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WEBHOOK

Headers

​
X-Helo-Webhook-Signature
string
required

HMAC-SHA256 signature of the request, formatted as t={timestamp},v1={signature}. Verify it against the webhook's signing key to authenticate the delivery.

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X-Helo-Webhook-Event-Id
string<uuid>
required

Unique identifier of the event, useful for idempotent processing.

​
X-Helo-Webhook-Test
enum<string>

Set to true when the delivery is a test, otherwise omitted.

Available options:
true

Body

application/json

Payload delivered for the delivered event.

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timestamp
string<date-time>
required

When the event occurred (ISO 8601 / RFC 3339).

​
messageId
string<uuid>
required

Unique identifier of the message the event relates to.

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channelId
string<uuid>
required

Unique identifier of the channel the message was sent from.

​
mailType
enum<string>
required
Available options:
transactional,
broadcast
​
recipient
string
required

The single recipient the event relates to.

​
eventType
enum<string>
required
Available options:
delivered
​
subject
string

Subject line of the message.

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tags
string[]

Tags associated with the message.

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metadata
object

Arbitrary key/value metadata associated with the message.

​
details
any

Unstructured, event-specific details. The shape depends on the event type.

Response

2XX

Return any 2XX status code to acknowledge receipt.