ccc-divider

A Claude Code add-on that draws full-width visual separators with a timestamp, so each turn is easy to scan. It provides two independently-tunable dividers:

Name	名稱	When it shows	Hook	Tuning knob
reply	回覆線	after each Claude response	Stop	SEP_MARGIN_REPLY
ask	提案線	with a choice / option card	PreToolUse(AskUserQuestion)	SEP_MARGIN_ASK

Stop says: ◆━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━  ⏱ 18:32:29

Each line dynamically fills the current terminal width, timestamp aligned right. The two dividers are tuned separately because Claude Code prepends a different prefix to each.

Install

curl -fsSL https://raw.githubusercontent.com/ayii0111/ccc-divider/main/install.sh | bash

Open a new Claude Code session afterwards — hooks load at startup.

Uninstall

curl -fsSL https://raw.githubusercontent.com/ayii0111/ccc-divider/main/uninstall.sh | bash

Tuning the two dividers

Set environment variables in Claude Code's env block in ~/.claude/settings.json. Smaller margin = longer line.

{
  "env": {
    "SEP_MARGIN_REPLY": "5",
    "SEP_MARGIN_ASK": "-6"
  }
}

The ask (提案線) is only visible after you answer the card (it lands in the scrollback), so calibrate it there.

All variables

Variable	Default	Divider	Description
SEP_MARGIN_REPLY	5	reply 回覆線	Width fine-tune for the after-response line.
SEP_MARGIN_ASK	-6	ask 提案線	Width fine-tune for the choice-card line.
SEP_MARGIN	—	reply	Legacy alias for SEP_MARGIN_REPLY.
SEP_COLOR	129,161,193	both	Line colour as R,G,B. Set to none to disable colour.
SEP_ICON	⏱	both	Icon before the timestamp. Set to "" to disable.

Defaults were calibrated on Ghostty with a Nerd Font where ◆ renders as 2 columns; other terminals or fonts may differ by ±1–2.

Background: why so many constraints?

1. TTY is detached — CC runs hooks in a subprocess disconnected from the terminal. Writing to stdout, stderr, or /dev/tty fails silently.
2. TUI owns the screen — raw ANSI writes from a subprocess are swallowed or overwritten.
3. systemMessage is the only channel — returning { "systemMessage": "..." } from a hook asks CC itself to render the string, including ANSI colour.
4. COLUMNS survives the detach — CC injects the terminal width into the hook's environment, so the line can be sized dynamically even without a real TTY.
5. Two prefixes — CC prepends a different label to Stop vs PreToolUse messages, which is why reply and ask need separate margins.