generated: '2026-08-13'
method: searched
source: https://headwayapp.co/appgain-changelog (Appgain WhatsApp Lite — Release Notes)
spec_type: none
asyncapi_published: false
webhooks_advertised: true
note: >-
  Appgain publishes no AsyncAPI document and no webhook reference page. It DOES
  advertise an outbound webhook surface, in its own release notes for WhatsApp Lite:
  delivery and user-reply events stream out to external destinations, and "outbound
  webhooks + n8n recipes" are listed as an LLM-ready hook. That is a provider claim
  about a real event surface, so it is recorded here — but the catalogue below is
  everything Appgain says about it. There is no event schema, no payload example, no
  signing/verification scheme, no retry policy, no subscription API, and no way to
  register an endpoint except through the dashboard. Nothing has been invented to
  fill those gaps.
direction: outbound-only
subscription:
  api: none
  method: configured in the Appgain dashboard (no documented REST endpoint to register or list webhooks)
events:
- name: delivery
  channel: WhatsApp Lite
  description: Message delivery events streamed to the configured destination.
  payload_schema: not published
  source_text: 'Webhook Out: Delivery & user-reply events stream to Zapier, MCP Server, BI stacks'
- name: user-reply
  channel: WhatsApp Lite
  description: Inbound customer replies streamed to the configured destination.
  payload_schema: not published
  source_text: 'Webhook Out: Delivery & user-reply events stream to Zapier, MCP Server, BI stacks'
documented_destinations: [Zapier, n8n, 'MCP server (customer-side)', BI stacks]
related_but_not_webhooks:
  note: >-
    Two things that look like a webhook surface in Appgain's docs but are not.
  items:
  - >-
    The n8n integration guide's "Trigger: Webhook (Order placed)" examples are n8n's
    OWN inbound webhooks receiving events from the customer's shop — Appgain is the
    HTTP client being called downstream, not the event source.
  - >-
    Automation-journey trigger points
    (GET/POST automessages/{projectId}/firevent/{trigger}/{userId}) are an INBOUND
    REST call the customer makes to fire a journey. They are the opposite direction
    from a webhook and are catalogued in mcp/appgain-mcp.yml.
event_catalogue_completeness: minimal
gaps:
- No payload schema or example for either event.
- No signature/HMAC verification scheme published, so a receiver cannot authenticate Appgain's callbacks.
- No retry, ordering or at-least-once delivery statement.
- Scoped to WhatsApp Lite only — no delivery/open/click/bounce webhooks documented for push, email, SMS or web push, even though those events are tracked internally (see the system-event table at https://docs.appgain.io/core-concepts/events/).