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

Automatically fill out forms for signing using cURL

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.

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 automatically fill out forms using curl

The airSlate SignNow API equips businesses with an exclusive range of features that enhance operational workflows. Discover the advantages of our automatically fill out forms using curl by signing up for a complimentary Sandbox account.

Follow these instructions to set up a Sandbox account:

Visit the airSlate SignNow Developers page. There you will find additional information regarding the API and can register for your Sandbox account.
Register for a trial. Enter your email address and click the Create API sandbox button to enroll.
Verify your email address. Check your inbox for the email and click the link provided to confirm your email address.
Access Developer Sandbox. Create a password to gain further access to your developer account.
Incorporate an application. Click Add App, provide a name for your app, and click Add to save your changes. The application’s API token will be generated automatically.
Test automatically fill out forms using curl. Explore all the features of airSlate SignNow and how they can enhance your business operations.

Follow these guidelines to assess airSlate SignNow's functionalities. Feel free to 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 get the required tokens

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

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.

Amazing & Efficent

5

Katya E

What do you like best?

My favorite part of this software is how easy it is to use. I can input where I need signatures, initials, dates or text on all of the documentation so easily, and I have not had one client ask how to use it or sign it, and my clients age from 23-65. It is so user friendly and makes my business run more efficiently than ever.

Read full review

Easy to use

5

User

What do you like best?

airSlate SignNow is simple to use and does everything I need. I've used it for both business and personal applications and have been satisfied overall. I've never had an issue with prospects receiving documents and the format has always turned out looking the way I expected.

Read full review

Easy to use and less expensive than competitiors

5

Chris A

What do you like best?

The interface is very easy to use, it is less expensive than the competition, and I don't use it every day, so it's not a service I am willing to shell out a ton on as far as a monthly fee. airSlate SignNow is fair.

Read full review