Avoid hard-coding configuration values directly in source files. Instead, externalize them using environment variables, configuration files, or external resources. This improves maintainability, enables environment-specific settings, and reduces bundle sizes. For runtime configuration, use environment variables: ```typescript // Instead of hard-coding: id: 'ep-20250627155918-4jmhg' // Use environment variables: id: process.env.MODEL_ID ``` For build-time configuration, consider external dependencies: ```typescript // Instead of bundling large resources: const minifiedCSS = cleanCSS.minify(reportCSS).styles; // Use external CDN resources in modern.config.js: // https://unpkg.com/@ui-tars/visualizer/dist/report/ ``` This approach enables different configurations per environment, reduces code coupling, and keeps sensitive or environment-specific values out of the codebase.