AI Vision MCP Server

# Plan: Fix Dynamic MAX_IMAGES_FOR_COMPARISON Schema Validation ## Problem Description The `compare_images` MCP tool has inconsistent validation: - **Schema validation** (server.ts): Hardcoded to max 4 images - **Tool implementation** (compare_images.ts): Respects `MAX_IMAGES_FOR_COMPARISON` environment variable This means users cannot use more than 4 images even if they configure `MAX_IMAGES_FOR_COMPARISON=6`. ## Root Cause The MCP tool registration in `server.ts` uses a static Zod schema that's defined at module load time, before configuration is available: ```typescript // Current - HARDCODED imageSources: z .array(z.string()) .min(2) .max(4) // ← Static value, ignores config ``` ## Solution Strategy ### Option 1: Lazy Schema Generation (Recommended) Move the schema creation inside the tool handler where config is available. ### Option 2: Dynamic Schema Factory Create a schema factory function that accepts max images parameter. ### Option 3: Configuration-based Registration Register tools after configuration is loaded. **Selected: Option 1** - Most straightforward and maintains existing patterns. ## Implementation Plan 1. **Modify server.ts**: - Move schema validation from registration to handler - Use manual validation with config values - Keep Zod for type safety but make limits dynamic 2. **Update validation logic**: - Read `MAX_IMAGES_FOR_COMPARISON` from config - Apply dynamic validation in handler - Maintain backward compatibility 3. **Preserve error consistency**: - Same error format as current Zod validation - Clear error messages for users ## Implementation Details ```typescript // Before (hardcoded) inputSchema: { imageSources: z.array(z.string()).min(2).max(4) } // After (dynamic) inputSchema: { imageSources: z.array(z.string()).min(2) // Remove max, validate in handler } // Handler validation: const { config } = getServices(); const maxImages = config.MAX_IMAGES_FOR_COMPARISON || 4; if (imageSources.length > maxImages) { throw new Error(`Maximum ${maxImages} images allowed`); } ``` ## Benefits - ✅ Respects user configuration - ✅ Consistent behavior across schema and implementation - ✅ No breaking changes to existing API - ✅ Maintains type safety ## Risk Assessment - **Risk Level**: Low - **Breaking Changes**: None - **Backward Compatibility**: Full - **Testing**: Can validate with different MAX_IMAGES_FOR_COMPARISON values ## Expected Outcome After fix: - `MAX_IMAGES_FOR_COMPARISON=6` → Users can compare up to 6 images - `MAX_IMAGES_FOR_COMPARISON=2` → Users can compare up to 2 images - Default behavior unchanged (max 4 images)