MWA integration issues found on Solana Seeker with Seed Vault — Unity MWA Example App

[mstevens843]

Is your feature request related to a problem? Please describe.
While building a Unity MWA example app tested on Solana Seeker with Seed Vault, I had to work around several missing features to achieve parity with the React Native MWA SDK. The SDK works,
but requires significant boilerplate for common MWA flows.

Working example app: https://github.com/mstevens843/unity-solana-mwa-example

1. LoginWalletAdapter() shows a wallet picker UI even when only one MWA adapter is available. Should auto-select.
2. Web3.Instance.Logout() only clears local state. No way to revoke MWA authorization.
3. No built-in auth token cache for MWA sessions. Had to build a custom IMwaAuthCache with PlayerPrefs.
4. GetCapabilities is not exposed in the SDK.
5. WebSocket Error: An exception has occurred during an OnMessage event fires on every MWA handshake. Non-blocking but pollutes logs.
6. No SignMessage(string) overload. Requires manual Encoding.UTF8.GetBytes().
7. No way to access the MWA auth token from LoginWalletAdapter() return value. Account only exposes PublicKey.

Describe the solution you'd like
Auto-select wallet adapter when only one is available (skip picker UI). Expose MWA auth token from LoginWalletAdapter() for external caching. Add built-in extensible auth cache layer (parity
with React Native SDK). Expose GetCapabilities for MWA 2.0. Add SignMessage(string) convenience overload. Suppress or fix WebSocket OnMessage exception during MWA handshake.

Describe alternatives you've considered
I built workarounds for all of these in the example app. Custom IMwaAuthCache interface with PlayerPrefs, manual byte conversion for SignMessage, hardcoded GetCapabilities defaults. These
work but should be in the SDK itself for React Native parity.

Additional context
Solana.Unity-SDK (latest via git), Unity 6000.4.1f1, IL2CPP, Solana Seeker hardware, Seed Vault wallet, Android API 35. All MWA flows confirmed working: authorize, sign message, sign
transaction, sign and send, disconnect, delete account, reconnect with cached auth.

Happy to contribute PRs for any of these.

[JoshhSandhu]

Hey @mstevens843 great writeup, and it's really useful validation that you hit the same gaps independently.

Several of these are already addressed in PR #269 (currently open and awaiting merge):

• Point 2 : Logout() now calls Deauthorize() RPC before clearing local state
• Point 3 : IMwaAuthCache abstraction is tracked in issue feat(MWA): Introduce IMwaAuthCache abstraction for secure auth token storage #271, with PlayerPrefs as the default fallback
• Point 4 : GetCapabilities() is implemented and exposed
• Point 2/reconnect : DisconnectWallet() and ReconnectWallet() lifecycle helpers added with OnWalletDisconnected / OnWalletReconnected events

All of these are tested on Solana Seeker hardware inside a gameplay loop, screen recording attached to the PR.

Points 1, 5, 6, and 7 are not covered by #269 and would make good follow-up issues or PRs. Happy to collaborate if you want to pick any of those up after #269 merges.

[mstevens843]

Hey @JoshhSandhu - appreciate the quick response and the work on #269. Great to see we landed on the same gaps independently.

I've gone ahead and opened PRs for two of the remaining points:

• Point 6: feat(WalletBase): add SignMessage(string) convenience overload - adds a string overload to
  IWalletBase and WalletBase so callers don't need manual Encoding.UTF8.GetBytes(). All derived wallet classes inherit it automatically.

• Point 1: feat(WebGL): auto-select wallet when only one adapter available - skips the picker UI in
  SetCurrentWallet() when Wallets.Length == 1. WebGL-scoped since Android/iOS handle selection natively.

Both are small, focused changes - no conflicts with #269.

For Points 5 and 7, I'll wait for #269 to merge since they touch overlapping files (SolanaMobileWalletAdapter.cs). Happy to open those as follow-ups once it's in.

Let me know if you'd like any changes on the two open PRs.