Configuration reference

Browser initialization

Option	Type	Default	Purpose
app	string	required	Stable application identity
release	string	injected when available	Release used by comparisons and maps
commit	string	injected when available	Source and build identity
buildTimestamp	string	injected when available	Build metadata
environment	string	injected Vite mode	Environment selector
sampleRate	number	1	Session inclusion probability from 0 to 1
transport	Transport	HTTP transport	Custom delivery implementation
endpoint	string	/__tracelens	HTTP collector URL
flushInterval	number	1000	Flush interval in milliseconds
batchSize	number	20	Maximum events per delivered batch
privacy	PrivacyOptions	restrictive defaults	URL and element policy
tracePropagation	TracePropagationOptions	disabled	Opt-in traceparent propagation

Explicit initialization values override Vite-injected metadata.

Privacy

privacy: {
  queryParameters: 'allowlist',
  allowedElementAttributes: ['data-tracelens-name', 'role', 'type'],
  url: {
    stripQuery: false,
    allowedQueryParameters: ['page'],
    redactSegments: ['users', 'accounts'],
    sanitize(url) {
      return url.replace(/\/orders\/[^/]+/, '/orders/[redacted]');
    },
  },
}

Input values, DOM text, request bodies, and headers are never collected. Query values are dropped unless both queryParameters: 'allowlist' and stripQuery: false are set.

Trace propagation

tracePropagation: {
  allowedOrigins: ['https://api.example.com'],
}

Trace propagation is off by default. Headers are added only to allowed HTTP(S) origins and never to the TraceLens collector request.

Vite metadata

tracelens({
  release: '1.0.0',
  commit: '7ac841f',
  environment: 'production',
});

Without explicit values, the plugin reads the nearest package version, the current Git commit, the build time, and the Vite mode.

Performance budgets

minimumSamples: 20
performance:
  inp:
    p75: 200
  lcp:
    p75: 2500
  cls:
    p75: 0.1
  longFramesPerSession:
    max: 1
routes:
  /checkout:
    inp:
      p75: 150

Unknown keys and duplicate YAML keys fail closed. Every configured check must meet minimumSamples.