CircleCI REST API V1

The CircleCI REST API v1 is the legacy API that provides access to build information, project details, and user data. While still available, CircleCI recommends migrating to the v2 API for newer features and improved functionality. The v1 API supports operations for retrieving build details, triggering builds, managing SSH keys, and accessing test metadata. Authentication is handled through API tokens passed as query parameters or HTTP headers.