> For the complete documentation index, see [llms.txt](https://multiset.gitbook.io/multiset/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://multiset.gitbook.io/multiset/basics/credentials/configuring-allowed-domains-cors.md).

# Configuring Allowed Domains (CORS)

If you are building a browser-based application (such as a React, Vue, or Angular app) that interacts directly with the MultiSet Public API, you must configure **Cross-Origin Resource Sharing (CORS)**.

For security reasons, browsers restrict cross-origin HTTP requests initiated from scripts. By adding your application's domain to the MultiSet whitelist, you instruct our servers to accept API requests coming from your specific web application.

### How to Add a Domain

1. Navigate to the **Credentials -> Settings** tab on the left sidebar.
2. Locate the **Domains** section.
3. Click the purple **Add +** button on the right side of the card.
4. Enter the full origin of your application. This includes the protocol and the port (if applicable).

<figure><img src="/files/QpAGpYEGFvCROIXE5rYj" alt=""><figcaption></figcaption></figure>

#### Recommended Setup

We recommend adding entries for both your local development environment and your production environment.

**1. Local Development**

To test the API while developing on your local machine, add your localhost address.

* **Protocol:** http
* **Domain:** localhost:3000 (or whichever port your local server uses)

**2. Production**

Once your application is deployed, add your live domain.

* **Protocol:** https
* **Domain:** [www.your-application.com](http://www.your-application.com)

> **Note:** Do not include trailing slashes (e.g., use localhost:3000, not localhost:3000/).

***

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