Cancel an envelope

// POST https://api.signatureapi.com/v1/envelopes/{envelope_id}/cancel
// X-API-Key: key_test_...
{
  "reason": "Price renegotiated by John D."
}

{
  "id": "55072f0e-b919-4d69-89cd-e7e56af00530",
  "title": "Dummy Agreement",
  "label": "Dummy Agreement for Order Ref. 25005",
  "message": "Please review the agreement at your convenience and provide your electronic signature.",
  "status": "canceled",
  "mode": "live",
  "routing": "sequential",
  "language": "en",
  "timezone": "UTC",
  "timestamp_format": "DD/MM/YYYY HH:mm:ss",
  "sender": {
    "name": "Jennifer Lee",
    "email": "jennifer@example.com",
    "organization": "Acme Enterprises"
  },
  "topics": [
    "sales",
    "project_blue"
  ],
  "metadata": {
    "customer_ref": "x9550501",
    "account_annual_revenue": "$4,500,000"
  },
  "documents": [
    {
      "id": "doc_3jBYlxa9gv0fGLzFAnfwxe",
      "envelope_id": "52872f0e-b919-4d69-89cd-e7e56af00548",
      "title": "Dummy Agreement",
      "page_count": 2,
      "url": "https://pub-e5051420e98a4fdfb3fd42a62fbf06fa.r2.dev/dummy.docx",
      "format": "docx",
      "data": {
        "date": "December 31st, 2025",
        "showAlert": true,
        "serviceProvider": {
          "name": "Jane Smith",
          "organization": "ACME Global, Inc."
        },
        "client": {
          "name": "Michael J. Miller",
          "organization": "Miller Industries"
        }
      },
      "places" : [
        {
          "key": "provider_signs_here",
          "type": "signature",
          "recipient_key": "service_provider"
        },
        {
          "key": "client_signs_here",
          "type": "signature",
          "recipient_key": "client"
        }
      ]
    }
  ],
  "recipients": [
    {
      "id": "re_26w2VVV5JVm4j459TY5BNM",
      "envelope_id": "52872f0e-b919-4d69-89cd-e7e56af00548",
      "type": "signer",
      "key": "provider",
      "name": "Emily Johnson",
      "email": "emily@example.com",
      "status": "pending",
      "ceremony_creation": "automatic",
      "delivery_type": "email",
      "completed_at": null,
      "status_updated_at": "2025-12-31T15:00:00.000Z"
    },
    {
      "id": "re_38UVwrWdCqX5kqeKFJUTtf",
      "envelope_id": "52872f0e-b919-4d69-89cd-e7e56af00548",
      "type": "signer",
      "key": "client",
      "name": "Michael Taylor",
      "email": "michael@example.com",
      "status": "pending",
      "ceremony_creation": "automatic",
      "delivery_type": "email",
      "completed_at": null,
      "status_updated_at": "2025-12-31T14:00:00.000Z"
    }
  ],
  "deliverable": null,
  "created_at": "2025-12-31T12:00:00.000Z",
  "completed_at": null
}