diff --git a/e2e/fixtures/api-mocks.ts b/e2e/fixtures/api-mocks.ts
index 8193efc3..79894e1e 100644
--- a/e2e/fixtures/api-mocks.ts
+++ b/e2e/fixtures/api-mocks.ts
@@ -11,6 +11,7 @@ export interface MockCoreApisOptions {
   paidImageFlow?: boolean;
   paidImageInsufficientCreditsFlow?: boolean;
   paidVoiceInsufficientCreditsFlow?: boolean;
+  psidLoginFlow?: boolean;
 }
 
 export async function mockCoreApis(page: Page, options: MockCoreApisOptions = {}) {
@@ -20,12 +21,14 @@ export async function mockCoreApis(page: Page, options: MockCoreApisOptions = {}
     paidImageFlow: options.paidImageFlow ?? false,
     paidImageInsufficientCreditsFlow: options.paidImageInsufficientCreditsFlow ?? false,
     paidVoiceInsufficientCreditsFlow: options.paidVoiceInsufficientCreditsFlow ?? false,
+    psidLoginFlow: options.psidLoginFlow ?? false,
   };
   const chatState = { hasExpiredChatSend: false, paidImageRequested: false, paidImageUnlocked: false };
 
   await registerAuthMocks(page, {
     chatSendTokenRefreshFlow: chatOptions.chatSendTokenRefreshFlow,
     isChatSendTokenExpired: () => chatState.hasExpiredChatSend,
+    psidLoginFlow: chatOptions.psidLoginFlow,
   });
   await registerUserMocks(page);
   await registerChatMocks(page, chatOptions, chatState);
diff --git a/e2e/fixtures/api/auth.ts b/e2e/fixtures/api/auth.ts
index 8aa97e41..7ac5a257 100644
--- a/e2e/fixtures/api/auth.ts
+++ b/e2e/fixtures/api/auth.ts
@@ -1,14 +1,24 @@
 import type { Page } from "@playwright/test";
 
 import { apiEnvelope } from "../data/common";
-import { emailLoginResponse, guestLoginResponse, refreshedEmailLoginResponse, refreshedGuestLoginResponse } from "../data/auth";
+import { emailLoginResponse, guestLoginResponse, psidLoginResponse, refreshedEmailLoginResponse, refreshedGuestLoginResponse } from "../data/auth";
 
 export interface AuthMockState {
   chatSendTokenRefreshFlow: boolean;
   isChatSendTokenExpired: () => boolean;
+  psidLoginFlow: boolean;
 }
 
 export async function registerAuthMocks(page: Page, state: AuthMockState) {
+  await page.route("**/api/auth/login/facebook/psid", async (route) => {
+    if (!state.psidLoginFlow) {
+      await route.continue();
+      return;
+    }
+
+    await route.fulfill({ json: apiEnvelope(psidLoginResponse) });
+  });
+
   await page.route("**/api/auth/guest", async (route) => {
     const response = state.chatSendTokenRefreshFlow && state.isChatSendTokenExpired() ? refreshedGuestLoginResponse : guestLoginResponse;
     await route.fulfill({ json: apiEnvelope(response) });
diff --git a/e2e/fixtures/data/auth.ts b/e2e/fixtures/data/auth.ts
index 57489b21..984a85cc 100644
--- a/e2e/fixtures/data/auth.ts
+++ b/e2e/fixtures/data/auth.ts
@@ -49,3 +49,15 @@ export const refreshedEmailLoginResponse = {
   token: "e2e-refreshed-email-token",
   refreshToken: "e2e-refreshed-email-refresh-token",
 };
+
+export const psidLoginResponse = {
+  token: "e2e-psid-guest-token",
+  refreshToken: "",
+  matchedBy: "psid",
+  fbAsid: "",
+  fbPsid: "e2e-facebook-psid",
+  hasCompleteFacebookIdentity: false,
+  isGuest: true,
+  user: e2eUser,
+  userId: e2eUser.id,
+};
diff --git a/e2e/specs/mock/auth/psid-login-from-external-entry.spec.ts b/e2e/specs/mock/auth/psid-login-from-external-entry.spec.ts
new file mode 100644
index 00000000..bd58194d
--- /dev/null
+++ b/e2e/specs/mock/auth/psid-login-from-external-entry.spec.ts
@@ -0,0 +1,46 @@
+import { expect, test } from "@playwright/test";
+
+import { mockCoreApis } from "@e2e/fixtures/api-mocks";
+import { clearBrowserState } from "@e2e/fixtures/test-helpers";
+
+const psid = "e2e-facebook-psid";
+
+test.beforeEach(async ({ baseURL, context, page }) => {
+  await clearBrowserState(context, page, baseURL);
+  await mockCoreApis(page, { psidLoginFlow: true });
+});
+
+test("user enters from an external PSID link and becomes a guest", async ({
+  page,
+}) => {
+  const psidLoginRequestPromise = page.waitForRequest(
+    "**/api/auth/login/facebook/psid",
+  );
+
+  await page.goto(`/external-entry?target=chat&psid=${psid}`);
+
+  const psidLoginRequest = await psidLoginRequestPromise;
+  expect(psidLoginRequest.method()).toBe("POST");
+  expect(psidLoginRequest.postDataJSON()).toMatchObject({
+    psid,
+    bindToGuest: true,
+  });
+  expect(psidLoginRequest.postDataJSON().deviceId).toEqual(expect.any(String));
+
+  await expect(page).toHaveURL(/\/chat$/);
+  await expect(page.getByRole("textbox", { name: "Message" })).toBeVisible();
+
+  await expect
+    .poll(() =>
+      page.evaluate(() => ({
+        loginProvider: localStorage.getItem("cozsweet:login_provider"),
+        guestToken: localStorage.getItem("cozsweet:guest_token"),
+        psid: localStorage.getItem("cozsweet:psid"),
+      })),
+    )
+    .toMatchObject({
+      loginProvider: "guest",
+      guestToken: "e2e-psid-guest-token",
+      psid,
+    });
+});
diff --git a/src/app/external-entry/external-entry-persist.tsx b/src/app/external-entry/external-entry-persist.tsx
index 1a5bfef4..cfe6c328 100644
--- a/src/app/external-entry/external-entry-persist.tsx
+++ b/src/app/external-entry/external-entry-persist.tsx
@@ -44,6 +44,7 @@ export default function ExternalEntryPersist({
   const authDispatch = useAuthDispatch();
   const [hasPersisted, setHasPersisted] = useState(false);
   const hasNavigatedRef = useRef(false);
+  const hasReinitializedForPsidRef = useRef(false);
   const targetRoute = resolveExternalEntryTarget({ target });
   const destination = resolveExternalEntryDestination({ target });
   const resolvedPromotionType = resolveExternalEntryPromotionType({
@@ -94,6 +95,16 @@ export default function ExternalEntryPersist({
 
   useEffect(() => {
     if (hasNavigatedRef.current || !hasPersisted) return;
+
+    // AuthStatusChecker can initialize before this entry has persisted PSID.
+    // Re-run the check so PSID direct login is not skipped by that race.
+    if (hasValue(psid) && !hasReinitializedForPsidRef.current) {
+      if (!authState.hasInitialized || authState.isLoading) return;
+      hasReinitializedForPsidRef.current = true;
+      authDispatch({ type: "AuthInit" });
+      return;
+    }
+
     if (!authState.hasInitialized || authState.isLoading) return;
     hasNavigatedRef.current = true;
 
@@ -138,3 +149,7 @@ export default function ExternalEntryPersist({
     </div>
   );
 }
+
+function hasValue(value: string | null): value is string {
+  return typeof value === "string" && value.trim().length > 0;
+}