ASysT Rendering — SysML v2 Viewer (early preview)

ASysT Rendering does what its name says: it renders your SysML v2 models. It is a viewer and layouter — not another editor: open a .sysml file (or a whole folder treated as one model) and get live, navigable diagrams beside your code — structure, internal wiring (ports & connections), state machines, action flows, requirements tables, sequences. Drill into parts, arrange and colour boxes, save named renderings, export diagrams and reports.

ASysT never touches your model. Your .sysml files are opened strictly read-only — ASysT will never rewrite, reformat, or "fix" your source, ever. The only things it writes are a few of its own small sidecar files next to your model: Rendering/*.asystrendering (your saved arrangements), a *.asystsession (where you left off), and — only if you ask for it — an asyst.manifest.json (treat this folder as one model). All plain text, all git-friendly, all safe to delete.

100% local. No cloud, no account, no telemetry. Your models never leave your machine.

This is an early preview shared for feedback. Expect rough edges — and please send notes! 🙏 Feedback, feature requests, bugs: asyst.rendering@gmail.com

Free, Alpha & Pro

Installing is free, and during the alpha release everyone runs the Alpha tier automatically — the Pro work products are open so you can test them. The header chip shows your tier.

¹ Bigger models still open, render and navigate — beyond the size cap, cross-file resolution covers the first 25 files and a banner explains what's missing. ² Diagrams that already carry colours always display them; the tier gates the colour-editing menus.

Pro keys (monthly or 1-year) unlock everything: during the alpha they are issued personally by the author — write to asyst.rendering@gmail.com. You'll receive a small license.asystkey file; put it at %APPDATA%\ASysT\license.asystkey and restart ASysT.

Enterprise — the same capabilities as Pro today, for larger organizations (volume licensing, invoicing): contact asyst.rendering@gmail.com.

1. Prerequisite (just one)

You only need Visual Studio Code (free): https://code.visualstudio.com/ — download "for Windows", run the installer, and open it. ASysT bundles everything else (the SysML engine + its runtime), so there's nothing else to install.

(Windows only for this preview.)

2. Install the extension

From the Marketplace (the normal way): open the Extensions panel in VS Code (the squares icon on the left, or Ctrl+Shift+X), search for "ASysT", and click Install. Updates arrive automatically.

From a .vsix file (if you were sent one directly): in the Extensions panel, click the ··· menu at the top → "Install from VSIX…" → pick the file. (Or Ctrl+Shift+P → "Install from VSIX".)

3. Use it

1. Open a SysML file (.sysml or .kerml) in VS Code.
2. Click "ASyst: Open Diagram" in the top-right of the editor toolbar — or press Ctrl+Shift+P and run "ASyst: Open Diagram".
3. A panel opens beside your file with the diagram.
   • The left panel is the project explorer (your files + saved layouts).
   • The right panel is Tools (legend, filter, auto-layout).
   • Drag nodes to arrange them; positions are saved next to your model under Rendering/*.asystrendering.

First run takes a few seconds while the local engine starts. Windows may show a firewall prompt for the engine listening on localhost — this is local-only; Allow it (Private networks).

4. If something looks wrong

• Blank panel / "did not become ready": reload the window (Ctrl+Shift+P → "Developer: Reload Window"), and if Windows showed a firewall prompt, make sure you clicked Allow.
• Another app is using port 8080: this preview's local engine uses port 8080. If something else on your machine already occupies it (a dev server, another tool), the panel can come up broken — stop that other app and reload the window. A dynamic-port version is on the roadmap.
• A blue "Windows protected your PC" screen (SmartScreen): can appear the first time the local engine runs, because it's a new unsigned binary. Click "More info" → "Run anyway" — the engine is local-only (it binds 127.0.0.1, see §5) and never phones home.
• See the logs: View → Output, pick "ASysT" in the dropdown. Share those if you report a bug.
• It never touches your .sysml content — it only reads it and saves diagram layout files.

5. Privacy & data

• No telemetry. ASysT sends nothing about you or your usage anywhere.
• No network calls beyond localhost. The bundled engine binds 127.0.0.1 only — it is not reachable from your network, and it never phones home. (The one exception: activating a Pro license key, if you have one, validates that key with our licensing provider — nothing else.)
• Your models never leave your machine. ASysT reads your .sysml files locally and writes only its own sidecar files next to them (Rendering/*.asystrendering, *.asystsession) — never your model source.
• Local logs, for your own troubleshooting. ASysT writes a small local log (.asyst/logs/frontend.jsonl, backend.log) so you — or we, if you choose to share it — can debug a problem. These logs can include file paths and element names from your model; review them before attaching to a bug report if your model is sensitive.

Send feedback, feature requests, or bugs to asyst.rendering@gmail.com — thanks for testing! 🛠️