fix: allow MCP prompts with spaces in name (#12910)

Co-authored-by: Abhi <43648792+abhipatel12@users.noreply.github.com>

packages/cli/src/services/McpPromptLoader.test.ts

@@ -175,6 +175,40 @@ describe('McpPromptLoader', () => {
       expect(commands[0].kind).toBe(CommandKind.MCP_PROMPT);
     });
 
+    it('should sanitize prompt names by replacing spaces with hyphens', async () => {
+      const mockPromptWithSpaces = {
+        ...mockPrompt,
+        name: 'Prompt Name',
+      };
+      vi.spyOn(cliCore, 'getMCPServerPrompts').mockReturnValue([
+        mockPromptWithSpaces,
+      ]);
+
+      const loader = new McpPromptLoader(mockConfigWithPrompts);
+      const commands = await loader.loadCommands(new AbortController().signal);
+
+      expect(commands).toHaveLength(1);
+      expect(commands[0].name).toBe('Prompt-Name');
+      expect(commands[0].kind).toBe(CommandKind.MCP_PROMPT);
+    });
+
+    it('should trim whitespace from prompt names before sanitizing', async () => {
+      const mockPromptWithWhitespace = {
+        ...mockPrompt,
+        name: '  Prompt Name  ',
+      };
+      vi.spyOn(cliCore, 'getMCPServerPrompts').mockReturnValue([
+        mockPromptWithWhitespace,
+      ]);
+
+      const loader = new McpPromptLoader(mockConfigWithPrompts);
+      const commands = await loader.loadCommands(new AbortController().signal);
+
+      expect(commands).toHaveLength(1);
+      expect(commands[0].name).toBe('Prompt-Name');
+      expect(commands[0].kind).toBe(CommandKind.MCP_PROMPT);
+    });
+
     it('should handle prompt invocation successfully', async () => {
       const loader = new McpPromptLoader(mockConfigWithPrompts);
       const commands = await loader.loadCommands(new AbortController().signal);

packages/cli/src/services/McpPromptLoader.ts

@@ -38,7 +38,8 @@ export class McpPromptLoader implements ICommandLoader {
     for (const serverName in mcpServers) {
       const prompts = getMCPServerPrompts(this.config, serverName) || [];
       for (const prompt of prompts) {
-        const commandName = `${prompt.name}`;
+        // Sanitize prompt names to ensure they are valid slash commands (e.g. "Prompt Name" -> "Prompt-Name")
+        const commandName = `${prompt.name}`.trim().replace(/\s+/g, '-');
         const newPromptCommand: SlashCommand = {
           name: commandName,
           description: prompt.description || `Invoke prompt ${prompt.name}`,