Skip to main content
The Onset API is a RESTful API accessed by an HTTP client such as curl or the HTTP library, which is part of most modern programming languages. You can use this API to build custom integrations or automate even more of your organization’s workflow.

​
Authentication

The Onset API uses API keys to authenticate requests. You can view and manage your API keys in the Onset Dashboard. Your API keys carry many privileges, so be sure to keep them secure! Do not share your secret API keys in publicly accessible areas such as GitHub, client-side code, and so forth. Authentication to the API is performed via HTTP Basic Auth. Provide your API key as the basic auth username value. You do not need to provide a password.
If you need to authenticate via bearer auth use -H "Authorization: Bearer API_KEY" instead of -u API_KEY.

​
Creating and publishing releases

Releases are created and edited as drafts, then published in a separate step. POST /v1/releases and PATCH /v1/releases/{id} never change a release’s status — publishing goes through a dedicated endpoint:
To publish at a future date, send {"status": "SCHEDULED", "scheduled_at": "2026-08-01T09:00:00.000Z"} instead. The same endpoint publishes a scheduled release early (RELEASED) or moves it to a different date. Publishing is what emits the release.published and release.scheduled webhooks, so integrations get an accurate signal of when a release actually went live.
Publishing over the API does not send subscriber emails or Slack and Discord announcements. Publish from the Onset dashboard to choose notification channels.

​
Versioning

The API is versioned with a single number, which is currently 1. This number symbolizes the major version number, as described by SemVer. Because of this, backward-incompatible changes require this version number to change. The minor version isn’t explicit, which allows for a stable API endpoint. New features can be added to the API in the same version number. API requests must be made over HTTPS and include the API version.