This page explains when to use an evaluation key and what the limitations are.
An evaluation key is a string which the developer platform generates for you to use during evaluation and development, such as when developing on
localhost. You may also use the evaluation key for hosted projects where you don't own the domain, such as on CodePen or CodeSandbox.
The evaluation key identifies you as the project owner. It has the following features and limitations:
- Works on localhost.
- Works on CodePen, CodeSandbox where the origin does not match your project verified origins.
- Tolerant when switching a signed-in user while items are open.
- Does not require a verified domain.
- Imposes a rate limit.
- Activity is not distributed to social networks.
For production use, associate one or more verified domains with your project.
When you create a new project, we automatically generate an evaluation key which is valid for 7 days by default. You may renew an expired key or generate a key with a distinct expiration date on the evaluation tab of your project.
You can only have one evaluation key per project.
When you finish developing, just leave your evaluation key on your website and rotate it on the development platform. This invalidates the key. Next time you make changes, create a new evaluation key and replace it on your website. Even if you should forget to invalidate your key, it will expire within a few days (unless you have set a longer expiration, which we do not recommend except for specific cases where your project doesn't have an origin, such as for a demo on CodePen). If we find a valid key and an origin on a website, we will use the origin and ignore the key.
evaluation-key meta property to your code while developing, with your API key in
<meta property="attach:evaluation-key" content="eval_01234567890123456789" />
Sometimes you have a demo project which you want to show on CodePen or CodeSandbox. These pages run on a domain which you don't own and which you therefore can't verify. In such cases, you may create a long-running evaluation key with an expiration date in the far future and use it on such pages as a permanent means of associating the page with your project. Be aware of the above limitations when not using your own origin.