Show deployments in the pull request pane with a one-click preview link

[vitalyiegorov]

When a provider like Vercel deploys a preview for a pull request, the link ends up buried in the PR pane: it flows through the commit statuses into the Checks section as a generic row, and its "Details" button looks exactly like every lint and test check. Opening the deployed preview — usually the thing you actually want mid-review — takes hunting through check rows.

Proposal

• Read GitHub's native Deployments API for the PR's head commit server-side (environment name, state, environmentUrl), keeping the latest deployment per environment.
• Add an optional deployments field to the pull request detail contract, following the existing pattern for host-conditional fields (absent means "not supported / could not ask", not "deploys nowhere").
• The Summary tab gets a Deployments section patterned on Checks: one row per environment with a status label (Live / Deploying / Failed / Inactive); the row opens the environment URL.
• The pane header gets a compact globe button — Open preview — for the newest successful deployment, so the preview is one click away.

Smallest useful scope

• GitHub provider only; GitLab / Bitbucket / Azure DevOps leave the field absent.
• Web and desktop PR pane; mobile untouched (it has no PR pane today).
• Rides the existing detail query and refresh — no new RPC, no extra polling. The deployments read goes through the existing GitHub GraphQL budget and degrades to absent on failure, so it can never break the detail view.
• No new settings.

Before / after

Before — the Vercel preview is two generic "Passed" rows inside Checks:

After — a Deployments section names the environment and its state:

And the header gains a one-click "Open preview" globe button:

(Screenshots are from a working prototype running against a real PR — t3-oss/create-t3-app#2243 with a live Vercel preview. Implementation is contracts + server + web, ~600 lines including tests; happy to open a PR if this is welcome.)

Related

• [Feature]: Add a stacked pull requests view to the PR panel #6995 — stacked pull requests view in the PR panel: same surface, different metadata.
• Today the preview URL already reaches the pane via statusCheckRollup.targetUrl as a generic check "Details" link; this proposal only promotes deployments to a first-class, clearly-labeled affordance.

[vitalyiegorov]

Update: the prototype now supports multiple preview environments.

• One live environment: the header globe button opens it directly, one click.
• Several live environments: the same button opens a menu naming each environment, newest first.

(Real data: vercel/commerce#1535, which deploys two Vercel environments per commit. Verified end-to-end — clicking a menu entry opens that environment's URL, and the single-environment case still opens its live preview directly.)

Also hardened after a review pass: the deployments read uses the API's full page window so a heavily-redeployed environment can't crowd others out, a live deployment with no address no longer falls back to opening its build log from a button that says "Open preview" (the log fallback now applies only to non-successful deployments, where logs are what you want), and the whole read remains one budgeted GraphQL call that degrades silently rather than ever failing the PR detail view.