Update MCP JupyterLab extension build and docs

Updated the MCP Active Cell Bridge JupyterLab extension build artifacts and package references after a rebuild. Added an 'instrmcp-setup' step to the development instructions in CLAUDE.md for improved extension linking.

Author: caidish

CLAUDE.md

@@ -143,6 +143,7 @@ Located in `instrmcp/extensions/jupyterlab/`. After modifying TypeScript:
 ```bash
 cd instrmcp/extensions/jupyterlab && jlpm run build
 pip install -e . --force-reinstall --no-deps
+instrmcp-setup  # Link extension to Jupyter data directory
 # Restart JupyterLab completely
 ```
 

instrmcp/extensions/jupyterlab/mcp_active_cell_bridge/labextension/package.json

@@ -64,7 +64,7 @@
     "extension": true,
     "webpackConfig": "./webpack.config.js",
     "_build": {
-      "load": "static/remoteEntry.53d8c3e6039a645261fc.js",
+      "load": "static/remoteEntry.aa0f00fdb8ca909a5e47.js",
       "extension": "./extension",
       "style": "./style"
     }

instrmcp/extensions/jupyterlab/mcp_active_cell_bridge/labextension/static/index.057bca2c715123d02dd6.js

@@ -1245,10 +1245,43 @@ const plugin: JupyterFrontEndPlugin<void> = {
       return div.innerHTML;
     };
 
-    // Pass through all output data including image base64.
-    // Image data is saved to temp files by the Python backend (image_utils.py).
+    // Maximum size for image data in bytes (10MB base64 ≈ 7.5MB raw image)
+    // Images larger than this will be replaced with a fallback message
+    const MAX_IMAGE_SIZE_BYTES = 10 * 1024 * 1024;
+
+    // Image MIME types to check for size limits
+    const IMAGE_MIME_TYPES = [
+      'image/png',
+      'image/jpeg',
+      'image/gif',
+      'image/svg+xml',
+      'image/webp',
+      'image/bmp',
+      'image/tiff'
+    ];
+
+    // Pass through output data, but replace overly large images with fallback message.
+    // Normal-sized images are saved to temp files by the Python backend (image_utils.py).
     const sanitizeOutputData = (data: Record<string, any>): Record<string, any> => {
-      return { ...data };
+      const result: Record<string, any> = {};
+
+      for (const [mimeType, content] of Object.entries(data)) {
+        if (IMAGE_MIME_TYPES.includes(mimeType) && typeof content === 'string') {
+          const sizeBytes = content.length;
+          if (sizeBytes > MAX_IMAGE_SIZE_BYTES) {
+            // Calculate approximate raw image size (base64 is ~1.33x raw size)
+            const rawSizeMB = (sizeBytes * 0.75) / (1024 * 1024);
+            result[mimeType] = `[IMAGE TOO LARGE: ~${rawSizeMB.toFixed(1)}MB - Use plt.savefig('/tmp/my_plot.png') to save large images to disk, then reference the file path]`;
+            console.log(`MCP Active Cell Bridge: Image too large (${rawSizeMB.toFixed(1)}MB), replaced with fallback message`);
+          } else {
+            result[mimeType] = content;
+          }
+        } else {
+          result[mimeType] = content;
+        }
+      }
+
+      return result;
     };
 
     // Handle patch consent request from kernel

instrmcp/extensions/jupyterlab/mcp_active_cell_bridge/labextension/static/index.5d05d381876db71b1f9d.js

@@ -64,7 +64,7 @@
     "extension": true,
     "webpackConfig": "./webpack.config.js",
     "_build": {
-      "load": "static/remoteEntry.53d8c3e6039a645261fc.js",
+      "load": "static/remoteEntry.aa0f00fdb8ca909a5e47.js",
       "extension": "./extension",
       "style": "./style"
     }

…atic/remoteEntry.53d8c3e6039a645261fc.js …atic/remoteEntry.aa0f00fdb8ca909a5e47.jsinstrmcp/extensions/jupyterlab/mcp_active_cell_bridge/labextension/static/remoteEntry.53d8c3e6039a645261fc.js renamed to instrmcp/extensions/jupyterlab/mcp_active_cell_bridge/labextension/static/remoteEntry.aa0f00fdb8ca909a5e47.js instrmcp/extensions/jupyterlab/mcp_active_cell_bridge/labextension/static/remoteEntry.53d8c3e6039a645261fc.js renamed to instrmcp/extensions/jupyterlab/mcp_active_cell_bridge/labextension/static/remoteEntry.aa0f00fdb8ca909a5e47.js

@@ -979,7 +979,7 @@ def move_cursor(target: str, timeout_s: float = 2.0) -> Dict[str, Any]:
     return result
 
 
-def get_active_cell_output(timeout_s: float = 2.0) -> Dict[str, Any]:
+def get_active_cell_output(timeout_s: float = 10.0) -> Dict[str, Any]:
     """
     Get the output of the currently active cell directly from JupyterLab frontend.
 
@@ -991,7 +991,7 @@ def get_active_cell_output(timeout_s: float = 2.0) -> Dict[str, Any]:
     frontend for the active cell's current outputs.
 
     Args:
-        timeout_s: How long to wait for response from frontend (default 2.0s)
+        timeout_s: How long to wait for response from frontend (default 10.0s)
 
     Returns:
         Dictionary with:

instrmcp/extensions/jupyterlab/src/index.ts

@@ -346,7 +346,7 @@ async def execute_editing_cell(self, timeout: float = 30.0) -> Dict[str, Any]:
 
             # 6. Fetch output using shared logic from get_active_cell_output
             # This is the same path used by notebook_read_active_cell_output
-            output_result = self.bridge.get_active_cell_output(timeout_s=2.0)
+            output_result = self.bridge.get_active_cell_output(timeout_s=10.0)
 
             # 7. Build combined result
             combined_result = {