subscription_started

This event is sent when a subscription starts: at free-trial activation (purchase.status: "trialing") and at the first successful positive payment (purchase.status: "succeeded"). A subscription that starts with a trial produces both, as two events with different event_id values. Deduplicate deliveries by event_id, including when different provider notifications refer to the same purchase.

Example

All values below are fictional test data. A normal payment event omits test_event, including a payment in a provider test account. Send test uses the flag for synthetic notifications.

{
  "event_id": "wh_evt_documentation_fixture",
  "event_type": "subscription_started",
  "created_at": "2026-09-04T00:00:03.000Z",
  "environment": "sandbox",
  "purchase": {
    "payment_id": "pay_test_fixture",
    "subscription_id": "sub_test_fixture",
    "status": "succeeded",
    "amount": { "minor_units": "4999", "currency": "USD" },
    "paid_at": "2026-09-04T00:00:00.000Z"
  },
  "provider": {
    "name": "stripe_direct",
    "event_id": "evt_test_fixture",
    "payment_reference_type": "invoice",
    "payment_reference_id": "in_test_fixture",
    "subscription_id": "sub_stripe_test_fixture",
    "customer_id": "cus_test_fixture"
  },
  "package": { "id": "pkg_test_monthly", "name": "Test Monthly" },
  "customer": { "id": "anon_test_fixture", "id_type": "anonymous_id", "email": "fixture@example.invalid" },
  "webflow": {
    "flow_id": "flow_test_fixture",
    "questionnaire": {
      "questionnaire_id": "questionnaire_test_fixture",
      "unit_preferences": { "weight": "kg" },
      "questions_and_answers": [
        {
          "question_id": "s_test_goal",
          "question": "What is your test goal?",
          "question_type": "single_select_text",
          "answer": [{ "id": "o_test_health", "text": "Build healthy habits" }]
        },
        {
          "question_id": "s_test_weight",
          "question": "What is your test weight?",
          "question_type": "numeric_input",
          "answer": [{ "text": "82", "unit": "kg" }]
        }
      ]
    }
  },
  "test_event": true
}

Trial activation

When a subscription starts on a free trial, no money has moved yet. The event has the same structure with these differences:

purchase.status is trialing and purchase.payment_id is absent.
purchase.amount.minor_units is "0", or purchase.amount is absent when the provider did not state a currency.
purchase.paid_at is the trial start; purchase.trial.started_at is the trial start and purchase.trial.ends_at is the first charge date when known.
provider.payment_reference_type is subscription, and provider.payment_reference_id is the provider subscription ID.

"purchase": {
  "subscription_id": "sub_test_fixture",
  "status": "trialing",
  "amount": { "minor_units": "0", "currency": "USD" },
  "paid_at": "2026-09-04T00:00:00.000Z",
  "trial": { "started_at": "2026-09-04T00:00:00.000Z", "ends_at": "2026-09-11T00:00:00.000Z" }
}

Field reference

Field	Required	Meaning
`event_id`	Yes	Stable FloKit event identifier and receiver deduplication key.
`event_type`	Yes	`subscription_started`.
`created_at`	Yes	Event creation time as a UTC timestamp string.
`environment`	Yes	`sandbox` or `production`; not independent proof of provider Test or Live mode.
`purchase.payment_id`	Paid events	FloKit payment reference, separate from the provider payment reference.
`purchase.subscription_id`	Yes	FloKit subscription reference.
`purchase.status`	Yes	`succeeded` for the first payment, `trialing` for a trial start.
`purchase.amount.minor_units`	With amount	`"0"` for a trial, otherwise a positive integer string in the currency’s minor units; use integer or decimal arithmetic.
`purchase.amount.currency`	With amount	Uppercase currency code.
`purchase.paid_at`	Yes	Payment time, or trial start for a trial, as a UTC timestamp string.
`purchase.trial`	Trials only	`started_at` and, when known, `ends_at` (first charge date).
`provider.name`	Yes	Provider name, for example `stripe_direct`.
`provider.event_id`	Yes	Payment-provider event reference; not the receiver deduplication key.
`provider.payment_reference_type`	Yes	`invoice`, `transaction`, or `order` for a payment; `subscription` for a trial start.
`provider.payment_reference_id`	Yes	Provider payment reference, such as a Stripe invoice ID.
`provider.subscription_id`	Yes	Provider subscription reference.
`provider.customer_id`	No	Provider customer reference when available.
`package.id`	Yes	Purchased FloKit Package reference.
`package.name`	Yes	Package name.
`customer.id`	Yes	FloKit user or anonymous reference.
`customer.id_type`	Yes	`user_id` or `anonymous_id`.
`customer.email`	No	Email when available; never use it as the deduplication key.
`webflow.flow_id`	Yes	FloKit Flow reference.
`webflow.questionnaire`	No	Omitted when the Flow has no questionnaire.
`webflow.questionnaire.questionnaire_id`	With questionnaire	Published questionnaire reference.
`webflow.questionnaire.unit_preferences`	No	Visitor display-unit preferences.
`webflow.questionnaire.questions_and_answers`	With questionnaire	Final answered questions in their relevant order.
`questions_and_answers[].question_id`	Yes	Published question reference.
`questions_and_answers[].question`	Yes	Published question text.
`questions_and_answers[].question_type`	Yes	Question type, such as `numeric_input`.
`questions_and_answers[].answer`	Yes	One or more answer objects.
`answer[].id`	For authored choices	Selected option or slot reference.
`answer[].text`	Yes	Answer label or numeric or date value represented as text.
`answer[].unit`	No	Relevant unit.
`test_event`	Test sends only	Literal `true` for a synthetic test notification.

The last answer paths are relative to webflow.questionnaire. Preserve order for multi-select, ranking, and schedule answers when meaningful. Unanswered and non-question screens are not included. Weight and height answer values use kg and cm. Display-unit preferences do not change those numeric units. Unavailable optional properties are omitted rather than set to null; there is no generic data wrapper or external version field. Verify the signature before interpreting the payload. Apply appropriate access, consent, and retention controls to customer identity and answers.

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subscription_started

Example

Trial activation

Field reference

​Example

​Trial activation

​Field reference

Example

Trial activation

Field reference