Upload a customer document for KYC or KYB verification. This is the first step of the server-to-server verification flow.

Documents are uploaded as base64-encoded strings along with metadata about the document type,
customer information, and document details. The document is validated and stored in preparation
for verification.

Supported document types

The metadata.idDocType field accepts the following values (lowercase):

• Individual customers: passport, id_card, drivers_license, selfie,
  residence_permit, utility_bill, bank_card,
  vehicle_registration_certificate, other

• Business customers: registration_certificate, company_doc,
  formation_document, ownership_document, proof_of_address,
  proof_of_address_document

Selfie documents must be an image (JPEG or PNG); PDF selfies are rejected.

Document subtypes

The supported document subtypes are as follows (case-sensitive, uppercase):

• FRONT_SIDE: Front side of document
• BACK_SIDE: Back side of document (if applicable)

File format

The filename extension and the decoded content MIME type must agree and must be one of: image/jpeg, image/png, application/pdf.

Size limits

The maximum decoded document size is 10 MB. The base64-encoded payload sent in content may be up to roughly 13.3 MB. Larger payloads are rejected at the ingress layer with a 413 before reaching the service.

Idempotency

The Idempotency-Key header is required on this endpoint. Replays of the same key with the same payload return the original response; replays with a different payload return 422.

After uploading all required documents, call the Initiate KYC S2S
endpoint to start the verification process.