Reading a mint's confidential transfers as its auditor

A Token-2022 mint with confidential transfers can name an auditor: an ElGamal public key in the mint's configuration. Every confidential transfer of that mint then carries its amount encrypted three times, for the sender, for the recipient and for the auditor, and Token-2022 refuses a transfer whose auditor copy does not check out. The auditor can read every amount; it cannot move anyone's tokens.

Since 3.3.0 the SDK turns that into a report: every deposit, confidential transfer and withdraw of a mint, with the transferred amounts decrypted, as data or as CSV.

The auditor key

The auditor's ElGamal key comes from a Solana wallet the auditor holds, the same way account keys come from their owners' wallets, so it never has to be stored:

import { deriveAuditorElgamalKeypair, getAuditorElgamalPubkey } from "@softseco/arcantis";

const auditorKeypair = await deriveAuditorElgamalKeypair(auditorWallet);
const auditorElgamalPubkey = getAuditorElgamalPubkey(auditorKeypair); // goes into the mint's config
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The mint's issuer puts auditorElgamalPubkey in the mint's confidential-transfer configuration when creating it. transfer() reads it from the mint and encrypts every amount to it.

Use a wallet that does nothing but audit. The auditor key comes from the same signature a wallet gives any site that reads its confidential balances, so a site the auditor's wallet signs that message for gets the key to every amount on every mint naming that auditor. Keep the wallet on its own device or hardware key, and connect it to nothing else.

The report

import { listConfidentialActivity, confidentialActivityToCsv } from "@softseco/arcantis";

const activity = await listConfidentialActivity({ rpc, mint, auditorKeypair });
// [{ kind: "transfer", fromOwner, toOwner, amount: 300n, decrypted: true, signature, blockTime, ... }, ...]

const csv = confidentialActivityToCsv(activity, { decimals: 6 });
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Each entry has the transaction signature, slot and time, the kind (deposit, transfer, withdraw), the token accounts on both sides and their owners, and the amount in base units. Deposits and withdraws have their amounts in the clear on chain; transfers are decrypted with the auditor key (decrypted: true). Entries are oldest first.

Options: since and until (dates) for a period, maxTransactions to read only the latest part of the history, concurrency to go easier on a rate-limited RPC.

Without writing code

npx @softseco/arcantis audit-report \
  --mint <mint address> --keypair auditor-wallet.json --rpc https://your-endpoint \
  --since 2026-10-01 --until 2026-11-01 --out october.csv
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--keypair is the auditor's Solana wallet file, the JSON array the Solana CLI writes. The CSV has one row per entry, with the amount both in base units and in tokens.

For records you keep, or hand to another system, --format json (or an --out name ending in .json) writes the same entries as a JSON report that names its format and version ("format": "arcantis.confidential-activity", "version": 1), with the mint, the auditor key and the time it was made. parseConfidentialActivityJson reads it back, and later releases keep reading this version; docs/formats.md describes it field by field.

What it does not cover yet

• Transfers on mints with a transfer fee (ConfidentialTransferWithFee) are listed, without the amount.
• Confidential mint and burn (the ConfidentialMintBurn extension) are not listed.
• A changed auditor key. The report checks that the key is the mint's current auditor key. For a mint whose key was changed, pass skipAuditorKeyCheck: transfers encrypted to the old key are then listed without an amount, with a note.
• Balances. The report lists movements, not balances. With the full history, an account's confidential balance is its deposits and incoming transfers minus its outgoing transfers and withdraws.

The report reads the mint's history through getSignaturesForAddress and getTransaction, so it needs an RPC that keeps that history for the period you ask for.