Cardano Mint and Burn

Tracks all the instances of a mint or burn of set of policy IDs.

If you're looking to track these assets after they've been minted, use the delayed state primitive.

Example

extensions:
  - name: "CARDANO-MINT-BURN"
    type: cardano-mint-burn
    policyIds:
      - "0fc891fb7368d3b7c7b88815c203fda0d6862b0f1d797222672e91fe"
      - "0fc891fb7368d3b7c7b88815c203fda0d6862b0f1d797222672e91ff"
    startSlot: 722300
    stopSlot: 733216
    scheduledPrefix: cmb
    network: CardanoNetworkConfigEntryName

Meaning

• startSlot is required and means that only mints events after that slot (exclusive) will be considered.
• stopSlot is optional, and it stops the indexing at that point.
• policyIds is an array with the collections to index.

Paima Concise format

The scheduled input for each event is of the following form.

cardanoMint = cmb|txId|metadata|assets

It can be parsed with a rule of the form:

const cardanoMint: ParserRecord<CardanoMint> = {
  txId: PaimaParser.NCharsParser(0, 64),
  metadata: PaimaParser.OptionalParser(null, PaimaParser.RegexParser(/[a-f0-9]*/)),
  assets: PaimaParser.Json(),
};

interface AssetAmount {
    policyId: string;
    assetName: string;
    amount: string;
}
export interface CardanoMint {
  txId: string;
  metadata: string | null;
  assets: { [policyId: string]: { [assetName: string]: string } };
  inputAddresses: { [address: string]: AssetAmount[] }
  outputAddresses: { [address: string]: AssetAmount[] }
}

• The metadata field is hex encoded (if any), and it's the metadata in binary form.
• The assets field has the minted or burned assets. The difference between a mint and a burn is in the sign of amount when interpreted as a number.
• The inputAddresses represents addresses who at least partially burned the tracked tokens
• The outputAddresses represents addresses who at least partially minted the tracked tokens

Detecting who minted and who burned

Some key facts about Cardano transactions to help understand how to parse this information:

• Cardano transactions can contain multiple mints & burns of different tokens in the same transaction
• Different addresses can mint/burn tokens in the same transactions (txs have multiple inputs & outputs)
• The same address can mint/burn multiple times in the same transaction (different inputs or different outputs)
• All mints & burns share the same metadata field

A consequence of this is that not all the token supply found in the input may have been burned. In other words, the following transaction is possible:

1. inputAddresses contains 50 token X
2. assets contains -30 token X
3. outputAddresses contains 20 token X