MIT /open source /C4 · DDD · governance

Architecture modelling,
not just drawing.

Diagrams go stale because the drawing is the document. Radical.Tools keeps one model — systems, containers, domains, decisions, requirements — and renders every diagram, table and wiki page from it. Change it once, every view follows.

Open Studio — free, in the browser Explore the Hub

No account, no cloud, no telemetry. Models are files on your disk — JSON or a folder of Markdown.

Metamodel01 The rules of your architecture: element and relation types, what may contain what, which properties each type carries. Three presets ship built in — C4, C4 + DDD, C4 + DDD + Governance — and a visual editor lets you extend or replace them. Model02 One graph of elements and relations, validated against the metamodel as you edit — wrong parent, wrong relation or too many of a kind are refused, not silently drawn. Add an element once and it exists in every view. Views03 Six readings of the same model: Structure diagrams, numbered Flow sequences, a drillable Hierarchy treemap, an editable Table, a dependency Matrix and a Wiki of element pages. Each view keeps its own scope, layout and camera. Milestones04 Freeze the model under a name at any point. Compare two milestones and see what was added, removed or changed as ghosts on the canvas; restore any of them. Decisions get a timeline.

Also in the box

Governance as first-class elements. ADRs, fitness functions and EARS requirements are model elements, linked to what they constrain, implement, satisfy or supersede. Type a requirement as a sentence — “When the user clicks save, the system shall persist the document” — and it is parsed into trigger, condition and action.
AI that edits the model, not the picture. Ask what depends on what, find gaps, or describe a change in plain language. The answer comes back as a patch that is validated against the metamodel, applied to the model and undoable. Claude, OpenAI, Gemini or local Ollama — your key, called directly, nothing proxied.
Concept Hub. 70+ curated requirements, ADRs, fitness functions, patterns and blueprints, rendered by the same engine as Studio. Fill in a template’s parameters, add it to your model, reconfigure later.
Layout that earns its name. Smart Layout runs layered (ELK), force-directed and simulated-annealing candidates, scores them for crossings and overlap, and keeps the best. Live physics keeps things tidy while you drag; a tree mode handles deep containment.
Three perspectives, one model. Designer edits. Viewer explores read-only — drag, collapse, re-layout without touching the saved model. Presenter turns views into slides that capture scope, layout and camera; flow views replay step by step.
Plain files, no lock-in. Save as a single .radical JSON file, or as a folder of Markdown — one .md per element with YAML front-matter, hierarchy as directories, layout in a sidecar. Diff it in git, edit it in any editor, script it. Autosaved either way.
Desktop, browser or VS Code — same code. The Electron app opens local files and folders and reloads a file you launched it with when it changes on disk. The web build needs no install and can still work on a local folder. The VS Code extension embeds the full editor for .radical files.

Start from the Hub

Don’t model from a blank canvas. Open a concept as a diagram, wiki page or table — exactly as it will look in your model — collect the ones you want and add them to Studio in one click.

Blueprints Patterns Requirements ADRs Fitness Functions

Run it locally

Node.js ≥ 18. The desktop app adds local folders, file watching and the Markdown-folder format with no browser permissions — or skip the install and use studio.radical.tools.

GitHub → Releases → Manual →

# clone, install, run
git clone https://github.com/radicaltools/radical.tools.git
cd radical.tools
npm install
npm run dev

Architecture modelling,not just drawing.

Also in the box

Start from the Hub

Run it locally

Architecture modelling,
not just drawing.