calcom · PeerRich · Apr 16, 2026
diff --git a/apps/extension/entrypoints/background/index.ts b/apps/extension/entrypoints/background/index.ts
@@ -456,7 +456,7 @@ export default defineBackground(() => {
 
         recordTokenOperation();
         if (storageAPI?.local) {
-          storageAPI.local.remove(["cal_oauth_tokens", "oauth_state"], () => {
+          storageAPI.local.remove(["cal_oauth_tokens", "oauth_state", "cal_region"], () => {
             const runtime = getRuntimeAPI();
             if (runtime?.lastError) {
               devLog.error("Failed to clear OAuth tokens:", runtime.lastError.message);
@@ -861,7 +861,24 @@ async function validateOAuthState(state: string): Promise<void> {
   }
 }
 
-const API_BASE_URL = "https://api.cal.com/v2";
+const REGION_STORAGE_KEY = "cal_region";
+
+async function getStoredRegion(): Promise<"us" | "eu"> {
+  const storageAPI = getStorageAPI();
+  if (!storageAPI?.local) return "us";
+  try {
+    const result = await storageAPI.local.get([REGION_STORAGE_KEY]);
+    const value = result[REGION_STORAGE_KEY];
+    return value === "eu" ? "eu" : "us";
+  } catch {
+    return "us";
+  }
+}
+
+async function getApiBaseUrl(): Promise<string> {
+  const region = await getStoredRegion();
+  return region === "eu" ? "https://api.cal.eu/v2" : "https://api.cal.com/v2";
+}
 
 const tokenOperationTimestamps: number[] = [];
 const TOKEN_RATE_LIMIT_WINDOW_MS = 60000;
@@ -888,7 +905,8 @@ async function validateTokens(tokens: OAuthTokens): Promise<boolean> {
   }
 
   try {
-    const response = await fetchWithTimeout(`${API_BASE_URL}/me`, {
+    const apiBaseUrl = await getApiBaseUrl();
+    const response = await fetchWithTimeout(`${apiBaseUrl}/me`, {
       headers: {
         Authorization: `Bearer ${tokens.accessToken}`,
         "Content-Type": "application/json",
@@ -934,9 +952,10 @@ async function getAuthHeader(): Promise<string> {
 async function fetchEventTypes(): Promise<unknown[]> {
   const authHeader = await getAuthHeader();
 
+  const apiBaseUrl = await getApiBaseUrl();
   // For authenticated users, no username/orgSlug params needed - API uses auth token
   // This also ensures hidden event types are returned (they're filtered out when username is provided)
-  const response = await fetchWithTimeout(`${API_BASE_URL}/event-types`, {
+  const response = await fetchWithTimeout(`${apiBaseUrl}/event-types`, {
     headers: {
       Authorization: authHeader,
       "Content-Type": "application/json",
@@ -992,7 +1011,8 @@ async function checkAuthStatus(): Promise<boolean> {
 async function getBookingStatus(bookingUid: string): Promise<Booking> {
   const authHeader = await getAuthHeader();
 
-  const response = await fetchWithTimeout(`${API_BASE_URL}/bookings/${bookingUid}`, {
+  const apiBaseUrl = await getApiBaseUrl();
+  const response = await fetchWithTimeout(`${apiBaseUrl}/bookings/${bookingUid}`, {
     method: "GET",
     headers: {
       Authorization: authHeader,
@@ -1039,7 +1059,8 @@ async function markAttendeeNoShow(
 ): Promise<Booking> {
   const authHeader = await getAuthHeader();
 
-  const response = await fetchWithTimeout(`${API_BASE_URL}/bookings/${bookingUid}/mark-absent`, {
+  const apiBaseUrl = await getApiBaseUrl();
+  const response = await fetchWithTimeout(`${apiBaseUrl}/bookings/${bookingUid}/mark-absent`, {
     method: "POST",
     headers: {
       Authorization: authHeader,

diff --git a/apps/extension/entrypoints/content.ts b/apps/extension/entrypoints/content.ts
@@ -160,7 +160,7 @@ export default defineContentScript({
           );
           return;
         }
-        handleTokenSyncRequest(event.data.tokens, iframe.contentWindow);
+        handleTokenSyncRequest(event.data.tokens, event.data.region, iframe.contentWindow);
       } else if (event.data.type === "cal-extension-clear-tokens") {
         if (!validateSessionToken(event.data.sessionToken)) {
           iframe.contentWindow?.postMessage(
@@ -281,9 +281,10 @@ export default defineContentScript({
 
     function handleTokenSyncRequest(
       tokens: { accessToken?: string; refreshToken?: string; expiresAt?: number },
+      region: "us" | "eu" | undefined,
       iframeWindow: Window | null
     ) {
-      chrome.runtime.sendMessage({ action: "sync-oauth-tokens", tokens }, (response) => {
+      chrome.runtime.sendMessage({ action: "sync-oauth-tokens", tokens, region }, (response) => {
         if (chrome.runtime.lastError) {
           devLog.error(
             "Failed to communicate with background script:",

diff --git a/apps/extension/wxt.config.ts b/apps/extension/wxt.config.ts
@@ -11,32 +11,48 @@ const browserTarget = process.env.BROWSER_TARGET || "chrome";
 /**
  * Get browser-specific OAuth configuration.
  * Falls back to default (Chrome) config if browser-specific config is not set.
+ *
+ * Returns both US (default) and EU values so the runtime can pick the right
+ * one based on the data region selected on the login screen.
  */
 function getOAuthConfig() {
   const defaultClientId = process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID || "";
   const defaultRedirectUri = process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI || "";
+  const defaultClientIdEu = process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID_EU || "";
+  const defaultRedirectUriEu = process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI_EU || "";
 
   switch (browserTarget) {
     case "firefox":
       return {
         clientId: process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID_FIREFOX || defaultClientId,
         redirectUri:
           process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI_FIREFOX || defaultRedirectUri,
+        clientIdEu: process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID_FIREFOX_EU || defaultClientIdEu,
+        redirectUriEu:
+          process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI_FIREFOX_EU || defaultRedirectUriEu,
       };
     case "safari":
       return {
         clientId: process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID_SAFARI || defaultClientId,
         redirectUri: process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI_SAFARI || defaultRedirectUri,
+        clientIdEu: process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID_SAFARI_EU || defaultClientIdEu,
+        redirectUriEu:
+          process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI_SAFARI_EU || defaultRedirectUriEu,
       };
     case "edge":
       return {
         clientId: process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID_EDGE || defaultClientId,
         redirectUri: process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI_EDGE || defaultRedirectUri,
+        clientIdEu: process.env.EXPO_PUBLIC_CALCOM_OAUTH_CLIENT_ID_EDGE_EU || defaultClientIdEu,
+        redirectUriEu:
+          process.env.EXPO_PUBLIC_CALCOM_OAUTH_REDIRECT_URI_EDGE_EU || defaultRedirectUriEu,
       };
     default:
       return {
         clientId: defaultClientId,
         redirectUri: defaultRedirectUri,
+        clientIdEu: defaultClientIdEu,
+        redirectUriEu: defaultRedirectUriEu,
       };
   }
 }
@@ -71,6 +87,8 @@ export default defineConfig({
       "https://companion.cal.com/*",
       "https://api.cal.com/*",
       "https://app.cal.com/*",
+      "https://api.cal.eu/*",
+      "https://app.cal.eu/*",
       "https://mail.google.com/*",
       "https://calendar.google.com/*",
       // Include localhost permission for dev builds (needed for iframe to load)

diff --git a/apps/mobile/app/(tabs)/(event-types)/event-type-detail.tsx b/apps/mobile/app/(tabs)/(event-types)/event-type-detail.tsx
@@ -47,6 +47,7 @@ import {
   showSuccessAlert,
 } from "@/utils/alerts";
 import { openInAppBrowser } from "@/utils/browser";
+import { getCalAppUrl } from "@/utils/region";
 import {
   buildLocationOptions,
   mapApiLocationToItem,
@@ -1526,7 +1527,10 @@ export default function EventTypeDetail() {
                       <Text className="mb-5 text-center text-[19px] font-bold text-black dark:text-white">
                         Select Available Durations
                       </Text>
-                      <ScrollView style={{ maxHeight: 400, marginBottom: 20 }} showsVerticalScrollIndicator={false}>
+                      <ScrollView
+                        style={{ maxHeight: 400, marginBottom: 20 }}
+                        showsVerticalScrollIndicator={false}
+                      >
                         {availableDurations.map((duration, index) => (
                           <TouchableOpacity
                             key={duration}
@@ -1571,7 +1575,10 @@ export default function EventTypeDetail() {
                     <Text className="mb-5 text-center text-[19px] font-bold text-[#333] dark:text-white">
                       Select Available Durations
                     </Text>
-                    <ScrollView style={{ maxHeight: 400, marginBottom: 20 }} showsVerticalScrollIndicator={false}>
+                    <ScrollView
+                      style={{ maxHeight: 400, marginBottom: 20 }}
+                      showsVerticalScrollIndicator={false}
+                    >
                       {availableDurations.map((duration, index) => (
                         <TouchableOpacity
                           key={duration}
@@ -2343,7 +2350,7 @@ export default function EventTypeDetail() {
                           showNotAvailableAlert();
                         } else {
                           openInAppBrowser(
-                            `https://app.cal.com/event-types/${id}?tabName=apps`,
+                            `${getCalAppUrl()}/event-types/${id}?tabName=apps`,
                             "Apps settings"
                           );
                         }
@@ -2378,7 +2385,7 @@ export default function EventTypeDetail() {
                           showNotAvailableAlert();
                         } else {
                           openInAppBrowser(
-                            `https://app.cal.com/event-types/${id}?tabName=workflows`,
+                            `${getCalAppUrl()}/event-types/${id}?tabName=workflows`,
                             "Workflows settings"
                           );
                         }
@@ -2413,7 +2420,7 @@ export default function EventTypeDetail() {
                           showNotAvailableAlert();
                         } else {
                           openInAppBrowser(
-                            `https://app.cal.com/event-types/${id}?tabName=webhooks`,
+                            `${getCalAppUrl()}/event-types/${id}?tabName=webhooks`,
                             "Webhooks settings"
                           );
                         }

diff --git a/apps/mobile/app/(tabs)/(more)/index.ios.tsx b/apps/mobile/app/(tabs)/(more)/index.ios.tsx
@@ -22,6 +22,7 @@ import { type LandingPage, useUserPreferences } from "@/hooks/useUserPreferences
 import { showErrorAlert, showNotAvailableAlert, showSilentSuccessAlert } from "@/utils/alerts";
 import { openInAppBrowser } from "@/utils/browser";
 import { getAvatarUrl } from "@/utils/getAvatarUrl";
+import { getCalAppUrl } from "@/utils/region";
 
 interface MoreMenuItem {
   name: string;
@@ -336,7 +337,9 @@ export default function More() {
         >
           The companion app is an extension of the web application.{"\n"}
           For advanced features, visit{" "}
-          <Text style={{ color: isDark ? "#D1D5DB" : "#1F2937" }}>app.cal.com</Text>
+          <Text style={{ color: isDark ? "#D1D5DB" : "#1F2937" }}>
+            {getCalAppUrl().replace(/^https?:\/\//, "")}
+          </Text>
         </Text>
       </ScrollView>
 

diff --git a/apps/mobile/app/(tabs)/(more)/index.tsx b/apps/mobile/app/(tabs)/(more)/index.tsx
@@ -18,6 +18,7 @@ import { useQueryContext } from "@/contexts/QueryContext";
 import { type LandingPage, useUserPreferences } from "@/hooks/useUserPreferences";
 import { showErrorAlert, showSilentSuccessAlert } from "@/utils/alerts";
 import { openInAppBrowser } from "@/utils/browser";
+import { getCalAppUrl } from "@/utils/region";
 
 interface MoreMenuItem {
   name: string;
@@ -79,30 +80,31 @@ export default function More() {
     }
   };
 
+  const calAppUrl = getCalAppUrl();
   const menuItems: MoreMenuItem[] = [
     {
       name: "Apps",
       icon: "grid-outline",
       isExternal: true,
-      onPress: () => openInAppBrowser("https://app.cal.com/apps", "Apps page"),
+      onPress: () => openInAppBrowser(`${calAppUrl}/apps`, "Apps page"),
     },
     {
       name: "Routing",
       icon: "git-branch-outline",
       isExternal: true,
-      onPress: () => openInAppBrowser("https://app.cal.com/routing", "Routing page"),
+      onPress: () => openInAppBrowser(`${calAppUrl}/routing`, "Routing page"),
     },
     {
       name: "Workflows",
       icon: "flash-outline",
       isExternal: true,
-      onPress: () => openInAppBrowser("https://app.cal.com/workflows", "Workflows page"),
+      onPress: () => openInAppBrowser(`${calAppUrl}/workflows`, "Workflows page"),
     },
     {
       name: "Insights",
       icon: "bar-chart-outline",
       isExternal: true,
-      onPress: () => openInAppBrowser("https://app.cal.com/insights", "Insights page"),
+      onPress: () => openInAppBrowser(`${calAppUrl}/insights`, "Insights page"),
     },
     {
       name: "Support",
@@ -202,7 +204,7 @@ export default function More() {
         >
           <TouchableOpacity
             onPress={() =>
-              openInAppBrowser("https://app.cal.com/settings/my-account/profile", "Delete Account")
+              openInAppBrowser(`${getCalAppUrl()}/settings/my-account/profile`, "Delete Account")
             }
             className="flex-row items-center justify-between bg-white px-5 py-4 active:bg-red-50"
             style={{ backgroundColor: theme.backgroundSecondary }}
@@ -243,9 +245,9 @@ export default function More() {
           For advanced features, visit{" "}
           <Text
             style={{ color: theme.text }}
-            onPress={() => openInAppBrowser("https://app.cal.com", "Cal.com")}
+            onPress={() => openInAppBrowser(calAppUrl, "Cal.com")}
           >
-            app.cal.com
+            {calAppUrl.replace(/^https?:\/\//, "")}
           </Text>
         </Text>
       </ScrollView>

diff --git a/apps/mobile/app/profile-sheet.ios.tsx b/apps/mobile/app/profile-sheet.ios.tsx
@@ -18,6 +18,7 @@ import { useUserProfile } from "@/hooks";
 import { showSuccessAlert } from "@/utils/alerts";
 import { openInAppBrowser } from "@/utils/browser";
 import { getAvatarUrl } from "@/utils/getAvatarUrl";
+import { getCalAppUrl, getCalWebUrl } from "@/utils/region";
 
 interface ProfileMenuItem {
   id: string;
@@ -57,34 +58,31 @@ export default function ProfileSheet() {
     avatarText: isDark ? "#FFFFFF" : "#4B5563",
   };
 
-  const publicPageUrl = userProfile?.username ? `https://cal.com/${userProfile.username}` : null;
+  const calAppUrl = getCalAppUrl();
+  const calWebUrl = getCalWebUrl();
+  const publicPageUrl = userProfile?.username ? `${calWebUrl}/${userProfile.username}` : null;
 
   const menuItems: ProfileMenuItem[] = [
     {
       id: "profile",
       label: "My Profile",
       icon: "person-outline",
-      onPress: () =>
-        openInAppBrowser("https://app.cal.com/settings/my-account/profile", "Profile page"),
+      onPress: () => openInAppBrowser(`${calAppUrl}/settings/my-account/profile`, "Profile page"),
       external: true,
     },
     {
       id: "settings",
       label: "My Settings",
       icon: "settings-outline",
-      onPress: () =>
-        openInAppBrowser("https://app.cal.com/settings/my-account/general", "Settings page"),
+      onPress: () => openInAppBrowser(`${calAppUrl}/settings/my-account/general`, "Settings page"),
       external: true,
     },
     {
       id: "outOfOffice",
       label: "Out of Office",
       icon: "moon-outline",
       onPress: () =>
-        openInAppBrowser(
-          "https://app.cal.com/settings/my-account/out-of-office",
-          "Out of Office page"
-        ),
+        openInAppBrowser(`${calAppUrl}/settings/my-account/out-of-office`, "Out of Office page"),
       external: true,
     },
 
@@ -105,14 +103,14 @@ export default function ProfileSheet() {
       id: "roadmap",
       label: "Roadmap",
       icon: "map-outline",
-      onPress: () => openInAppBrowser("https://cal.com/roadmap", "Roadmap page"),
+      onPress: () => openInAppBrowser(`${calWebUrl}/roadmap`, "Roadmap page"),
       external: true,
     },
     {
       id: "help",
       label: "Help",
       icon: "help-circle-outline",
-      onPress: () => openInAppBrowser("https://cal.com/help", "Help page"),
+      onPress: () => openInAppBrowser(`${calWebUrl}/help`, "Help page"),
       external: true,
     },
   ];