A built-in text editor and a real terminal
Two tools you reach for all the time while coding with Claude are built into Osiris: a text editor that leaves your files the way they were, and a terminal that starts your own shell in the project folder. Both run locally on Windows, macOS and Linux.
The text editor
The editor opens as Editor in the Osiris sidebar or in a window of its own. Osiris becomes the default app for text files such as .txt, .md, .yml, .json, .ini, .properties, .toml and .xml, so a double-click opens the file straight in an editor window.
- Tabs that keep their state — every tab has its own undo history, selection and scroll position.
- Syntax colours for Java, YAML, JSON, Markdown and more.
- Find and replace in a bar at the top, with every match marked in the text.
Encoding and line endings stay as they were
When the editor reads a file, it remembers how the file is built — encoding, byte order mark,
line ending — and writes exactly that back. A CRLF file stays CRLF, a file with a BOM keeps it.
UTF-8, UTF-16 and Windows-1252 are recognised, so an old .ini or
.properties file does not lose its umlauts on saving. Mixed line endings are
unified to the most frequent one, and Osiris tells you before it does. Files that are not text
are refused instead of being damaged.
The terminal
The built-in terminal opens from the sidebar or with Ctrl+`. Every tab is your usual shell, started in the folder of the connected project: zsh on macOS, the shell set for your account on Linux (usually bash), PowerShell on Windows. Switch to another view and the terminal is hidden; the shells keep running.
- Tabs — several shells side by side, + for a new one.
- From anywhere — the terminal buttons in Projects and Files open a tab right there; your system's terminal is one click away.
- Only for you — Osiris checks which user account is at the other end of the connection and accepts no connection from the network.
What works where
On macOS and Linux the terminal is complete: colours, full-screen programs and resizing work. On Windows it is more limited for now: PowerShell runs in line mode — commands work, but there is no tab completion, Ctrl+C does not stop a running command, and full-screen programs such as vim or Claude Code belong in the system's terminal.
Part of the whole
Editor and terminal sit next to Studio, the project view in IntelliJ or VS Code style, and next to the chat with Claude, which draws on the rules and notes in the brain.