Nitro Software Sign Webhooks

generated: '2026-07-20'
method: searched
source: https://developers.gonitro.com/docs/build-nitro/webhook
type: Webhooks
spec_type: WebhookCatalog
note: >-
  Nitro offers two notification mechanisms. Sign webhooks are long-lived per-application
  subscriptions delivering real-time envelope/signature events (documented; general
  availability noted as upcoming). PDF Services callbacks are per-request point-to-point
  POSTs fired once when an async job is accepted. No provider-published AsyncAPI document
  exists; this is a captured webhook/event catalog.
sign_webhooks:
  registration: one webhook URL per application, registered in the Nitro Admin Portal
  transport: HTTP POST (JSON), TLS required
  envelope:
    fields: [id, type, created, data]
    id: unique event id (use for de-duplication)
    created: UTC timestamp
  delivery:
    ordering: not guaranteed
    retry: 5xx/network errors retried; 2xx and 4xx are terminal (acknowledged)
    consumer_timeout_seconds: 15
    idempotency: consumers must build idempotent, order-independent handlers keyed on event id
  security:
    signing: RFC 9421 HTTP Message Signatures
    algorithm: hmac-sha256 (client secret as key)
    signed_components: ['@method', '@path', host, date, content-digest]
    headers: [Content-Digest, Signature-Input, Signature]
    keyid: clientId
  event_types:
  - EnvelopeCreated
  - EnvelopeDocumentAdded
  - EnvelopeDocumentDeleted
  - EnvelopeSentForSignature
  - EnvelopeCancelled
  - SignatureRequestReassigned
  - SignatureRequestDeclined
  - SignatureRequestSigned
  - EnvelopeSigningCompleted
  - EnvelopeSealed
  - OwnerMessaged
pdf_services_callbacks:
  configured: per-request, in request body delivery.callback
  trigger: 'Prefer: respond-async header set on the job request'
  fires: once, on job acceptance (acknowledgement, not completion)
  payload_fields: [jobID, location]
  auth: optional custom headers in delivery.callback.headers[]
  completion: poll GET {location} (result) or GET {location}/status; or use uploadResultTo/uploadResultsTo