diff --git a/.env.local.example b/.env.local.example
index badced10f4..d5b4f33b4d 100644
--- a/.env.local.example
+++ b/.env.local.example
@@ -113,6 +113,9 @@ INTERNAL_API_SECRET=changeme
 # Access disable happens later in worker preflight; pending requests can be cancelled.
 # Keep production values off preview deployments; rotate Cloud+CSA together.
 SUPPORT_API_SECRET=changeme
+# CSA Vercel Deployment Protection automation bypass (header only, never a query param).
+# Required when CSA has Vercel Authentication enabled.
+CSA_VERCEL_PROTECTION_BYPASS=
 # Git token service persisted-authorization disconnect
 GIT_TOKEN_SERVICE_API_URL=http://localhost:8802
 # Optional public HTTPS origin for Bitbucket Code Reviewer webhooks.
diff --git a/ENVIRONMENT.md b/ENVIRONMENT.md
index d3dbf28302..3ecabebbd8 100644
--- a/ENVIRONMENT.md
+++ b/ENVIRONMENT.md
@@ -45,6 +45,7 @@ Manage shared web env var additions and rotations with `pnpm web:env set <VARIAB
 - `CUSTOMERIO_TRACK_BASE` - Optional Customer.io Track API base override for local user-deletion cleanup; defaults to `https://track.customer.io`. [SERVER]
 - `SUBSTACK_PUBLICATION_URL` - Substack publication origin used by user-deletion subscriber cleanup; defaults to `https://blog.kilo.ai`. Must be `blog.kilo.ai` or a `*.substack.com` host. The Substack admin search URL is hardcoded to `https://kilocode.substack.com/publish/subscribers`, not this publication. [SERVER]
 - `CSA_APP_BASE_URL` - CSA origin used by the Cloud deletion worker to call `POST /api/internal/cloud/users/gdpr-scrub`. Example: the production CSA app URL. [SERVER]
+- `CSA_VERCEL_PROTECTION_BYPASS` - CSA Vercel Deployment Protection automation bypass. Cloud sends it as the `x-vercel-protection-bypass` header on Cloud → CSA `POST /api/internal/cloud/users/gdpr-scrub`, never as a query parameter. Required when CSA has Vercel Authentication enabled; without it Vercel returns 401 before the CSA route. Distinct from `SUPPORT_API_SECRET`. `[SECRET]`
 - `SENTRY_ORG` - Sentry organization slug for source map uploads; used in `apps/web/next.config.mjs`. `[SECRET]`
 - `SENTRY_PROJECT` - Sentry project slug for source map uploads; used in `apps/web/next.config.mjs`. `[SECRET]`
 - `SENTRY_AUTH_TOKEN` - Sentry auth token for source map uploads; used in `apps/web/next.config.mjs`. `[SECRET]`
diff --git a/apps/web/src/lib/user/deletion-queue/deletion-hints.test.ts b/apps/web/src/lib/user/deletion-queue/deletion-hints.test.ts
index 4cbe5a04a3..97a15031ab 100644
--- a/apps/web/src/lib/user/deletion-queue/deletion-hints.test.ts
+++ b/apps/web/src/lib/user/deletion-queue/deletion-hints.test.ts
@@ -16,6 +16,9 @@ describe('deletionAttentionHint', () => {
     expect(deletionAttentionHint('usage_prefix_progress_invalid')?.action).not.toMatch(/Mark done/);
     expect(deletionAttentionHint('delete_ready_missing')?.action).toMatch(/delete-ready/);
     expect(deletionAttentionHint('csa_unauthorized')?.title).toMatch(/CSA/);
+    expect(deletionAttentionHint('csa_unauthorized')?.action).toMatch(
+      /CSA_VERCEL_PROTECTION_BYPASS/
+    );
   });
 
   it('falls back for other HTTP statuses', () => {
diff --git a/apps/web/src/lib/user/deletion-queue/deletion-hints.ts b/apps/web/src/lib/user/deletion-queue/deletion-hints.ts
index 22fa353c76..6964c448fb 100644
--- a/apps/web/src/lib/user/deletion-queue/deletion-hints.ts
+++ b/apps/web/src/lib/user/deletion-queue/deletion-hints.ts
@@ -326,7 +326,8 @@ const KNOWN_HINTS: Record<string, DeletionAttentionHint> = {
   },
   csa_unauthorized: {
     title: 'CSA rejected the support-DB scrub',
-    action: 'Confirm SUPPORT_API_SECRET matches CSA KILO_SUPPORT_API_SECRET, then Retry.',
+    action:
+      'Confirm SUPPORT_API_SECRET matches CSA KILO_SUPPORT_API_SECRET and CSA_VERCEL_PROTECTION_BYPASS matches CSA Vercel automation bypass, then Retry.',
   },
   csa_blocked_email: {
     title: 'CSA refused this email as a relay or internal target',
diff --git a/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.test.ts b/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.test.ts
index a62b8ac059..281b5a8f3f 100644
--- a/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.test.ts
+++ b/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.test.ts
@@ -6,10 +6,12 @@ import { handleCsaSupportDb } from '@/lib/user/deletion-queue/handlers/csa-suppo
 describe('handleCsaSupportDb', () => {
   const originalSecret = process.env.SUPPORT_API_SECRET;
   const originalBase = process.env.CSA_APP_BASE_URL;
+  const originalBypass = process.env.CSA_VERCEL_PROTECTION_BYPASS;
 
   beforeEach(() => {
     process.env.SUPPORT_API_SECRET = 'shared-support-secret';
     process.env.CSA_APP_BASE_URL = 'https://csa.example.test';
+    delete process.env.CSA_VERCEL_PROTECTION_BYPASS;
   });
 
   afterEach(() => {
@@ -18,6 +20,8 @@ describe('handleCsaSupportDb', () => {
     else process.env.SUPPORT_API_SECRET = originalSecret;
     if (originalBase === undefined) delete process.env.CSA_APP_BASE_URL;
     else process.env.CSA_APP_BASE_URL = originalBase;
+    if (originalBypass === undefined) delete process.env.CSA_VERCEL_PROTECTION_BYPASS;
+    else process.env.CSA_VERCEL_PROTECTION_BYPASS = originalBypass;
   });
 
   it('succeeds when CSA returns updated', async () => {
@@ -76,6 +80,27 @@ describe('handleCsaSupportDb', () => {
     const init = fetchSpy.mock.calls[0]?.[1] as RequestInit;
     expect((init.headers as Record<string, string>)['X-Actor-Email']).toBeUndefined();
   });
+
+  it('omits the Vercel protection bypass header when unset', async () => {
+    const fetchSpy = mockCsa({ status: 200, body: { status: 'updated' } });
+    await handleCsaSupportDb(handlerArgs());
+    const init = fetchSpy.mock.calls[0]?.[1] as RequestInit;
+    expect((init.headers as Record<string, string>)['x-vercel-protection-bypass']).toBeUndefined();
+  });
+
+  it('sends the Vercel protection bypass header when configured', async () => {
+    process.env.CSA_VERCEL_PROTECTION_BYPASS = 'csa-vercel-bypass';
+    const fetchSpy = mockCsa({ status: 200, body: { status: 'updated' } });
+    const outcome = await handleCsaSupportDb(handlerArgs());
+    expect(outcome).toEqual({ kind: 'succeeded' });
+    const init = fetchSpy.mock.calls[0]?.[1] as RequestInit;
+    expect((init.headers as Record<string, string>)['x-vercel-protection-bypass']).toBe(
+      'csa-vercel-bypass'
+    );
+    expect(fetchSpy.mock.calls[0]?.[0]).toBe(
+      'https://csa.example.test/api/internal/cloud/users/gdpr-scrub'
+    );
+  });
 });
 
 function handlerArgs(request: Partial<UserDeletionRequest> = {}): {
diff --git a/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.ts b/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.ts
index d68e2ceb0b..509766b540 100644
--- a/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.ts
+++ b/apps/web/src/lib/user/deletion-queue/handlers/csa-support-db.ts
@@ -33,6 +33,8 @@ export const handleCsaSupportDb: DeletionHandler = async ({ request, context })
   };
   const actorEmail = request.requested_by_email?.trim();
   if (actorEmail) headers['X-Actor-Email'] = actorEmail;
+  const protectionBypass = getEnvVariable('CSA_VERCEL_PROTECTION_BYPASS').trim();
+  if (protectionBypass) headers['x-vercel-protection-bypass'] = protectionBypass;
 
   const result = await deletionFetch(context, `${baseUrl}/api/internal/cloud/users/gdpr-scrub`, {
     method: 'POST',