zoetrope

Claude Code writes a JSONL transcript for every session under ~/.claude/projects/. zoetrope reads it and draws the session as a graph in your terminal: the main agent, the subagents and workflows it spawns, and the tools each one runs, updating live as it goes. Point it at a finished run and it replays, paced by the session's own timestamps. Point it at a running one and it follows along. It's read-only, and nothing leaves your machine.

Built on ratatui and rataflow.

Installation

cargo install zoetrope

The binary is zoe. Or build from source:

git clone https://github.com/furkankly/zoetrope
cd zoetrope
cargo build --release
./target/release/zoe

No install at all: try it in your browser. Drop a transcript on the page and get the same graph.

Usage

zoe                          # follow the current project's live session
zoe <dir>                    # follow another project's session
zoe <file.jsonl>             # replay a recording from the start
zoe <file.jsonl> --follow    # open a recording at its live edge
zoe <file.jsonl> --speed N   # playback speed (default 8.0)
zoe inspect <file.jsonl>     # print the session tree and exit (no TUI)

Give it a file and it reads the whole transcript, then keeps watching for new lines. Give it a directory, or no argument at all, and it finds the newest session in that project and follows it live. Whichever way you start, the controls are the same: scrub, follow, pause, jump back to live.

The same engine also runs in the browser, compiled to WebAssembly via ratzilla. Open a session from disk, or drop a transcript on the page. It stays local there too.

Features

The graph

• A node per agent: the main session, its subagents, and workflow groups with their children nested underneath
• Status, current tool, tool count and output tokens on every card
• Edges animate while an agent is working, and settle when it finishes
• Tool calls surface as chips beneath their agent (⚒ bash ×5, or ⚒ bash 0.5s ticking during a single call), resolving to ✓ or ✗
• A minimap showing where your viewport sits once the graph outgrows the screen

Time travel

• One scrubbable timeline over both live and replayed sessions
• Indexed by event rather than wall-clock, so a busy minute gets room instead of collapsing into a sliver
• Scrub, pause, step between prompt eras, or snap back to the live edge
• Seek backwards and you see the session exactly as it stood at that moment. Agents un-finish, tool counts fall, the graph shrinks back
• Optional gap compression, to skip dead air or keep faithful real-time pacing

Inspection

• Click any agent for its provenance: the prompt that spawned it, the reasoning around it, its model, and every tool call it made with timings
• Session info overlay: mode, permissions, queued ops, file edits, last prompt
• zoe inspect prints the whole tree headlessly, so it runs anywhere without a TTY

Reading your sessions

• Follows a running session live, or replays a finished one
• Reads everything a session writes: the main transcript, its subagents, and workflows with their own children, so the graph is the whole picture
• Keeps going when Claude Code writes something it hasn't seen: unfamiliar records are skipped, never fatal
• Read-only, and no network at all (see below)

Keys

space play/pause · [ ] prev/next prompt · End or g jump to live · drag the bar to seek · ? for everything else.

j / k scroll the detail panel when an agent is selected, otherwise they pan the graph.

Hand the camera to the action with f and it glides to whichever agent just did something. This is what watching a live run looks like:

Or drive it yourself: pan, zoom where you point, open an agent's panel, and drag the scrubber to travel back through the session.

Under the Hood

zoetrope treats the transcript as an append-only event log. It tails the files, parses each line defensively, and folds them into a derived model of agents, tool calls, and prompts. Nothing is mutated in place. The model is a pure function of the facts seen so far, so seeking backwards is exact.

A few of the pieces that turn a log into a watchable session:

• Two clocks, kept apart. Content time comes from the transcript's own timestamps; presentation time is the playhead you control. Every pacing decision (speed, gap compression, scrubbing) touches only the second one, so no display choice can ever alter what the session says happened.
• One timeline for live and replay. Behind the live edge it paces forward; at the edge it pins and folds in new appends as they land. A live session and a saved recording differ only in where the playhead starts. Same engine, same controls.
• Ground truth over heuristics. Parentage, completion and naming come from what the format actually records (a subagent's toolUseId, a workflow's runId, a journal result) rather than from guessing at strings or timing.
• You own the camera, not the history. The recording is immutable and the graph never rearranges itself under you (r to relayout). The camera follows the action until you touch it, then stays where you put it.
• Zero network, provably. There is no HTTP client anywhere in the dependency tree, and tokio is pulled in without its net feature. cargo tree is the proof. This is a property you can check, not a promise.

The model, the timeline and the rendering all live in the portable core, a library with no IO that compiles for any target, including WebAssembly. The native frontend (the zoe binary in this crate) and the browser frontend (the zoetrope-web crate under web/wasm/, which runs the hosted app) sit on top of it and differ only in their IO and event loop.

See docs/DESIGN.md for the module map and the transcript format, and docs/ARCHITECTURE.md for the invariants above in full.

A note on the transcript format

The JSONL format zoetrope reads is undocumented and internal to Claude Code, so it can change without warning. zoetrope is built to degrade rather than break: unrecognized records are skipped, missing fields fall back, and a malformed line never takes down the session. If a new Claude Code release makes something render oddly, please open an issue.

Contributing

Pull requests are welcome.

• This project follows Conventional Commits for all commit messages (e.g. feat(timeline): index the playhead by event instead of wall-clock, `fix(tailer): fold appends at the live edge withou