Provider APIs
Request shape
The shared request facts behind each provider API.
Provider APIs create upstream signing ceremonies. They are not local Signatures backends: the provider owns links, notifications, recipients, envelopes, and audit UX. SignatureKit keeps the calls boring: typed input, Redacted credentials, SignatureHttpClient, and SignatureKitError on recoverable failures.
npm install @signature-kit/core @signature-kit/clicksign @signature-kit/assinafy @signature-kit/zapsign @signature-kit/docuseal @signature-kit/documensoProviders
Clicksign
v1 document + signer flow, one document per request.
Assinafy
Document, signer, and assignment inside an account.
ZapSign
Bearer-token PDF upload with first signing URL.
DocuSeal
Open-source PDF submissions with submitter links.
Documenso
Open-source v2 envelopes with optional distribution.
Shared request shape
Every provider starts from the same SignatureKit request facts: title, documents, recipients, optional subject, message, send, expiresAt, and redirectUrl. Each provider page explains how those facts map to its upstream protocol.
Local vs remote
Use @signature-kit/pdf + Signatures when SignatureKit must sign bytes. Use provider request functions when an upstream platform owns the ceremony.