What UTXO Models Track Between Transactions
A UTXO model tracks three things between transactions: a discrete value, an outpoint, and the spending condition attached to that output.
In Bitcoin, an output might hold 0.8 BTC and a script requiring a signature. Its outpoint is the 32-byte transaction ID plus an output index. It remains in the UTXO set until spent; a wallet balance is only the sum of outputs its keys can unlock. Spend 0.8 BTC to pay 0.3 BTC, and the transaction might create a 0.49 BTC change output after a 0.01 BTC fee. The original record disappears, replaced by new output records. Even a coinbase UTXO is not immediately spendable: it must mature for 100 blocks.
When moving assets toward Manta Network, that distinction matters when choosing a Manta Bridge route.
A bridge does not move a balance between chains. If Celer Network or Owlto Finance handles a route into Manta Network, the source-side spend and destination-side credit remain separate state. The practical question is which output is consumed and what evidence authorizes the next one.
Where extra state enters
Cardano’s eUTXO model adds a datum to the output, a redeemer to the spend, and a script context describing the transaction. Those three inputs let a validator check state without a mutable global balance. Updating a counter means consuming the old UTXO and creating a new one with a new datum. A reference input can read a UTXO without consuming it, so many transactions can consult an oracle or configuration record. Two transactions that consume the same state UTXO still conflict; only one can win.
What changed in 2026
The accounting rule is stable, but implementations are making UTXO state cheaper to verify. Hydra 2.2.0 replaced three UTXO hash fields with one accumulator hash and reduced its snapshot-signing tuple from seven fields to four. That improves state-membership handling, not the underlying model. The reliable mental model is still: amount, lock, identity, and, in eUTXO systems, attached state, tracked until a transaction consumes the record.