# Registering and using API Keys

### Prerequisite

First, you need to have [a memento](https://docs.rememberizer.ai/~/changes/8nxu1gB5bGpm7B5IZlQ8/personal/mementos-filter-access) created and refined using your indexed knowledge files.

### Creating a common knowledge

To create a common knowledge, sign in into your Rememberizer account and visit [your common knowledge page](https://rememberizer.ai/personal/common-knowledge). Click on "Add Shared Knowledge" on the right hand side.

<figure><img src="https://2952947711-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyNqpTh7Mh66N0RnO0k24%2Fuploads%2FWP7xNKLoPPNf9tl5pBN4%2Fyour-common-knowledge-add.png?alt=media&#x26;token=dc4e4317-8323-461e-ab24-55b9e1375ee4" alt=""><figcaption></figcaption></figure>

Then pick one of the mementos you have created previously, you can also choose "All" or "None".

<div align="center" data-full-width="false"><figure><img src="https://2952947711-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyNqpTh7Mh66N0RnO0k24%2Fuploads%2FoY8UPTG44JIGFLfVMRuX%2Fcreate-common-knowledge-1.png?alt=media&#x26;token=d569193b-d901-41ca-beb4-23cd637d8d28" alt="" width="375"><figcaption></figcaption></figure></div>

Finally fill out the common knowledge's name, description and give it a representative photo.

<figure><img src="https://2952947711-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyNqpTh7Mh66N0RnO0k24%2Fuploads%2F9e6lbuN564oD59aUhJ9m%2Fcreate-common-knowledge-2.png?alt=media&#x26;token=f358acc7-f1f5-4598-bbe3-f37aab84b4ce" alt="" width="375"><figcaption></figcaption></figure>

After you have filled the form, click on "Share knowledge" in the bottom to create your common knowledge. You now are ready to obtain its API Key and access its documents via API calls.

### Getting the API Key of a common knowledge you created

For your common knowledge, click on the three dots on its top right, then choose "API Key". If there is none yet, one will be created for you. If the API Key exists it will be returned.

<figure><img src="https://2952947711-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyNqpTh7Mh66N0RnO0k24%2Fuploads%2FvXjGqN2BIWSZq0M3pAD7%2Fcreate-api-key.png?alt=media&#x26;token=d22b83cc-fa42-4dab-a536-bb1a83bee10c" alt=""><figcaption></figcaption></figure>

In the "Manage your API Key" panel, you can click on the "eye" button to show/hide, the "copy" button to copy the key to clipboard, and "Regenerate API Key" to invalidate the old key and create a new one (apps that are accessing your documents through api calls won't be able to access until you have updated the new key into them).

<figure><img src="https://2952947711-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyNqpTh7Mh66N0RnO0k24%2Fuploads%2FvGdn7eu2EvIg5PfruGDs%2Fcopy-api-key.png?alt=media&#x26;token=211dfb8f-dbb1-4329-9dbc-5f1142592063" alt=""><figcaption></figcaption></figure>

After obtaining the API Key, you can proceed to using it in your API calls to Rememberizer to query your indexed documents and contents.

### Using the API Key

To access Rememberizer endpoints, you will use the API Key in the `X-API-Key` header of your API requests. Please check out the [API Documentation](https://docs.rememberizer.ai/~/changes/8nxu1gB5bGpm7B5IZlQ8/developer/api-documentations) to see the endpoints that Rememberizer provides.

You can also use the API Key in a custom GPT app. Start by [creating a GPT in the ChatGPT UI](https://chat.openai.com/gpts/editor). Make sure to choose the Authentication Type as "API Key", Auth Type as "Custom" and the header as "X-Api-Key", then paste the key you copied previously into the API Key textbox.

<figure><img src="https://2952947711-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyNqpTh7Mh66N0RnO0k24%2Fuploads%2FQ4sNbXLtDPuGFHrbEbCB%2Fgpt-app-using-api-key.png?alt=media&#x26;token=98909618-c149-4b04-b296-ff1d285ca49e" alt="" width="375"><figcaption></figcaption></figure>