Lacuna

Lacuna is an open-source tool for macOS that brings LLM assistance into any text input. Type a phrase in curly braces, such as {this}, and press Shift-Command-K (or a shortcut you choose). Lacuna is an opinionated approach to invoking LLMs in this way.

Lacuna sends the bracketed phrase along with the surrounding text to an LLM you configure, then uses the generated text to replace the bracketed phrase. The author built it by prompting and shares it for others who may find it useful, noting that he uses it day to day.