diff --git a/.github/workflows/ci-gate.yml b/.github/workflows/ci-gate.yml
new file mode 100644
index 0000000..1011837
--- /dev/null
+++ b/.github/workflows/ci-gate.yml
@@ -0,0 +1,97 @@
+# CI Gate — watches every other check on a PR and blocks merge if any failed.
+# Synced to all repos via syncWorkflows.yml. The org ruleset requires exactly
+# this check, which transitively requires every other check to pass.
+name: CI Gate
+
+on:
+  pull_request:
+  merge_group:
+
+concurrency:
+  group: ci-gate-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  checks: read
+  statuses: read
+
+jobs:
+  ci-gate:
+    runs-on: ubuntu-latest
+    timeout-minutes: 90
+    steps:
+      - name: Wait for all checks and gate merge
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const sha = context.payload.pull_request?.head?.sha
+                     ?? context.payload.merge_group?.head_sha
+                     ?? context.sha;
+            const { owner, repo } = context.repo;
+            const SELF = 'ci-gate';
+            const GRACE_MS  = 15_000;       // let other workflows register
+            const POLL_MS   = 30_000;       // check every 30 s
+            const TIMEOUT_MS = 80 * 60_000; // 80 min (under job timeout)
+
+            const PASS_CONCLUSIONS = new Set(['success', 'neutral', 'skipped']);
+
+            core.info(`Gating on commit ${sha}`);
+            await new Promise(r => setTimeout(r, GRACE_MS));
+
+            const start = Date.now();
+            while (Date.now() - start < TIMEOUT_MS) {
+              // ── Check Runs (GitHub Actions, third-party apps) ──
+              const runs = await github.paginate(
+                github.rest.checks.listForRef,
+                { owner, repo, ref: sha, per_page: 100, filter: 'latest' }
+              );
+              const others = runs.filter(r => r.name !== SELF);
+
+              // ── Commit Statuses (legacy status API) ──
+              const rawStatuses = await github.paginate(
+                github.rest.repos.listCommitStatusesForRef,
+                { owner, repo, ref: sha, per_page: 100 }
+              );
+              const latest = new Map();
+              for (const s of rawStatuses) {
+                const prev = latest.get(s.context);
+                if (!prev || s.id > prev.id) latest.set(s.context, s);
+              }
+              const statuses = [...latest.values()];
+
+              // ── Are any still running? ──
+              const pendingRuns     = others.filter(r => r.status !== 'completed');
+              const pendingStatuses = statuses.filter(s => s.state === 'pending');
+
+              if (pendingRuns.length > 0 || pendingStatuses.length > 0) {
+                const names = [
+                  ...pendingRuns.map(r => r.name),
+                  ...pendingStatuses.map(s => s.context),
+                ];
+                core.info(`Waiting on ${names.length}: ${names.join(', ')}`);
+                await new Promise(r => setTimeout(r, POLL_MS));
+                continue;
+              }
+
+              // ── All done — evaluate ──
+              const failed = [
+                ...others.filter(r => !PASS_CONCLUSIONS.has(r.conclusion))
+                         .map(r => `${r.name} (${r.conclusion})`),
+                ...statuses.filter(s => s.state !== 'success')
+                           .map(s => `${s.context} (${s.state})`),
+              ];
+
+              if (failed.length > 0) {
+                core.setFailed(
+                  `Blocked — ${failed.length} check(s) failed:\n` +
+                  failed.map(f => `  ✗ ${f}`).join('\n')
+                );
+                return;
+              }
+
+              const total = others.length + statuses.length;
+              core.info(`All ${total} check(s) passed.`);
+              return;
+            }
+
+            core.setFailed('Timed out waiting for checks to complete (80 min).');