Redeemer Tag¶

enum cardano_redeemer_tag_t¶

The redeemer tags act as an enumeration to signify the purpose or context of the redeemer in a transaction.

When a Plutus script is executed, the specific action type related to the redeemer can be identified using these tags, allowing the script to respond appropriately.

Values:

enumerator CARDANO_REDEEMER_TAG_SPEND¶

Indicates the redeemer is associated with a Spending script.

A spending script validates the spending of a UTXO. A UTXO can have either a public key address or a script address. To spend a UTXO with a script address, the script whose hash matches the script address must be included in the transaction (either directly, or as a reference script), and is executed to validate it.

enumerator CARDANO_REDEEMER_TAG_MINT¶

Indicates the redeemer is associated with a Minting script.

Minting scripts, sometimes also referred to as minting policies, are used to approve or reject minting of new assets.

In Cardano, we can uniquely identify an asset by its CurrencySymbol and TokenName. If a transaction attempts to mint some new assets, then for each unique CurrencySymbol in the new assets, the script whose hash matches the CurrencySymbol must be included in the transaction, and is executed to validate the minting of that CurrencySymbol.

enumerator CARDANO_REDEEMER_TAG_CERTIFYING¶

Indicates the redeemer is associated with a Certifying script.

A certifying script can validate a number of certificate-related transactions, such as: (1) registering a staking credential, and in doing so, creating a reward account associated with the staking credential; (2) de-registering a staking credential, and in doing so, terminating the reward account; (3) delegating a staking credential to a particular delegatee.

In all these cases except registration, if the staking credential in question contains a script hash (as opposed to a public key hash), the script with that hash must be included in the transaction, and is executed to validate the action.

enumerator CARDANO_REDEEMER_TAG_REWARD¶

Indicates the redeemer is associated with a Rewarding script.

As previously stated, a UTXO’s address can be either a public key address or a script address. Both kinds of addresses can optionally have a staking credential. A UTXO may contain Ada, and the Ada it contains can be delegated to an SPO to earn staking rewards. Staking rewards are deposited into a reward account corresponding to the staking credential.

A staking credential can contain either a public key hash or a script hash. To withdraw rewards from a reward account corresponding to a staking credential that contains a script hash, the script with that particular hash must be included in the transaction, and is executed to validate the withdrawal.

enumerator CARDANO_REDEEMER_TAG_VOTING¶

Indicates the redeemer is associated with a Voting script.

A voting script validates votes cast by a Delegated Representative (DRep) or a constitutional committee member (CCM) in a transaction. A DRep or a CCM can be associated with a script hash. If a transaction contains one or more votes from a DRep or a constitution committee member associated with a script hash, the script with that hash must be included in the transaction, and is executed to approve or reject the vote.

enumerator CARDANO_REDEEMER_TAG_PROPOSING¶

Indicates the redeemer is associated with a Proposing script.

A proposing script, also known as constitution script or guardrail script, validates two kinds of governance actions: cardano_parameter_change_action_t and cardano_treasury_withdrawals_action_t`.

There is a key distinction between proposing scripts and other kinds of scripts: proposing scripts are not written by regular users. At any given point in time, there is exactly one active proposing script being used by the entire chain. This proposing script must be included in transactions that propose cardano_parameter_change_action_t and cardano_treasury_withdrawals_action_t`. The ledger enforces that no other proposing script is accepted.

The proposing script is updated only when there is a change to the constitution, via the cardano_new_constitution_action_t governance action.

Note

The proposing script decides whether the proposal of a governance action is allowed to go through, rather than whether the governance action will be enacted. After a proposal goes through, it will need to meet the appropriate criteria (such as gathering enough votes from constitution committee members, DReps and/or SPOs) in order to be enacted.