support.* events

A reply to a member is recorded and queued for delivery.

When this fires

A creator or team member replies to a member, from any surface: the dashboard inbox, the relay DM on the connector, the REST API, or the reply_support_conversation MCP tool.

It does not fire when:

  • The reply was recorded as an internal note. Notes are private remarks for your team, are never delivered to the member, and raise no event.
  • An automated acknowledgement goes out. The project's auto-reply is a system message, not a creator reply.

This fires when the reply is recorded and queued, not when the member receives it. Delivery happens on a queue and can still fail; a member who has blocked the bot is unreachable. Read delivery_status from the support API for the outcome.

Caveats

  • The payload does not say who replied. Read author_user_id from the conversation messages endpoint if you need to attribute it to a specific team member.
  • The member sees the reply prefixed with the project's support name, so it reads as coming from a person rather than from the bot. That prefix is added at delivery and is not part of the stored body.
  • Pairing this with support.message.received gives you first-response time. The conversation's own first_response_at is stamped only once, on the first human reply, which is the more reliable SLA measure.

Related events

  • support.message.received: the member's side.
  • support.conversation.resolved: usually the next step after a reply.
postWebhooksupport.message.sent

Headers

SB-Signaturestring required

t=<unix seconds>,v1=<hex>: the HMAC-SHA256 of "<t>.<raw body>" under the endpoint's secret. Verify it before acting, and refuse a t more than 300 seconds from now. During a secret rotation a v0= signature under the previous secret may precede v1=.

SB-Event-Idstring required

The event's ULID, bare. The envelope's id is the same ULID prefixed evt_, so strip the prefix before comparing. Deduplicate on it: a retry carries the same id.

SB-Event-Namestring required

The event name, the same as the envelope's type.

Content-Typestring required

Always application/json.

User-Agentstring required

Always Subscriby-Webhooks/1.0.

Payload

idstring required

A ULID unique to the event, prefixed evt_. Every retry carries the same id, so it is the key to deduplicate on.

type'support.message.sent' required

The event name, always support.message.sent here.

created_atstring date-time required

When the event was emitted, server time, ISO 8601.

api_versionstring required

The contract version of the payload shape, 2026-05-01 today. A breaking change to a shape ships under a new version.

project_idstring uuid nullable required

The project the event belongs to; null for team-scoped and billing events.

Response

Your endpoint acknowledged the delivery. Any 2xx status within 30 seconds marks it delivered; the response body is ignored.

Changes

Webhooks have no change history: a webhook is keyed by its event name rather than a path and method, so no recorded change can name it.