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15 votes
Accepted

What is a Redeemer?

From https://iohk.io/en/blog/posts/2021/04/13/plutus-what-you-need-to-know/: When validating an address, the script will access the data being carried by the output, the transaction being validated, ...
Matthias Sieber's user avatar
11 votes

What is a Redeemer?

In simple terms, redeemer is the data that the user of the smart contract provides to the smart contract. In the simple UTxO model, redeemer is your signature. By providing your signature, you prove ...
Jelil Akjaly's user avatar
6 votes

What is a Redeemer?

Before (E)UTxO - There Was UTxO Understanding how a UTxO model works (such as BTC) may help you understand the implementation of (E)UTxO in Cardano. The UTxO Model A UTxO model, meaning: unspent ...
Dilworth's user avatar
  • 211
5 votes
Accepted

Plutus datum and redeemer on cardano-cli

Have a look at the following source Cardano-Api Haddock. Here you will find all about the conversion between Haskell data types and the Json format the cardano-cli uses. I noticed that you used the ...
Fermat's user avatar
  • 1,892
3 votes
Accepted

Decoding transaction redeemers to JSON

A hash is the product of a one way function. It is not possible to decode the redeemer hash. The redeemer itself is stored onchain inside the witness set of the transaction, see cddl spec (rfc8610). ...
james's user avatar
  • 1,550
3 votes
Accepted

What is the mkValidator Script

A validator script locks transaction outputs. This function is where you define conditions to unlock them. https://plutus.readthedocs.io/en/latest/tutorials/basic-validators.html
james's user avatar
  • 1,550
3 votes

What is the mkValidator Script

On Cardano logic can be enforced on how UTxO's are spend by attaching a "script" to the transaction + some inputs that will be used to run the script (the datum, redeemer and context). ...
Fermat's user avatar
  • 1,892
3 votes

Plutus datum and redeemer on cardano-cli

{ "constructor": 0, "fields": {int: 42} } This isn't valid because fields must be an array. The index of the constructor and fields will match the order of types defined for the ...
james's user avatar
  • 1,550
3 votes

Is Redeemer similar to <ScriptSig> in bitcoin context?

One way to think of it is that: The Datum is a piece of data that's attached to the UTXO by the producer, The Redeemer is a piece of data that's provided by the consumer, When the UTXO is consumed, ...
insitu's user avatar
  • 224
2 votes

What is where executed and when?

One detail to add here: In short: if another Tx generator wants to use the same script, but one or more blocks later, it will need the datum (previous state of the script), which must be exposed by ...
hsteamroller's user avatar
2 votes

Is it possible to consume a script UTxO in the same block?

If the first output is in the mempool, you can use it in a subsequent transaction without the node throwing an error. However, there is no assurance that both transactions will be part of the same ...
Prashanth S.'s user avatar
2 votes

Meaning of Index of Redeemer in Serialization Lib 10.4

I was digging in this topic because I struggled with some transactions. I was reading the CDLL, the serialization lib, docs, etc.. but I couldn't find anything about the meaning of this index. After ...
Juantxu's user avatar
  • 21
1 vote

Error Applying Redeemer Lucid

You probably already did, but check that you are actually passing the utxos to the tx, and check that the datum is the right one, the datum seems to be hash or its just a bytestring? how does quering ...
Roberto Cerrud's user avatar
1 vote
Accepted

blockfrost.io API, reference inputs and redeemer tx_index

AIUI, when using the blockfrost.io API, the tx_index field in a redeemer contains the index of the enclosing transaction's input that it consumes (is that true ?). The index holds different meaning ...
Sourabh's user avatar
  • 320
1 vote

Can one see Redeemer value on Blockchain?

The redeemer is stored in the transaction, so is visible onchain. CardanoScan.io is one example of a blockchain explorer that displays the redeemer value for transactions that execute a plutus script (...
james's user avatar
  • 1,550
1 vote
Accepted

Script Execution Failure PT8

See here, PT8 means PlutusTx.List.head: empty list Perhaps it's because you're using head on an empty txInfoSignatories. You must use --required-signer or --required-signer-hash flags when building ...
james's user avatar
  • 1,550
1 vote

What is where executed and when?

The blockchain does not only store hashes. It also stores the datum and the script of spent UTxOs. It would otherwise not be possible to validate the transaction in retrospect. So while you don't need ...
Jey's user avatar
  • 1,549
1 vote

Auction example: How does Bob know the redeemer of the UTXO sitting at the script address?

Finding transactions Bob (the person) doesn't have to necessarily know that there's an auction going in the blockchain, but he can launch a transaction and look for UTXOs of this type of contract. If ...
joaquimgamero's user avatar
1 vote

Can all redeemers in a transaction be retrieved at once?

This was Lars response to this question in the ppp Q&A on 25/Jan/22. Recording timestamp 0:43:17 You cant retrieve all redeemers at once, You can only see your own redeemer, You are always in ...
LexTRX's user avatar
  • 343
1 vote

Does the redeemer have to be from a wallet address/contract?

You seem to be misunderstanding how smart contracts work on Cardano. Does the redeemer have to be from a wallet address(?) Redeemers don't come from wallet address, they are included on transactions....
Mitchell Turner's user avatar
1 vote

How does the final transaction in the auction example know who did the bid?

Each change in state in the auction contract passes a new datum (arbitrary data). The auction datum is made up of the 'Auction' and 'Bid' records. The bid record has a 'bBidder' field which is the ...
micahkendall's user avatar
1 vote

Finding the redeemer of another UTxO in a transaction

if I got you right, what you want to do is not possible. The spending transaction sends the reedemer for each UTXO the transaction wants to spend. The spending transaction is created by your offline ...
sbcdn's user avatar
  • 66
1 vote

What is a Redeemer?

There is an interesting example in one of the Pioneer lectures which implements Uniswap on Cardano. A redeemer is not only used to justify that a UTxO can be spent, but also the manner in which it ...
Chrismo's user avatar
  • 524

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