Visma Sign API v1 for electronic signatures

Visma Sign is automatable today through Visma Sign API v1 at https://sign.visma.net/api/docs/v1/. An organisation account is required. API credentials and a staging environment are ordered from kumppanit.sign@visma.com. Credentials are a client identifier and a secret key. Organisation requests use an Amazon-style HMAC: the Authorization header is Onnistuu, the client identifier, and a base64 SHA-512 HMAC over the verb, content MD5, content type, date, and path. The API creates a document, adds one PDF file, creates invitations, lists authentication methods, and reads document status. A document currently holds one PDF, under 15 MB in production and 1.5 MB in staging. The signed file is fetched with GET /api/v1/document/{uuid}/files/0. Staging does not require a Finnish, Swedish, or Danish SSN or bank credentials, and Visma says it can differ from production. The public homepage offers a trial of 5 signatures and then an upgrade. The footer names Visma Solutions Oy. No MCP server, SDK, CLI, or webhook contract was established on the pages opened. Connector catalogs were not opened. Computer-use viability is unassessed. The API scores 6 because signature collection is documented and partner-issued credentials plus the single-PDF limit are material constraints.

Best path today: api · Overall automatability: 6/10