Crescendo Lab Maacgo Webhooks

generated: '2026-07-18'
method: searched
source: openapi/crescendo-lab-maacgo-openapi.yaml (webhooks) + https://sms.cresclab.com/developers.html
type: Webhooks
api: MAAC Go API
transport: HTTP POST to your configured endpoint
configure_at: https://sms.cresclab.com/developers.html
signing:
  algorithm: HMAC-SHA256
  header: X-Cresclab-Signature
  verify: 'hex(hmac_sha256(webhook_secret, raw_request_body)) == header_value'
delivery:
  retry: exponential backoff 0s -> 2s -> 8s (3 attempts)
  ack: any 2xx acknowledges
events:
- name: sms.sent
  description: Message accepted by carrier (interim state).
- name: sms.delivered
  description: Message reached the recipient's handset (MAAC DLR confirmed).
- name: sms.failed
  description: Permanent delivery failure (invalid/blocked/undeliverable); wallet auto-refunded.
payload:
  shape: '{ event, data: { id, to, status, error }, created_at }'
note: >-
  MAAC Go publishes webhooks via the OpenAPI 3.1 webhooks block, not a standalone
  AsyncAPI document. This file captures the webhook catalog verbatim from that
  surface. No fabricated AsyncAPI spec is emitted.