Issues/1546

packages/client/src/default-modules.ts

@@ -63,6 +63,7 @@ import { toolFocusLossModule } from './features/tools/tool-focus-loss-module';
 import { markerNavigatorModule, validationModule } from './features/validation/validation-modules';
 import { viewportModule } from './features/viewport/viewport-modules';
 import { zorderModule } from './features/zorder/zorder-module';
+import { mcpModule } from './mcp/mcp-module';
 
 export const DEFAULT_MODULES = [
     defaultModule,
@@ -104,7 +105,8 @@ export const DEFAULT_MODULES = [
     statusModule,
     resizeModule,
     searchPaletteModule,
-    searchPaletteDefaultSuggestionsModule
+    searchPaletteDefaultSuggestionsModule,
+    mcpModule
 ] as const;
 
 /**

packages/client/src/index.ts

@@ -230,6 +230,9 @@ export * from './features/viewport/viewport-tool';
 export * from './features/viewport/zoom-viewport-action';
 export * from './features/zorder/bring-to-front-command';
 export * from './features/zorder/zorder-module';
+export * from './mcp/mcp-export-png';
+export * from './mcp/mcp-get-selection';
+export * from './mcp/mcp-module';
 export * from './model';
 export * from './re-exports';
 export * from './standalone-modules';

packages/client/src/mcp/mcp-export-png.ts

@@ -0,0 +1,182 @@
+/********************************************************************************
+ * Copyright (c) 2026 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import {
+    Action,
+    CommandExecutionContext,
+    CommandResult,
+    ExportPngMcpAction,
+    ExportPngMcpActionResult,
+    GModelElement,
+    GModelRoot,
+    HiddenCommand,
+    isExportable,
+    isHoverable,
+    isSelectable,
+    isViewport,
+    IVNodePostprocessor,
+    TYPES
+} from '@eclipse-glsp/sprotty';
+import { inject, injectable } from 'inversify';
+import { VNode } from 'snabbdom';
+import { GLSPSvgExporter } from '../features/export/glsp-svg-exporter';
+
+/**
+ * This class extends {@link GLSPSvgExporter} in order to make use of the SVG creation logic.
+ * It then uses the SVG string to generate an equivalent PNG instead.
+ *
+ * This class should not be used for standard SVG generation, but only for generating PNG for MCP purposes.
+ */
+@injectable()
+export class GLSPMcpPngExporter extends GLSPSvgExporter {
+    async exportPng(root: GModelRoot, request?: ExportPngMcpAction): Promise<void> {
+        if (!request) {
+            return;
+        }
+
+        return new Promise((resolve, reject) => {
+            if (typeof document === 'undefined') {
+                reject(new Error('Failed to find document.'));
+                return;
+            }
+
+            let svgElement = this.findSvgElement();
+            if (!svgElement) {
+                reject(new Error('Failed to find SVG element.'));
+                return;
+            }
+
+            svgElement = this.prepareSvgElement(svgElement, root);
+            const serializedSvg = this.createSvg(svgElement, root, request?.options ?? {}, request);
+            const svgExport = this.getSvgExport(serializedSvg, svgElement, root);
+
+            const svgBlob = new Blob([svgExport], { type: 'image/svg+xml;charset=utf-8' });
+            const url = URL.createObjectURL(svgBlob);
+
+            const img = new Image();
+
+            img.onload = async () => {
+                try {
+                    const bitmap = await createImageBitmap(img);
+
+                    const aspect = bitmap.width / bitmap.height;
+                    const width = request?.options?.width ?? 1024;
+                    const height = width / aspect;
+                    const offscreen = new OffscreenCanvas(width, height);
+                    const ctx = offscreen.getContext('2d');
+
+                    if (!ctx) {
+                        reject(new Error('Failed to get offscreen context.'));
+                        return;
+                    }
+
+                    ctx.fillStyle = 'white';
+                    ctx.fillRect(0, 0, width, height);
+                    ctx.drawImage(bitmap, 0, 0, width, height);
+
+                    const outBlob = await offscreen.convertToBlob({ type: 'image/png' });
+                    const reader = new FileReader();
+                    reader.onloadend = () => {
+                        URL.revokeObjectURL(url);
+                        const result = reader.result as string;
+                        this.actionDispatcher.dispatch(
+                            ExportPngMcpActionResult.create(
+                                result.replace('data:image/png;base64,', ''),
+                                request.mcpRequestId,
+                                request.options
+                            )
+                        );
+                        resolve();
+                    };
+                    reader.readAsDataURL(outBlob);
+                } catch (err) {
+                    reject(err);
+                }
+            };
+
+            img.onerror = () => {
+                URL.revokeObjectURL(url);
+                reject(new Error('Failed to load SVG into image element.'));
+            };
+
+            img.src = url;
+        });
+    }
+}
+
+/**
+ * See sprotty's `ExportSvgCommand`
+ */
+export class ExportPngMcpCommand extends HiddenCommand {
+    static readonly KIND = ExportPngMcpAction.KIND;
+
+    constructor(@inject(TYPES.Action) protected action: ExportPngMcpAction) {
+        super();
+    }
+
+    execute(context: CommandExecutionContext): CommandResult {
+        if (isExportable(context.root)) {
+            const root = context.modelFactory.createRoot(context.root);
+            if (isExportable(root)) {
+                if (isViewport(root)) {
+                    root.zoom = 1;
+                    root.scroll = { x: 0, y: 0 };
+                }
+                root.index.all().forEach(element => {
+                    if (isSelectable(element) && element.selected) {
+                        element.selected = false;
+                    }
+                    if (isHoverable(element) && element.hoverFeedback) {
+                        element.hoverFeedback = false;
+                    }
+                });
+                return {
+                    model: root,
+                    modelChanged: true,
+                    cause: this.action
+                };
+            }
+        }
+        return {
+            model: context.root,
+            modelChanged: false
+        };
+    }
+}
+
+/**
+ * See sprotty's `ExportSvgPostprocessor`
+ */
+@injectable()
+export class ExportPngMcpPostprocessor implements IVNodePostprocessor {
+    protected root: GModelRoot;
+
+    @inject(GLSPMcpPngExporter)
+    protected pngExporter: GLSPMcpPngExporter;
+
+    decorate(vnode: VNode, element: GModelElement): VNode {
+        if (element instanceof GModelRoot) {
+            this.root = element;
+        }
+        return vnode;
+    }
+
+    postUpdate(cause?: Action): void {
+        if (this.root && cause !== undefined && cause.kind === ExportPngMcpAction.KIND) {
+            this.pngExporter.exportPng(this.root, cause as ExportPngMcpAction);
+        }
+    }
+}

packages/client/src/mcp/mcp-get-selection.ts

@@ -0,0 +1,58 @@
+/********************************************************************************
+ * Copyright (c) 2026 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import {
+    Command,
+    CommandExecutionContext,
+    CommandReturn,
+    GetSelectionMcpAction,
+    GetSelectionMcpResultAction,
+    IActionDispatcher,
+    isSelectable,
+    toArray,
+    TYPES
+} from '@eclipse-glsp/sprotty';
+import { inject, injectable } from 'inversify';
+
+@injectable()
+export class GetSelectionMcpCommand extends Command {
+    static readonly KIND = GetSelectionMcpAction.KIND;
+
+    @inject(TYPES.IActionDispatcher)
+    protected actionDispatcher: IActionDispatcher;
+
+    constructor(@inject(TYPES.Action) protected readonly action: GetSelectionMcpAction) {
+        super();
+    }
+
+    execute(context: CommandExecutionContext): CommandReturn {
+        const selection = context.root.index
+            .all()
+            .filter(e => isSelectable(e) && e.selected)
+            .map(e => e.id);
+        const result = GetSelectionMcpResultAction.create(toArray(selection), this.action.mcpRequestId);
+        this.actionDispatcher.dispatch(result);
+        return { model: context.root, modelChanged: false };
+    }
+
+    undo(context: CommandExecutionContext): CommandReturn {
+        return { model: context.root, modelChanged: false };
+    }
+
+    redo(context: CommandExecutionContext): CommandReturn {
+        return { model: context.root, modelChanged: false };
+    }
+}

packages/client/src/mcp/mcp-module.ts

@@ -0,0 +1,31 @@
+/********************************************************************************
+ * Copyright (c) 2026 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { configureCommand, FeatureModule, TYPES } from '@eclipse-glsp/sprotty';
+import { ExportPngMcpCommand, ExportPngMcpPostprocessor, GLSPMcpPngExporter } from './mcp-export-png';
+import { GetSelectionMcpCommand } from './mcp-get-selection';
+
+export const mcpModule = new FeatureModule(
+    (bind, _unbind, isBound) => {
+        configureCommand({ bind, isBound }, GetSelectionMcpCommand);
+
+        bind(ExportPngMcpPostprocessor).toSelf().inSingletonScope();
+        bind(TYPES.HiddenVNodePostprocessor).toService(ExportPngMcpPostprocessor);
+        configureCommand({ bind, isBound }, ExportPngMcpCommand);
+        bind(GLSPMcpPngExporter).toSelf().inSingletonScope();
+    },
+    { featureId: Symbol('mcp') }
+);