Balance

::: {.module} Cardano.Node.Client.Balance :::

Iterative exact-fee transaction balancing for Conway-era transactions.

balanceTx
    :: PParams ConwayEra
    -> [(TxIn, TxOut ConwayEra)]
    -> Addr
    -> Tx ConwayEra
    -> Either BalanceError (Tx ConwayEra)

Algorithm

1. Collect all input UTxOs and compute total available ADA
2. Start with fee = 0
3. Build candidate transaction with change output
4. Compute exact fee via getMinFeeTx
5. Add 106-byte VKey witness padding using ppMinFeeAL
6. If new fee > current fee, repeat from step 3
7. Converges in at most 10 rounds

Errors

data BalanceError
    = InsufficientFee Coin Coin
    -- ^ required fee, available ADA

Limitations

• ADA-only fee inputs (no multi-asset coin selection)
• Single key witness assumed
• Callers must construct script inputs separately