1. Connect your everyday wallet
Bunker discovers Solana Wallet Standard wallets such as Phantom, Solflare, and Backpack. Connecting reads your public account; it does not grant permission to move assets. The public mainnet app currently stops at read-only balances.
2. Create a separate authorization key
In the isolated test build, the browser generates independent random one-time key material using its cryptographic random-number generator. It is not derived from your Solana wallet. An encrypted recovery file contains the vault identity, current authority, network, and key state.
The file uses Web Crypto AES-256-GCM and PBKDF2-SHA256 with 600,000 iterations, a random 16-byte salt, and a random 12-byte IV. Use a long, unique password and keep it separately. Re-open the file to verify it before creating a vault.
3. Create the vault and deposit
The program derives the vault address from a random identity. The account stores a 32-byte authority commitment and a monotonically increasing nonce. Your wallet pays network fees and rent. SOL goes to this vault; classic SPL tokens go to its associated token accounts.
Creating the vault does not deposit assets automatically. Review the asset, amount, and address in a separate deposit transaction.
4. Withdraw with an exact authorization
The signed message commits to the domain, program, vault, nonce, asset type, mint, exact destination account, amount, and next authorization commitment. A withdrawal moves one asset at a time.
A full signature is 1,088 bytes. To stay within legacy transaction limits without truncating the digest, the app uploads it in two bounded, append-only chunks. A third transaction verifies the complete signature, transfers the asset, and rotates authority atomically. Successful completion also reclaims proof-account rent.
5. Recover an interrupted transfer
The newest pending recovery file includes the exact signed transfer and the next key. Keep it even if your connection drops or your wallet rejects a fee transaction. Restore that file and resume the same transfer. If it already completed, the app recognizes the next on-chain authority and restores it.
Never sign a different message with the old key. Browser history alone is not sufficient protection against stale backups on another device. This limitation is a mandatory part of the external review.
Run and review the implementation
The source bundle includes setup instructions, the canonical wire format, local validator tests, a reviewer checklist, and a deployment configuration. No wallet credentials are shipped. Production mainnet custody remains disabled.
Get the working repository