Append a new page (tab) to the current diagram WITHOUT touching existing pages or unsaved user changes. Use this when the user wants "another diagram alongside" — e.g. "add a CNN page" — instead of create_new_diagram which wipes everything.

Inputs:

• name: optional display name for the tab (defaults to Page-N where N = existing-page-count + 1)

• id: optional explicit page id; if omitted the server generates a short alphanumeric id

• xml: optional starting content: the mxCell elements of the page (root cells "0" and "1" are added), or a bare . If omitted, the page starts blank.

Returns the new page's id, name, and index so the caller can immediately target it with edit_diagram.

Create a NEW diagram, REPLACING the whole document: every page and any unsaved user changes (the previous state stays in History). To add a tab use add_page; to change cells use edit_diagram.

Before using icon shapes (AWS, Azure, GCP, Kubernetes, Cisco...), call get_shape_library first. Follow the drawing guide returned by start_session (call get_drawing_guide if it is no longer in your context). Pass screenshot: true on the last call of a complex diagram to check the result.

Accepted xml:

1. Only the mxCell elements of one page (recommended). The server adds , , and the root cells "0" and "1":

2. A bare with (one page).

3. A full with one or more pages. Every page's must start with .

Rules: cells are siblings (never nested), ids are unique per page and start from "2", parent only for shapes inside a container, no XML comments, and shapes stay within x 0 to 800 and y 0 to 600. A style used by several cells is defined once with before the cells and used by name (see the drawing guide); html=1 and whiteSpace=wrap are added automatically.

To clear the canvas to one blank page, send only the two root cells ; the previous diagram stays in History.

Delete a page (tab) from the current diagram. At least one of page_id / page_name / page_index is required. Refuses to delete the last remaining page — the editor needs at least one tab.

Edit a specific page in the current diagram by ID-based operations (update/add/delete cells).

All-or-nothing: if any operation fails, nothing is applied and every failure is listed.

Freshness: the server remembers the last diagram state you have seen, and rejects this call only if the user edited the diagram in the browser since then. You do NOT need to call get_diagram before every edit: a rejected call changes nothing and includes the current XML of the page, so you can rebuild your operations and retry.

Call get_diagram first only when you don't know the current diagram content (cell IDs, structure) — e.g. the diagram wasn't created in this conversation, or you're unsure your memory of it is accurate.

Multi-page targeting:

• page_id / page_name / page_index are optional; when all omitted, the FIRST page is targeted

• Use list_pages to discover what pages exist

Operations:

• add: Add a new cell. Provide cell_id (new unique id within the page) and new_xml. One cell per operation.

• update: Replace an existing cell by its id. Provide cell_id and complete new_xml.

• delete: Remove a cell by its id. Only cell_id is needed. Its children and connected edges are deleted too, so give only a container's id.

For add/update, new_xml is the complete mxCell (inside its wrapper when it has custom data, see the drawing guide) in the compact form (a shape with x, y, w, h; an edge with source and target). No XML comments. Every " inside new_xml must be escaped as " in the JSON.

Example - Add a rectangle on the default (first) page: {"operations": [{"operation": "add", "cell_id": "rect-1", "new_xml": "<mxCell id="rect-1" value="Hello" style="rounded=1;" x="100" y="100" w="120" h="60"/>"}]}

Example - Delete a cell on the default page: {"operations": [{"operation": "delete", "cell_id": "rect-1"}]}

Export the current diagram to a file. Supports .drawio (XML), .png, .svg, and .drawio.svg (an SVG with the diagram embedded, which draw.io and load_diagram can open again). The format is auto-detected from the file extension, or can be specified explicitly. Images get a 20 px margin; a PNG has a white background (or the page's own background color) unless transparent is true.

Multi-page behaviour:

• .drawio with NO page selector: writes the full (all pages).

• .drawio with a page selector: writes a single-page containing only that page.

• .png / .svg with NO page selector: exports the currently active page in the browser.

• .png with a page selector: renders that page without changing what the user sees.

• .svg / .drawio.svg with a page selector: temporarily loads that page into the browser, captures it, then restores the full document (the user sees a brief flicker).

Get the current diagram XML (fetches latest from browser, including user's manual edits). Call this when you don't know the current diagram content (cell IDs, pages, structure) — e.g. before editing a diagram you didn't create in this conversation, or after edit_diagram was rejected because the user changed the diagram in the browser.

Returns the full by default. If a page selector is provided, returns just that page's embedded in a one-page wrapper.

Return the drawing guide: XML format, layout, edge routing, style and editing rules. start_session already returns it; call this only if the guide is no longer in your context. With topic, returns a short XML reference for tables, layers or groups.

Return the cells the user has selected in the preview: their ids and labels, for edges the source and target ids, for shapes the position and size, and the page they are on. Call this when the user refers to what they selected ("this box", "these arrows", "the selected shapes"), then act on the ids with edit_diagram. Says when nothing is selected. Needs the preview tab to be open.

Get the style syntax and shape names of a draw.io icon library. Call this BEFORE drawing with cloud, network or other icon shapes, and use the exact names it returns; never guess them.

Libraries:

• Cloud: aws4, azure2, gcp2, alibaba_cloud, openstack, salesforce

• Networking: cisco19, network, kubernetes, vvd, rack

• Business: bpmn, lean_mapping

• General: flowchart, basic, arrows2, infographic, sitemap

• UI/Mockups: android, material_design

• Enterprise: citrix, sap, mscae, atlassian

• Engineering: fluidpower, electrical, pid, cabinets, floorplan

• Icons: webicons

List every page (tab) in the current diagram. Returns each page's id, name, 0-based index, and cell count. Use this to discover what pages exist before targeting one with edit_diagram, get_diagram, export_diagram, rename_page, or delete_page.

List the diagrams saved by earlier sessions (auto-save files), newest first, with their pages. Continue one with start_session session_id=; the file path also works with load_diagram.

Load a .drawio diagram into the current session, REPLACING the entire diagram (all pages). To change an existing file, load it here, edit with edit_diagram, then export_diagram to the same path; never rewrite the file by hand. Provide ONE of two mutually exclusive sources: 'path' (the server reads the file from disk — you do NOT need to read the file yourself or pass its XML through create_new_diagram) or 'xml' (the raw file content you already have — from another tool, a repository read, or an API response — so no temporary file needs to be written first). Both accept plain XML and draw.io's compressed save format. .drawio.svg (Editable SVG, the format export_diagram writes) is accepted too; .png files (also draw.io's editable PNG) and plain .svg files cannot be loaded.

After loading from 'path' (or from compressed 'xml'), call get_diagram before edit_diagram — you haven't seen the file's cell IDs yet. Plain-XML 'xml' content you supplied yourself is already known and can be edited immediately.

Rename an existing page (tab). At least one of page_id / page_name / page_index is required to identify which page to rename. The new_name becomes the visible tab label in the editor.

Undo: put an earlier version of the diagram from History back on the canvas (the current canvas is kept in History, so this can be undone too). Use it when the user asks to undo, revert or go back.

Render the diagram in the preview and return it as a PNG image, so you can see your own result. Call this once after drawing or heavily editing a complex diagram, then fix overlaps and edges that cross shapes. Without a page selector it shows the page on screen; with one it renders that page without changing what the user sees. Needs the preview tab to be open.

Start a new diagram session, or continue a saved one with session_id, and open the browser for real-time preview. Starts an embedded server and opens a browser window with draw.io. The browser will show diagram updates as they happen. The result includes the drawing guide; follow it when drawing.