The activity envelope

One activity as it travels to POST /v1/activities. Its features are checked against the activity's catalogue entry; the envelope is the same for every activity.

{
  "activity_id": "0192f1a4-7c3e-7b21-9d0a-5e3f8c2a1b45",
  "activity": "completed_order",
  "ts": "2026-10-17T20:00:00+02:00",
  "owner_ref": "evx:ee69a000-d48d-11ec-8515-8b933281c556",
  "identifiers": [
    { "type": "email", "value": "ana@example.com", "role": "buyer" },
    { "type": "phone", "value": "06 24681357", "role": "buyer" }
  ],
  "anonymous_customer_id": "evx_web_8f21c0",
  "revenue": { "amount": "45.00", "currency": "EUR" },
  "features": { "order_id": "…", "ticket_count": 2, "touch": { "utm": { "source": "newsletter" } } },
  "geo": [{ "kind": "home", "role": "buyer", "city": "Amsterdam", "postal_code": "1012 AB", "country": "NL" }],
  "link": "https://dashboard.eventix.io/orders/…",
  "_source": "platform:weeztix@order-v10"
}

Field	Required	Meaning
`activity_id`	yes	A UUID. The idempotency key: the same id twice stores one activity. Derive it from what the activity is, so a retry can never double-count.
`activity`	yes	The name in the catalogue: a core name such as `issued_ticket`, or an organiser's own `custom.…`.
`ts`	yes	When it happened, RFC 3339 with an offset. The payment's move to paid, not the moment of sending.
`owner_ref`	with a platform or group key	The organiser the activity belongs to, as `<type>:<value>`: `evx:` an Eventix company id, `wzt:` a Weeztix id, `own:` an owner id. With a single-owner key it is optional and must match.
`owner`	no	With a platform key: `{ "name", "country" }` registers an organiser on first mention.
`identifiers`	no	Who the activity is about: a list of `{ type, value, role, namespace, confidence }`. See identifiers.
`anonymous_customer_id`	no	The visitor's anonymous id (`evx_web_…`), when the activity happened in a browser the SDK knows. It becomes a `device` identifier.
`revenue`	only on revenue-bearing activities	`{ "amount": "45.00", "currency": "EUR" }`: a decimal string, never a number. See revenue.
`features`	depends on the activity	The activity's own fields, as its page lists them, with the touch block where the activity carries one.
`geo`	no	Where the people on the activity live or were. See the geo block.
`link`	no	A deep link to the record in the sending system, for support.
`_source`	no	A platform sender's provenance, e.g. `platform:weeztix@order-v10`. Other senders get it from their key class.

Anything the processor moves out of features (identifier and attribute fields) is not stored with them; what it stores is the features the catalogue declares, plus the touch block where the activity carries one.

A batch

The request body is { "batch": [ …activities… ] }, up to 500 KB, with optional writeKey (a browser key), traceparent (W3C trace context, when the header cannot be set) and debug (return the verdicts). The batch is accepted or refused as a whole; refusals concern the key, the owner, the limits or an activity that is not one. See sending activities.

A batch​

A batch