Error: Expo: Android Grid sign-in fails (crypto.getRandomValues / network)

[lopeselio]

Summary

I have been running mallory locally on web, but when i tried loggin in using the same OAuth account on expo, i encountered the following

• On a fresh Android build, the onboarding flow crashes when it tries to create a conversation because uuidv4() calls crypto.getRandomValues, which doesn’t exist on React Native by default.
• After that, the Grid auto-init repeatedly throws TypeError: Network request failed because the client hits http://localhost:3001, which is unreachable from the emulator.

Steps to Reproduce

1. Clone the repo, bun install.
2. Start the backend (bun run server) or leave it stopped to see both failures.
3. In another terminal: cd apps/client && bun run android.
4. In the Android emulator (Pixel 9 Pro XL), sign in with Google. Android Studio must be installed
5. Wait for the onboarding conversation and Grid auto-init to fire.

Actual Result

• Client logs show:

  ERROR ❌ CRITICAL ERROR creating new conversation: [Error: crypto.getRandomValues() not supported. See https://github.com/uuidjs/uuid#getrandomvalues-not-supported]
  

• Even after polyfilling manually, Grid sign-in logs:

  ERROR ❌ [Grid Client] Sign-in start error: [TypeError: Network request failed]
  

  because the request targets http://localhost:3001as set in the client .env file

Expected Result

• The onboarding conversation is created (no UUID crash).
• Grid auto-init reaches the backend, triggering the OTP flow instead of a network error.

Environment

• macOS 15.0 (Darwin 25.0.0)
• Node.js v23.10.0
• Bun v1.3.2
• Expo CLI (via bun run android)
• Emulator: Android Pixel 9 Pro XL, Android 14 (API 34)
• Backend: Mallory server from this repo (bun run server)

Relevant Logs / Notes

ERROR ❌ CRITICAL ERROR creating new conversation: [Error: crypto.getRandomValues() not supported. See https://github.com/uuidjs/uuid#getrandomvalues-not-supported]
...
ERROR ❌ [Grid Client] Sign-in start error: [TypeError: Network request failed]

Running curl http://localhost:3001/health on the Mac succeeds, but inside the emulator you must use http://10.0.2.2:3001/health. Here 10.0.2.2 is Android’s alias for your computer

Suggested fixes:

I have made slight changes to my apps/client/polyfills.js and apps/client/lib/config.ts to solve the issue highlighted here. Fixes include:

• apps/client/polyfills.js
  Added react-native-get-random-values (with an expo-random fallback) whenever Platform.OS !== 'web'. This polyfills crypto.getRandomValues so uuidv4() works on Android.
• apps/client/lib/config.ts
  Added a platform-aware helper: if the backend URL contains localhost/127.0.0.1 and we’re on Android, rewrite it to 10.0.2.2 so the emulator hits the host machine.

Next steps:

• I will bite off a PR if other developers are also facing the same issue.

[edgarpavlovsky]

got it - good catch. it feels like the problem is conceptually simple: we don't have a good solution for uuidv4().

can we just use expo-crypto?

import * as Crypto from 'expo-crypto';

const id = Crypto.randomUUID();

should solve this for us out of the box

[lopeselio]

@edgarpavlovsky i have submitted a PR to fix errors faced in this issue and few other react native issues faced on android with improved error handling