eSign API

star-rating
4.7 on

Embed eSignatures to your app in 3 API calls

Signeasy’s developer-friendly eSignature API helps you automate document workflows, and you pay only for completed envelopes.

icon-tick
99.9% uptime
icon-tick
Thorough documentation
icon-tick
Pay only for signed envelopes
POST /v3/rs/envelope/
Trusted by 48,000+ businesses, from startups to global enterprises

Platform

Everything you need to manage and automate eSign API workflows in your app

Contact Us
Signing a document

Embedded signing and sending

Let users prepare, send, and sign documents without leaving your app using eSign API.

View Documentation →
POST /v3/rs/envelope/{id}/signing/url
Document status tracking

Webhooks

Track document status in real time and trigger workflows in your own app.

View Documentation →
Developer debugging

Troubleshooting

Debug faster with eSign API Logs and Webhook Logs in the developer portal.

AI-ready document

AI-ready documentation

Get markdown docs and an MCP server that Claude, Cursor, and Codex can read.

Secure document verification

2-step verification

Authenticate signers with a one-time password sent by SMS.

Customers

What teams building on the Signeasy's eSignature API say

Rappi on building with the Signeasy API
Pecan POS on building with the Signeasy API
Halvor Lines on building with the Signeasy API
Property Masters on building with the Signeasy API

How it works

Get started with eSignature API in 3 simple steps

1

Create a Signeasy account

Sign up for a Signeasy developer account to start testing your eSign API.

Create AccountSign-in form for a Signeasy developer account
2

Generate API key and configure

Create your sandbox API key and set up webhook and callback URLs.

Generate API KeyAPI key field
3

Send your first signature request

Use the API to send a test document and experience the eSignature flow.

Test API CallDocument sent for signature

A public Postman collection is available if your team wants to explore the API before writing any code.

Open Collection →

Why Signeasy

Developers get a simple eSign API. Businesses get 16 years of trust.

48,000+ global businesses trust Signeasy for their eSignature and contract workflows.

Easy-to-use REST APIs

Integrate faster with intuitive endpoints and lean payloads that keep your code simple.

Pay-on-completion billing

Pay only when a document is completed, never when it’s sent, declined, or expired.

Custom branding

Add your logo to every email notification so signers know it’s from you.

Reliable developer support

Get a dedicated account manager and 24×7 integration support, backed by 99.9% uptime.

AI-ready documentation

Build with Claude, Cursor, Codex, or Copilot, all of which read our docs natively.

Volume discounts

Save more per envelope after 2,000 envelopes, with special rates for nonprofits.

Certified and secure for all businesses

Get enterprise-grade security to protect your contracts from threats and ensure compliance with international and industry-specific eSignature laws.

ESIGN and UETA badge

ESIGN & UETA

eIDAS badge

eIDAS

AICPA SOC badge

AICPA SOC

GDPR badge

GDPR

HIPAA badge

HIPAA

PAdES-BLT Digital Seal badge

PAdES-BLT Digital Seal

Comparison

How does Signeasy compare to other eSignature APIs?

Features
Signeasy
Docusign
Adobe Acrobat Sign
PandaDoc
Dropbox Sign
airSlate SignNow
Pricing (Advanced Plan)
$250/month (Transparent)
$480/month
Enterprise plan (Hidden with add-ons)
Enterprise plan (Hidden with add-ons)
$250 – $259/month
$146 – $250/month
API Sandbox
✓
✓
✓
✓
✓
✓
Signature Requests
2,000/year
1,200/year
500/month, even on Enterprise plans
Hidden
1,200/year
1,000 – 2,000/year
Billing
Completed envelopes only
Initiated
Initiated
Initiated
Initiated
Initiated
Embedded Signing
✓
Higher plans only
✓
✓
✓
✓
Embedded Templates
Unlimited
Higher plans only
Higher plans only
Higher plans only
15
Higher plans only
MFA Support
✓
+ Add on
✓
+ Add on
✓
Higher plans only
Dedicated Manager
✓
+ Add on
+ Add on
+ Add on
+ Add on
+ Add on

Pricing

eSign API pricing, billed only on completed documents

Pick a plan, or test everything for free in the sandbox first.

Starter

Free

Free sandbox, 100 eSignature requests.

Create Free Sandbox

Advanced

$2,999
/ year

2,000 completed envelopes per year.

Get Started

Custom

Let’s talk

Volume pricing above 2,000 envelopes.

Get Volume Pricing

Every tier bills on completion, not on send. A document that’s voided, declined, or never signed doesn’t count against your plan.

Test the full eSign API in the free sandbox

A public Postman collection is available to explore the API before writing any code.

Partnership program

Interested in partnering with Signeasy?

Signeasy Partner Program helps you embed secure, scalable eSignature capabilities into your product. You get access to partner-only eSign APIs, priority support, co-marketing opportunities, and tools to drive revenue.

Become Partner

Frequently asked questions

What is an eSignature API?

An eSignature API, also known as an Electronic Signature API, is a software solution that enables developers to integrate electronic signature capabilities into their applications and websites. This allows users to electronically sign and send documents for signatures on a single app, thus eliminating the need for physical signatures.

The eSign APIs come equipped with functionalities such as document creation, authentication, tracking, and compliance, resulting in enhanced efficiency in document workflows and reduced paper usage, particularly beneficial for businesses.

How do eSignature APIs work?

Electronic Signature APIs enable developers to seamlessly incorporate electronic signature capabilities into their applications.

Users can either upload existing documents or create new ones, designate signing locations, authenticate their identity, and trigger the signing process.

The API then creates a distinct digital signature, securely attaches it to the document, and encrypts the file for enhanced security. Users receive notifications upon successful signing, and certain eSign API solutions provide options for document storage and the creation of audit trails as well.

These APIs ensure compliance with legal standards, guaranteeing the validity of electronic signatures.

What are the benefits of using an eSignature API?

Using an eSignature API, or Electronic Signature API, provides many advantages. It enhances efficiency by simplifying the signing process, enabling quick document turnaround.

Additionally, it offers accessibility for remote signing on various devices, reducing the reliance on physical paper documents, and contributing to cost savings and environmental sustainability.

The eSign API ensures robust security through encryption, authentication, and audit trails, making electronic signatures legally binding and compliant with regulations in many jurisdictions.

It seamlessly integrates with existing systems, aids in document management, and scales to suit businesses of all sizes, fostering collaborative signing among multiple parties.

How can I integrate an eSignature API solution into my application?

Signeasy offers easy-to-integrate eSignature APIs with well-defined documentation for developers to quickly build, test, and go-live.

To integrate an eSign API into your application, follow the below steps
1. Select a suitable provider and obtain API credentials.
2. Thoroughly review the API documentation for guidance on endpoints, authentication, and usage.
3. Implement authentication to secure access and design the user interface for document preparation and signing.
4. Integrate API endpoints to enable actions like document creation, signing, and management through HTTP requests.
5. Develop error-handling mechanisms and conduct extensive testing to ensure proper functionality.
6. Adhere to legal and security standards, offer user training if necessary, and deploy your application once testing is successful.
7. Continuously monitor, maintain, and optimize your integration as your application evolves.

How can I try out the Signeasy's eSign API solution?

Please Contact us and our solution expert will reach out to you within 24–48 business hours, with the details on how to provision a sandbox account for yourself to try out our eSignature APIs.

How long are the credits valid for?
The credits are valid for the plan's subscription period (one year).
What is an envelope, and how are documents and envelopes related?

At Signeasy, an envelope is a wrapper for documents that you send to a recipient to sign. An envelope can have one document or many documents, and one signer or many signers. Envelopes have statuses (i.e. sent, completed, voided) and also contain information about the sender and timestamps that indicate the progress of the delivery procedure.

Envelopes help you better manage the documents that are usually sent together and need to be signed together to complete a deal, an onboarding process, contract, etc.

Regardless of how many documents, fields, and signers a given envelope contains, it still counts as only one.

Does Signeasy API offer an extra authentication layer at the time of signing documents?
Yes. Signeasy's eSignature APIs support OTP authentication via SMS.
What is the maximum number of signers supported per signature request?
The maximum number of signers supported per signature request is 45 recipients.
What is the maximum file size allowed per document?
25 MB is the maximum file size allowed per document.
Does Signeasy remind signers about signature requests sent via eSign API?
Yes. We remind the signers of a pending signature request for up to 7 days.
How many apps can I create in the developer portal?
You can create a maximum of 3 apps in the Free plan. In the Paid Plans (Starter, Intermediate and Advanced) you can create a maximum of 10 apps. If you need to increase the number of applications please reach out to our electronic signature API support team.
What happens if my plan expires?
If the eSign API plan expires your endpoint access will be restricted and you will not be able to send any signature requests. There will be reminder notifications for plan expiry and credits utilized. Please ensure renewal of the plan ahead of time to ensure continued usage.
Does Signeasy offer a free API sandbox?
Yes, Signeasy offers a free API sandbox for developers who want to test the API before going live. You can create a developer account, build a sandbox application, generate a test access token, and make API calls using limited free credits. The sandbox is designed for testing and development rather than production transactions.
Is the Signeasy API secure?
Yes, the Signeasy API is secure. It is designed to support secure eSignature workflows through OAuth-based access and document security controls. Signeasy uses AES 128-bit encryption for data at rest and SSL 256-bit encryption in transit. It also maintains audit trails, supports additional signer authentication, holds SOC 2 certification, and supports major eSignature compliance requirements.
How do I upload documents using the Signeasy API?
To upload documents using the Signeasy API, send a POST request to the /v3/original/ endpoint with multipart form data and a valid Bearer token. Include the source file and filename in the request. The endpoint accepts files up to 25 MB, does not support Base64 uploads, and returns an original ID for creating subsequent signature requests.