lopecode
Lopecode
Lopecode is a web-based modable programming environment where a small microkernel core defines minimal features to enable live coding applications to be built.
The kernel has no UI and defines programming mechanisms for
- reactive dataflow programming model
- hot code swapping
- modules
Everything else is implemented in userspace, including code editors and a multi-notebook UI which can be live edited. There is no external source code, instead the runtime itself is decompiled on demand, according to a runtime-is-the-source-of-truth principle.
One userspace module, the Exporter, can self-serialize the entire runtime to a single HTML file, so you can use it offline from the local filesystem. There are no dependencies other than a web browser.
Table of Contents
Gallery
Browse all notebooks at the Lopebook Gallery.
Getting Started
| Notebook | Description |
|---|---|
| Blank Notebook | Start here — a fresh notebook with links to guides and resources |
| Tour of Lopecode | Interactive introduction to lopecode and what you can build |
| Vision Statement | The endgoal explained — itself a hackable lopebook |
| How the Observable Runtime Works | Living documentation on the underlying runtime |
Applications
| Notebook | Description |
|---|---|
| RISC-V Linux SBC | Browser-based RV32IMA emulator that boots Linux 6.1 with BusyBox shell |
| ATProto Comments | Read-only Bluesky comments widget — fetches and displays AT Protocol post threads |
| Notes | Offline notetaking app using Dexie.js, with detailed technical design |
| Audio Sequencer | Non-trivial application with persistent runtime state |
| Circular Barcode Simulator | Simplifying pose estimation with circular barcodes |
| Fast 1D Circular Barcode Matching | Barcode matching via the Mobius transform |
| SARS-CoV-2 Analytics | Natural selection analysis of SARS-CoV-2 |
| Unaggregating CloudWatch Metrics | AWS CloudWatch metric unaggregation |
Platform Modules
| Notebook | Description |
|---|---|
| Exporter 2 | Single-file serializer — self-exports the runtime to HTML |
| Editor 5 | Reactive userspace cell editor (CodeMirror-based) |
| Lopepage | Multi-notebook split-pane UI layout |
| Lopepage URLs | URL DSL for lopepage layouts |
| Module Selection | Explorer for composing modules into notebooks |
| Jumpgate | Transforms Observable notebooks to lopecode |
| Local Change History | Persistent local change tracking |
| Secrets | AES-256-GCM encrypted key-value storage in notebook source code |
Developer Tools
| Notebook | Description |
|---|---|
| Atlas | Runtime overview visualization |
| Debugger | Notebook dataflow debugger (ndd) |
| Cell Map | Maps reactive variables to notebook cells, grouped by module |
| Reactive Reflective Testing | Reactive testing framework for lopebooks |
| Notebook Semantics | Test notebook for runtime semantics |
| Dataflow Templating | Dynamic dataflow templating — function-like semantics for dataflow |
| Spectral Layout | Minimize crossings with spectral circular graph layout |
AI Collaboration
| Notebook | Description |
|---|---|
| Claude Code Pairing | Claude Code notebook collaboration |
| Roboco-op 2.1 | AI notebook collaborator |
| Roboco-op 3 | Agents-as-functions |
Experiments
| Notebook | Description |
|---|---|
| Editable Markdown | Inline editable markdown |
| Direct Manipulation Plot | Direct manipulation for plots |
| My Lopebooks | Personal lopebooks index |
| Compile Zig | Zig compiler running in-browser via WASM — fully offline |
Feel free to open discussions and bugs in the Github repository