In case you missed it, GPT builder now supports different authentication methods and testing for custom actions. This small change may have gone unnoticed, but it's a significant improvement for all GPT builders looking to enhance their GPTs with custom actions.
In the custom actions editor, you can now tap on the test button to check every API call from your specification. Additionally, if you want your APIs to be protected with specific authentication, you can choose from various OAuth options or simply use an API key.
Recently, custom GPTs also became available to free users, which is expected to increase their usage. Looking ahead, the next major update expected in the upcoming month is the release of a new voice model. This will likely bring more people on board with custom GPTs through the voice conversation mode.