Configure under observatory in your app nuxt.config.ts.

export default defineNuxtConfig({
    observatory: {
        instrumentServer: true, // Instrument the server for SSR/Nitro fetch and composable tracking. Enable this when using SSR so server-side composable calls are captured. Disable for SPA projects to avoid double-registration caused by the transform running on both builds.
        fetchDashboard: true, // Enable useFetch dashboard
        provideInjectGraph: true, // Enable provide/inject graph
        composableTracker: true, // Enable composable tracker
        renderHeatmap: true, // Enable render heatmap
        transitionTracker: true, // Enable transition tracker
        composableNavigationMode: 'route', // 'route' clears entries on navigation (default), 'session' persists across navigation
        heatmapThresholdCount: 5, // Highlight components with 5+ renders
        heatmapThresholdTime: 1600, // Highlight components with render time above this (ms)
        heatmapHideInternals: true, // Hide node_modules and internal components in the render heatmap
        debugRpc: false, // Enable RPC handshake debug logs (useful for troubleshooting)
        maxFetchEntries: 200, // Max fetch entries to keep in memory
        maxPayloadBytes: 10000, // Max payload size (bytes) per fetch entry
        maxTransitions: 500, // Max transition entries to keep in memory
        maxComposableHistory: 50, // Max composable history events per entry
        maxComposableEntries: 300, // Max composable entries to keep in memory
        maxRenderTimeline: 100, // Max render timeline events per entry
    },
})

Configuration notes

  • route composable navigation mode clears on page navigation.
  • session mode keeps history across navigations for investigation sessions.
  • debugRpc helps diagnose host/iframe bridge issues.
  • Caps reduce memory growth during long dev sessions.

Environment variables

Most options can also be set through environment variables (see .env.example). Nuxt config values take precedence over .env values.