Unify

⚠️ Currently in very early stages, likely to change significantly in the future. It is pre-alpha and not been tested by anyone but myself.

A BIP78 over Nostr Payjoin wallet.

Config

• Upon first launch RPC and Nostr credentials are automatically created for you (you can edit them, rpcauth will automatically update).
• Export the rpcauth (from Config) to your bitcoin.conf.
• Select the appropriate rpcport (8332 for mainnet, 18332 testnet, 38332 signet, 18443 regtest).
• Restart your node.
• Select the rpcwallet you'd like to use.
• Add a BIP39 mnemonic (its a hot wallet for now).

Receive

• Granted your node credentials are correct click "Receive".
• An rpc command is sent to your node to automatically generate a new address from the specified rpcwallet or enter any address (BIP84).
• Export the QR/text format of the Payjoin invoice to the sender.
• Once the sender receives your invoice they will add their input and sign the transaction, the signed psbt is then sent to you.
• Once Unify receives the signed psbt from the sender it will display the (mandatory) option to add an input and output in the Receive flow.
• After adding an additional input and output Unify will sign the additional inputs, finalize the psbt, encrypt it and send it back to the Sender via Nostr.
• Once the Sender recieves the "Payjoin proposal" a series of checks is made on the Sender side, the psbt is finalized, a complete raw transaction is created with the option to export or broadcast it.

Send

• Click "Send".
• Scan/paste an invoice.
• Select an input(s) to pay the invoice with or opt for automatic selction.
• Tap "Payjoin this utxo" to pay the invoice with the selected utxo.
• Unify then builds and signs a psbt, encrypts it and sends it to the recipient via nostr.
• The recipient will do its thing and when complete will send the "Payjoin proposal" to the sender.
• Upon recipt of the "Payjoin proposal" the UI will update and carry out a series of checks on the psbt to ensure we are not being duped into signing a transaction we shouldn't be.
• If all checks pass you will see the raw transaction in hex format with an export or broadcast button enabled.
• Tap broadcast to send the transaction.

Limitations

• Native segwit inputs and outputs only.
• Must have a BIP39 signer that can sign for your inputs.
• Tor is not currently used for nostr traffic, a VPN is recommended, your messages will not be identifiable as bitcoin transactions to the relay.

Wishlist

• NIP44? (currently utilizes NIP4 for cross compatibility).
• Manual change address selection (currently Bitcoin Core will automatically add a change output if needed).
• A "PSBT" tab, where the user can create a psbt by adding inputs/outputs as they wish or by uploading a PSBT.
• More fine grained settings.
• Support different script types, not just BIP84.
• Silent payments.

TODO

• Watch-only capability, add ability to export each psbt for signing and paste back in.
• Allow sender to add additional inputs/outputs.
• Submit PR to BIP78 nostr addendum to include a txid message when either party broadcasts the transaction.