S SignFlow

Open-source · self-hosted · API-first

Electronic signatures, without the vendor lock-in

SignFlow is an open-source, API-first e-signature platform — a self-hosted alternative to DocuSign with multi-recipient routing, drag-and-drop PDF templates, bulk send, and a full audit trail.

Full audit trail & signed certificates HMAC-signed webhooks Your infrastructure, your data API-key & token authentication

Everything you need to get documents signed

Multi-recipient routing

Sequential, parallel, mixed, or conditional signing order — route an envelope exactly the way your process requires, not the way the tool forces you to.

Drag-and-drop templates

Design reusable PDF templates once, with versioning and rollback, so every new envelope starts from a clean, tested layout.

Bulk send

Upload a CSV or spreadsheet and send hundreds of envelopes at once, with a dry-run preview, pause/cancel, and per-row retry.

Smart merge tags

A real templating engine — conditionals and loops, not just flat find-and-replace — for documents that adapt to the data.

Full audit trail

Every view, field completion, and signature is logged, with a signed Certificate of Completion and a public hash-verification page.

Signed webhooks

HMAC-signed, retried-with-backoff webhook deliveries so your other systems always know what just happened.

API keys & integrations

A full REST API with API-key auth for server-to-server integrations, independent of any one user's login session.

Self-hosted, your data

Open-source and self-hostable — run it on your own infrastructure instead of trusting a vendor with your contracts.

How it works

1

Create a template

Upload a PDF and place signature, date, and data fields once.

2

Add recipients & routing

Assign roles and decide who signs in what order.

3

Send

Envelopes go out immediately, with automatic reminders.

4

Track & verify

Watch it complete, then download a signed audit certificate.

Simple, transparent pricing

Start free. Upgrade as you grow.

Monthly Yearly Save 20%

Free

  • 5 envelopes/mo
  • 1 users
  • 1 GB storage
  • ✗ API access
  • ✗ Webhooks
  • ✗ SMS notifications
Get started

Starter

  • 50 envelopes/mo
  • 5 users
  • 9 GB storage
  • ✗ API access
  • ✗ Webhooks
  • ✗ SMS notifications
Get started

Most popular

Business

  • 500 envelopes/mo
  • 25 users
  • 93 GB storage
  • ✓ API access
  • ✓ Webhooks
  • ✗ SMS notifications
Get started

Enterprise

  • Unlimited envelopes
  • Unlimited users
  • Unlimited storage
  • ✓ API access
  • ✓ Webhooks
  • ✓ SMS notifications
Get started

Trusted by teams who own their process

“We moved our whole contract pipeline over in an afternoon. Bulk send alone paid for the switch.”

— Operations Lead, Mid-size logistics company

“Being able to self-host mattered more to our compliance team than any feature checklist.”

— IT Director, Regional healthcare provider

“The webhook signing and audit trail meant we didn't have to build any of that ourselves.”

— Founding Engineer, B2B SaaS startup

Frequently asked questions

Is SignFlow really open-source?

Yes — SignFlow is an open-source, API-first e-signature platform you can self-host, built as a self-hosted alternative to closed platforms like DocuSign.

Can I use my own domain and branding?

Your organization's logo and brand colors already appear on every signing invitation and notification email sent to your recipients.

Do you support bulk sending?

Yes — upload a CSV or spreadsheet of recipients against a template and send hundreds of envelopes in one batch, with a dry-run preview first.

Is there a free plan?

Yes, the Free plan covers small volumes indefinitely with no credit card required — see the pricing table above.

Where can I find more detailed guides?

Visit the Help Center for step-by-step walkthroughs.

Ready to send your first envelope?

Free forever for low volume. No credit card required.

Start free