EventRecord

The row every destination writes: one per event, with the same fields for every event. This page lists each field and who sets it, and shows example records.

Fields

Field	Set by	What it holds
`specVersion`	Hub	The version of the record shape, from the Hub that assembled the record.
`id`	Producer	A UUID minted by the producer for this event.
`sessionId`	Hub, from the request	The visitor's session identifier, or `null` when the storage policy stored none.
`name`	Producer	The event name, as passed to `track()`.
`location`	Producer	The page URL in the browser; the `Referer` header on the server.
`occurredAt`	Producer's clock	When `track()` was called.
`sentAt`	Producer's clock	When the event was handed to the Hub.
`receivedAt`	Hub's clock	When the Hub received the event.
`producerType`	Hub	`"remote"` for events that came in over HTTP through the collector, `"local"` for events from a server producer.
`producerName`	Producer	Names the source stream, e.g. `"browser"`. A claim from a remote producer; your own configuration on a local one.
`producerProperties`	Producer	The `track()` properties merged over the producer's `properties()`. JSON you define.
`hubProperties`	Hub	The request values the Hub collects (`userAgent`, `forwardedFor`, `acceptLanguage`) merged under your `hubProperties()`. `forwardedFor` is the raw `X-Forwarded-For` header. JSON you define.
`consent`	Hub, from the request	The visitor's decision when the event arrived: `"accepted"`, `"denied"` or `"unset"`.

In TypeScript, a record has the EventRecord type from @eventrail/nextjs/core.

Examples

Records as a destination receives them. The browser and server events come from the same visit, so they share a sessionId. In each, userId comes from a hubProperties() function like the one in Server-resolved user IDs.

Browser event

{
  specVersion: 1,
  id: "1f2a9c3e-6b8d-4f1a-9e2c-7d4b5a6f8e10",
  sessionId: "9d2c7e4b-1f8a-4c3d-8e2b-7a6f5e4d3c2b",
  name: "upgrade_plan_button_clicked",
  location: "https://yourapp.com/pricing",
  occurredAt: "2026-09-23T12:00:00.081Z",
  sentAt: "2026-09-23T12:00:00.092Z",
  receivedAt: "2026-09-23T12:00:00.140Z",
  producerType: "remote",Came in over HTTP, through the collector.
  producerName: "browser",
  producerProperties: { plan: "pro" },
  hubProperties: {
    userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36",
    forwardedFor: "203.0.113.7",
    acceptLanguage: "en-US,en;q=0.9",
    userId: "usr_42"
  },
  consent: "accepted"
}

Server event

{
  specVersion: 1,
  id: "7c1e4d2a-3b5f-4a8e-9d6c-2f1b0a9e8d7c",
  sessionId: "9d2c7e4b-1f8a-4c3d-8e2b-7a6f5e4d3c2b",Same identifier as the click: read from the same visitor's cookies.
  name: "plan_upgraded",
  location: "https://yourapp.com/pricing",The Referer of the request the event was fired in.
  occurredAt: "2026-09-23T12:00:01.204Z",
  sentAt: "2026-09-23T12:00:01.204Z",
  receivedAt: "2026-09-23T12:00:01.205Z",
  producerType: "local",
  producerName: "server",
  producerProperties: { plan: "pro" },
  hubProperties: {
    userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36",
    forwardedFor: "203.0.113.7",
    acceptLanguage: "en-US,en;q=0.9",
    userId: "usr_42"
  },
  consent: "accepted"
}

Webhook

{
  specVersion: 1,
  id: "b3d8f1a6-0c2e-4f7b-8a9d-5e6c4b3a2f10",
  sessionId: null,A webhook request carries no visitor cookies, so there is no identifier.
  name: "subscription_renewed",
  location: null,
  occurredAt: "2026-09-24T03:14:07.512Z",
  sentAt: "2026-09-24T03:14:07.512Z",
  receivedAt: "2026-09-24T03:14:07.513Z",
  producerType: "local",
  producerName: "server",
  producerProperties: { plan: "pro" },
  hubProperties: {
    userAgent: "PaymentProvider-Webhooks/1.0",
    forwardedFor: "198.51.100.23",
    acceptLanguage: null,
    userId: null
  },
  consent: "unset"No decision on the request: unset, not denied.
}

Consent denied

{
  specVersion: 1,
  id: "e4a7c2f9-8b1d-4e3a-a6f5-0d9c8b7a6e54",
  sessionId: null,Under the optIn and optOut policies, a visitor who denied has no stored identifier.
  name: "page_view",
  location: "https://yourapp.com/",
  occurredAt: "2026-09-23T14:32:10.018Z",
  sentAt: "2026-09-23T14:32:10.020Z",
  receivedAt: "2026-09-23T14:32:10.071Z",
  producerType: "remote",
  producerName: "browser",
  producerProperties: { referrer: "https://www.google.com/" },Added by the page view tracker: on the first page view after the page loads, the page the visitor came from.
  hubProperties: {
    userAgent: "Mozilla/5.0 (iPhone; CPU iPhone OS 18_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.6 Mobile/15E148 Safari/604.1",
    forwardedFor: "192.0.2.44",
    acceptLanguage: "nl-NL,nl;q=0.9",
    userId: null
  },
  consent: "denied"
}

Relating events

Link events by sessionId. Browser events and server events fired during the same visitor's request carry the same identifier.
Without a sessionId, relate events by request values. Events with a null sessionId can still be grouped into approximate visits by IP address, user agent and language. See Relating events without a sessionId.
Deduplicate on id. The same event written twice has the same id. The Postgres table has no unique constraint on it, and BigQuery's deduplication on it is best-effort.
Order on receivedAt. It comes from your server's clock. occurredAt and sentAt come from the producer's clock, which on a visitor's device can be wrong.