tracker.setContext()

Attach arbitrary key-value metadata to every subsequent event. Context persists until explicitly cleared — it does not reset between events or page navigations.

tracker.setContext(attrs: Record<string, unknown>): void

Parameters

attrs

Type: Record<string, unknown>

Key-value pairs to merge into the persistent context. These are attached to TrackerEvent.context on every event emitted after this call.

• Setting a key to null removes it from the persistent context.
• Keys are merged — calling setContext() multiple times accumulates context, it does not replace it.

Behavior

tracker.setContext({ appVersion: '2.1.0', region: 'eu-west' })
// All subsequent events: { context: { appVersion: '2.1.0', region: 'eu-west' } }

tracker.setContext({ tenant: 'acme' })
// All subsequent events: { context: { appVersion: '2.1.0', region: 'eu-west', tenant: 'acme' } }

tracker.setContext({ tenant: null })
// All subsequent events: { context: { appVersion: '2.1.0', region: 'eu-west' } }

Examples

App Version and Environment

import { tracker } from '@ndriadev/vite-plugin-monitor/client'

// Set at app startup, before init
tracker.setContext({
  appVersion: import.meta.env.VITE_APP_VERSION,
  environment: import.meta.env.MODE,
  region: import.meta.env.VITE_REGION,
})

A/B Testing

const variant = getABVariant('checkout-v2')

tracker.setContext({
  abVariant:    variant,
  experimentId: 'checkout-v2',
})

Feature Flags

const flags = await featureFlagService.getAll()

tracker.setContext({
  featureFlags: Object.keys(flags).filter(k => flags[k]),
})

Tenant / Org Context (Multi-Tenant Apps)

authService.onLogin((user) => {
  tracker.setUser(user.id)
  tracker.setContext({
    orgId:   user.orgId,
    orgName: user.orgName,
    plan:    user.plan,
  })
})

authService.onLogout(() => {
  tracker.setUser(null)
  tracker.setContext({ orgId: null, orgName: null, plan: null })
})

Per-Event Context Override

To set context for a single event only (without affecting the persistent context), use opts.context in tracker.track():

tracker.track('experiment:viewed', {}, {
  context: { experimentId: 'onboarding-v3', variant: 'B' }
})