Transaction v1

L1 Status: ACTIVE CONSENSUS | SilverScript: OFFICIAL RELEASE v1.0.0

Toccata introduces a new transaction serialization format (v1). This is required to support Covenants, ZK Proofs, and precise compute pricing.

The Cryptographic Identity Matrix

A critical mistake when working with Kaspa Covenants is assuming that txid, tx::hash, and the sighash commit to identical data. They do not.

To safely orchestrate transactions, you must understand exactly what each identifier commits to:

Field	Commits to txid?	Commits to tx::hash?	Script-Visible?	Consensus Relevance
Inputs (Outpoints)	Yes	Yes	Yes	UTXO consumption
Outputs (Scripts/Amounts)	Yes	Yes	Yes	UTXO creation
Transaction Version	Yes	Yes	Yes	Schema validation
Lock Time	Yes	Yes	Yes	Time locks
Subnetwork ID	Yes	Yes	Yes	L1/L2 domains
Compute Budget	NO	Yes	NO	Replaces sig_op_count
Payload / Lane Data	NO	Yes	NO	Sequencing & vProgs
Covenant Bindings	Yes	Yes	Yes	Covenant lineage

Why doesn't txid commit to compute_budget?

By excluding compute_budget and the payload from the txid, Kaspa allows nodes (or PSKT coordinators) to adjust the compute budget or attach sequencing data without altering the topological identity of the transaction in the DAG.

If you are tracking an artifact in HardKAS, your artifactId tracks the logical intent, but the network uses the txid.

Output Covenant Bindings

A v1 transaction output can optionally specify a Covenant Binding. This is an index mapping an output to a specific covenant_id (managed by consensus).

• Do not conflate bindings with the covenant ID itself. The binding is merely the transaction-level pointer that says "This output belongs to covenant family X."
• The actual state transition logic is still validated by the Kaspa Script inside the output's scriptPublicKey.

HardKAS Support

HardKAS natively supports building and signing v1 transactions.

Status: IMPLEMENTED / QUALIFIED

• The hardkas tx plan command automatically upgrades to v1 when covenant logic or compute_budget options are detected.
• The HardKAS PSKT adapter (delegating to upstream rusty-kaspa v2.1.0) preserves all v1 metadata, compute budgets, and bindings during offline signing rounds.