feat: added runtime env config endpoint

backend/src/server/plugins/serve-ui.ts

@@ -2,7 +2,7 @@ import path from "node:path";
 
 import staticServe from "@fastify/static";
 
-import { IS_PACKAGED } from "@app/lib/config/env";
+import { getConfig, IS_PACKAGED } from "@app/lib/config/env";
 
 // to enabled this u need to set standalone mode to true
 export const registerServeUI = async (
@@ -15,6 +15,26 @@ export const registerServeUI = async (
     dir: string;
   }
 ) => {
+  // use this only for frontend runtime static non-sensitive configuration in standalone mode
+  // that app needs before loading like posthog dsn key
+  // for most of the other usecase use server config
+  server.route({
+    method: "GET",
+    url: "/runtime-ui-env.js",
+    handler: (_req, res) => {
+      const appCfg = getConfig();
+      void res.type("application/javascript");
+      const config = {
+        CAPTCHA_SITE_KEY: appCfg.CAPTCHA_SITE_KEY,
+        POSTHOG_API_KEY: appCfg.POSTHOG_PROJECT_API_KEY,
+        INTERCOM_ID: appCfg.INTERCOM_ID,
+        TELEMETRY_CAPTURING_ENABLED: appCfg.TELEMETRY_ENABLED
+      };
+      const js = `window.__INFISICAL_RUNTIME_ENV__ = Object.freeze(${JSON.stringify(config)});`;
+      void res.send(js);
+    }
+  });
+
   if (standaloneMode) {
     const frontendName = IS_PACKAGED ? "frontend" : "frontend-build";
     const frontendPath = path.join(dir, frontendName);