Case StudiesDevelopers & APIHow a SaaS team embedded document signing without building their own signing engine

Developers & APICore workflow

How a SaaS team embedded document signing without building their own signing engine

8 min read
app.woltsign.com
API Integration card on a template detail page showing cURL example
API integration
curl -X POST https://api.woltsign.com/v1/envelopes \
-H "Authorization: Bearer sk_live_…" \
-d '{"template_id":"tmpl_nda","signers":[...]}'

Old process

  • Users completed registration but signed agreements in a separate DocuSign email
  • Product access could not gate on signature without manual ops checks
  • Building an in-house signing engine was estimated at 3 to 6 months
  • Webhook and status sync did not exist in the onboarding funnel

With WoltSign

  • Backend creates envelopes from a template on registration
  • Signing URL surfaced inline in the product onboarding flow
  • Webhook updates user access when the envelope completes
  • Ops no longer manages an out-of-band signing thread
Draft
Sent
Pending
Approved
Completed

SaaS products that touch agreements need to collect signatures inside the product. Building a signing engine from scratch often takes 3 to 6 months. The alternative is to embed e-signature in SaaS through a document signing API that returns hosted signing URLs and completion events.

Why product teams evaluate an e-signature API integration

Property tech, HR software, and legal ops tools all gate paid access on a signed service agreement. Manual email routing breaks the funnel. Users finish registration, then wait for an external email they may not open the same session.

Start with the WoltSign API for developers and the API integration documentation. For audit records after completion, see certificate of completion in dispute resolution.

What breaks down when signing lives outside the product

A bootstrapped B2B team was building onboarding that required a signed agreement before paid access. Building in-house failed the cost/benefit check. Manual DocuSign sends broke the product flow. There was no webhook to flip access when the user finished signing.

How a SaaS team embeds a signing workflow with the WoltSign API

Step 1: Create the service agreement template

The team builds one template in WoltSign with a single signer role and signature fields on the agreement PDF. The template ID is stored in application config.

Step 2: POST /api/envelopes on registration

When registration completes, the backend creates an envelope from the template with the user name and email. The API returns an envelope ID and signing URL.

Step 3: Show the signing link in onboarding

The product surfaces the signing URL on the next onboarding step. The user signs without leaving the funnel for a separate email thread.

Step 4: Configure webhooks for Completed status

A webhook endpoint receives POST events when the envelope status changes. The handler verifies the payload and updates the user record.

Step 5: Grant access when the agreement is on file

Paid features unlock only after the webhook confirms completion. Support can verify status from the same envelope ID in the WoltSign workspace.

app.woltsign.com
API Integration card on a template detail page showing cURL example
NDA — Standard
Last updated Mar 1, 2026
Edit template
Template roles, documents, and field map preview.

What changes when signing is part of the onboarding funnel

The integration shipped in one sprint. The product team no longer manages an out-of-band signing flow. See full API reference at WoltSign documentation and the blog post e-signature API guide.

What changes when the workflow is structured

Integration time

One sprint

Industry benchmark; results vary by org and volume

Signer experience

Hosted link

WoltSign generates the signing page

Status sync

Webhook driven

On envelope Completed event

FAQ

Frequently asked questions

Short answers to the questions teams ask most often about this topic.

Do I need to build a custom signing UI?

No. WoltSign generates a signing URL that opens a hosted signing page. Your product links to it or opens it in a modal.

How do I know when the user finishes signing?

Set up a webhook endpoint. WoltSign POSTs an event to your URL when the envelope status changes to Completed.

Is the API key per workspace or per account?

API keys are scoped to a workspace. See /documentation for the authentication reference.

Related case studies

See if WoltSign fits your developers & api workflow

Most teams are set up and sending within a day. No implementation fee. Cancel any time.