E-Signature API Integration: A Complete Guide for Developers

Worldwide adoption of e-signatures surged by 69% in 2024. This is hardly surprising, considering its many advantages, such as robust security, convenience, effective time management, and cost savings — estimated at $28 per agreement.  

However, to enjoy these benefits, developers must consider integrating e-sign capabilities directly into apps, allowing users to sign PDFs online. Don’t know how? Well, continue reading as we walk you through the steps to help you get started.

Preparing for e-signature API integration

Here’s a step-by-step guide to successful API implementation.

Assessing organizational needs and goals

Start by defining your organization’s goals for incorporating e-signatures. This clarity will steer you toward a solution that satisfies your specific requirements. Think about  factors like:
 

• Volume and frequency. Determine how many documents will be electronically signed each month. This insight will help you select a solution that can scale as needed.
   
• Use cases. Identify the specific scenarios where online PDF signatures will be utilized, such as contracts, approvals, or customer forms. Different providers may offer features tailored to these different scenarios.
   
• User experience. Will it make the process of inserting electronic signatures into PDFs simpler or more complicated for all parties?
   
• Compliance and security. Ensure that the chosen solution complies with industry-specific regulations to uphold the integrity of your electronic signatures in PDF processes.

Selecting the right e-signature API provider

The choice of API source is pivotal to the success of your integration. Consider these criteria when evaluating potential providers:

• Features and capabilities. Does the API offer the specific features you need, such as custom branding, templates, or advanced authentication methods?

• Ease of integration. To simplify the incorporation, look for comprehensive documentation, SDKs, and developer support resources.

• Cost. Consider the pricing models and ensure they fit within your budget. Some hosts offer pay-as-you-go options, while others have subscription plans.
   

• Reliability and Performance. Research the provider’s uptime history and performance reviews to guarantee a dependable service.
   
• Customer Support. Choose a host that offers responsive technical assistance and customer service to address any questions or issues that may arise.

Obtaining API access and credentials

Once you’ve selected a provider, you’ll need to obtain API access and credentials. 

1. Register an account with the chosen e-sign host. This may require providing some basic information about your organization.
    
2. Request the API keys or tokens that will authorize your application to interact with the online signature PDF service.
    
3. Some providers have a sandbox environment. Use it to thoroughly test your integration without affecting live data.

1. Set up read/write access, user roles, and other necessary permissions for your API credentials.

Authentication and security

Robust validation and security measures are paramount when integrating an e-signature gateway. They protect your private data, shut out third-party interference, and guarantee the integrity of the e-signing.

API authentication methods

E-signature APIs typically offer several authorization methods, each with its own security considerations:

1. API keys

API keys are a common validation method used in e-signature endpoints. They are unique identifiers that allow applications to access third-party software services.

• Simple to use: API keys are straightforward to implement, requiring only the key to be included in the request header or URL parameter.
   
• Limited scope: They often have limited permissions, making them suitable for less delicate operations.
   
• Precaution: The keys are static and could make your asset vulnerable. To prevent breaches, transfer encrypted API keys with HTTPS only; don’t use the keys in client-side code.

2. OAuth 2.0

OAuth 2.0 is a more robust authorization framework that delegates access control. It involves obtaining access tokens from the application host, which your application then uses to authenticate requests:

• Token-based access: OAuth 2.0 uses short-lived and refreshable tokens. This reduces the risk of compromised credentials.
   
• Granular permissions: Allows fine-grained access control by granting specific permissions, enhancing security.
   
• User consent. It enables users to grant or revoke access to their data without revealing login credentials, thereby enhancing overall security.

Implementing secure authentication

Whatever choice you use, make sure to follow these security standards:

• Use secure passwords. Ensure that all accounts linked to your API have strong and unique passwords.
   
• Regularly rotate credentials. Regularly update your keys and tokens to minimize the risk of unauthorized access.
   
• Error handling. Implement proper error handling to avoid exposing sensitive information. This might include signature loans online or medical records.
   
• Monitor usage. Continuously monitor your usage of the application programming interface to detect any unusual activity that could indicate a security breach.

Best practices for managing API credentials

Effective management of API credentials is crucial for maintaining the security and integrity of your e-signature integration:

• Store credentials securely. Store API keys and tokens securely in environment variables or secure vaults, avoiding hardcoding them in your application.
   
• Restrict permissions to only what is essential for each system or user to perform their intended functions. This minimizes the potential impact of a compromised system or account.
   
• Remove any unused credentials. Promptly invalidate any dormant keys or tokens to plug potential security gaps.

Integrating e-signature APIs

With preparations complete, it’s time to begin the incorporation procedure. This involves connecting your application to the e-signature API, enabling seamless document signing within your workflows.

Overview of the integration process
The integration typically follows these general steps:

1. Authentication. Your application obtains the credentials (API keys or access tokens) to interact with the access point securely.
    
2. Document preparation. Documents are uploaded or referenced, and signature fields are defined within the document.
    
3. Signature workflow. The document is sent to recipients to insert signatures in PDF, and the signing procedure is initiated.
    
4. Status tracking. The application monitors the document’s signing status.
    
5. Completion. After all signatures are collected, the fully signed document is retrieved and stored.

Implementing basic API calls
Let’s break down some common API calls involved in the integration:

1. Authentication and access tokens

Get access tokens from the provider’s authentication API. You’ll need these tokens for making other API calls. Store the tokens safely and refresh them if they expire.

2. Uploading documents for e-signature

To upload a document, use the API and provide either the file contents or a URL where the document is hosted. You can optionally specify a file name and apply password protection.

3. Defining signature fields and positions

Use the API to provide the position and type of signature fields in the document. This could include defining the placement and page numbers, as well as the use of templates.

4. Sending documents for signature

Use the API to start the signing process. Specify the recipients, the signing sequence in which signatures are drawn online, and any other settings. Typically, the API will auto-generate a signature URL for each recipient.

5. Tracking document status and retrieving signed documents

Get live updates on the document’s journey (e.g., sent, viewed, signed). After all signatures are collected, retrieve the signed document —  all from the API user interface.

Remember that the particular API calls and parameters will differ based on your selected provider. Thoroughly review their documentation and leverage any SDKs or libraries they offer to simplify the incorporation

Conclusion 

E-signature APIs improve your business operations by protecting the confidentiality and integrity of crucial documents while also creating trust in partners, clients, and suppliers. Begin by examining your organization’s requirements and selecting a reputable provider like Lumin, known for its performance, ease of use, and support.