Interactive TUI

The interactive mode (cogo on a TTY) is a Bubble Tea program with streaming responses, syntax-highlighted markdown, and several overlays.

Layout

┌─ Cogo · gemini-3.1-pro-preview      ~/projects/cogo · vertex · ask · σ ↑1234/↓456/$0.0021 ─┐
│                                                                                            │
│  ❯ Summarize the agent loop in three bullets.                                              │
│                                                                                            │
│  Cogo's agent loop:                                                                        │
│  • Sends the user's prompt + project memory to Gemini …                                    │
│  • Streams partial events back to the TUI as they arrive.                                  │
│  • Tool calls are gated by the permission system before exec.                              │
│  ↑1234 in · ↓456 out · $0.0021                                                             │
│                                                                                            │
└─ Type a message, or /help…                                                                 ┘
  /help · /quit · Ctrl+C to exit

Header — model name, working directory, provider, permission mode badge, running session totals.
History viewport — scrollable; every message is rendered with a per-role style.
Input area — multi-line textarea with rounded border.
Footer — context-sensitive hints.

Keymap

Key	Action
Enter	Send the current prompt.
Shift+Enter / Ctrl+J	Insert a newline.
Ctrl+C	Cancel current turn (while streaming) / exit (second press).
Ctrl+L	Clear the viewport (history is preserved).
Ctrl+U	Clear the textarea.
PgUp / PgDn	Scroll the viewport.
↑ / ↓	Recall previous prompts (when input is empty).
`/` (start of input)	Open slash-command palette.
`@` (anywhere)	Open file picker.
Esc	Close any open overlay.
Tab	Fill the highlighted palette item without submitting.

Streaming

Assistant responses stream in token by token. While streaming:

The textarea stays usable — you can compose your next prompt in the background.
Submit (Enter) is disabled until the current turn finishes, so you don’t accidentally enqueue mid-thought.
Markdown is rendered through Glamour once the turn completes (during stream, raw text is shown for low latency).

Modal overlays

Three modal flows take over key handling when active:

Permission modal — appears when the agent wants to do something the permission gate flagged. Reply with y / s / a / n (or Esc).
Model picker — /model opens it; ↑/↓ navigate, Enter selects, Esc cancels.
MCP elicitation modal — appears when an MCP server requests user input. Form mode lets you fill fields with Tab navigation; URL mode shows a URL with o to open in a browser.

Theming

Cogo’s markdown renderer (Glamour) auto-detects light vs dark terminal background once at startup. The palette uses adaptive colors so it works under both.

The permission-mode badge in the header is colored: ask is accent-colored, yolo is bold red so you can never miss it.

Slash Commands