docs(repo): Document next-env.d.ts behavior and restore workflow

[sfanahata]

Problem
Every time next.js wants to update next-env.d.ts on pnpm dev or pnpm build, it shows up in the branch's commits.

Solution
.gitignore the file and add a new CI rule so that no one has to deal with this manually.

• Added an explanation to agents.md and contributing.md why next-env.d.ts shows as modified when Next.js regenerates it, and why it's in .gitignore, as well as future state once we upgrade.

• Added next-env.d.ts to .gitignore so the same behavior is available for everyone.

• Added new CI rule to run typegen be fore running the type-check so that next-env.d.ts is added into the check.

• In .github/workflows/test.yml, in the Lint job, added a step before pnpm lint:ts: Step: Run pnpm next build.

  • Reason: next-env.d.ts is in .gitignore, so it isn’t in the repo. The lint job only runs install and then pnpm lint:ts (type-check). TypeScript expects next-env.d.ts (it’s in tsconfig include), so without it the type-check would fail.

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PRE-MERGE CHECKLIST

Make sure you've checked the following before merging your changes:

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

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Project	Deployment	Actions	Updated (UTC)
develop-docs	Ready	Preview, Comment	Mar 13, 2026 11:42pm
sentry-docs	Ready	Preview, Comment	Mar 13, 2026 11:42pm

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

Bugbot Autofix prepared fixes for both issues found in the latest run.

• ✅ Fixed: CI build step will fail, blocking type-check
  • Replaced 'pnpm next build' with 'pnpm next typegen' to generate type definitions without running a full build that requires doctree.json
• ✅ Fixed: Sentry DSN validation weakened for all CI workflows
  • Changed bypass check from GITHUB_ACTIONS to NEXT_TYPEGEN to narrow the scope to only the typegen step, preserving validation for production builds

Or push these changes by commenting:

@cursor push aedfc55282

Preview (aedfc55282)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -40,8 +40,10 @@
 
       - run: pnpm install --frozen-lockfile
 
-      # Generate next-env.d.ts (in .gitignore); required before type-check. Replace with `next typegen` when on Next 15.5+
-      - run: pnpm next build
+      # Generate next-env.d.ts (in .gitignore); required before type-check
+      - run: pnpm next typegen
+        env:
+          NEXT_TYPEGEN: 'true'
 
       # Additional checks
       - run: pnpm lint:ts

diff --git a/next.config.ts b/next.config.ts
--- a/next.config.ts
+++ b/next.config.ts
@@ -90,7 +90,7 @@
 if (
   process.env.NODE_ENV !== 'development' &&
   !process.env.NEXT_PUBLIC_SENTRY_DSN &&
-  !process.env.GITHUB_ACTIONS
+  !process.env.NEXT_TYPEGEN
 ) {
   throw new Error(
     'Missing required environment variable: NEXT_PUBLIC_SENTRY_DSN must be set in production'

_{This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.}

[sergical]

is it only the test workflow we need this in? nothing in the build / dev commands?

[sfanahata]

is it only the test workflow we need this in? nothing in the build / dev commands?

Correct. Basically, those build steps automatically run through getting that file as a part of its process, so they're fine.

From my bot friend: The test workflow is different: it only runs pnpm install and then pnpm lint:ts (tsc). It never runs build or dev, so the file wouldn’t exist unless we add a step. We added pnpm next typegen there so tsc has the file without doing a full build.