Configuration

pulse.config.js sets the performance and load thresholds that Pulse enforces across your application. All fields are optional — the defaults match Google's Core Web Vitals "good" band. Configuration here is not about enabling features; it is about deciding where, if anywhere, you need to lower a guaranteed baseline.

Full schema

// pulse.config.js
export default {
  port: 3000,

  lighthouse: {
    // Category scores — 0 to 100. Default: 100 for all four.
    performance:   100,
    accessibility: 100,
    bestPractices: 100,
    seo:           100,

    // Core Web Vitals and timing metrics.
    // Defaults are the Google "good" thresholds.
    lcp: 2500,   // Largest Contentful Paint (ms)
    cls: 0.1,    // Cumulative Layout Shift
    tbt: 200,    // Total Blocking Time (ms)
    fcp: 1800,   // First Contentful Paint (ms)
    si:  3400,   // Speed Index (ms)
    inp: 200,    // Interaction to Next Paint (ms)
  },

  load: {
    duration:    10,
    connections: 10,
    thresholds: {
      rps:    undefined,  // minimum req/s (optional)
      p99:    undefined,  // maximum p99 latency ms (optional)
      errors: 0,
    },
  },

  environments: {
    // Environment names are bespoke — choose whatever suits your project.
    local:   { url: 'http://localhost:3000', default: true },
    staging: {
      url:     'https://staging.myapp.com',
      headers: { Authorization: `Bearer ${process.env.STAGING_TOKEN}` },
      load:       { duration: 30, connections: 50 },
      lighthouse: { performance: 90 },
    },
    production: { url: 'https://myapp.com' },
  },

  routes: {
    // Per-route overrides — merged on top of global lighthouse/load config.
    // Only specify what differs from the global defaults.
    '/dashboard': {
      lighthouse: {
        performance: 85,
        lcp:         4000,
      },
    },
    '/embed': {
      lighthouse: {
        bestPractices: 85,
      },
    },
  },
}

port

lighthouse

Global Lighthouse thresholds that every page must meet. /pulse-report enforces these after every audit — any page that falls below a threshold is reported as a failure, not a warning.

routes

Route-specific overrides let you lower a threshold for a specific page without relaxing the global guarantee. Only specify the fields that differ — everything else inherits from the global config.

routes: {
  // This route uses a third-party chart library — relax performance only.
  '/dashboard': {
    lighthouse: {
      performance: 85,
      lcp:         4000,
    },
  },
}

load

Load test thresholds enforced by /pulse-load. All fields are optional — omitting a threshold means that check is not enforced.

load: {
  duration:    30,
  connections: 20,
  thresholds: {
    rps:    100,   // fail if below 100 req/s
    p99:    500,   // fail if p99 exceeds 500ms
    errors: 0,
  },
},

Per-route overrides follow the same pattern as lighthouse:

routes: {
  '/feed': {
    load: { connections: 5, thresholds: { rps: 20 } },
  },
}

Results are saved to .pulse/load-reports/ and displayed in the Load Tests tab of the report dashboard, alongside the Lighthouse Performance tab for the same route.

environments

Named environments let you enforce thresholds against different targets — local, staging, production — from the same config. Thresholds are applied per-environment, so staging and production can have different performance floors.

Threshold merge order: global config → environment override → per-route override.

environments: {
  local:   { url: 'http://localhost:3000', default: true },
  staging: {
    url:     'https://staging.myapp.com',
    headers: { Authorization: `Bearer ${process.env.STAGING_TOKEN}` },
    load:       { duration: 30, connections: 50, thresholds: { rps: 500 } },
    lighthouse: { performance: 90 },
  },
  production: { url: 'https://myapp.com' },
}

CWV default thresholds

The default metric thresholds match the Google "good" band from the Core Web Vitals specification: