Optional MCP Tools

These MCP tools support live browser editing. They are not the default runtime for Draw.io Skill 2.2.0.

Use them only when:

• next-ai MCP is configured
• the user wants real-time browser refinement

The default workflow is still offline-first with .drawio + sidecars.

start_session

Open a new browser editing session.

Purpose

• start the embedded HTTP server
• open draw.io in the browser
• create a live session bridge for later tool calls

Parameters

None.

Notes

• required before any other MCP diagram calls
• intended only for live refinement workflows

create_new_diagram

Create a new diagram from full mxGraphModel XML.

Parameters

Name	Required	Description
xml	Yes	Full mxGraphModel XML string

Notes

• use for fresh diagrams or full replacement
• IDs 0 and 1 remain reserved root cells

get_diagram

Fetch the latest diagram XML from the browser.

Why it matters

Always call get_diagram before edit_diagram so you do not overwrite manual edits made in the browser.

edit_diagram

Update, add, or delete cells by ID.

Parameters

Name	Required	Description
operations	Yes	Array of update, add, or delete operations

Operation shape

Field	Required	Description
operation	Yes	update, add, or delete
cell_id	Yes	Existing ID for update/delete, new ID for add
new_xml	For add/update	Full <mxCell> element including <mxGeometry>

export_diagram

Export the current live diagram to disk.

Parameters

Name	Required	Description
path	Yes	Output file path
format	No	drawio, png, or svg; inferred from extension when omitted

Live Workflow

1. start_session
2. create_new_diagram
3. get_diagram
4. edit_diagram
5. export_diagram

When Not to Use MCP

Prefer the local CLI and sidecar bundle when:

• you are creating a diagram from scratch without needing a browser
• you want version-controlled edits
• you need repeatable export commands
• you are working in CI or scripted environments

Related

• Getting Started
• Editing Diagrams
• Export & Save