The SendX REST API enables developers and power users to programmatically interact with SendX and build custom integrations that automate data syncing across their tools. Instead of managing contacts, campaigns, and events manually through the dashboard, you can now use API endpoints to create, update, or delete contacts and lists while pushing custom and revenue events directly from your systems.
This guide will show you how to access the API documentation, authenticate your requests, and start making your first API calls to automate your SendX workflows and create seamless connections between SendX and your CRM, website, or product systems.
Before You Begin
Before starting to work with the SendX REST API, make sure you have:
API key access: Ensure you can navigate to Settings > API and Webhooks to copy your team API key.
Basic API knowledge: Understand fundamental concepts like API endpoints, requests, and JSON responses.
Development environment: Have a tool or platform ready to make API calls (like Postman, curl, or your application code).
Contact and list data planned: Know what contact information and which lists you want to work with via the API.
Step-by-Step Instructions
Step 1: Access the API Reference
Log in to your SendX dashboard.
Click on the API Reference tab from the navigation bar.
In the sidebar menu, select Get All Lists.
Under this section, click the Try It button to explore the API call in action.
Step 2: Retrieve Your API Key
Click on your Profile icon at the top-right corner.
Select Settings from the drop-down.
Go to API and Webhooks from the left navigation.
Copy your API Key — you'll need this to authenticate your API requests.
Step 3: Execute the API Request
In the Try It form, paste your API Key into the Xteam API Key field.
Click Send to execute the request.
In the API response, locate and note:
The List Name
The List ID (this is essential for the next step
Step 4: Create a Contact
Under the Contacts section, click on Create a Contact.
On the page, click the Try It button.
In the form:
Enter the email address
Fill in any other necessary contact details
Under the List section, click + Add an Item
Enter the previously noted List ID
Click Send to create the contact.
Step 5: Verify Contact Creation
A success message will appear indicating the contact has been created.
Navigate to the Audience tab in the navigation bar.
Click on Contacts.
Confirm that the contact (email) has been successfully added to your list.
Tips & Best Practices
Here are some helpful ways to make the most of the SendX REST API:
Always test with the "Try it" button first: Use the API reference interface to test your requests before implementing them in your code.
Copy API keys securely: Keep your API keys safe and never expose them in client-side code or public repositories.
Verify responses: Check the success messages and response data to ensure your API calls are working correctly.
Start with simple operations: Begin with basic contact creation before moving to more complex automation workflows.
Test in the SendX dashboard: After making API calls, verify the results by checking your contacts and lists in your SendX account.
Troubleshooting Common Issues
API integration can present technical challenges, but here are solutions to common problems:
Problem: "I'm getting authentication errors when making API calls."
Solution: Verify that you've copied the correct API key from Settings > API and Webhooks. Ensure you're entering it in the "X-team-API-key" field exactly as shown in the API documentation.
Problem: "The 'Try it' button isn't responding or showing errors."
Solution: Check that you've entered the API key correctly in the form. Also, ensure you're using the production server settings in the API reference documentation.
Problem: "I can't find the list ID I need for adding contacts."
Solution: First, run the "Get all lists" endpoint to retrieve all your lists and their corresponding IDs. Copy the exact ID from the response before using it in the contact creation endpoint.
Problem: "My contact creation is failing even with the correct API key."
Solution: Ensure you're providing a valid email address and that you've added the list ID correctly in the "plus add an item" section. Check that the list ID matches exactly what you copied from the list's response.
Problem: "I can't see the contact I created via API in my SendX dashboard."
Solution: Refresh your contacts page in SendX. If the contact still doesn't appear, check the API response for any error messages and verify that the request was actually successful.
Related Articles
Now that you understand the basics of the SendX REST API, here are ways to expand your automation capabilities:
How to Use Revenue API to Add Revenue For A Contact: Check out this article to know how to track and record revenue data for your contacts using SendX's Revenue API endpoints.
How to integrate Stripe with Sendx: Set up automated revenue tracking by connecting your Stripe payment data directly to SendX. Learn how to do that in this guide.