[RaviTharuma]

Summary

• coalesce concurrent latest-version lookups and cache successful metadata for a bounded TTL
• preserve explicit no-cache/no-store refresh semantics and invalidate after successful updates
• bound upstream metadata bodies and emit private ETag-aware GET responses

Tests

• npx eslint src/lib/system/versionCheck.ts src/app/api/system/version/route.ts tests/unit/system-version-cache-8278.test.ts tests/unit/system-version-check-4100.test.ts --no-cache --suppressions-location config/quality/eslint-suppressions.json
• node --import tsx/esm --import ./open-sse/utils/setupPolyfill.ts --import ./tests/_setup/isolateDataDir.ts --test --test-force-exit tests/unit/system-version-cache-8278.test.ts tests/unit/system-version-check-4100.test.ts (19 passed)
• git diff --check

Closes #8278

🤖 Generated with Claude Code

[RaviTharuma]

CI note: the failing fast-path shards include repository-wide baseline failures outside this PR’s changed files (for example DashScope video assertions appear on multiple unrelated PRs). The focused tests listed in this PR body pass locally. I am still checking for any failure attributable to this patch.

[RaviTharuma]

Ownership/status update:

• No maintainer reviews, inline comments, or requested changes are currently present.
• The branch remains GitHub-mergeable against the latest release/v3.8.49; a local merge-tree check found no conflict markers. No rebase was needed, preserving the focused four-file diff.
• Fresh focused verification passes: 19/19 version-cache/version-check tests, focused ESLint, and git diff --check.
• The broad failing checks are repository baseline: merged PRs fix(dashboard): stop sidebar RSC prefetch storms #8292 and fix(backend): add structure-aware chat admission #8296 show the same Docs Gates, Fast Quality Gates, Vitest, and all four unit-shard failures. None of the failing paths identified in perf(api): coalesce and safely cache version resolution #8301 are in this PR diff.

No PR-attributable fix is pending. The PR is ready for maintainer review/merge despite the known baseline failures.

[RaviTharuma]

Rebased the single focused commit onto the current release/v3.8.49 tip and safely force-pushed with an explicit lease.

• New base: c525a0f452a725ca59af29ad39dd60584a7f5643
• New head: 7ccb24da2
• Commits above base: 1 (perf(api): singleflight version lookups (#8278))
• Minimal diff remains 4 files: 267 insertions, 9 deletions
• Focused tests: 19 passed, 0 failed
• Focused ESLint: passed
• git diff --check: passed

No unrelated baseline failures were modified.

[diegosouzapw]

Merged into release/v3.8.49 — thanks @RaviTharuma! Validated via local merge-train (32-core .113) + a per-file discriminator confirming zero regressions vs the pure release tip; CI reds on this PR were pre-existing base-red drift (tracked separately). 🙏