Input editor

The input editor is the rounded-box component at the bottom of the terminal: > prompt, multi-line editing, history and kill-ring, undo — the text-editing machinery comes from the underlying pi-tui Editor; Blue layers context and enhancements on top.

Slash-command context

Input starting with / turns the frame primary blue and enters command context:

• Fuzzy autocomplete — the query splits on whitespace into tokens, each matched as a subsequence, ranked by score; every dropdown entry shows a two-part hint — description, Enter accepts the preselected entry and submits.
• Discovery hints — while the dropdown is closed, the hint line flashes up to three fuzzy matches sharing the same filter — the discovery path into slash commands.
• Argument ghost hints — shown at most one space after /command (e.g. /resume <session-id>); a leading space is added before you type the separator.

All commands live in the Slash commands reference.

! bash mode

When the buffer is exactly !, bash mode engages (the ! never enters the buffer) with a triple cue: the ! prompt, the ! shell mode frame label, and the shellMode violet frame. Submitting returns to prompt mode automatically.

Commands run through Blue's own executor and echo as shell cards (sanitized, truncated per stream: 200 lines / 64KB each), failures keep an exit code N line — deliberately outside the session transcript, invisible to the model. Prompt and bash submissions share one history (Up recall is not mode-filtered).

@ file completion

@ triggers file-path completion: fd first, filesystem scan fallback, 200-entry cap, fuzzy-ranked. Completion covers file paths; command-argument completion is deferred.

Ctrl-V image paste

Ctrl-V stores the clipboard image in the attachment library and inserts an [image #N] marker at the cursor; on submit the markers split into image content blocks. Markers survive theme switches.

Dependencies and limits: probes wl-paste then xclip on Linux; 10MB per image, 8 images / 30MB / 16M pixels per message; the model must accept image input (see the FAQ).

Editor-context keys

With the editor focused, a contextual key chain applies (see Key bindings): Escape first dismisses the completion popup, then closes a side-question pane mounted above, then clears the draft, then interrupts a running agent; Ctrl-C clears → interrupts → a second press within 1 second exits; Ctrl-S steers the non-empty draft into the current turn; ↑/↓ on an empty buffer scroll the side pane first, then recall queued messages (without the queue pane, they go to editor history).

Draft survival

The unsubmitted draft, input mode (bash triple cue included), and hint history are mirrored into a draft stash — a /theme hot-switch rebuilds the editor fiber and restores everything, so a just-submitted /theme light won't vanish from Up history either.