Skill: Demo Video Generation

Generate demo assets from a real tmux E2E run and viewer screenshots.

Proven Workflow

1) Record terminal session in tmux with asciinema

bash
tmux new-session -d -s demo -x 160 -y 46
tmux send-keys -t demo "asciinema rec /tmp/claude-tap-recordings/demo.cast" Enter
tmux send-keys -t demo "cd /path/to/claude-tap && scripts/run_real_e2e_tmux.sh" Enter
# ... wait until run finishes ...
tmux send-keys -t demo "exit" Enter

Notes:

• Enter is the submit key for Claude Code TUI in tmux.
• Use tool-triggering first prompt text so trace includes tool_use.

2) Convert .cast to GIF with agg

bash
agg /tmp/claude-tap-recordings/demo.cast /tmp/claude-tap-recordings/demo.gif

3) Convert GIF to MP4 with ffmpeg

bash
ffmpeg -y -i /tmp/claude-tap-recordings/demo.gif -movflags +faststart -pix_fmt yuv420p .agents/recordings/demo.mp4

Browser Screenshots (HTML Viewer)

Use Playwright CDP to attach to a running Chrome/Chromium instance on port 9222.

python
browser = playwright.chromium.connect_over_cdp("http://127.0.0.1:9222")
page = browser.contexts[0].pages[0]

Reliable UI interactions

• Click entries by visible text content, for example:

python
page.query_selector('text="轮次 22"').click()

• Open diff view by clicking button text:

python
page.query_selector('text="对比上次"').click()

• For SPA/overflow layouts, scroll actual scrollable containers (not window):

python
page.evaluate("""
() => {
  for (const el of document.querySelectorAll('*')) {
    if (el.scrollHeight > el.clientHeight) {
      el.scrollTop += 300;
    }
  }
}
""")

Output Targets

• docs/demo.gif
• .agents/recordings/demo.mp4
• Optional localized variants (docs/demo_zh.gif, .agents/recordings/demo_zh.mp4)

Avoid

• Do not reference non-existent scripts such as cast_to_gif_ultra.py or make_final_demo_v2.py.
• Do not hardcode selectors like .detail unless verified in the current viewer build.