FAQ
Why is everything a mouse click?
Section titled “Why is everything a mouse click?”So that every key belongs to your programs. Terminal multiplexers usually reserve a prefix key and a set of shortcuts, which then collide with your shell, your editor or your agent, and which you have to learn. In cornercase there is nothing to learn: you see a button, you click it. Your keyboard goes, untouched, to the program in front of you, unless you turn on the optional prefix key.
Can I use the keyboard instead?
Section titled “Can I use the keyboard instead?”Yes. Pick a prefix key in Settings → UI → prefix key; pressing it opens a menu where one more key switches tabs, workspaces or projects, splits, finds files, opens the changes and more. The menu is on screen, so there’s nothing to learn by heart. See Keyboard shortcuts. Inside cornercase’s own dialogs, Enter confirms and Esc cancels, and lists can be driven with the arrow keys.
Does it replace tmux?
Section titled “Does it replace tmux?”It overlaps: both keep shells running after you detach and split them into panes, and both can be driven from scripts (Scripts and agents). cornercase is organised around projects, workspaces and git worktrees, can start coding agents on issues, and is driven by the mouse. If you rely on tmux’s copy mode (searching the scrollback, selecting with the keyboard) or its many commands, keep using it; you can even run cornercase inside a tmux window.
Can an agent drive cornercase?
Section titled “Can an agent drive cornercase?”Yes. The cornercase command opens tabs, types into panes, starts agents in their own worktrees, waits until they finish or need you, and reads what they wrote, so an agent in one tab can coordinate others. Install the skill so your agents know about it.
Is it fast?
Section titled “Is it fast?”Yes. We measured it in October 2026 on one machine, an 8-core x86_64 virtual machine running Linux, against the agent workspaces that run there, all opening the same repository with the same worktree and the same uncommitted changes (20 files, +794 −76):
| cornercase 0.1.15 | Warp 0.2026.09.30 | Orca 1.4.220 | Emdash 1.2.7 | |
|---|---|---|---|---|
| Open, until the workspace is usable | 34 ms | 0.45 s | 3.2 s | 8.5 s |
| Show the changes, first time | 2 ms | 0.41 s | 1.1 s | 0.43 s |
| Show the changes again | 2 ms | 0.09 s | 0.33 s | 0.14 s |
| Memory | 53 MB | 432 MB | 793 MB | 1.9 GB |
| Download | 4.8 MB | 148 MB | 219 MB | 229 MB |
| Installed | 12 MB | 353 MB | 642 MB | 807 MB |
Times run from launching the app, or clicking, until the result is on screen; they are medians of 3 to 5 runs. cornercase shows its changes instantly because it computes the diff in the background. The changes are all files at once in cornercase, Warp (code review panel) and Orca (view all), and one file in Emdash, which has no view with every file. Memory is the proportional set size (PSS) of each app’s own processes, without the shells. The desktop apps ran on a virtual display without a GPU, so they rendered in software, which adds memory and time a real GPU would not; the difference is still one to two orders of magnitude. Superset (947 MB download, 2.8 GB installed) needs an account to start, so it is not in the table; Conductor and cmux run only on macOS.
Opening and searching files, in a clone of Orca’s own repository (32,255 files) with a TypeScript file of 3,472 lines, each query typed in one go:
| cornercase 0.11.5 | Warp 0.2026.09.30 | Orca 1.4.222 | Emdash 1.2.7 | |
|---|---|---|---|---|
| Open a file, until it is coloured | 0.14 s | 0.65 s | 1.33 s | 0.47 s |
| Open it again | 0.08 s | 0.57 s | 0.39 s | 0.21 s |
| Find a file by its name | 19 ms | 0.30 s | 0.19 s | none |
| Search the text of every file, until matches show (472 in all) | 69 ms | 0.43 s | 0.49 s | 0.10 s |
These are medians of 5 to 7 runs, from the click, or the query arriving, until the result is on screen. cornercase shows the file’s text in 15 ms and colours it after; Warp shows both at once. cornercase shows all 472 matches at once; Warp shows its first ones at 0.43 s and the rest by 1.6 s. The name is found in each app’s quick open (Emdash has none); Orca’s lists the first 20,001 files, so in this repository it could not find the file we opened, and we searched a name it lists.
Against the terminal multiplexers, each with its default settings and /bin/sh in every pane:
| cornercase 0.1.15 | tmux 3.6 | zellij 0.45.1 | |
|---|---|---|---|
| From the command to a prompt, server included | 33 ms | 30 ms | 368 ms |
| Attach to a running session | 10 ms | 10 ms | 122 ms |
cat of a 51 MB text file in a pane |
0.54 s | 2.31 s | 4.20 s |
| From a key to the screen | 2.5 ms | 0.3 ms | 12.3 ms |
| Memory with ten shells | 16 MB | 12 MB | 189 MB |
Each one ran in a 160×48 pseudo-terminal driven by a script that answers the questions a terminal answers at startup and reads the output as fast as it can. These are medians of 20 starts and attaches, 300 keys and 7 runs of cat. tmux puts a key on the screen faster; at under 3 ms cornercase is still well inside one frame of a 120 Hz display.
How is it different from Orca, Warp or Conductor?
Section titled “How is it different from Orca, Warp or Conductor?”Orca and Warp are desktop applications that build an IDE around their terminals, with an editor, a file tree and review tools; Conductor is a desktop app for macOS. cornercase is a terminal multiplexer: it runs inside the terminal you already use, on your machine or on any server you reach over SSH, and gives every agent a worktree, a tab, a status, its diff and its files, all one click away. It shows files, images included, but doesn’t edit them or preview pages; your editor and your browser do that.
It is also much lighter: it opens in 34 ms and uses about 50 MB, where the desktop apps we measured take 0.45 to 8.5 seconds and 0.4 to 1.9 GB (see Is it fast?). Like Orca, it keeps your agents running when you close it; Warp stops them.
Does it work over SSH?
Section titled “Does it work over SSH?”Yes, two ways. Run cornercase on the remote machine: the server lives there, your shells keep running when the connection drops, and you reattach when you log in again. Or run cornercase remote <host> on your laptop: the window stays on your laptop, the shells and agents on the other machine, and when the connection drops the window waits and reconnects by itself (see Remote machines). Either way, copying uses OSC 52, so the text lands in your local clipboard.
Do my shells survive a reboot?
Section titled “Do my shells survive a reboot?”No. Programs live in the server, and the server doesn’t survive a reboot, cornercase kill-server or a restart after an update. What survives is the layout: your projects, workspaces, tabs and splits come back, each pane with a fresh shell in its folder. Claude Code and Codex come back in the conversation they had, resumed in their tabs.
Which coding agents does it support?
Section titled “Which coding agents does it support?”Claude Code, Codex, Gemini CLI, opencode, Grok Build, Cursor CLI, GitHub Copilot CLI, Amp, Droid, pi, Qwen Code, Kimi, Cline, Goose and Aider out of the box, and any other command-line agent you add with agent_commands.
Which issue trackers?
Section titled “Which issue trackers?”GitHub (through the gh CLI), GitLab (gitlab.com or self-hosted), Shortcut, Linear, Jira Cloud, Plane (Cloud or self-hosted) and Asana.
Will it delete my branches?
Section titled “Will it delete my branches?”Never. Removing a worktree workspace deletes the worktree’s folder, after asking you, and leaves the branch and its commits in the repository.
Where are my tokens stored?
Section titled “Where are my tokens stored?”In secrets.json next to your config.json, readable only by you, or in the GITLAB_TOKEN, SHORTCUT_API_TOKEN, LINEAR_API_KEY, JIRA_API_TOKEN, PLANE_API_KEY and ASANA_ACCESS_TOKEN environment variables if you prefer. They are never written to logs, to the issue cache or to the screen.
Does it respect my terminal’s colour theme?
Section titled “Does it respect my terminal’s colour theme?”Yes. cornercase asks your terminal for its colours when it starts and draws its interface with palette colours, so it follows light and dark themes. The programs in your panes get the same colours.
The exceptions are greys. Grey text, such as titles, the buttons at the bottom and the tree’s arrows, uses your theme’s bright black unless that colour is too close to the background, as in Solarized Dark, or your terminal does not say what it is, as Warp does not. Then cornercase uses a fixed grey that shows on any dark or light background. Borders, separators and tree lines always use a fixed grey a step quieter than the text, so they stay in the background.
Can it show images?
Section titled “Can it show images?”Yes, in the files panel: click a PNG, JPEG, GIF, WebP, BMP or ICO file and your terminal draws it, in Ghostty, kitty, iTerm2, WezTerm, foot, Konsole and others, also over SSH and inside tmux. Pictures that programs in your panes draw, such as kitten icat, don’t show; see Known limitations.
Which platforms does it run on?
Section titled “Which platforms does it run on?”Linux and macOS, on x86_64 and arm64. The prebuilt Linux binaries need glibc 2.35 or newer; elsewhere, build from source.
How do I update it?
Section titled “How do I update it?”From the app: when a new version is out, a button with its number appears next to Settings. Click it to update, then restart; before restarting it says what is running and will stop, and your layout comes back with new shells, agents in their conversations. From a shell, cornercase update does the same at any time. Homebrew installs update with brew update && brew upgrade cornercase. See Update.
Does it phone home?
Section titled “Does it phone home?”It asks GitHub for the latest release when the server starts and then every hour. Nothing about you or your projects is sent. Turn it off in settings → UI → check for updates, or with "check_updates": false in config.json.
The star prompt that now and then asks for a star on GitHub sends nothing and doesn’t check whether you starred; it only copies the link when you answer yes.
With a Telegram or Discord bot set up, it also talks to that service, as that bot, and while you are away sends your chat the agents’ messages. check_updates doesn’t change that: remove the bot in Settings › Remote, under Telegram or Discord, to stop it.
Can I run two independent sessions?
Section titled “Can I run two independent sessions?”Yes, with CORNERCASE_SOCKET: each socket gets its own server, with its own settings and session. See A separate server.
Can I scroll back through a pane’s output?
Section titled “Can I scroll back through a pane’s output?”Yes, with the mouse wheel: each pane keeps its last 10 MB of output, about 14,000 lines at 80 columns. See Scroll back. There is no search in it yet; see Known limitations.
What license is it under?
Section titled “What license is it under?”MIT or Apache-2.0, at your option.