Update leads via API

Already added a lead and need to change its data later — fix a typo, attach a fresh custom variable, or push an updated email from your CRM? The Update Lead API lets you patch an existing lead in place, without creating a duplicate.

✅ What you'll need before you start

Before using this API, make sure you have:

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

2. The lead's id you want to update

📘 👉 Not sure how to get your API credentials? Follow this guide

💡 You get a lead's id from the Get Leads endpoint (the id field on each lead).

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🔗 API Endpoint

Send a PATCH request to this endpoint to update a lead:

PATCH https://app.reactin.io/api/[organizationId]/lists/[listId]/leads

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🔐 Authentication & Headers

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

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🧾 What to include in your request (Body)

The only required field is leadId. Every other field is optional — send just the ones you want to change. This is a true partial update: fields you omit are left untouched.

⚠️ Updating a lead resets its enrichment status, so ReactIn will try to auto-enrich it again with the new data. It also fires the LEAD_UPDATED webhook if you have one connected.

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🧪 Example (JavaScript)

await fetch("https://app.reactin.io/api/[organizationId]/lists/[listId]/leads", {
  method: "PATCH",
  headers: {
    'Content-Type': 'application/json',
    'Authorization': 'YOUR_API_KEY'
  },
  body: JSON.stringify({
    leadId: 'lead_a1b2c3',
    email: 'john.doe@newcompany.com',
    companyName: 'New Company',
    customVariable1: 'Renewed'
  })
});

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🧾 Response format

{
  "success": true
}

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🚫 Common Errors

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💡 Best Practices

• 🔎 Fetch the lead's id from the Get Leads endpoint before updating

• ✂️ Only send the fields you actually want to change

• 🔐 Keep your API key private — use a backend server or proxy

• 🔁 Add retry logic for occasional network or server errors

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💡 Pro tip: Because updates re-trigger enrichment, batching several changes into a single PATCH is cheaper than sending one request per field.