Vercel should expose an environment variable for the Git branch specific URL

[ruohola]

Currently the only URL environment variable that Vercel exposes for running apps is VERCEL_URL (in the format <project-name>-<unique-hash>-<scope-slug>.vercel.app) which links to the unique id of that one deployment (this is the so called automatic deployment URL).

But the URL that the Vercel bot links in GitHub pull request's comments for preview enviroments is not this same deployment URL, but instead the branch specific URL (this is the so called automatic branch URL).

This is problematic, since now in one's code there is no way to programmatically access this branch specific URL which is the actual URL that the preview application is actually most likely accessed from.

Suggestion:

Expose a VERCEL_BRANCH_URL environment variable during runtime (and NEXT_PUBLIC_VERCEL_BRANCH_URL etc. during build time) which contain the URL for the branch, in the format: <project-name>-git-<branch-name>-<scope-slug>.vercel.app.

[fvpDev]

Or something close to VERCEL_GIT_REPO_SLUG...maybe VERCEL_GIT_REPO_BRANCH. It would be particularly useful for having multiple versions of a site based on the git branch, exposing certain components based on what version of the site is being viewed.

[fvpDev]

Ok, so after some console logging I found the variable actually. It's called VERCEL_GIT_COMMIT_REF. I dare say, it's not an intuitive variable name for the value that it actually exposes. I think it should be changed to VERCEL_GIT_REPO_BRANCH.