PSBT Offline Signing

A transfer in AENET Wallet is an intent, not a signed transaction. The wallet

prepares an unsigned PSBT, sends it across the signing boundary, and the

external hardware signer produces the signature.

TRANSFER INTENT
    ↓  fee quote · treasury approval · UTXO reservation
UNSIGNED PSBT
    ↓  signing boundary
EXTERNAL HARDWARE SIGNER
    ↓  physical confirmation
SIGNED PSBT
    ↓  intent validation
BROADCAST

Why PSBT

PSBT (Partially Signed Bitcoin Transaction) is a standardized format for

moving a transaction between parties that each contribute signatures. It lets

AENET Wallet prepare intents in the online domain and sign them entirely on

the external device.

The intent lifecycle

Every transfer is identified by a Transfer Code (txr_…) — a public

identifier for the intent, never a signed transaction. Intents pass treasury

policy review, receive a Bitcoin Network Fee quote, reserve UTXOs, and only

then cross the signing boundary.

Boundary guarantee

The online wallet domain produces unsigned PSBTs and validates signed results.

It never signs. The public snapshot never contains signed or unsigned PSBT

bytes, UTXOs, private keys or signer identifiers.

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