon

Jack Damon is a macOS text tool that generates LLM text replacements for bracketed phrases using a keyboard shortcut.

Lacuna is an opinionated utility tool designed for macOS that integrates large language models into any text input field. Users type bracketed phrases and use a keyboard shortcut to send the phrase and surrounding text to a configured LLM. The program returns three candidate phrases to replace the original text through a fully keyboard navigable interface. It is frequently used for tasks like drafting emails and quick phrasing assistance. The project is open source and inspired by the keyboard-based window tiling app Rectangle.

Jack Damon at a glance

Best for: Writer, Software engineer
Runs on: macOS
Pricing: Free
Released: October 2026
Category: AI writing tool
Website: jackdamon.org

Key features

Invokes LLMs into any text input
Uses bracketed phrases for prompts
Triggered via keyboard shortcut
Returns 3 candidate replacement phrases
Fully keyboard navigable interface

Use it for

Drafting emails with quick phrasing help
Generating text replacements inside text inputs

Alternatives to Jack Damon

Lacuna by Tiptree Systems — Traces code imports and comments directly to the foundational research papers.
Blurt — Fast, native open-source dictation with server-side LLM cleanup and no subscription.
DeepL — Delivers accurate, enterprise-grade translations while preserving original layout and context.
Sudowrite — It analyzes your style and tone to suggest the next 300 words in your voice.
Jarq — Translates and dictates text in any app without switching tabs or copying and pasting.
WriteMage — Integrates ChatGPT natively into any macOS app and iOS keyboard.
Rewrite — Free with no account, no word limit, and works completely offline.
GPTLocalhost — Enables the use of custom local LLM servers directly within Microsoft Word.
Loqui — It inserts corrected text directly into any app without plugins.
Quillbot — It uses artificial intelligence to rewrite and paraphrase text.
Lex — Clean writing app with an AI editor built in
Tidy — It runs entirely on-device and fixes text with a single keystroke.

All Jack Damon alternatives