| name | preview-versions |
| description | Preview documentation at a branch, commit or pull request without changing production. Use when debugging content on /tree/:branch, /blob/:sha or /pr/:number, or explaining how ISR and GitHub-pinned content work.
|
Preview versions
Content is served at request time. Production is pinned to a commit SHA; any branch, commit or pull request can be previewed through versioned URLs.
| Mode | URL | Content |
|---|
| prod | /getting-started/introduction | pinned production SHA |
| tree | /tree/main/getting-started/introduction | latest commit touching the content directory |
| blob | /blob/<sha>/getting-started/introduction | immutable commit |
| pr | /pr/<number>/getting-started/introduction | the PR's head commit (follows new pushes) |
Commit and PR previews are authorized: a /blob/ SHA must be in production history or belong to a PR (same-repo, or a fork PR carrying the preview:enabled label), and /pr/ applies the same rule. Unauthorized refs answer 404.
Raw markdown mirrors exist at /raw/** for production pages only — preview pages serve HTML.
Two cache tiers: ISR-cached page HTML at the edge, and a per-parser-version, per-content-SHA runtime cache for parsed Markdown bodies. A GitHub push to the production branch hits /api/revalidate and purges ISR.
Keyboard shortcut g h toggles the version-history panel on a docs page.
Read more: Architecture, Versioned previews.
