Common Types

The types used within the different library methods

Transaction Type

enum TxType {
  • TxType.Deposit: the deposit via token approval

The type TxType.Deposit is supported but isn't in active use because it requires an extra approve transaction from the user. Use TxType.BridgeDeposit instead.

  • TxType.Transfer: move tokens inside a pool to the destination zk-addresses

  • TxType.Withdraw: withdrawal tokens from the pool to the destination 0x-address

  • TxType.BridgeDeposit: deposit tokens to the privacy pool via permit scheme (the primary type for deposit tx)

Relayer Raw Fee

interface RelayerFee {
    fee: {
        permittableDeposit: bigint;
        transfer: bigint;
        withdrawal: bigint;
        deposit: bigint;
    oneByteFee: bigint;
    nativeConvertFee: bigint;


  • fee - base cost of the transaction execution depending on the transaction type.

In most cases of deposit fee.permittableDeposit is used instead of fee.deposit (because the 2nd one belongs to the deposits via approve which is not currently used on the deployed pools)

  • oneByteFee - calldata byte cost (may be zero depended on relayer configuration).

  • nativeConvertFee - additional cost needed to swap withdrawn tokens to native coins (only for the withdrawal transactions).

Fee Amount Required for Request

interface FeeAmount {
  total: bigint;
  txCnt: number;
  calldataTotalLength: number;
  relayerFee: RelayerFee;
  insufficientFunds: boolean;


  • total - absolute fee value needed to process request (in pool dimension)

  • txCnt - number of transactions needed to process request

  • calldataTotalLength - number of calldata bytes occupied by all transactions

  • relayerFee - RelayerFee which was used for fee estimation

  • insufficientFunds - true when the local balance is insufficient for requested tx amount

Pool Limits

interface Limit {
    total: bigint;
    available: bigint;

interface PoolLimits {
    deposit: {
        total: bigint;
        components: {
            singleOperation: bigint;
            dailyForAddress: Limit;
            dailyForAll: Limit;
            poolLimit: Limit;
    withdraw: {
        total: bigint;
        components: {
            dailyForAll: Limit;
    dd: {
        total: bigint;
        components: {
            singleOperation: bigint;
            dailyForAddress: Limit;
    tier: number;


  • Limit - is an abstract limit with total and available tokens in the pool dimension

  • PoolLimits.deposit - limits for deposit from the specified address

    • total - total available to deposit from specified address right now

    • components.singleOperation - maximum deposit amount in the single tx

    • components.dailyForAddress - deposit limit for the specified address during that day

    • components.dailyForAll - deposit limit for any address during that day

    • components.poolLimit - TVL limit

  • PoolLimits.withdraw - limits for withdrawal transaction

    • total - total available to withdraw right now

    • components.dailyForAll - withdraw limit for any address during that day

  • PoolLimits.dd - limits for direct deposit transaction

    • total - total available to direct deposit right now

    • components.singleOperation - maximum direct deposit amount in the single tx

    • components.dailyForAddress - direct deposit limit for the specified address during that day

  • tier - provided address tier (the higher tier - the higher limits), default 0

Prover Mode

enum ProverMode {
  • Local - use local prover (most secure)

  • Delegated - use external proving machine (aka Delegated Prover)

  • DelegatedWithFallback - work primarily in Delegated mode; switch to Local is Delegated is unavailable

Tree State

interface TreeState {
    root: bigint;
    index: bigint;


  • root - Merkle root value (assuming all leaves placed at indices greater than or equal to index should be zeroed)

  • index - the index in Merkle tree where the next transaction will be placed


const exampleState: TreeState = {
    root: 20259123668790783065614334268308370728058669663334716067122266810210516357394n,
    index: 533760n

Gift-Card Properties

class GiftCardProperties {
    sk: Uint8Array;
    birthIndex: number;
    balance: bigint;
    poolAlias: string;


  • sk - spending key (keep it in secret: everybody who know the key is able to use the gift-card's funds)

  • birthIndex - index in Merkle tree where gift-card was created. It's needed to speed-up card redeeming process

  • balance - preassigned card balance in pool dimension (it's not an actual balance, just a label for smooth UI)

  • poolAlias - the card destination privacy pool name (it should be defined in client configuration)

Service Version

It's a common interface to keep external service version information. Currently external service include relayer and delegated prover

interface ServiceVersion {
  ref: string;
  commitHash: string;


  • ref - short version string (e.g. 3.1.0)

  • commitHash - corresponded commit hash in version control system (e.g. 4535bc9592057706614d62889713be2ba9555838)

History Record

A single history record always describes a single transaction to the pool.

enum HistoryTransactionType {
  Deposit = 1,

enum HistoryRecordState {
  Pending = 1,

interface TokensMoving {
  from: string,
  to: string,
  amount: bigint,
  isLoopback: boolean,
  ddFee?: bigint,

class HistoryRecord {
    type: HistoryTransactionType,
    timestamp: number,
    actions: TokensMoving[],
    fee: bigint,
    txHash: string,
    state: HistoryRecordState,
    failureReason?: string,
    extraInfo?: any,


  • HistoryTransactionType describes all possible transaction types

  • HistoryRecordState describes the transaction state. Pending state means tx was sent to the relayer but not mined on the pool contract yet. The transaction in HistoryRecordState.Mined state is a finalized one. HistoryRecordState.RejectedByRelayer and HistoryRecordState.RejectedByPool reflect transactions which wasn't completed

  • TokensMoving is an universal interface describing tokens amount and direction. A single history record may contain a few TokensMoving objects

    • TokensMoving.from and contain origin and destination addresses of the funds transferring. There are no strict restrictions for these fields. E.g. field may contain 0x address for the withdrawal transaction as well as shielded address for the outgoing transfers inside a privacy pool. Due to privacy transactions nature one of these fields are always void string

    • TokensMoving.amount is a token transferring value in the pool dimension

    • TokensMoving.isLoopback is applicable for the outgoing transfers only. This field contain true in case of transferring funds to the own account

    • TokensMoving.ddFee is an optional field which exists only for direct-deposit associated transactions and contains a direct deposit fee amount

  • HistoryRecord.type is one of the HistoryTransactionType enum members

  • HistoryRecord.timestamp is an associated transaction time (in seconds since Jan 01 1970)

  • HistoryRecord.actions is a set of token moves (e.g. a multitransfer transaction may contain several destination addresses)

  • HistoryRecord.fee is a transaction cost (relayer's reward) in pool token dimension. The incoming transfers always have zero in this field

  • HistoryRecord.txHash is an associated transaction hash (to the pool smart contract)

  • HistoryRecord.state is a transaction state (an HistoryRecordState member)

  • HistoryRecord.failureReason is an optional string field which contain a problem description in case the history record is in a rejected state

  • HistoryRecord.extraInfo is an optional field of any type which may contain transaction related info. For example, direct deposits made with the payment link may contain the following object in that field:

interface DDPaymentInfo {
  note: string | null;
  sender: string;
  token: string;

Compliance History Record

The compliance history record provides additional details than the regular history record. It contains fields needed to provide evidence of historical ownership. Anyone can provide a regular history to the 3rd parties. But only the compliance-based history proves the records are unmodified and that all of them belong to the concrete account.

class ComplianceHistoryRecord extends HistoryRecord {
  public index: number;
  public nullifier?: Uint8Array;
  public nextNullifier?: Uint8Array;
  public encChunks: { data: Uint8Array, index: number }[];
  public ecdhKeys:  { key: Uint8Array, index: number }[];
  public acc?: Account;
  public notes:  { note: Note, index: number }[];
  public inputs?: {
    account: {index: number, account: Account},
    intermediateNullifier: string,
    notes: {index: number, note: Note}[],


  • index - the transaction index in the Merkle tree (the first leaf index)

  • nullifier - transaction nullifier needed to chain the transaction sequence (undefined for incoming transfers)

  • nextNullifier - the nullifier based on the transaction output account (will be used in the next transaction)

  • encChunks - encrypted elements (a chunk corresponds to encrypted account or note)

  • ecdhKeys - keys to decrypting chunks at the corresponding indexes

  • acc - decrypted output account (undefined for incoming transfers)

  • notes - a set of decrypted notes

  • inputs - transaction inputs (undefined for incoming txs)

    • account - decrypted input account (the first transaction has always zero account in that field)

    • intermediateNullifier - a nullifier pre-image, may be safely disclosed to 3rd parties without sharing intermediate key η\eta. Used to calculate nullifier in conjunction with input account.

    • notes - set of decrypted input notes which were aggregated to the account balance

Shielded Address Components

The shielded address decomposition on the low-level components (see shielded address structure for details)

interface IAddressComponents {
    format: string;
    d: string;
    p_d: string;
    checksum: Uint8Array;
    pool_id: string;
    derived_from_our_sk: boolean;
    is_pool_valid: boolean;


  • format is one of the following values:

    • 'old' - prefix-less address format, deprecated

    • 'pool' - pool-specific address which should be used on the concrete privacy pool

    • 'generic' - universal address which may be used on any pool

  • d - address diversifier (a random number, decimal string)

  • p_d - diversifier public part (derived from the diversifier and account intermediate key η\eta, decimal string)

  • checksum - 4 bytes to verify address correctness

  • pool_id - the pool ID in string representation which the address belongs to ('any' for generic addresses)

  • derived_from_our_sk - indicating is it own address

  • is_pool_valid - indicating is the address can be used on the current pool

Signature Request

The signature can be requested from the user during depositing funds into the shielded pool. The following interface describes request details. There are two signature types which can be requested depends on the deposit scheme (deposit scheme defined in the pool configuration)

enum SignatureType {
    PersonalSign, // signature for deposit-via approve
    TypedDataV4,  // permit deposit scheme

interface SignatureRequest {
    type: SignatureType,
    data: any,  // an string for personal sign, object for typed signatures


  • format is one of the following values:

    • 'old' - prefix-less address format, deprecated

    • 'pool' - pool-specific address which should be used on the concrete privacy pool

    • 'generic' - universal address which may be used on any pool

  • d - address diversifier (a random number, decimal string)

  • p_d - diversifier public part (derived from the diversifier and account intermediate key η\eta, decimal string)

  • checksum - 4 bytes to verify address correctness

Transfer Request

The following object is used to describe transfers inside a privacy pool or withdrawal directional in some cases

interface TransferRequest {
  destination: string;
  amountGwei: bigint;


  • destination is an address of funds receiver (shielded or 0x)

  • amountGwei - token amount in pool dimension

Transfer Config

The following object describes configuration of the single transfer/withdrawal transaction to the privacy pool

interface TransferConfig {
  inNotesBalance: bigint;
  outNotes: TransferRequest[];
  calldataLength: number;
  fee: bigint;
  accountLimit: bigint;


  • inNotesBalance is a sum of input note values which will be aggregated on the account when transaction processed

  • outNotes - set of transfer requests processed with the transaction

  • calldataLength - transaction's calldata bytes count

  • fee - absolute transaction fee (in pool dimension)

  • accountLimit - minimum account remainder after transaction (not in use currently, always 0n)

Direct Deposit Type

enum DirectDepositType {
  • Token - sending token to the pool

  • Native - sending native coins to the pool (available only for pools which are serve the native wrapped token like WETH)

DirectDepositType.Native is only available for pools which are serve the native wrapped token like WETH. Such pools must have isNative = true in the theClient Configuration

Direct Deposit

The following object describes direct deposit transaction in the different states

enum DirectDepositState {
    Queued,    // was sent to the DD queue contract
    Deposited, // was included in the privacy pool's state
    Refunded,  // was returned to the fallback address

interface DirectDeposit {
    id: bigint;
    state: DirectDepositState;
    amount: bigint;
    destination: string;
    fallback: string;
    timestamp: number;
    queueTxHash: string;


  • id unique DD identifier

  • state - Queued/Deposited/Refuded

  • amount - DD value (in pool dimension, without fee)

  • destination - zk-address in the privacy pool to be deposited

  • fallback - 0x address to refund DD in case of it wasn't processed in time

  • timestamp - when it got into the current state

  • queueTxHash - initial transaction hash

Ephemeral Address

Ephemeral addresses are used in the external deposit scheme. This is an EOA with the key management inside the library

interface EphemeralAddress {
    index: number;
    address: string;
    tokenBalance: bigint;
    nativeBalance: bigint;
    permitNonce: number;
    nativeNonce: number;


  • index - index of address inside a pool (last HD path component)

  • address - 0x native address

  • tokenBalance - token balance in pool dimension (meaning the token on which the pool operates)

  • nativeBalance - native address balance in wei

  • permitNonce - number of executed permit allowances (token transfers)

  • nativeNonce - number of outgoing native transactions

Synchronization Statistic

interface SyncStat {
  txCount: number;
  cdnTxCnt: number;
  decryptedLeafs: number;
  fullSync: boolean;
  totalTime: number;
  timePerTx: number;


  • txCount - total transactions fetched (relayer + CDN)

  • cdnTxCnt - number of transactions fetched in binary format from CDN (cold storage)

  • decryptedLeafs - number of loaded leafs in the Merkle tree (deposit/withdrawal = 1 leaf, transfer = 1 + notes_cnt leafs)

  • fullSync - true in case of bulding full Merkle tree on the client

  • totalTime - syncing time in milliseconds

  • timePerTx - average time per transaction in milliseconds

Client Library State Callback

The callback is used to notify the application that the internal state has been updated. There are regular and continuous states. The second one has a progress property (a number from 0 to 1).

type ClientStateCallback = (state: ClientState, progress?: number) => void;

enum ClientState {
  // the following routines belongs to the full mode only
  StateUpdating,           // fast sync
  StateUpdatingContinuous, // sync which takes longer than threshold

The following client library states distinguished:

  • Initializing - the state during the client instantiation. This state is short-term. After client initialization the state sets to AccountlessMode

  • AccountlessMode - the client library is ready to operate but no account was attached. Limited functionality is available in that state (see Account-less Mode Operations)

  • SwitchingPool - the client switches current privacy pool. Most routines are unavailable during this state

  • AttachingAccount - the user account is initializing. This state also appears on pool switching when the client operates in full mode (if account was already attached to another pool it should be reattached to the new one)

  • FullMode - Regular state: client and account are ready to operate. All routines are available

  • StateUpdating \ StateUpdatingContinuous- the client is syncing the user account state with the pool. The continuous state using in case of state sync take over threshold (1 sec currently)

  • HistoryUpdating - the history synchronization. Additional activities are needed to produce history records from the local state so it may take some time.

Forced Exit State

Forced exit is an optional pool contract feature for emergency withdraw of user funds if the relayer is unavailable.

enum ForcedExitState {


  • NotStarted - the regular account state: forced exit was not initiated

  • CommittedWaitingSlot - forced exit was committed (the first stage) but the exit window isn't opened yet (and you cannot send the execute transaction)

  • CommittedReady - the first stage (commit) was performed and exit window is available, so you are able to execute your committed forced exit now

  • Completed - the forced exit was executed and the account was destroyed

  • Outdated - forced exit was committed but the exit window has passed. You cannot execute a forced exit but you can cancel it and create a new one.

Committed Forced Exit

The committed forced exit retrieved from the pool contract

interface CommittedForcedExit {
  nullifier: bigint;
  to: string;
  operator: string;
  amount: bigint;
  exitStart: number;
  exitEnd: number;
  txHash: string;


  • nullifier - the last account nullifier which was marked for forced exit

  • to - an address to withdraw funds

  • operator - address who allowed to execute forced exit (no execution limitations in case of operator equals zero address)

  • amount - value to withdraw (in pool dimension)

  • exitStart - timestamp when exit window opened (in seconds)

  • exitEnd - timestamp when exit window closed (in seconds)

  • txHash - commit transaction hash

Finalized Forced Exit

The executed or cancelled forced exit retrieved from the pool contract

interface FinalizedForcedExit {
  nullifier: bigint;
  to: string;
  amount: bigint;
  cancelled: boolean;
  txHash: string;


  • nullifier - the last account nullifier associated with the forced exit

  • to - an address to withdraw funds

  • amount - value to withdraw (in pool dimension)

  • cancelled - false for successful forced exit, true for canceled one

  • txHash - execute transaction hash

Transaction to be Send

The following interface describes the transaction request which should be sent by the superior user or application. It can be approve or direct deposit transaction. For example:

interface PreparedTransaction {
    to: string;
    amount: bigint;
    data: string;
    selector?: string;


  • to - transaction destination address

  • amount - amount of native coins to be sent with transaction

  • data - prepared raw transaction data (depends on underlying blockchain)

  • selector - an optional field which can be used on some chains (e.g. Tron) where selector is separated from transaction data (for EVM networks selector is included in data field so that field remains undefined)

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