Instance, state & constructors

📝 Draft. This chapter has not been reviewed yet — content may be incomplete or change.

Problem. Deploy a contract once and then act on it repeatedly — persisting the compile params and tracking the live UTXO set across transactions.

🚧 This recipe is a stub. Outline of what it will cover:

• The three-file model in practice: manifest / instance / state.
• Classes: grouping methods under a typed contract with fields.
• Constructors (is_constructor: true) and create_instance: writing the instance file with resolved field values.
• The state file: how covenant outputs are added and spent inputs removed after each broadcast.
• provided_inputs: pre-filling a counterparty's UTXO inline (the website-to-wallet integration pattern).

See Spec.md §12–13 in the meantime.