MIT / open source / C4 & beyond

Architecture modelling,
not just drawing.

Diagrams go stale because the drawing is the document. Radical.Tools makes the model the document - views are derived from it, always consistent.

How it works ↓ Run locally ↓
How it works

Four layers. One source of truth.

Metamodel defines the rules. Model holds the truth. Views render slices. Milestones track history.

01

Metamodel

The vocabulary of your architecture.

Defines what kinds of things can exist: node types, relation types, allowed properties. C4 ships by default - Person, Software System, Container, Component. Extend it or replace it entirely. More metamodels are coming.

Person → uses → Software System metamodel rule
02

Model

The single source of truth.

A graph of concrete nodes and relations that conforms to the metamodel. Add an element once - it's available in every view. No copy-pasting between diagrams. No drift between levels.

PaymentService → calls → StripeAPI model instance
03

View

A filtered window onto the model.

Different audiences need different levels of detail. Static views show structure - System Context, Containers, Components. Dynamic views show interaction sequences with numbered steps on the edges. Each view has its own layout, the model stays shared.

Dynamic View → Login flow: 1 → 2 → 3 view instance
04

Milestone

A named snapshot of the model.

Tag any state of the model with a name and date. Browse history, diff two milestones side by side, and restore any previous state. Architecture decisions get a timeline.

v2 → v3 diff: +3 nodes, -1 relation milestone diff
Features

Beyond the model itself.

Milestones & History

Name a snapshot at any moment. Browse history, diff two versions side by side, and restore a previous state with one click.

Smart Layout

Three layout engines: ELK (hierarchical), WebCola (live force-directed), and a simulated-annealing pipeline tuned for crossing minimisation.

AI Analysis

Ask the model questions, detect gaps, or describe a change in plain language and let an LLM apply it as a structured patch. Works with Claude, OpenAI, Gemini, and local Ollama - your key, your API, nothing proxied.

Desktop & Web

Electron desktop app or browser - same codebase, same file format. No account, no cloud, no telemetry.

Presentation Mode

Sequence views into a slide deck. Dynamic views replay interaction flows step by step. Fullscreen walkthrough turns any model review into a structured session.

Plain JSON, No Lock-in

Models are JSON files on your disk. Diff in git, edit in any text editor, automate with any script.

Screenshots

What it looks like.

Radical.Tools main canvas - C4 banking architecture diagram with 27 nodes, left panel showing element types, right panel showing node tree
Designer Full C4 model on the canvas. Element palette on the left, node tree on the right. Smart Layout arranges everything automatically.
Milestones panel showing v1 through v4 history of the architecture with node counts and dates
Milestones Named snapshots with dates and node counts. Diff any two versions visually, restore with one click.
Viewer / presentation mode showing views list and slide deck at the bottom with Present button
Viewer Sequence views into a slide deck. Hit Present for a fullscreen, presenter-ready walkthrough.
Install

Run it locally.

Node.js ≥ 18, npm ≥ 9.

Terminal
# Clone the repository
git clone https://github.com/tomasz-zajac-opensource/radical.tools.git
cd radical.tools

# Install dependencies
npm install

# Start in development mode
npm run dev

# Build for production
npm run build && npm start
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