diff --git a/admin-ui/src/app/providers.tsx b/admin-ui/src/app/providers.tsx
index f9a5528..361f1e7 100644
--- a/admin-ui/src/app/providers.tsx
+++ b/admin-ui/src/app/providers.tsx
@@ -3,6 +3,18 @@
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { useState, useEffect } from "react";
 import { syncStoredApiKey } from "@/lib/api";
+import { EnvironmentProvider, useEnvironment } from "@/lib/EnvironmentContext";
+
+/** Invalidates all queries whenever the active environment changes. */
+function QueryInvalidatorOnEnvChange({ queryClient }: { queryClient: QueryClient }) {
+  const { environment } = useEnvironment();
+  useEffect(() => {
+    if (environment != null) {
+      void queryClient.invalidateQueries();
+    }
+  }, [environment, queryClient]);
+  return null;
+}
 
 export function Providers({ children }: { children: React.ReactNode }) {
   useEffect(() => {
@@ -17,7 +29,13 @@ export function Providers({ children }: { children: React.ReactNode }) {
         },
       })
   );
+
   return (
-    <QueryClientProvider client={client}>{children}</QueryClientProvider>
+    <QueryClientProvider client={client}>
+      <EnvironmentProvider>
+        <QueryInvalidatorOnEnvChange queryClient={client} />
+        {children}
+      </EnvironmentProvider>
+    </QueryClientProvider>
   );
 }
diff --git a/admin-ui/src/components/EnvironmentSwitcher.tsx b/admin-ui/src/components/EnvironmentSwitcher.tsx
new file mode 100644
index 0000000..a42b030
--- /dev/null
+++ b/admin-ui/src/components/EnvironmentSwitcher.tsx
@@ -0,0 +1,60 @@
+"use client";
+
+import { useEffect } from "react";
+import { useQuery } from "@tanstack/react-query";
+import { useTranslations } from "next-intl";
+import { fetchEnvironments } from "@/lib/api";
+import { useEnvironment } from "@/lib/EnvironmentContext";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+
+export function EnvironmentSwitcher() {
+  const t = useTranslations("EnvironmentSwitcher");
+  const { environment, setEnvironment } = useEnvironment();
+  const { data } = useQuery({
+    queryKey: ["environments"],
+    queryFn: fetchEnvironments,
+  });
+
+  const environments = data?.environments ?? [];
+  const defaultEnv = data?.default ?? null;
+
+  useEffect(() => {
+    if (environments.length > 0 && !environment && defaultEnv) {
+      setEnvironment(defaultEnv);
+    }
+  }, [environments.length, environment, defaultEnv, setEnvironment]);
+
+  if (environments.length === 0) return null;
+
+  const value = environment ?? defaultEnv ?? environments[0];
+
+  const handleChange = (next: string) => {
+    setEnvironment(next);
+  };
+
+  return (
+    <div className="flex items-center gap-2">
+      <span className="shrink-0 text-xs font-medium text-gray-500 uppercase tracking-wide">
+        {t("label")}:
+      </span>
+      <Select value={value} onValueChange={handleChange}>
+        <SelectTrigger className="h-8 w-full min-w-0 max-w-[140px] text-xs">
+          <SelectValue />
+        </SelectTrigger>
+        <SelectContent>
+          {environments.map((env) => (
+            <SelectItem key={env} value={env} className="text-xs">
+              {env}
+            </SelectItem>
+          ))}
+        </SelectContent>
+      </Select>
+    </div>
+  );
+}
diff --git a/admin-ui/src/lib/EnvironmentContext.tsx b/admin-ui/src/lib/EnvironmentContext.tsx
new file mode 100644
index 0000000..586c3d9
--- /dev/null
+++ b/admin-ui/src/lib/EnvironmentContext.tsx
@@ -0,0 +1,37 @@
+"use client";
+
+import { createContext, useContext, useState, useEffect, type ReactNode } from "react";
+import { getCurrentEnvironment, setCurrentEnvironment } from "@/lib/api";
+
+type EnvironmentContextType = {
+  environment: string | null;
+  setEnvironment: (env: string) => void;
+};
+
+const EnvironmentContext = createContext<EnvironmentContextType>({
+  environment: null,
+  setEnvironment: () => {},
+});
+
+export function EnvironmentProvider({ children }: { children: ReactNode }) {
+  const [environment, setEnv] = useState<string | null>(null);
+
+  useEffect(() => {
+    setEnv(getCurrentEnvironment());
+  }, []);
+
+  function setEnvironment(env: string) {
+    setCurrentEnvironment(env);
+    setEnv(env);
+  }
+
+  return (
+    <EnvironmentContext.Provider value={{ environment, setEnvironment }}>
+      {children}
+    </EnvironmentContext.Provider>
+  );
+}
+
+export function useEnvironment() {
+  return useContext(EnvironmentContext);
+}