A real e-signature API — $30/mo, $0.20 a signature.
Wire signing into your own app with a clean REST API and webhooks. It's the $30/month Business plan: 40 signatures included, then a flat $0.20 each. No per-envelope meter creeping toward $4.80, no five-figure enterprise gate — just honest, predictable math you can build on.
The API tax nobody talks about
Here's the part of e-signature pricing that catches builders off guard: the app might look affordable, but the moment you want to send documents from your own software, the meter changes. API envelopes are commonly billed individually — somewhere in the neighborhood of $1.25 to $4.80 each — or the API is locked behind an enterprise plan that can run into the hundreds or even thousands of dollars a month. Automate a workflow and watch the bill scale right along with your success.
We do charge for the API — but we keep the math honest. API access is the $30/month Business plan, and it includes 40 signatures. Past that, every signature is a flat $0.20: no per-envelope mystery, no jump to a five-figure enterprise contract, no per-seat surcharge. At $0.20 a signature you're paying a fraction of the $1.25 to $4.80 rivals meter — and the people who just want to sign documents stay on the $3 Pro plan, untouched. Manual signing through sign.pink remains unlimited and free of any per-signature cost for a single user; the $0.20 only ever applies to API signatures beyond the included 40.
Simple enough to ship today
It's a straightforward REST API: authenticate with a key, post a document, place fields, add signers, and send. Webhooks tell your app the moment something happens, so you're never polling for status. And every document you send programmatically carries the same tamper-evident audit trail as one sent by hand.
What the API gives you
Clean REST endpoints
Create documents, place fields, add signers, and send — all with predictable JSON over HTTPS. If you've used a REST API, you already know this one.
Webhooks for events
Get a callback the moment a document is sent, opened, signed, or completed, so your app reacts in real time instead of polling.
Simple API keys
Generate a key, send the header, you're authenticated. No OAuth ceremony required just to fire off a signing request.
Templates over the wire
Trigger a saved template programmatically, fill the variable fields, and send — perfect for sending the same document at scale.
API pricing, side by side
The app price is only half the story. Here's what happens when you want to send from your own code.
| sign.pink | DocuSign | Dropbox Sign | PandaDoc | |
|---|---|---|---|---|
| Per-signature API fee | $0.20 | ~$1.25–$4.80 | Metered | Metered |
| Signatures included | 40/mo | — | — | — |
| Five-figure enterprise plan to unlock the API | ||||
| Webhooks | ||||
| Same audit trail as the app | ||||
| Monthly price for API access | $30/mo | Hundreds–thousands/mo | Add-on | Per-seat + API |
Competitor figures are illustrative of API/enterprise pricing as of June 2026 and often require annual billing or custom quotes. Verify current pricing before purchase.
No usage cliff
A flat $0.20 per signature past the included 40 — the rate never jumps and there's no enterprise tier that quietly turns $30 into a four-figure invoice.
Same features, programmatic
Signing order, templates, and the audit trail all work through the API exactly as they do in the app.
API FAQ
API access is on the Business plan: $30/month, which includes 40 signatures. Past that, it's a flat $0.20 per signature — no tiers, no negotiation, no enterprise contract. That's well under the $1.25 to $4.80 per envelope many tools meter, and there's no five-figure enterprise plan to graduate into.
Build on a real e-signature API — $30/month, then $0.20 a signature.
No credit card to start. No envelope limits. No surprises.