Electronic Signature
Developers
Features
API for eSignature Solutions
Automatically fill out forms for signing using API

Automatically fill out forms for signing using API

Add data to fillable forms using the airSlate SignNow API. Prefill date, text, and initials fields right from your app or website on any device, without the need to manually type data. You can then download a completed PDF or send it for signing in seconds.

Free to test
Fast to deploy
Powerful & secure

Easily fill out forms using the airSlate SignNow API

Automatically insert data into the smart fields of your fillable document using airSlate SignNow code samples.

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.

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

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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

Get started with uninterrupted eSignature API: automatically fill out forms for signing using API

Consolidate and streamline your eSignature workflows and establish seamless processes. Try the airSlate SignNow API, implement eSignature workflows into your custom apps and websites in minutes, and seamlessly automatically fill out forms for signing using API.

Automatically fill out forms for signing using API the airSlate SignNow API for uninterrupted eSignature API

Click API on the airSlate SignNow main page and create your API Sandbox account.
Open your email to confirm the registration and specify a password for accessing your Developer Sandbox environment.
Find the list of your apps at the top of the page. By default, you can also find a Test App for testing the API.
Click its name to access the Client ID and Basic Authorization Token.
Launch the API using the information from the previous step.
Use the code samples from the airSlate SignNow library.
When you're ready to go live, go to your airSlate SignNow account and choose a subscription plan.
If you can't find a subscription that suits your needs, contact the Sales team.
Change the test URL in your requests to the production environment URL.
Delight your customers and partners with a streamlined eSignature experience.

The airSlate SignNow API is straightforward to embed, test, and work with (no vendor engaged). Gain the opportunity to automatically fill out forms for signing using API conveniently. Choose airSlate SignNow to get more effective eSignature workflows.

How it works

Create an account and get the required tokens

Use code samples to automatically fill out forms for signing using API

Enjoy the power of eSignature in your 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.

This service is really great! It has helped...

5

anonymous

This service is really great! It has helped us enormously by ensuring we are fully covered in our agreements. We are on a 100% for collecting on our jobs, from a previous 60-70%. I recommend this to everyone.

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I've been using airSlate SignNow for years (since it...

5

Susan S

I've been using airSlate SignNow for years (since it was CudaSign). I started using airSlate SignNow for real estate as it was easier for my clients to use. I now use it in my business for employement and onboarding docs.

Read full review

Everything has been great, really easy to incorporate...

5

Liam R

Everything has been great, really easy to incorporate into my business. And the clients who have used your software so far have said it is very easy to complete the necessary signatures.

Read full review