Electronic Signature
Developers
Features
API for eSignature Solutions
Write text on a PDF document for eSignature with C# SDK for API

Write text on a PDF document for eSignature with C# SDK using the API

Write anything you want on a PDF document using the airSlate SignNow API. Put a text field next to the information you need to complement and share text with your recipients after sending.

Free to test
Fast to deploy
Powerful & secure

Edit PDFs by writing text anywhere on a document.

Adjust the text to fit your needs by fixing its size and location in a document.

C#

Java

Copy code

public class ResponseDocumentFieldsModel
    {
        public ResponseDocumentField[] fields { get; set; }
        public object[] signatures { get; set; }
        public object[] texts { get; set; }
        public object[] checks { get; set; }
        public object[] radiobuttons { get; set; }
        public object[] attachments { get; set; }
        public Enumeration_Options[] enumeration_options { get; set; }
    }

public class Enumeration_Options
    {
        public string id { get; set; }
        public string enumeration_id { get; set; }
        public string data { get; set; }
        public string created { get; set; }
        public string updated { get; set; }
        public string json_attributes { get; set; }
    }
    public class ResponseDocumentField
    {
        public string id { get; set; }
        public string type { get; set; }
        public string role_id { get; set; }
        public ResponseJson_Attributes json_attributes { get; set; }
        public string role { get; set; }
        public string originator { get; set; }
        public string fulfiller { get; set; }
        public string field_request_id { get; set; }
        public string element_id { get; set; }
        public object field_request_canceled { get; set; }
        public string template_field_id { get; set; }
        public string field_id { get; set; }
        public Radio[] radio { get; set; }
    }
    public class ResponseJson_Attributes
    {
        public int page_number { get; set; }
        public int x { get; set; }
        public int y { get; set; }
        public int width { get; set; }
        public int height { get; set; }
        public bool required { get; set; }
        public string label { get; set; }
        public object prefilled_text { get; set; }
        public string custom_defined_option { get; set; }
        public string name { get; set; }
        public dynamic calculation_formula { get; set; }
        public string formula { get; set; }
        public bool italic { get; set; }
        public bool bold { get; set; }
        public int calculation_precision { get; set; }
        public string validator_id { get; set; }
        public int size { get; set; }
        public string font { get; set; }
        public int line_height { get; set; }
    }
    public class RequestUpdateFieldValueModel
    {
        public object[] texts { get; set; }
        public object[] signatures { get; set; }
        public object[] checks { get; set; }
        public object[] radiobuttons { get; set; }
        public object[] attachments { get; set; }
        public List<RequestFieldModel> fields { get; set; }
        public int client_timestamp { get; set; }
    }
    public class RequestFieldModel
    {
        public int page_number { get; set; }
        public string role { get; set; }
        public string type { get; set; }
        public string name { get; set; }
        public bool required { get; set; }
        public int width { get; set; }
        public int height { get; set; }
        public int x { get; set; }
        public int y { get; set; }
        public object prefilled_text { get; set; }
        public string label { get; set; }
        public bool bold { get; set; }
        public bool underline { get; set; }
        public string align { get; set; }
        public string valign { get; set; }
        public string arrangement { get; set; }
        public int max_chars { get; set; }
        public int max_lines { get; set; }
        public string font { get; set; }
        public int size { get; set; }
        public bool custom_defined_option { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public Radio[] radio { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public IEnumerable<string> enumeration_options { get; set; }
        public object calculation_formula { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public int calculation_precision { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public bool italic { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public string formula { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public float line_height { get; set; }
    }
public partial class RestSharpSamples
    {
        /// <summary>
        /// Get Set prefilled values based on field unique name.
        /// </summary>
        public static void SetTemplateInitialValues(string accessToken, string apiUrl, string templateId, Dictionary<string,object> fieldValue)
        {
            if (!fieldValue.Any())
            {
                return;
            }
            var client = new RestClient { BaseUrl = new Uri(apiUrl) };

var request = new RestRequest($"/document/{templateId}", Method.GET)
                .AddHeader("Accept", "application/json")
                .AddHeader("Authorization", $"Bearer {accessToken}");

var response = client.Execute(request);

if (response.StatusCode != HttpStatusCode.OK)
            {
                throw new Exception(response.Content);
            }
            var documentResponse = JsonConvert.DeserializeObject<ResponseDocumentFieldsModel>(response.Content);
            var fieldUpdateRequest = new List<RequestFieldModel>();
            foreach (var field in documentResponse.fields)
            {
                var foundField = fieldValue.FirstOrDefault(e => e.Key.Equals(field.json_attributes.name));
                if (foundField.Value != null)
                {
                    field.json_attributes.prefilled_text = foundField.Value;
                }

var customDefValue = field.json_attributes.custom_defined_option == "1" ? true : false;

var fieldModel = new RequestFieldModel
                {
                    height = field.json_attributes.height,
                    label = field.json_attributes.label,
                    name = field.json_attributes.name,
                    page_number = field.json_attributes.page_number,
                    prefilled_text = field.json_attributes.prefilled_text,
                    required = field.json_attributes.required,
                    role = field.role,
                    width = field.json_attributes.width,
                    x = field.json_attributes.x,
                    y = field.json_attributes.y,
                    font = field.json_attributes.font,
                    formula = field.json_attributes.formula,
                    bold = field.json_attributes.bold,
                    calculation_formula = field.json_attributes.calculation_formula,
                    calculation_precision = field.json_attributes.calculation_precision,
                    italic = field.json_attributes.italic,
                    line_height = field.json_attributes.line_height,
                    custom_defined_option = customDefValue,
                    type = field.type,
                    size = field.json_attributes.size,
                    radio = field.radio                   
                };
                if (field.type == "enumeration")
                {
                    fieldModel.enumeration_options = documentResponse.enumeration_options.Where(e => e.id == field.id).Select(e => e.data);
                }
                fieldUpdateRequest.Add(fieldModel);
            }

var updateField = new RequestUpdateFieldValueModel {
                checks = documentResponse.checks,
                attachments = documentResponse.attachments,
                radiobuttons = documentResponse.radiobuttons,
                signatures = documentResponse.signatures,
                texts = documentResponse.texts,
                fields = fieldUpdateRequest
            };

var documentUpdateRequest = new RestRequest($"/document/{templateId}", Method.PUT)
                .AddHeader("Accept", "application/json")
                .AddHeader("Authorization", $"Bearer {accessToken}");

documentUpdateRequest.RequestFormat = DataFormat.Json;
            documentUpdateRequest.AddBody(updateField);

var updateResponse = client.Execute(documentUpdateRequest);
            if (response.StatusCode != HttpStatusCode.OK)
            {
                throw new Exception("Updating field values failed: " + updateResponse.Content);
            }
        }
    }
}

We provide developers with complete SDKs for all popular languages, allowing them to integrate eSignature workflows without writing a single line of code.
With our detailed documentation, integrating the airSlate SignNow API is a breeze.
The airSlate SignNow API not only provides you with eSignatures: use it to create fillable forms, request payments, and download & archive documents using simple API calls.

View full API reference

airSlate SignNow regularly wins awards for ease of use and setup

Read our reviews on the trusted resources

Tech Data uses airSlate SignNow to improve our internal and external customer service while increasing our speed to revenue.

Bob Dutkowsky | CEO

Select an API package for your business

Integrate eSignatures into your software and get 250 legally-binding signature invites with your API free trial.

Check API pricing

Solution engineers

We are here to help you configure eSignature API to your workflow.

Review airSlate SignNow’s API documentation

The detailed API tutorial will guide you through the entire integration process and provide clear coding examples.

Video guides

Watch our video guides for instructions on how to easily build custom integrations.

Start with any of our SDKs

Get complete SDKs for Node.js, Python,
PHP, Java, C#.

Enterprise-grade security and compliance

airSlate SignNow is committed to protecting your sensitive information by complying with global industry-specific security standards.

Learn more

GDPR compliance

Regulates the use and holding of personal data belonging to EU residents.

SOC 2 Type II Certified

Guarantees the security of your data & the privacy of your clients.

PCI DSS certification

Safeguards credit/debit card data for every monetary transaction a customer makes.

21 CFR Part 11

FDA-backed standards for electronic documentation and electronic signatures.

HIPAA compliance

Protects the private health information of your patients.

CCPA compliance

Enhances the protection of personal data and the privacy of California residents.

Watch the airSlate SignNow API in action

Evaluate airSlate SignNow's write text on a pdf document with c sdk for api

The airSlate SignNow API equips organizations with an exceptional set of features that facilitate more efficient business operations. Discover the benefits of our write text on a pdf document with c sdk for api by signing up for a complimentary Sandbox account.

Follow these instructions to set up a Sandbox account:

Access the airSlate SignNow Developers page. There, you can find additional information about the API and register for your Sandbox account.
Register for a trial. Provide your email address and click the Create API sandbox button to sign up.
Verify your email address. Open the message you receive and follow the link to confirm your email address.
Navigate to Developer Sandbox. Establish a password to permit further access to your developer account.
Add an application. Click Add App, name your application, and click Add to save changes. The API token for the application will be generated automatically.
Evaluate write text on a pdf document with c sdk for api. Investigate all airSlate SignNow features and how they can improve your business processes.

Follow these instructions to evaluate airSlate SignNow's features. You can reach out to the support team if you have any inquiries. Improve your business workflows with airSlate SignNow today.

How it works

Create an account and access the API Dashboard

Copy required code from the library to write text on a PDF document for eSignature with C# SDK using the API

Track how your productivity grows with accelerated workflows

Watch our instructions to build custom integrations with ease

airSlate SignNow offers a free testing environment to explore the eSignature.

Trusted eSignature solution — what our customers are saying

Explore how the airSlate SignNow eSignature platform helps businesses succeed. Hear from real users and what they like most about electronic signing.

Great and easy to use eSignature program

5

User in Real Estate

What do you like best?

I have been using airSlate SignNow for several years and it is easy to upload docs, create signatures and send to my clients. My clients love using it as well because of its ease of use.

Read full review

Easy, efficient, and green

5

User in Internet

What do you like best?

We send over Agreements for our clients to review and digitally sign. Clients find it easy, hassle-free and we love less paper!

Read full review

Very easy to use, will recommend

5

Juliette C

What do you like best?

The drag and drop options to complete a PDF. It makes it very simple for us to create and even easier to show people where to sign properly.