develop
version of your API. For example, when you add a field to a block’s response, Frontstack processes all related updates and revalidates the data automatically — making the updated API immediately available for developers to build and test new features.
preview
stage. This gives you a consistent snapshot of your API endpoints and data, which you can test and validate. Once you’re ready, you can publish this version with a single click — replacing your current public version.
Your changes flow through these stages:
Make changes in your workspace
develop
version.Preview Version
preview
version captures a full snapshot of your project’s workspace
at a specific point in time. You can promote this version to public or
replace it with a new preview.Publish Version
public
version is updated when you promote a preview. It serves as the
default for all requests from your frontend applications.public
. To promote, open the release drawer, and click Promote to Public.
Unlike creating a preview, promotion is instant — the promoted preview directly replaces your current public
version.public
or replaced by a new preview, the version token is automatically invalidated.
Version tokens are passed to the API using the FS-Version
HTTP header. This header allows Frontstack to identify incoming requests and route them to the correct version of your API.
If you’re using our CLI, you don’t need to manage this manually — the token is automatically embedded in the generated client SDK. This creates a stable and predictable contract between your frontend and your API.
When a version token becomes invalid (for example, after promotion), or if no token is provided, the API gracefully falls back to the latest public
version. This makes the transition from preview to public seamless — you don’t need to remove or update the token in your codebase. Your frontend will continue to function correctly, automatically using the production API when needed.
develop
version requires a version token that includes a
secret. This ensures that only authorized environments can use unstable or
work-in-progress API versions.Make changes in your workspace
Generate an updated client SDK
develop
stage.Use the updated client in your frontend
Deploy new preview
Review, test and deploy
Promote to public
preview
to public
. Your frontend will continue
to work seamlessly — it first uses the preview version, and once that version
is promoted, it gracefully falls back to the corresponding public release.develop
, preview
, or public
) the API version currently resides in.