--- title: User Agent now mandatory author_name: pengwynn --- After an almost six week grace period, we're now enforcing the [User Agent header][1] for all API requests. Most HTTP libraries (including cURL) set this header by default. If you're experiencing an increase in `403` responses, be sure and check your code. [1]: /v3/#user-agent-required If you have any questions or feedback, please drop us a line at [support@github.com](mailto:support@github.com?subject=User Agent Requirement).