A branching Python notebook canvas. Cells form a DAG instead of a linear list — split execution into parallel branches, compare results side-by-side, and converge.
Forkbook Core is open source and local-first. Forkbook Cloud is paid for teams, sync, storage, AI, and compute.
Run Python, see streaming output
Split into branches, compare strategies side by side
Most notebooks force you into a single linear chain of cells. Forkbook lets you:
- Fork any cell into multiple parallel branches
- Run branches independently with separate outputs
- Compare results side-by-side on a canvas
- Converge branches back into a single cell
- Drag nodes freely on a whiteboard-style canvas
Built for research workflows where you want to try multiple approaches without copying an entire notebook.
Requires Python 3.10+ and Node 18+.
git clone https://github.com/yourname/forkbook
cd forkbook
# Windows
start-dev.bat
# Linux / Mac
./start-dev.shFrontend: http://localhost:5173
Backend: http://localhost:8000
# Terminal 1 — backend
cd backend
python -m venv .venv
.venv/Scripts/activate # Windows
# source .venv/bin/activate # Linux/Mac
pip install -r requirements.txt
uvicorn app.main:app --reload
# Terminal 2 — frontend
cd frontend
npm install
npm run dev| Layer | Tech |
|---|---|
| Backend | FastAPI, SQLite, SQLAlchemy async, jupyter_client |
| Frontend | React, Vite, React Flow, CodeMirror 6, Zustand, Tailwind |
| Execution | Jupyter kernel (real Python, streaming output via WebSocket) |
- One Jupyter kernel per notebook — shared state across all branches
- Cells stored in SQLite with
parent_idforming the tree - Run — executes ancestors then the cell
- Run Only — executes just that cell
- Run All — topological sort across all branches
- WebSocket per notebook at
/ws/{notebook_id}streams output live
Forkbook Core is licensed under the GNU Affero General Public License v3.0.
AGPL means: you can use, modify, and distribute the code freely, including commercially — but if you run a modified version as a network service, you must publish your source code under the same license.
Forkbook Cloud — team workspaces, cloud sync, version history, shared compute, AI assistant, and enterprise features — is a separate commercial product.
Issues and pull requests are welcome. See CONTRIBUTING.md for guidelines.