Asciinema Recorder

asciinema-recorder

Generate ready-to-copy commands for recording Claude Code sessions with asciinema. Dynamically creates filenames based on workspace and datetime.

Platform: macOS, Linux (requires asciinema CLI)

Self-Evolving Skill: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues.

When to Use This Skill

Use this skill when:

• Starting a new terminal recording session
• Creating demos or documentation recordings
• Capturing Claude Code sessions for review or sharing
• Generating workspace-specific recording filenames

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Why This Skill?

This skill generates ready-to-copy recording commands with:

• Dynamic workspace-based filename
• Datetime stamp for uniqueness
• Saves to project's tmp/ folder (gitignored)

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Requirements

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Workflow Phases

Phase 0: Preflight Check

Purpose: Verify asciinema is installed.

# Check asciinema CLI
which asciinema && asciinema --version

If asciinema is NOT installed, use AskUserQuestion:

• question: "asciinema not found. How would you like to proceed?" header: "Setup" multiSelect: false options:
  • label: "Install asciinema (Recommended)" description: "Run: brew install asciinema (macOS) or apt install asciinema (Linux)"
  • label: "Show manual instructions" description: "Display installation commands for all platforms"
  • label: "Cancel" description: "Exit without recording"

Based on selection:

• "Install asciinema" → Run appropriate install command based on OS:

  # macOS
  brew install asciinema
  
  # Linux (apt)
  sudo apt install asciinema
  
  # Linux (pip)
  pip install asciinema
  

  Then proceed to Phase 1.0.

• "Show manual instructions" → Display the commands above, then exit skill.

• "Cancel" → Exit skill without action.

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Phase 1.0: Recording Location

Purpose: Let user choose where to save the recording.

Use AskUserQuestion:

• question: "Where should the recording be saved?" header: "Location" multiSelect: false options:
  • label: "$PWD/​tmp/ (Recommended)" description: "Project tmp directory (gitignored)"
  • label: "~/​asciinema/" description: "Global recordings directory"
  • label: "Custom path" description: "Specify your own directory"

Based on selection:

• "$PWD/​tmp/" → Set OUTPUT_DIR="$PWD/​tmp"
• "~/​asciinema/" → Set OUTPUT_DIR="$HOME/​asciinema" and create if missing: mkdir -p ~/​asciinema
• "Custom path" → Use user's "Other" input as OUTPUT_DIR

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Phase 1.1: Recording Options

Purpose: Let user configure recording behavior.

Use AskUserQuestion:

• question: "Which recording options would you like?" header: "Options" multiSelect: true options:
  • label: "Add title/​description" description: "Include session title in recording metadata (-t flag)"
  • label: "Disable idle time limit" description: "Keep full pauses instead of 2s max (--idle-time-limit 0)"
  • label: "Quiet mode" description: "Suppress asciinema status messages (-q flag)"

Based on selections, build command flags:

• "Add title" → Continue to title selection question, add -t "title" flag
• "Disable idle time limit" → Add --idle-time-limit 0 flag
• "Quiet mode" → Add -q flag

If "Add title" was selected, follow up with:

• question: "Enter a title for this recording:" header: "Title" multiSelect: false options:
  • label: "Use workspace name" description: "Title: ${WORKSPACE}"
  • label: "Use workspace + datetime" description: "Title: ${WORKSPACE} ${DATETIME}"
  • label: "Custom title" description: "Enter your own title"

Based on title selection:

• "Use workspace name" → Set TITLE="${WORKSPACE}"
• "Use workspace + datetime" → Set TITLE="${WORKSPACE} ${DATETIME}"
• "Custom title" → Use user's "Other" input as TITLE

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Phase 1.2: Detect Context & Generate Command

Purpose: Generate a copy-paste ready recording command.

Step 1.2.1: Detect Workspace

Extract workspace name from $PWD:

/​usr/​bin/​env bash << 'SKILL_SCRIPT_EOF'
WORKSPACE=$(basename "$PWD")
echo "Workspace: $WORKSPACE"
SKILL_SCRIPT_EOF

Step 1.2.2: Generate Datetime

/​usr/​bin/​env bash << 'SKILL_SCRIPT_EOF_2'
DATETIME=$(date +%Y-%m-%d_%H-%M)
echo "Datetime: $DATETIME"
SKILL_SCRIPT_EOF_2

Step 1.2.3: Ensure Output Directory Exists

Create the output directory selected in Phase 1.0:

mkdir -p "${OUTPUT_DIR}"

Step 1.2.4: Construct Command

Build the recording command using:

• OUTPUT_DIR from Phase 1.0 (location selection)
• Flags from Phase 1.1 (options selection)
• TITLE if "Add title" was selected

# Base command
CMD="asciinema rec"

# Add flags from Phase 1.1 options
# (Claude builds this based on user selections)

# Final command format:
asciinema rec ${FLAGS} "${OUTPUT_DIR}/​${WORKSPACE}_${DATETIME}.cast"

Example outputs:

# Default (no options selected):
asciinema rec /​home/​user/​projects/​my-app/​tmp/​my-app_2025-12-21_14-30.cast

# With title + quiet mode:
asciinema rec -t "my-app Demo" -q /​home/​user/​projects/​my-app/​tmp/​my-app_2025-12-21_14-30.cast

# With all options:
asciinema rec -t "my-app 2025-12-21 14:30" -q --idle-time-limit 0 ~/​asciinema/​my-app_2025-12-21_14-30.cast

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Phase 2: User Guidance

Purpose: Explain the recording workflow step-by-step.

Present these instructions:

## Recording Instructions

1. **Exit Claude Code** - Type `exit` or press `Ctrl+D`
2. **Copy the command** shown above
3. **Paste and run** in your terminal (starts a recorded shell)
4. **Run `claude`** to start Claude Code inside the recording
5. Work normally - everything is captured
6. **Exit Claude Code** - Type `exit` or press `Ctrl+D`
7. **Exit the recording shell** - Type `exit` or press `Ctrl+D` again

Your recording will be saved to:
`$PWD/​tmp/​{workspace}_{datetime}.cast`

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Phase 3: Additional Info

Purpose: Provide helpful tips for after recording.

## Tips

- **Environment variable**: `ASCIINEMA_REC=1` is set during recording
- **Playback**: Use `asciinema-player` skill or `asciinema play file.cast`
- **Upload (optional)**: `asciinema upload file.cast` (requires account)
- **Markers**: Add `asciinema marker` during recording for navigation points

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TodoWrite Task Templates

Template: Record Claude Code Session

1. [Preflight] Check asciinema CLI installed
2. [Preflight] Offer installation if missing
3. [Context] Detect current workspace from $PWD
4. [Context] Generate datetime slug
5. [Context] Ensure tmp/ directory exists
6. [Command] Construct full recording command
7. [Guidance] Display step-by-step instructions
8. [Guidance] Show additional tips (playback, upload)
9. Verify against Skill Quality Checklist

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Post-Change Checklist

After modifying this skill:

1. Command generation still uses $PWD (no hardcoded paths)
2. Guidance steps remain clear and platform-agnostic
3. TodoWrite template matches actual workflow
4. README.md entry remains accurate
5. Validate with quick_validate.py

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CLI Options Reference

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Troubleshooting

"Cannot record from within Claude Code"

Cause: asciinema must wrap the program, not be started from inside.

Fix: Exit Claude Code first, then run the generated command.

"Recording file too large"

Cause: Long sessions produce large files.

Fix:

• Use asciinema upload to store online instead of locally
• Split long sessions into smaller recordings

"Playback shows garbled output"

Cause: Terminal size mismatch.

Fix: Use -r flag during playback to resize terminal.

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Reference Documentation

• asciinema CLI Documentation
• asciinema Markers

Post-Execution Reflection

After this skill completes, reflect before closing the task:

1. Locate yourself. — Find this SKILL.md's canonical path before editing.
2. What failed? — Fix the instruction that caused it.
3. What worked better than expected? — Promote to recommended practice.
4. What drifted? — Fix any script, reference, or dependency that no longer matches reality.
5. Log it. — Evolution-log entry with trigger, fix, and evidence.

Do NOT defer. The next invocation inherits whatever you leave behind.