Chrome DevTools MCP

/** * @license * Copyright 2025 Google LLC * SPDX-License-Identifier: Apache-2.0 */ import {zod, PredefinedNetworkConditions} from '../third_party/index.js'; import {ToolCategory} from './categories.js'; import {defineTool} from './ToolDefinition.js'; const throttlingOptions: [string, ...string[]] = [ 'No emulation', 'Offline', ...Object.keys(PredefinedNetworkConditions), ]; export const emulate = defineTool({ name: 'emulate', description: `Emulates various features on the selected page.`, annotations: { category: ToolCategory.EMULATION, readOnlyHint: false, }, schema: { networkConditions: zod .enum(throttlingOptions) .optional() .describe( `Throttle network. Set to "No emulation" to disable. If omitted, conditions remain unchanged.`, ), cpuThrottlingRate: zod .number() .min(1) .max(20) .optional() .describe( 'Represents the CPU slowdown factor. Set the rate to 1 to disable throttling. If omitted, throttling remains unchanged.', ), geolocation: zod .object({ latitude: zod .number() .min(-90) .max(90) .describe('Latitude between -90 and 90.'), longitude: zod .number() .min(-180) .max(180) .describe('Longitude between -180 and 180.'), }) .nullable() .optional() .describe( 'Geolocation to emulate. Set to null to clear the geolocation override.', ), }, handler: async (request, _response, context) => { const page = context.getSelectedPage(); const {networkConditions, cpuThrottlingRate, geolocation} = request.params; if (networkConditions) { if (networkConditions === 'No emulation') { await page.emulateNetworkConditions(null); context.setNetworkConditions(null); } else if (networkConditions === 'Offline') { await page.emulateNetworkConditions({ offline: true, download: 0, upload: 0, latency: 0, }); context.setNetworkConditions('Offline'); } else if (networkConditions in PredefinedNetworkConditions) { const networkCondition = PredefinedNetworkConditions[ networkConditions as keyof typeof PredefinedNetworkConditions ]; await page.emulateNetworkConditions(networkCondition); context.setNetworkConditions(networkConditions); } } if (cpuThrottlingRate) { await page.emulateCPUThrottling(cpuThrottlingRate); context.setCpuThrottlingRate(cpuThrottlingRate); } if (geolocation !== undefined) { if (geolocation === null) { await page.setGeolocation({latitude: 0, longitude: 0}); context.setGeolocation(null); } else { await page.setGeolocation(geolocation); context.setGeolocation(geolocation); } } }, });