Getting Started With SignNow API

Welcome to your comprehensive guide for getting started with the SignNow API, specifically tailored for .NET developers. Whether you’re building a new application or integrating eSignature workflows into an existing system, SignNow’s robust API and .NET SDK make it easy to automate document signing, streamline approvals, and deliver a seamless digital experience to your users. In this guide, you’ll discover the core capabilities of the SignNow API, learn how to set up your development environment, and walk through practical steps to authenticate, upload, send, and retrieve signed documents — all with real-world examples and visuals to help you succeed.

Understanding the SignNow API and Its Capabilities

The SignNow API empowers businesses and developers to embed legally binding electronic signature workflows directly into their applications, websites, or CRMs. With a RESTful architecture and comprehensive SDKs, SignNow enables you to automate document preparation, signature collection, status tracking, and secure storage — all without leaving your own platform. Key features include:

• Uploading documents with fillable fields (signatures, text, dates, checkboxes, and more)
• Configurable multi-step signing workflows with role-based invites
• Real-time status tracking and audit trails
• Secure OAuth 2.0 authentication and compliance with major regulations (GDPR, HIPAA, SOC 2, and more)
• Support for embedded signing, bulk invites, reminders, and branded experiences

SignNow’s API is trusted by hundreds of Fortune 500 companies and handles billions of API calls, ensuring reliability and scalability for businesses of any size.

Overview of the SignNow .NET SDK

The SignNow .NET SDK is a powerful library that simplifies integration with the SignNow API for .NET developers. It supports .NET Framework 4.5+, .NET Standard 2.0, and runs seamlessly on Windows, Linux, and macOS. This flexibility means you can integrate eSignature workflows into both legacy and modern .NET applications without worrying about compatibility issues or rewriting code during upgrades. With the SDK, you gain access to intuitive methods for authentication, document management, sending invites, and retrieving signed files. The SDK is open-source and available on GitHub, with detailed documentation and community support to help you get started quickly.

System Requirements and Compatibility

Before you begin, ensure your development environment meets the following requirements:

• .NET Framework 4.5+ or .NET Standard 2.0+ (compatible with .NET Core and .NET 5+)
• Operating system: Windows, Linux, or macOS
• Access to the SignNow .NET SDK on NuGet
• A SignNow account to create API applications and obtain credentials

This broad compatibility ensures you can integrate SignNow into both new and existing projects, regardless of your tech stack. The SDK’s cross-platform support means you can develop and deploy your eSignature workflows wherever your business operates.

Installing the SignNow .NET SDK

Getting started with the SignNow .NET SDK is straightforward. You can install the SDK directly from NuGet using your preferred method:

• .NET CLI: dotnet add package SignNow.Net
• Package Manager Console: Install-Package SignNow.NET
• Project File Reference: Add <PackageReference Include="SignNow.NET" /> to your .csproj file

After installation, you’ll need to create an API application in your SignNow account to obtain your Client ID and Client Secret. These credentials are essential for authenticating your API requests. For detailed setup instructions and troubleshooting, refer to the official SignNow .NET SDK documentation.

Authentication and Authorization

To interact with the SignNow API, your application must authenticate using OAuth 2.0. This process ensures secure access and protects sensitive data. Here’s how it works:

• Register your application in the SignNow dashboard to obtain your Client ID and Client Secret.
• Use these credentials, along with your user email and password, to request an access token from the SignNow API.
• The access token is then used to authorize all subsequent API requests.

A typical authentication flow in C# might look like this:

// Set API base URL (Sandbox or Production)
Uri apiBaseUrl = new Uri("https://api-eval.signnow.com");

// Your credentials
string clientId = "your-client-id";
string clientSecret = "your-client-secret";
string userLogin = "your-email@company.com";
string userPassword = "your-password";

// Create OAuth2 service and obtain token
var oauth = new OAuth2Service(apiBaseUrl, clientId, clientSecret);
var token = await oauth.GetTokenAsync(userLogin, userPassword, Scope.All);

Tip: Always use the correct API base URL for your environment (Sandbox for testing, Production for live applications) to avoid credential errors.

Creating and Managing the SignNow Service Context

Once authenticated, you’ll create a SignNow service context — a central object that manages all API interactions for your session. This context holds your API base URL and access token, allowing you to access document, invite, and user services through a unified interface.

// Create the SignNow service context
var signNowContext = new SignNowContext(apiBaseUrl, token);

This approach streamlines your code and ensures you can access all SignNow API features from a single entry point. It’s recommended to use one service container per session for efficiency and maintainability.

Uploading Documents and Sending for Signature

With your service context ready, you can automate document workflows — from uploading files to sending signature invites. Here’s a typical workflow:

• Read the document file from your system
• Upload the document to SignNow and retrieve its unique ID
• Create a signing invite and send it to the recipient’s email
• Monitor the signing status and download the signed document when complete

Below is a code example demonstrating these steps in C#:

// Upload document
await using var fileStream = File.OpenRead("/path/to/document.pdf");
var uploadResponse = await signNowContext.Documents.UploadDocumentAsync(fileStream, "Example.pdf");

// Send signing invite
var signerEmail = "recipient@example.com";
var invite = new FreeFormSignInvite(signerEmail)
{
    Message = $"{signerEmail} invited you to sign the document",
    Subject = "Please sign this document"
};
await signNowContext.Invites.CreateInviteAsync(uploadResponse.Id, invite);

The recipient receives an email invitation and can sign the document using SignNow’s intuitive signing interface. This process is fully automated and can be customized to fit your business workflow.

Retrieving and Downloading Signed Documents

After a document is signed, you can programmatically retrieve its status and download the completed file for storage or further processing. The SignNow API provides methods to:

• Check the signing status of a document
• Download the signed PDF in various formats
• Store the signed document locally or upload it to your system

Here’s a sample code snippet:

// Check document status
var document = await signNowContext.Documents.GetDocumentAsync(documentId);
if (document.Status == DocumentStatus.Completed)
{
    var signedDoc = await signNowContext.Documents.DownloadDocumentAsync(document.Id, DownloadType.PdfCollapsed);
    // Save signedDoc.Document stream to your storage
}

The SignNow signing interface is designed for clarity and ease of use, guiding signers through required fields and providing instant feedback on completion status. Once the document is signed, you can access the final PDF, complete with legally binding signatures and an audit trail.

Frequently Asked Questions

Below you’ll find answers to common questions about getting started with the SignNow API and .NET SDK. For more details, visit the SignNow API documentation or reach out to our support team.

Frequently Asked Questions

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