Application

Application level authentication would generally be considered the default way of authenticating yourself on the API. Version 3 is controlled by one of either a single query parameter, api_key, or by using your access token as a Bearer token. You can request an API key by logging in to your account on TMDB and clicking here.

API Key

Once you have been issued a key, an example API key based request looks like this:

curl --request GET \
     --url 'https://api.themoviedb.org/3/movie/11?api_key=<<api_key>>'

Bearer Token

Another option for you to authenticate with is your access token. If you head into your account page, under the API settings section, you will see a new token listed called API Read Access Token. This token is expected to be sent along as an Authorization header. A simple cURL example using this method looks like the following:

curl --request GET \
     --url 'https://api.themoviedb.org/3/movie/11' \
     --header 'Authorization: Bearer <<access_token>>'

Using the Bearer token has the added benefit of being a single authentication process that you can use across both the v3 and v4 methods. Neither one of them provides any more or less access so which one you choose is completely up to you.