---
title: "A reply to a member is recorded and queued for delivery."
method: POST
path: "support.message.sent"
tags: ["support.* events"]
---

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

`POST support.message.sent` (webhook)

### 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`](https://docs.subscriby.net/mcp/v1/tools/support/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](https://docs.subscriby.net/api/v1/reference/support-inbox) 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.

## Headers

- `SB-Signature` string, required
- `SB-Event-Id` string, required
- `SB-Event-Name` string, required
- `Content-Type` string, required
- `User-Agent` string, required

## Payload

- object: The envelope every event is delivered in.
  - `id` string, 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_at` string, date-time, required: When the event was emitted, server time, ISO 8601.
  - `api_version` string, required: The contract version of the payload shape, `2026-05-01` today. A breaking change to a shape ships under a new version.
  - `project_id` string, uuid, nullable, required: The project the event belongs to; null for team-scoped and billing events.
  - `data` object, required: The event-specific payload. Keys that do not apply to a given emission are omitted rather than sent as null, so check for presence.
    - `message_id` string, uuid, required: The stored reply.
    - `conversation_id` string, uuid, required: Thread the reply belongs to.
    - `project_id` string, uuid, required: Mirrors the envelope `project_id`.
    - `subscriber_id` string, uuid, required: The member the reply is addressed to.
    - `type` string, required: `text`, or the media kind when the reply carried an attachment.

## Acknowledgement `2XX`

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

## Other responses

- `default`: Any other status, a connection failure, or no answer within 30 seconds counts as a failed attempt. The delivery is retried 8 times, after 10 seconds, 30 seconds, 2 minutes, 10 minutes, 1 hour, 6 hours, 1 day, 3 days; the last failure dead-letters it, and it can be retried from the dashboard or `POST /v1/webhook-deliveries/{delivery}/retry`. After 20 consecutive failures the endpoint is paused until it is resumed.

---

[API](https://skmtc.dev/memberpass/apis/subscriby-rest-api.md) · [All operations](https://skmtc.dev/memberpass/apis/subscriby-rest-api/llms.txt) · [OpenAPI document](https://skmtc.dev/memberpass/apis/subscriby-rest-api/revisions/59c4df91d764?raw)