Session Replay

Session Replay

Turn a Claude Code session JSONL file into an animated GIF that plays back the conversation as typed terminal output.

The skill orchestrates three steps: parse the session file into turns, generate a VHS tape from those turns, and hand off to scry for GIF rendering.

When To Use

• Creating demos of development workflows
• Adding visual evidence to pull requests
• Sharing session highlights to Slack or GitHub
• Embedding session replays in tutorials

When NOT To Use

• Writing blog posts from sessions (use scribe:session-to-post)
• Generating API documentation (use scribe:doc-generator)
• Recording live terminal commands (use scry:vhs-recording directly)

Integration Points

Workflow

Step 0: Pick a Session (when no path is provided)

When the user invokes /session-replay without a path argument, use scribe.session_parser.list_sessions() to discover recent session files from ~/.claude/projects/.

The function returns a list of SessionInfo objects sorted by modification time (most recent first), each containing:

• path: full path to the .jsonl file
• modified: mtime timestamp
• first_user_message: preview of the first human message
• turn_count: number of user turns in the session
• project_name: parent directory name

Present the list to the user as a numbered menu:

Recent sessions:
 1. [my-project] "implement auth module" (8 turns, 2h ago)
 2. [api-server] "fix rate limiting bug" (3 turns, 5h ago)
 3. [docs-site]  "update installation guide" (12 turns, 1d ago)

Ask the user to pick a number. Use the selected session's path for the remaining steps.

If list_sessions returns an empty list, report that no sessions were found and suggest providing a path directly.

Step 1: Parse the Session

Use scribe.session_parser.parse_session() to read the JSONL file. The parser:

• Extracts user and assistant turns
• Skips sidechain (subagent) records
• Collapses tool calls into readable summaries
• Wraps text at the configured column width
• Truncates long responses at the configured row count

Apply filters based on user options:

• --turns selects specific turn ranges (e.g. 1-5)
• --show controls which layers appear: user, assistant, tools, thinking (thinking is excluded by default)

Step 2: Generate VHS Tape

Use scribe.tape_generator.generate_tape() to convert the parsed turns into a VHS tape file. The generator:

• Creates the Output directive and Set commands
• Types user messages at 30ms/char with $ prefix
• Types assistant responses at 15ms/char
• Types tool summaries at 100ms with two-space indent
• Adds 1.5s pauses between turns
• Holds the final frame for 3s
• Scales all timing by the --speed multiplier
• Truncates when --max-duration is exceeded

Write the tape to a temp file: {tempdir}/session-replay-{timestamp}.tape

Step 3: Render GIF

Invoke Skill(scry:vhs-recording) with the tape file path. Scry validates the tape, runs VHS, and produces the GIF at the path specified in the Output directive.

After successful rendering, delete the temp tape file.

Error Handling

Example

# Pick from recent sessions interactively
/session-replay

# Replay a specific file directly
/session-replay ~/.claude/projects/my-project/abc123.jsonl

# First 5 turns only, faster playback
/session-replay --turns 1-5 --speed 1.5

# Show only the conversation, no tool calls
/session-replay --show user,assistant --output demo.gif

Output (interactive picker):

Recent sessions:
 1. [my-project] "implement auth module" (8 turns, 2h ago)
 2. [api-server] "fix rate limiting bug" (3 turns, 5h ago)
 3. [docs-site]  "update installation guide" (12 turns, 1d ago)

Pick a session [1-3]: 1

Parsed 42 turns from session (12 user, 15 assistant, 15 tools)
Generated tape: /tmp/session-replay-1711234567.tape
Rendering GIF via scry...
Done: session-replay.gif (18s, 960x540)

Exit Criteria

• VHS tape file written to {tempdir}/session-replay-{timestamp}.tape before rendering is attempted
• GIF produced at the path specified in the tape's Output directive and its size reported (duration, dimensions)
• Temp tape file deleted after the GIF renders successfully
• If VHS is not installed, error reported with the install command go install github.com/charmbracelet/vhs@latest rather than silently failing
• If no JSONL path is given and list_sessions() returns empty, user is told no sessions were found and directed to provide a path directly

Source: athola/claude-night-market → plugins/scribe/skills/session-replay/SKILL.md