fix(dashboard): add defensive null checks for MCP host compatibility

Add null/undefined checks throughout the MCP client and dashboard code
to handle hosts that may pass null values in callbacks. This improves
compatibility with different MCP Apps hosts.

Changes:
- Add null checks in ontoolresult, ontoolinput, onhostcontextchanged handlers
- Wrap supportsServerTools() in try/catch with null check
- Add null check for callServerTool result
- Add defensive checks in handleToolResult and handleToolInput

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: JAORMX

ui/compliance-dashboard/src/dashboard.ts

@@ -153,15 +153,23 @@ export function initDashboard(): void {
  * This is called when the LLM invokes a Minder tool and the host pushes the result.
  */
 function handleToolResult(result: ToolResultParams): void {
+  // Defensive null check - result may be null/undefined from some hosts
+  if (!result) {
+    console.warn('[Dashboard] Received null/undefined tool result');
+    return;
+  }
+
   // Extract the tool name and content from the result
   // The result may contain structuredContent or content array
   let data: unknown = null;
 
   // Check for structuredContent first (preferred for rich data)
+  // Use defensive access to avoid "Cannot convert undefined or null to object"
   const structuredContent = result.structuredContent as
     | Record<string, unknown>
-    | undefined;
-  if (structuredContent) {
+    | undefined
+    | null;
+  if (structuredContent && typeof structuredContent === 'object') {
     data = structuredContent;
   } else if (
     result.content &&
@@ -267,6 +275,11 @@ function isRepositoriesApiResponse(data: unknown): data is RepositoriesApiRespon
  * Extracts project_id from arguments for use in subsequent calls.
  */
 function handleToolInput(input: ToolInputParams): void {
+  // Defensive null check - input may be null/undefined from some hosts
+  if (!input) {
+    console.warn('[Dashboard] Received null/undefined tool input');
+    return;
+  }
   // Extract project_id from the tool arguments if present
   const args = input.arguments as Record<string, unknown> | undefined;
   if (args && typeof args.project_id === 'string' && args.project_id) {

ui/compliance-dashboard/src/mcp-client.ts

@@ -66,6 +66,11 @@ export class MCPAppsClient {
     this.onToolResultCallback = callback;
     this.app.ontoolresult = (result): void => {
       console.log('[MCP] Received tool result notification:', result);
+      // Defensive null check - some hosts may pass null/undefined
+      if (!result) {
+        console.warn('[MCP] Received null/undefined tool result');
+        return;
+      }
       if (this.onToolResultCallback) {
         this.onToolResultCallback(result);
       }
@@ -80,6 +85,11 @@ export class MCPAppsClient {
     this.onToolInputCallback = callback;
     this.app.ontoolinput = (input): void => {
       console.log('[MCP] Received tool input notification:', input);
+      // Defensive null check - some hosts may pass null/undefined
+      if (!input) {
+        console.warn('[MCP] Received null/undefined tool input');
+        return;
+      }
       if (this.onToolInputCallback) {
         this.onToolInputCallback(input);
       }
@@ -94,6 +104,11 @@ export class MCPAppsClient {
     this.onDimensionsCallback = callback;
     this.app.onhostcontextchanged = (context): void => {
       console.log('[MCP] Received host context change:', context);
+      // Defensive null check - some hosts (e.g., Goose) may pass null/undefined
+      if (!context) {
+        console.warn('[MCP] Received null/undefined host context change');
+        return;
+      }
       if (context.containerDimensions && this.onDimensionsCallback) {
         const dims = context.containerDimensions as ContainerDimensions;
         this.onDimensionsCallback(dims);
@@ -117,9 +132,19 @@ export class MCPAppsClient {
    * Check if the host supports calling server tools directly.
    */
   supportsServerTools(): boolean {
-    const caps = this.app.getHostCapabilities();
-    // serverTools is an object when supported, undefined when not
-    return caps?.serverTools !== undefined;
+    try {
+      const caps = this.app.getHostCapabilities();
+      // serverTools is an object when supported, undefined when not
+      // Some hosts may return null instead of an object
+      if (!caps) {
+        console.log('[MCP] Host capabilities is null/undefined');
+        return false;
+      }
+      return caps.serverTools !== undefined;
+    } catch (error) {
+      console.warn('[MCP] Error checking host capabilities:', error);
+      return false;
+    }
   }
 
   async disconnect(): Promise<void> {
@@ -166,9 +191,15 @@ export class MCPAppsClient {
 
     const result = await this.app.callServerTool({
       name,
-      arguments: args,
+      arguments: args ?? {},
     });
 
+    // Defensive null check for result
+    if (!result) {
+      console.warn('[MCP] callServerTool returned null/undefined');
+      throw new Error('Tool call returned no result');
+    }
+
     // Extract the content from the tool result
     if (
       result.content &&
@@ -177,6 +208,7 @@ export class MCPAppsClient {
     ) {
       const firstContent = result.content[0];
       if (
+        firstContent &&
         firstContent.type === 'text' &&
         typeof firstContent.text === 'string'
       ) {