Secure, Scalable eSignature API Built for Developers
Embed secure, legally binding e-signatures in any app or system with Blueink's REST electronic signature API. Embedded and white-label signing, webhooks, and SDKs, with a free sandbox to start building today.
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What You Can Build with Blueink’s eSignature API
Embedded Signing API
- Allow users to review and sign documents without leaving your web or mobile app.
- Send signature requests directly through your eSignature integration.
- Support multi-step signing flows with multiple signers and actions per signer.
- Increase document completion rates and streamline user workflows.
Custom Branding & White-Label eSignature
- Replace Blueink logos with your own brand assets and design styles.
- Match signing pages to your website’s colors, fonts, and layout.
- Customize notification emails, signer pages, and confirmation screens.
- Deliver a white-label eSignature experience that strengthens brand trust.
Real-Time Webhooks & API Events
- Receive instant updates when documents are signed, completed, or expire.
- Automate workflows triggered by signing, rejection, or completion events.
- Maintain real-time status sync across CRMs, HR systems, or databases.
- Eliminate manual tracking with automated webhook integrations.
Smart Auto Field Placement
- Use text field or placeholders to predefine where signers must enter data.
- Automatically convert tags into form fields during upload.
- Reduce setup time with intelligent auto-field recognition.
- Minimize human error with consistent document formatting.
Multi-Layer Identity Verification
- Verify signer identity via government ID, selfie match,or SMS PIN.
- Add verification layers based on document sensitivity.
- Protect against fraud with secure signer authentication flows.
- Comply with eIDAS, ESIGN, and other verification standards.
Custom Reminders & Signer Control
- Schedule reminders based on signer order or specific time intervals.
- Customize email and SMS notifications for each recipient.
- Improve completion rates with automated reminder campaigns.
- Reduce manual tracking by letting the API handle notification timing.
Secure, Compliant eSignature API Built for Global Standards
FERPA, and more.
Developer Tools and Support for Your eSignature API Integration
High-Quality Documentation
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Developer-Ready SDKs and Tooling
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Dedicated API Success Team
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Robust and Reliable Infrastructure
Send Your First Envelope in Minutes with Our SDKs
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Python SDK
JavaScript SDK
PHP SDK
Why Choose Blueink’s eSignature API
30M+
50%
Pay for the eSignature API usage you need
Volume Discounts
API Envelopes
$0.95
53% DISCOUNT
What’s Included
Volume Discounts
No Expiration
Free to Test
Up to 5 users
Developer dashboard
API Envelopes
Price per Envelope
Discount
Up to 1,000
$0.95
Scale pricing as you grow
5,000
$0.75
Save 21%
25,000
$0.60
Save 37%
100,000
$0.45
Save 53%
250,000
$0.35
Save 63%
500,000
$0.28
Save 71%
1,000,000
Best Value
$0.24
Save 75%
Up to 1,000
Scale pricing as you grow
$0.95
per envelope
5,000 Envelopes
Save 21%
$0.75
per envelope
25,000 Envelopes
Save 37%
$0.60
per envelope
100,000 Envelopes
Save 53%
$0.45
per envelope
250,000 Envelopes
Save 63%
$0.35
per envelope
500,000 Envelopes
Save 71%
$0.28
per envelope
1,000,000 Envelopes
Best Value
Save 75%
$0.24
per envelope
Developer Resources for the Blueink REST API
Quick Start
SDK
How-to Guides
Postman Collection
API Reference
Live Examples
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FAQs
An eSignature API (also called an electronic signature API, e-signature API, or eSign API) allows developers to integrate electronic signature capabilities into any website, app, or platform. You can send, sign, verify, and track documents programmatically with secure, compliant workflows.
Yes. Blueink complies with eIDAS (EU), the ESIGN Act (US), and UETA (US), ensuring every signature is legally valid and enforceable across multiple jurisdictions. Every envelope includes a detailed audit trail of who signed, when, and how they were verified.
The cost of Blueink’s eSignature API depends on your usage and plan. API credits start at $0.95 per envelope, with volume discounts that can reduce the cost to $0.24 per envelope. Credits never expire, and testing in the sandbox is free. Visit our API plans & pricing page for full details.
You can create a free sandbox account or request a demo. The sandbox is free with unlimited test envelopes and no time limit, so you can build and test embedded signing, webhooks, and templates before going live. Follow the installation guide and SDK documentation, and our API Success Team is available during your trial for technical support.
Yes. Use the REST API to send documents and templates for signature, embed signing in your app, track status in real time with webhooks, and download completed documents with their audit trail.
The terms are often used interchangeably. Strictly, a digital signature is a type of electronic signature that uses certificate-based encryption. Blueink’s eSignature API focuses on legally binding electronic signatures with identity verification options and full audit trails.
API plans include a limited number of “regular” envelopes, allowing you to send envelopes from the Blueink Dashboard and via the API. However, if you need to regularly send envelopes from the Dashboard and via our API, an Enterprise plan is probably the best fit for your organization. Please contact our sales team to discuss options.
Yes, for many standard eSignature workflows. Blueink supports document sending, embedded signing, templates, webhooks, tracking, and API automation. If your Docusign implementation relies on broader agreement-management features, you should review those requirements before migrating.