2.5 KiB
Agent Note: Drop the TUI /cancel slash command
Status: implemented Archived: 2026-07-26
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Problem
The TUI exposed two identical ways to cancel a running turn: the Esc (and Ctrl+C) keybinding and a /cancel slash command. Both called agent.cancel('cancelled from terminal') with the same reason; when idle, /cancel only printed a "The agent is already idle." notice while the keybindings stayed silent. The running status line already advertises the keybinding (Enter sends steering, Esc cancels), and cancelling by keystroke needs no editor submission, so the slash command was a second, less discoverable path to the same effect — surface area with no behavior of its own.
Decision
/cancel is removed. Cancelling a running turn is a keybinding-only affordance (Esc, or Ctrl+C while running), which the status-line hint and the /help shortcut list already document. The baseCommands autocomplete entry, the /help command line, the case '/cancel' branch in the editor submit handler, and the "already idle" notice it owned are gone; every other slash command (/help, /clear, /reasoning, /tools, /redraw, /reload, /resume, /exit, /skill:<name>) is unchanged. Typing /cancel now falls through to the generic Unknown command: warning like any other unrecognized slash input.
Alternatives considered
Keep /cancel as a discoverability alias — rejected: the running status line and /help both name Esc, so a typed alias adds a maintained code path and a per-idle-state notice for an action a single keystroke already performs more directly. No consumer needed the editor-submission route to cancellation.
Testing
packages/ui/tui/tests/tui.spec.ts asserts agent.cancelled contains 'cancelled from terminal', driven by the Esc/Ctrl+C keystrokes in that turn — the sole cancel affordance. The errors-and-help and disposed-terminal snapshots pin the /help line without /cancel; per-file coverage on packages/ui/tui/src stays at 100%.
Consequences
There is no way to cancel a turn by editor submission; cancellation is keybinding-only. This is a net removal of a redundant path and its idle-state notice, matching the single-primitive shape the rest of the stop surface already follows (public stop surface). Restoring a typed cancel would return with the autocomplete entry, the submit-handler branch, and its own test.