Start developing with Klaviyo

If you want to test custom integrations and applications without any risk of impacting your production account, create an additional Klaviyo account (for free) to use for testing. This is an optional step, but may offer peace of mind when testing your code. Once created, you can easily switch between multiple accounts when logged in.

To do this:

1. Log out of your existing Klaviyo account.
2. Head to Klaviyo and click Sign Up.
3. Create a new account using the same email and password as your existing account, but choose a different business name for your test account.
4. Once you complete the setup wizard, you will be able to toggle between accounts using the account button in the lower-left of your Klaviyo account.

Learn more about setting up a test account.

Klaviyo’s Sample Data Generation Tool will populate your test account with sample data for testing purposes. Three types of data are available: marketing data, ecommerce data, and catalog data.

To generate sample data:

1. Be sure you are in your test account.
2. Click Integrations > Developer tools (upper-right corner) > Sample data.
3. Select the types of data you want to populate in your account.
4. Click Add Data.

Data will populate in your account shortly. A green success message will appear when generation is complete. Rarely, the tool may fail to generate all or part of the data requested. If you receive an error message, refresh the page and re-attempt generating data following the steps above.

Learn more about sample data in your account.

Klaviyo offers SDKs in Python, PHP, Ruby, and Node (with more on the horizon), as well as iOS, Android, and React Native mobile SDKs to help you build quickly. You do not have to use an SDK, but it is highly recommended since it makes the development process much more efficient.

Explore our SDKs.

Locate your public and private API keys under Account name > Settings > API keys. Remember, to manage API keys, you must have an Owner, Admin, or Manager user role.

Learn more about managing API keys.

All of our API endpoints use private API keys to authenticate requests. If you do not use a private API key for your requests, or you use a key from the wrong account, your call will return a 400 error.

Authenticate by setting a request header.

Test your connection to confirm your authentication is working and that your application can connect with Klaviyo’s servers. Use Klaviyo's Postman collections to easily test using pre-built API requests.

Learn more about making your first test call.

Build the technical requirements needed for your design to work with Klaviyo. Think through the tradeoffs between different technical considerations, decide on how you will build your end-to-end experience, and start your dev work. Check out our course on mapping your data into Klaviyo for tips on how to design your custom solutions.

Once your code is in place, you should run a variety of tests to feel confident about what you’ve built before you ship it. It’s a good idea to conduct unit tests on the smaller components of your code as you build, in addition to end-to-end testing. Use your test account and the sample data you’ve generated to ensure that data is populating in the UI the way you expect.

Follow this guide for a detailed breakdown of tests to run before going live.