api reference · v1
The Usign REST API.
A predictable, versioned, Stripe-style API. Every resource is JSON over HTTPS. Idempotency keys are built in. Base URL:
https://api.usign.upfluence.com/v1
Authentication
Authenticate with a workspace API key in the Authorization header. Keys are scoped to one workspace and never expire until revoked.
curl https://api.usign.upfluence.com/v1/contracts \
-H "Authorization: Bearer sk_live_…"
The two-phase model
Create never sends. POST /v1/contracts always returns a draft. Email is dispatched only by POST /v1/contracts/:id/send. There is no single call that creates and sends, by design.
Contracts
Templates
Templates are immutable per version. List them, fetch one, and inspect its merge-field registry before drafting.
Webhooks
Every lifecycle event POSTs an HMAC-signed payload to your endpoint, carrying the external_reference you supplied at creation. Verify the Usign-Signature header against your signing secret.
{
"event": "contract.completed",
"contract_id": "ctr_8fK2a",
"external_reference": "deal_4821",
"status": "completed",
"sealed_pdf_url": "https://…/ctr_8fK2a.pdf"
}