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LeadDuo REST API Documentation

⚡ Real-time form submissions with instant notifications

The LeadDuo API allows you to submit form data via a simple REST endpoint, retrieve form submissions programmatically, and integrate with your CRM via webhooks or REST API. Each submission triggers optional email and SMS alerts if configured.

LeadDuo is part of the Three Core AI developer suite, alongside EngageAI and AgileAI.

Authentication

The LeadDuo API uses API keys for authentication. You can generate an API key from your form settings page.

Note: Keep your API key secure. Do not expose it in client-side code or public repositories.

Submit Form Data

POSThttps://api.leadduo.io/api/v1/form/{formId}

Request Body

{
  "ld_key": "your_form_key_here",
  "email": "user@example.com",
  "name": "John Doe",
  "message": "I'm interested in your services"
}

Response

{
  "ok": true
}

Code Examples

Choose your preferred language to see how to submit form data

const formData = {
  ld_key: 'your_form_key_here',
  email: 'user@example.com',
  name: 'John Doe',
  message: "I'm interested in your services"
};

fetch('https://api.leadduo.io/api/v1/form/YOUR_FORM_ID', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify(formData)
})
  .then(response => response.json())
  .then(data => {
    if (data.ok) {
      console.log('Form submitted successfully!');
    }
  })
  .catch(error => console.error('Error:', error));

HTML Form Submission (No JavaScript)

You can submit forms directly using standard HTML forms without any JavaScript. This is perfect for static sites, Webflow, Notion, or any platform where you can edit HTML.

POSThttps://api.leadduo.io/api/v1/form/{formId}

HTML Example

<form action="https://api.leadduo.io/api/v1/form/YOUR_FORM_ID" method="POST">
  <input type="hidden" name="ld_key" value="YOUR_FORM_KEY">
  
  <label for="name">Name:</label>
  <input type="text" name="name" id="name" required>
  
  <label for="email">Email:</label>
  <input type="email" name="email" id="email" required>
  
  <label for="message">Message:</label>
  <textarea name="message" id="message"></textarea>
  
  <button type="submit">Submit</button>
</form>

✨ What happens after submission:

Instant SMS + email alerts sent (if configured)
Lead appears in LeadInbox immediately
AI scoring applied (if AI Intelligence add-on is active)
User redirected to thank you page or custom URL

Use Cases

🌐 Webflow / Notion

Replace your form action URL with LeadDuo's endpoint. Keep all your existing fields.

🔗 Zapier / Make.com

Use webhooks to send form data from any platform to LeadDuo.

⚡ Static Sites

Add contact forms to static HTML sites without backend code.

📱 Custom Integrations

Build custom form integrations using the REST API endpoint.

Content-Type Support

Content-Type	Use Case
application/json	API integrations, JavaScript fetch/axios
application/x-www-form-urlencoded	HTML forms, standard POST requests
multipart/form-data	Forms with file uploads (coming soon)

Get Submissions

GEThttps://api.leadduo.io/api/v1/submissions?formId={formId}

Headers

X-API-Key: your_api_key_here

Query Parameters

Parameter	Type	Description
formId	string	Required. Your form ID
limit	number	Optional. Number of submissions to return (default: 50)
offset	number	Optional. Number of submissions to skip (default: 0)

Response

{
  "ok": true,
  "submissions": [
    {
      "id": 123,
      "formId": "form_abc123",
      "formName": "Contact Form",
      "data": {
        "email": "john@acmecorp.com",
        "name": "John Smith",
        "company": "Acme Corp",
        "message": "Looking for enterprise solution..."
      },
      "createdAt": "2025-11-07T00:00:00.000Z",
      "emailSent": true,
      "smsSent": false,
      "spamFlag": false,
      "aiScore": 85,
      "aiTier": "hot",
      "aiQualified": true,
      "aiAnalysis": {
        "source": "ai_intelligence",
        "reasons": ["Business email", "Company provided", "Detailed message"],
        "confidence": "high",
        "details": {
          "classification": {
            "intent": "demo_request",
            "urgency": "high",
            "persona": "decision_maker",
            "sentiment": "positive"
          },
          "enrichment": {
            "companyName": "Acme Corp",
            "companySize": "51-200",
            "industry": "SaaS"
          },
          "confidence": 0.85,
          "reasoning": "High-intent demo request from decision maker"
        },
        "scoringBreakdown": {
          "baseScore": 60,
          "aiBoost": 25,
          "total": 85
        },
        "disclaimer": "AI-generated analysis. May not be 100% accurate.",
        "timestamp": "2025-11-07T00:00:00Z"
      }
    }
  ],
  "total": 150,
  "limit": 50,
  "offset": 0,
  "hasMore": true
}

🤖 AI Intelligence Fields (Add-On Subscription): When AI Intelligence is enabled, the response includes:

aiScore: 0-100 lead quality score
aiTier: "hot" (70+), "warm" (50-69), or "cold" (0-49)
aiQualified: true/false based on score threshold
aiAnalysis: Reasons, confidence level, and detailed classification
Note: These fields are null if AI Intelligence add-on is not active

Code Examples

Retrieve submissions with authentication

fetch('https://api.leadduo.io/api/v1/submissions?formId=YOUR_FORM_ID&limit=10', {
  method: 'GET',
  headers: {
    'X-API-Key': 'your_api_key_here'
  }
})
  .then(response => response.json())
  .then(data => {
    console.log('Submissions:', data.submissions);
    console.log('Total:', data.total);
  })
  .catch(error => console.error('Error:', error));

Rate Limits

Form Submissions: 10 requests per hour per IP address + form key combination

API Requests: 10 requests per hour per API key + IP address combination

Rate limits help prevent abuse and ensure service reliability for all users.

Error Codes

Error	Description
missing_ld_key	Form key is required
invalid_ld_key	Form key is invalid
form_not_found	Form does not exist
form_inactive	Form is paused
rate_limited	Too many requests, please try again later
invalid_api_key	API key is invalid or missing
unauthorized	You don't have permission to access this resource

Learn More

Integrations Guide →Integration Examples →Pricing Plans →

Need Help?

Have questions about the API? Contact our support team