Modes MCP Server

Instructions

Implementation Reference

• src/index.ts:457-483 (handler)

  The handler function for the 'validate_mode' tool. It extracts the mode object from the request arguments, attempts to parse/validate it using CustomModeSchema.parse(), and returns a success message or an error message with isError: true.

  case 'validate_mode': {
    const { mode } = request.params.arguments as {
      mode: z.infer<typeof CustomModeSchema>;
    };
  
    try {
      CustomModeSchema.parse(mode);
      return {
        content: [
          {
            type: 'text',
            text: 'Mode configuration is valid',
          },
        ],
      };
    } catch (error) {
      return {
        content: [
          {
            type: 'text',
            text: `Invalid mode configuration: ${error instanceof Error ? error.message : String(error)}`,
          },
        ],
        isError: true,
      };
    }
  }

• src/index.ts:50-56 (schema)

  Zod schema (CustomModeSchema) defining the structure and validation rules for a custom mode configuration, used directly in the validate_mode handler for input validation.

  const CustomModeSchema = z.object({
    slug: z.string().regex(/^[a-z0-9-]+$/),
    name: z.string().min(1),
    roleDefinition: z.string().min(1),
    groups: z.array(GroupSchema),
    customInstructions: z.string().optional(),
  });

• src/index.ts:305-325 (registration)

  Tool registration in the list_tools handler, defining the name, description, and JSON input schema for the validate_mode tool.

  {
    name: 'validate_mode',
    description: 'Validate a mode configuration without saving it',
    inputSchema: {
      type: 'object',
      properties: {
        mode: {
          type: 'object',
          properties: {
            slug: { type: 'string' },
            name: { type: 'string' },
            roleDefinition: { type: 'string' },
            groups: { type: 'array' },
            customInstructions: { type: 'string' },
          },
          required: ['slug', 'name', 'roleDefinition', 'groups'],
        },
      },
      required: ['mode'],
    },
  },