cmux-capture — Claude Code skill for window capture
Capture a cmux window as an image or video from the CLI. Use it to show a visual change in a pull request or attach evidence to a bug report.
npx skills add manaflow-ai/cmux --skill cmux-capture -a claude-codeWhat cmux-capture does
The skill uses cmux shot for a still image and cmux record for motion such as a drag or animation. You can set a window region, choose PNG, JPEG, MP4, or GIF, and add captions to a recording. Both commands can return their response as --json.
A recording ends when it reaches --max-seconds, which defaults to 15 and cannot exceed 120. Only one recording can run at a time, so another record start is rejected until it stops. Capture is limited to cmux windows; another app in front of one will not appear in the video.
What it helps with
- capture a cmux window for a pull request
- record a drag or animation as a GIF
- save a selected window region
- caption moments in a screen recording
Example prompts for the agent
- Capture the current cmux window for a pull request.
- Record the sidebar being dragged as a GIF and caption the key moment.
- Capture region
0,0,420,900and save the sidebar's final state.
How to install cmux-capture
1Skills CLI (Vercel)
npx skills add manaflow-ai/cmux --skill cmux-capture -a claude-code2Manually: put the files in place
~/.claude/skills/cmux-capture/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/cmux-capture/
1Skills CLI (Vercel)
npx skills add manaflow-ai/cmux --skill cmux-capture -a codex2Manually: put the files in place
.agents/skills/cmux-capture/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add manaflow-ai/cmux --skill cmux-capture -a cursor2Manually: put the files in place
.cursor/skills/cmux-capture/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install manaflow-ai/cmux cmux-capture2Manually: put the files in place
.github/skills/cmux-capture/SKILL.md1Skills CLI (Vercel)
npx skills add manaflow-ai/cmux --skill cmux-capture -a gemini-cli2Platform CLI
gemini skills install https://github.com/manaflow-ai/cmux --path skills/cmux-captureManually: put the files in place
.devin/skills/cmux-capture/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add manaflow-ai/cmux --skill cmux-capture -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: How to install skills in Claude Code: five ways
Questions about cmux-capture
How do I install cmux-capture in Claude Code?
Run npx skills add manaflow-ai/cmux --skill cmux-capture -a claude-code. The skill is installed at ~/.claude/skills/cmux-capture/SKILL.md.
What does cmux-capture do?
It guides an agent to capture a cmux window from the CLI, either as a still image or as a video. Recordings can include captions and cover a chosen region.
Can it record more than one window at a time?
No. A second record start is rejected while a recording is active. Check its state with cmux record list.
