Unify CALM authoring and visualisation tooling (Hub, VS Code, Studio)

[rocketstack-matt]

Feature Proposal

Important

This issue supersedes #2600 (Consolidate the CALM platform) and #2857 (CalmStudio roadmap H2 2026). Both are closed in favour of this one. The direction agreed on 2026-07-28 (#2857 comment, WG 2026-07-28) is the starting point here, not the desktop-Studio target state in #2600.

Target Project:

Cross-cutting: calm-hub, calm-hub-ui, calm-plugins/vscode, calm-widgets, shared, calm-models, calm-studio. Led by @byrash, with @jpgough-ms and @initcron contributing.

Description of Feature:

Unify the CALM authoring and visualisation tooling onto one stack:

Layer	Target
Visualisation	One React Flow visualisation package, used by CALM Hub UI and the VS Code extension
Layout	One layout model (x, y, w, h per node), persisted identically by Hub and VS Code
Editing	Hub gains a studio mode (edit node/relationship properties, save through the Hub API); VS Code extension edits the same documents
Backend	CALM Hub API decoupled from Hub UI; OIDC and Git/SCM backing stores
CalmStudio	Useful pieces (node packs, palette, validation panel, nested containers) move into Hub; the SvelteKit app retires at parity

Enterprises that must stay read-only get Hub in standalone mode; studio mode is opt-in.

User Stories:

• As an architect, I want the same diagram in Hub and VS Code so that a layout I save in one renders identically in the other.
• As an architect, I want to edit an architecture visually in Hub or VS Code so that I do not need a third tool.
• As a platform owner, I want one visualisation stack so that a rendering fix is made in one place.
• As an enterprise admin, I want Hub to run read-only so that governed content cannot be edited in place.

Current Limitations:

• Three renderers (Hub UI, VS Code extension, CalmStudio) with divergent layout formats.
• CalmStudio duplicates validation, MCP, and node packs the platform already owns.
• Hub UI and Hub API are coupled; Hub has no edit surface.

Proposed Implementation:

Tracked as sub-issues of this issue. Existing issues are attached as-is; new ones are opened as phases start.

Phase	Scope	Issue
1	VS Code extension on React Flow, with editing	#2869
1	Layout persistence parity Hub ↔ VS Code	#2953
1	Controls at interface level	#2868
1	SVG import in VS Code	#3025
2	Extract shared React Flow visualisation package	new
2	Hub API independent of Hub UI	#2943
2	Multi-IDP developer experience	#2944
2	OIDC + Git/SCM backing store	#2867, PR #3001
3	Studio mode MVP in Hub	new
3	Modes design note (standalone vs studio)	new
4	Migrate node packs, palette, validation panel, nested containers from CalmStudio	new
4	Retire the SvelteKit app	new

Disposition of the #2600 track issues:

Issue	Disposition
#2649 Track A structural cleanup	Stays open; still valid
#2650 Track B capability convergence	Stays open; validator/MCP convergence still applies
#2651 Track C Studio as desktop editor	Close; superseded by phases 3–4
#2652 Track D docs consolidation	Stays open
#2690 RFC shared semantics layer	Folds into the phase 2 visualisation package

Testing Strategy:

Per sub-issue. The shared visualisation package needs a render-parity test between Hub UI and the VS Code extension.

Documentation Requirements:

• Hub docs: standalone vs studio mode.
• VS Code extension docs (PR docs(vscode): update documentation for CALM Canvas v1.0.0 #2937 in flight).
• Migration note for CalmStudio users at retirement.

Implementation Checklist:

• Design reviewed and approved
• Implementation completed
• Tests written and passing
• Documentation updated
• Relevant workflows updated (if needed)
• Performance impact assessed

Additional Context:

The static render path (calm-widgets, docs embed, SVG export) stays separate from the interactive React Flow canvas: one set of view semantics, two render targets. Views (#2344) are the common contract.

The #2857 thread proposed @jpgough-ms as lead. I would like input from the other maintainers here on whether @byrash leads overall with Jim owning the Hub pieces, or the reverse.

[byrash]

Hello @rocketstack-matt ,

Adding more details on what is expected and being implemented out of this issue along with changes being done.

Thank You.

CALM.mp4