safari_get_performance_metrics
Retrieve page performance metrics from Safari to analyze loading times, resource usage, and browser performance data for optimization.
Instructions
Get page performance metrics
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| sessionId | Yes | Session identifier |
Implementation Reference
- src/safari-driver.ts:351-376 (handler)Core handler implementation in SafariDriverManager that executes JavaScript to fetch browser performance metrics using the Performance Timing API and paint entries.
async getPerformanceMetrics(sessionId: string): Promise<PerformanceMetrics> { const session = this.getSession(sessionId); if (!session) { throw new Error(`Session ${sessionId} not found`); } try { const metrics = await session.driver.executeScript(` const timing = performance.timing; const paintEntries = performance.getEntriesByType('paint'); return { navigationStart: timing.navigationStart, loadEventEnd: timing.loadEventEnd, domContentLoadedEventEnd: timing.domContentLoadedEventEnd, firstPaint: paintEntries.find(entry => entry.name === 'first-paint')?.startTime, firstContentfulPaint: paintEntries.find(entry => entry.name === 'first-contentful-paint')?.startTime }; `); return metrics; } catch (error: unknown) { const errorMessage = error instanceof Error ? error.message : String(error); throw new Error(`Failed to get performance metrics: ${errorMessage}`); } } - src/safari-mcp-server.ts:374-385 (handler)MCP server handler method that extracts the sessionId from arguments, calls the driver manager, and formats the metrics as a text response.
private async getPerformanceMetrics(args: Record<string, any>): Promise<Array<{ type: string; text: string }>> { const { sessionId } = args; const metrics = await this.driverManager.getPerformanceMetrics(sessionId); return [ { type: 'text', text: `Performance Metrics:\n\n${JSON.stringify(metrics, null, 2)}` } ]; } - src/safari-mcp-server.ts:176-186 (registration)Tool registration entry in the MCP server's tool list, including the name, description, and input schema definition.
{ name: 'safari_get_performance_metrics', description: 'Get page performance metrics', inputSchema: { type: 'object', properties: { sessionId: { type: 'string', description: 'Session identifier' } }, required: ['sessionId'] } }, - src/safari-mcp-server.ts:176-186 (schema)Input schema definition for the tool, specifying the required sessionId parameter.
{ name: 'safari_get_performance_metrics', description: 'Get page performance metrics', inputSchema: { type: 'object', properties: { sessionId: { type: 'string', description: 'Session identifier' } }, required: ['sessionId'] } },