bulkEvent()

churn.bulkEvent(
  events: BulkEventItem[],
  options?: CallOptions
): Promise<{ ok: boolean; accepted: number }>

interface BulkEventItem {
  userId: string
  event: string
  properties?: EventProperties   // optional key-value metadata
  timestamp?: string             // ISO 8601 — defaults to server time if omitted
}

const events = historicalData.map((row) => ({
  userId: row.user_id,
  event: row.event_name,
  properties: row.metadata,
  timestamp: row.created_at,
}))

const { accepted } = await churn.bulkEvent(events)
console.log(`Accepted ${accepted} events`)

const buffer: BulkEventItem[] = []

function trackLater(userId: string, event: string, props?: Record<string, unknown>) {
  buffer.push({ userId, event, properties: props })
}

// Flush every minute
setInterval(async () => {
  if (buffer.length === 0) return
  const batch = buffer.splice(0, 500)
  await churn.bulkEvent(batch)
}, 60_000)

const CHUNK_SIZE = 500

async function backfill(allEvents: BulkEventItem[]) {
  for (let i = 0; i < allEvents.length; i += CHUNK_SIZE) {
    const chunk = allEvents.slice(i, i + CHUNK_SIZE)
    await churn.bulkEvent(chunk)
    console.log(`Flushed events ${i}–${i + chunk.length}`)
  }
}

{
  ok: true,
  accepted: 247   // number of events successfully ingested
}