4.2 Add leads via API

✅ What you’ll need before you start

Before you can use this API, make sure you have:

1. A ReactIn API SmartList

2. Your Organization ID, List ID, and API Key

📘 Not sure where to find that?
👉 Check this guide first to get your API credentials

🔗 API Endpoint

Send a POST request to this endpoint to add a lead:

POST https://app.reactin.io/api/[organizationId]/webhooks/reactin/[listId]

ReactIn will automatically route the lead to your selected SmartList.

🔐 Authentication & Headers

You’ll need to add the following headers to your request:

🔒 Keep your API key private and only use it from secure backend code — never from the browser.

🧾 What to include in your request (Body)

You need to send your lead’s data in JSON format.
You must provide at least one of these two:

• An email

• A linkedinUrl

Here’s what you can send:

💡 To enable auto-enrichment, make sure to include:

• email

• firstName

• lastName

  OR

• linkedinUrl
  

  When all 3 are present, ReactIn will automatically try to find missing data like profile links, roles, etc.

🧪 Example (JavaScript)

await fetch("https://app.reactin.io/api/[organizationId]/webhooks/reactin/[listId]", {
  method: "POST",
  headers: {
    'Content-Type': 'application/json',
    'authorization': 'YOUR_API_KEY'
  },
  body: JSON.stringify({
    email: 'john.doe@example.com',
    firstName: 'John',
    lastName: 'Doe',
    linkedinUrl: 'https://www.linkedin.com/in/johndoe/',
    companyName: 'Example Corp',
    customVariable1: 'Offer A',
    customVariable2: 'Campaign 3'
  })
});

✏️ You can copy this and test directly from Postman, Insomnia or a backend script.

✅ If everything works

You’ll get a 200 OK response, meaning the lead was successfully added to your SmartList.

🚫 If something goes wrong

💡 Best Practices

• 🔐 Keep your API key secure and use it only from a backend

• ✅ Validate lead data before sending

• ⏳ Add retry logic for temporary errors

• 📊 Don’t spam: avoid sending hundreds of leads at once

💡 Pro tip: Always validate data before sending it via the API to reduce errors and improve enrichment quality.

Ready to move on?
👉 Next Step: Get Leads from ReactIn via API →