Rainfrog is a terminal-based database client that connects to multiple database engines, combining schema browsing, interactive SQL query execution, and inline data editing into a single terminal interface. It provides a tree navigator for exploring tables, columns, and indexes, and an inline cell editor that automatically constructs and executes the necessary UPDATE statements when a cell value is changed. The application also supports modal Vim-style keyboard shortcuts for cursor movement and editing, making it usable entirely from the keyboard.
Query results are fetched in chunks and paginated on demand, allowing smooth scrolling through large datasets without overwhelming the terminal. System metadata is cached at connection time to speed up schema tree navigation, and the user interface is built on a retained-mode widget tree that renders via a framebuffer with mouse and keyboard event handling. Keybindings, display settings, and mouse capture behavior are all configurable through a YAML file loaded at startup.
Connections can be configured using connection strings or individual parameters such as host, port, and credentials. The client supports saving frequently used SQL queries as named favorites for quick replay and can export query results or entire tables to CSV files saved to the system downloads directory.