Methods

The @fairblock/stabletrust SDK exposes two clients:

ConfidentialTransferClient: direct onchain transfers with encrypted amounts (sender address visible). Covered below.
AnonymousTransferClient: relay-routed transfers that also hide the sender’s address. Signatures are listed below; see the Unlinkable Transfers guide for usage.

Amount types. confidentialDeposit takes a BigInt (base units, from ethers.parseUnits). confidentialTransfer and withdraw take a number (cast with Number(ethers.parseUnits(...))).

ConfidentialTransferClient

Manages direct onchain interactions with the confidential transfer contract. Amounts and balances are encrypted with homomorphic encryption; the sender’s wallet address remains visible onchain.

Constructor

new ConfidentialTransferClient(rpcUrl, chainId)
new ConfidentialTransferClient(rpcUrl, contractAddress, chainId) // custom deployment

Parameter	Type	Description
`rpcUrl`	`string`	HTTP JSON-RPC endpoint of the network
`contractAddress`	`string`	(optional) Explicit Stabletrust contract address for a custom deployment
`chainId`	`number`	Chain ID. The SDK resolves the contract address from this when not passed explicitly

`ensureAccount(wallet, options?)`

Creates a confidential account onchain (if one doesn’t exist) and waits for finalization. Must be called before any confidential operation.

Returns: { publicKey, privateKey }: derived ElGamal keypair for this wallet.
options.waitForFinalization (default true): wait for the account to be finalized.
options.maxAttempts (default 225): maximum polling attempts.

`getAccountInfo(address)`

Fetches onchain account state: exists, finalized, elgamalPubkey, txId, etc.

`getConfidentialBalance(address, privateKey, tokenAddress)`

Decrypts and returns the available and pending balances.

Returns: { amount, available: { amount, ciphertext }, pending: { amount, ciphertext } }

`confidentialDeposit(wallet, tokenAddress, amount, options?)`

Deposits ERC-20 tokens into the confidential contract. Handles ERC-20 approval automatically. amount is a BigInt in token base units.

Returns: Transaction receipt.

`confidentialTransfer(senderWallet, recipientAddress, tokenAddress, amount, options?)`

Transfers a confidential amount to a recipient. The recipient must have an existing confidential account. amount is a number in token base units.

Returns: Transaction receipt.

`withdraw(wallet, tokenAddress, amount, options?)`

Withdraws from the confidential available balance back to public ERC-20. amount is a number in token base units. A fixed fee may be charged in the fee token at request time. An optional percentage of the withdrawn tokens may also be taken on success, so the wallet can receive less than amount.

Returns: Transaction receipt.

`getFeeToken()`

Returns the fee token address for the current chain (address(0) = native currency).

`getNonAnonymousTransferFee()`

Returns the fixed fee for a direct confidential transfer, in the fee token’s base units.

`getNonAnonymousWithdrawFee()`

Returns the fixed fee for a direct confidential withdraw, in the fee token’s base units.

`getNonAnonymousWithdrawFeePpm()`

Returns the percentage withdraw fee in parts per million (out of 1_000_000). Taken from the withdrawn token on success.

`getPublicBalance(address, tokenAddress)`

Returns the public ERC-20 balance for an address as a BigInt.

AnonymousTransferClient

Routes all operations through the Fairycloak relay, which pays gas (except deposits) and keeps the sender’s wallet address offchain. See the Unlinkable Transfers guide for setup, account-ID rules, and end-to-end examples.

Constructor

new AnonymousTransferClient({ fairycloakUrl, chainId, rpcUrl })

Pass enableNativeFeeToken: true (default false) only when the deployment’s fee token is native ETH; leave it off otherwise.

Accounts & keys

Method	Description
`deriveAnonymousKeys(authWallet, accountId)`	Derives the per-account ElGamal keypair `{ publicKey, privateKey }`
`createAccount(authWallet, accountId, elgamalPublicKey, options?)`	Creates a new anonymous account via the relay. The fee payer funds an initial fee deposit (`options.initialFeeDeposit`, defaults to the contract minimum) that seeds the account’s prepaid balance
`ensureAnonymousAccount(authWallet, accountId, elgamalPublicKey, options?)`	Idempotent create-if-absent; returns `{ accountId, accountInfo, created }`
`updateAuthKeys(authWallet, accountId, { add, remove }, options?)`	Adds/removes authorised signers
`getAnonymousAccountInfo(accountId)`	Onchain state: `exists`, `finalized`, `hasPendingAction`, `txId`, `elgamalPubkey`, `authNonce`
`isAuthorizedSigner(accountId, signerAddress)`	Whether an address is an authorised signer

Balances

Method	Description
`getBalance(accountId, tokenAddress, elGamalPrivateKey)`	Decrypted totals `{ amount, available, pending }`
`getAnonymousBalance(accountId, tokenAddress, elGamalPrivateKey)`	Decrypted balances including raw ciphertexts

Moving funds

Method	Gas paid by	Description
`deposit(authWallet, accountId, tokenAddress, amount, options?)`	User	Deposits tokens into an anonymous account
`transferToPublic(authWallet, accountId, params, options?)`	Relay	Transfers to a public EVM address
`transferToAnonymous(authWallet, senderAccountId, params, options?)`	Relay	Transfers between two anonymous accounts
`applyPending(authWallet, accountId, options?)`	Relay	Moves pending incoming balance into available (call after receiving)
`withdraw(authWallet, accountId, params, options?)`	Relay	Withdraws to a public EVM address. Fixed prepaid fee at request time; optional percentage of withdrawn tokens on success
`generateTransferProof(privateKey, params)`	N/A	Generates a transfer proof for manual-proof mode
`generateWithdrawProof(elGamalPrivateKey, params)`	N/A	Generates a withdraw proof for manual-proof withdraws

Prepaid fees

Create, updateAuthKeys, transfer, applyPending, and withdraw each charge a fixed fee from the account’s prepaid balance when the request is accepted. createAccount seeds that balance with an initial deposit in the fee token. Top it up any time with depositFees. Withdrawals can also take an optional percentage of the withdrawn tokens on success.

Method	Description
`getFeeToken()`	Currently configured fee token address (`address(0)` = native)
`getAnonymousCreateAccountFee()`	Fee charged on account creation, raw units
`getAnonymousMinimumInitialFeeDeposit()`	Minimum initial fee deposit required at creation
`getAnonymousUpdateKeysFee()`	Fee for an `updateAuthKeys` call, raw units
`getAnonymousApplyPendingFee()`	Fee for an `applyPending` call, raw units
`getAnonymousInlineTransferFee()`	Fee for an anonymous transfer, raw units
`getAnonymousInlineWithdrawFee()`	Fixed fee for an anonymous withdraw, raw units
`getAnonymousWithdrawFeePpm()`	Percentage withdraw fee in parts per million (out of `1_000_000`)
`getPrepaidFeeBalance(accountId, token)`	Prepaid fee balance for an account and fee token
`depositFees(authWallet, accountId, amount, options?)`	Tops up the prepaid fee reserve (user pays gas)
`withdrawFees(authWallet, accountId, { token, destination, amount }, options?)`	Withdraws a specific fee token amount
`withdrawAllFees(authWallet, accountId, { destination }, options?)`	Withdraws all prepaid fee balances across all fee tokens

Request tracking

All relay operations return { request_id, tx_hash, status }.

Method	Description
`waitForRequest(request_id)`	Polls until a terminal state (completed / confirmed / failed)
`getRequestStatus(request_id)`	Current status of a request
`getRequestEvents(request_id)`	Full event history (useful for reconnect/recovery)

Get Started

Confidential Assets and Transfers

Protected Execution

API Reference

Resources

ConfidentialTransferClient

Constructor

`ensureAccount(wallet, options?)`

`getAccountInfo(address)`

`getConfidentialBalance(address, privateKey, tokenAddress)`

`confidentialDeposit(wallet, tokenAddress, amount, options?)`

`confidentialTransfer(senderWallet, recipientAddress, tokenAddress, amount, options?)`

`withdraw(wallet, tokenAddress, amount, options?)`

`getFeeToken()`

`getNonAnonymousTransferFee()`

`getNonAnonymousWithdrawFee()`

`getNonAnonymousWithdrawFeePpm()`

`getPublicBalance(address, tokenAddress)`

AnonymousTransferClient

Constructor

Accounts & keys

Balances

Moving funds

Prepaid fees

Request tracking

​ConfidentialTransferClient

​Constructor

​ensureAccount(wallet, options?)

​getAccountInfo(address)

​getConfidentialBalance(address, privateKey, tokenAddress)

​confidentialDeposit(wallet, tokenAddress, amount, options?)

​confidentialTransfer(senderWallet, recipientAddress, tokenAddress, amount, options?)

​withdraw(wallet, tokenAddress, amount, options?)

​getFeeToken()

​getNonAnonymousTransferFee()

​getNonAnonymousWithdrawFee()

​getNonAnonymousWithdrawFeePpm()

​getPublicBalance(address, tokenAddress)

​AnonymousTransferClient

​Constructor

​Accounts & keys

​Balances

​Moving funds

​Prepaid fees

​Request tracking

ConfidentialTransferClient

Constructor

`ensureAccount(wallet, options?)`

`getAccountInfo(address)`

`getConfidentialBalance(address, privateKey, tokenAddress)`

`confidentialDeposit(wallet, tokenAddress, amount, options?)`

`confidentialTransfer(senderWallet, recipientAddress, tokenAddress, amount, options?)`

`withdraw(wallet, tokenAddress, amount, options?)`

`getFeeToken()`

`getNonAnonymousTransferFee()`

`getNonAnonymousWithdrawFee()`

`getNonAnonymousWithdrawFeePpm()`

`getPublicBalance(address, tokenAddress)`

AnonymousTransferClient

Constructor

Accounts & keys

Balances

Moving funds

Prepaid fees

Request tracking