Git Refs in URLs

Container metaframes can be pinned to a specific git commit, branch, or tag by encoding the ref in the container URL. Combined with URL parameter substitution, this makes a metapage a versioned, URL-addressable view of a git repository.

Hard-code a git ref

Append tree/<ref> to the GitHub repo URL in the container metaframe configuration:

https://github.com/myorg/myrepo/tree/affeff5e706b446358f4b619058c6e93afe8836f

The container is built from that exact commit every time.

Dynamic git ref via URL parameter

Use the _git-ref_ placeholder in the container URL:

https://github.com/myorg/myrepo/tree/_git-ref_

Then pass git-ref as a URL parameter on the metapage:

https://metapage.io/m/<id>?git-ref=affeff5e706b446358f4b619058c6e93afe8836f

At runtime, _git-ref_ is substituted with the URL parameter value. Changing the URL changes the version — no edits to the metapage definition needed.

This makes the metapage URL a function of the repository state. You can navigate through git history simply by changing the git-ref parameter.

URL parameters as container env vars

All metapage URL parameters are available as environment variables inside the container. So ?git-ref=abc123 also makes git-ref=abc123 available in the container environment — useful for scripts that need to know which version they're running.

See URL parameters for the full parameter substitution reference.