diff --git a/frontend/assets/js/config.js b/frontend/assets/js/config.js
new file mode 100644
index 0000000..9c07fad
--- /dev/null
+++ b/frontend/assets/js/config.js
@@ -0,0 +1,70 @@
+(function () {
+  "use strict";
+
+  const DEFAULT_DEV_BACKEND = "http://127.0.0.1:8000";
+
+  function isLocalHost(hostname) {
+    return hostname === "localhost" || hostname === "127.0.0.1" || hostname === "::1";
+  }
+
+  function hasOwn(object, property) {
+    return Object.prototype.hasOwnProperty.call(object || {}, property);
+  }
+
+  function resolveConfiguredBackendBaseUrl() {
+    const explicitConfig = window.HLL_FRONTEND_CONFIG || {};
+    if (hasOwn(explicitConfig, "backendBaseUrl")) {
+      return String(explicitConfig.backendBaseUrl || "");
+    }
+
+    const body = document.body;
+    if (body && body.dataset && hasOwn(body.dataset, "backendBaseUrl")) {
+      const bodyValue = body.dataset.backendBaseUrl;
+      if (bodyValue === DEFAULT_DEV_BACKEND && !isLocalHost(window.location.hostname)) {
+        return "";
+      }
+      return String(bodyValue || "");
+    }
+
+    return isLocalHost(window.location.hostname) ? DEFAULT_DEV_BACKEND : "";
+  }
+
+  function rewriteUrl(input) {
+    const configuredBaseUrl = resolveConfiguredBackendBaseUrl();
+    if (typeof input !== "string") {
+      return input;
+    }
+
+    if (configuredBaseUrl === "") {
+      if (input.startsWith(`${DEFAULT_DEV_BACKEND}/`)) {
+        return input.slice(DEFAULT_DEV_BACKEND.length);
+      }
+      return input;
+    }
+
+    if (input.startsWith(`${DEFAULT_DEV_BACKEND}/`)) {
+      return `${configuredBaseUrl}${input.slice(DEFAULT_DEV_BACKEND.length)}`;
+    }
+
+    return input;
+  }
+
+  const nativeFetch = window.fetch.bind(window);
+  window.fetch = function hllConfiguredFetch(input, init) {
+    if (typeof input === "string") {
+      return nativeFetch(rewriteUrl(input), init);
+    }
+    if (input instanceof Request) {
+      const rewrittenUrl = rewriteUrl(input.url);
+      if (rewrittenUrl !== input.url) {
+        return nativeFetch(new Request(rewrittenUrl, input), init);
+      }
+    }
+    return nativeFetch(input, init);
+  };
+
+  window.HLL_FRONTEND_CONFIG = Object.freeze({
+    ...window.HLL_FRONTEND_CONFIG,
+    backendBaseUrl: resolveConfiguredBackendBaseUrl(),
+  });
+})();