"signature_base64": "MEUCIQD...", "key_id": "arn:aws:kms:us-east-1:...", "timestamp": "2026-04-17T10:00:00Z"
Response:
POST /v1/sign Authorization: Bearer <token> Content-Type: application/json "key_alias": "invoice-signing-key-2025", "hash_algorithm": "SHA-256", "data_base64": "SGVsbG8gV29ybGQ=" keysign connector