JSON-RPC API
dApps can get account status, send transactions, and call other functions via zkLink API.
The zkLink API follows the JSON-RPC standard and is accessed via POST.
API OVERVIEW
getSupportChains: get the configuration of all supported chains.
getSupportTokens: get the data of all tokens with on-chain contract addresses.
getLatestBlockNumber: get the latest block height info.
getTokenReserve: get the withdrawable limit of a token on a certain L1 chain.
JSON-RPC API METHODS
getSupportChains
Get the configuration of all supported chains.
Parameters
None
ChainResp
Field | Type | Description |
---|---|---|
chainId | uint32 | Defined by zkLink |
chainType | uint8 | Defined by zkLink {0:"EVM", 1:"STARKNET"} |
layerOneChainId | uint32 | The chain ID of L1 blockchains |
mainContract | address(EVM|StarkNet) | The address of zkLink main contract that interacts with the rest module contracts |
layerZeroContract | address(EVM|StarkNet) | The address of layerZero bridge that syncs L1 states |
web3Url | string | The url of L1 RPC |
feeCap | unit | The max transaction fee when L1 RPC send the transaction |
gasTokenId | uint32 | The id of the gas token, defined by zkLink |
validator | address(EVM|StarkNet) | Validator address |
getSupportTokens
Get the data of all tokens with on-chain contract addresses.
Parameters
None
It returns a HashMap<TokenId,TokenResp>
, which has a unique token id and is used for all token-related queries in the RPC service. Symbols are used only for display on the UI and do not promise uniqueness.
TokenResp
Field | Description |
---|---|
id | Token id |
symbol | Token symbol |
usdPrice | Token price |
chains |
|
ChainTokenResp
Field | Description |
---|---|
chainId | Defined by zkLink |
address | The on-chain contract address of the token |
decimals | The decimals of the token on L1 |
fastWithdraw | Whether the token supports fast withdraw |
The decimal is the accuracy of the token on L1, which is not always 18 (6 for USDC and 18 for ZKL), and varies on different chains for the same token (6 for USDC on Ethereum and 18 for USDC on BSC).
When a user deposits to zkLink from connected networks, the front-end needs to calculate the amount required for calling the contract according to the accuracy:
getLatestBlockNumber
Get the latest block height info.
Parameters
None
BlockNumberResp
Field | Description |
---|---|
lastBlockNumber | The block height of the latest batch |
timestamp | The timestamp of the last block |
committed | The block height of the latest block committed to L1 |
verified | The block height of the latest block executed on L1 |
getBlockByNumber
Get the block info by block height.
Parameters
blockNumber
: the block height, and returns the latest block height if nullincludeTx
: whether contains transaction details: returns transaction hash if false. only successful transactions will be included in a block. callgetTransactionByHash
to query the failed transactions.includeUpdate
: whether contains the state change by transactions; valid only whenincludeTx
is true.
BlockResp
Field | Description |
---|---|
number | The block height |
commitment | The commitment of the block, similar to the block hash of Ethereum |
rootHash | The root hash of the state tree |
feeAccountId | The id of the fee account |
blockSize | The maximum chunk number that a block can contain |
opsCompositionNumber | The vk of generating ZKPs |
timestamp | The block timestamp |
transactions | Returns |
BlockTxResp
Field | Description |
---|---|
txHash | The transaction hash |
tx |
|
executedTimestamp | The unix timestamp of transaction execution |
updates |
|
StateUpdateResp
The success of transaction execution will lead to the change of the state tree:
AccountCreate: create a new account in the state tree
AccountChangePubkeyUpdate: change in pubkey and nonce
BalanceUpdate: change in account balance and nonce
OrderUpdate: change in account slot
AccountCreate
Field | Description |
---|---|
type | AccountCreate |
updateId | The position of the update in the block |
accountId | The id of the new account |
address | The account address |
Example:
Transactions that may generate AccountCreate
include:
Deposit
Transfer
AccountChangePubkeyUpdate
Field | Description |
---|---|
type | AccountChangePubkeyUpdate |
updateId | The position of the update in the block |
accountId | The account id |
oldPubkeyHash | The old pubkeyHash |
newPubkeyHash | The new pubkeyHash |
oldNonce | The old nonce |
newNonce | The new nonce |
Example:
only ChangePubKey
will generate AccountChangePubkeyUpdate
BalanceUpdate
Field | Description |
---|---|
type | BalanceUpdate |
updateId | The position of the update in the block |
accountId | The account id |
subAccountId | The id of the sub account |
coinId | Token id |
oldBalance | The balance of the sub account before change |
newBalance | The balance of the sub account after change |
oldNonce | The old nonce |
newNonce | The new nonce |
Example:
All ZkLinkTx
will generate BalanceUpdate
OrderUpdate
Field | Description |
---|---|
type | OrderUpdate |
updateId | The position of the update in the block |
accountId | The account id |
subAccountId | The id of the sub account |
coinId | Token id |
oldTidyOrder | The |
newTidyOrder | The |
TidyOrder
Field | Description |
---|---|
nonce | Slot nonce |
residue | Slot residue |
Example:
Only OrderMatching
will generate OrderUpdate
getPendingBlock
Get info of transactions waiting to be batched.
Parameters
transaction execution time, the timestamp in the return can only be bigger than it.
includeTx
: whether to include transaction details. False: return transaction hash only. Only successful transactions will be batched in the block. CallgetTransactionByHash
to query failed transaction details.includeUpdate
: whether to include the state change by the transaction. Valid only whenincludeTx
is true.
getBlockOnChainByNumber
Get transaction information in a block executed on L1 blockchains. Every block will be submitted to and executed on every L1 chain.
Parameters
chain_id
BlockOnChainResp
Field | Description |
---|---|
committed | Transaction info committed to L1, with type |
verified | Transaction info executed on L1, with type |
OnChainResp
Field | Description |
---|---|
chain_id | The chain id defined by zkLink |
tx_hash | The hash of the transaction on L1 blockchains |
Noted that since blocks are committed to and executed on L1 blockchains in batches, the on-chain data of blocks in the same batch is the same. For example, when blocks [4906, 4910] are in the same batch, their on-chain transaction info is the same.
Commitment and batching are asynchronous. For example, when the current block height is 1000, the committed block height can be 980, and the verified block height can be 950. The API caller should query the on-chain infor by the committed and verified block height via getLatestBlockNumber
. For example, when the latest verified block height is 950, the return of the on-chain block info that is after 950 must be null.
getAccount
Get account info by address or account id.
Parameters
Address|AccountID - Address(20Bytes or 32Bytes) or integer account id.
AccountInfoResp
Field | Description |
---|---|
id | Account id |
address | Account address |
nonce | Account nonce |
pubKeyHash | Account pubKeyHash |
subAccountNonces | Nonce of the subaccount, HashMap<SubAccountId,Nonce> |
pubKeyHash
being 0x0000000000000000000000000000000000000000
means unactivated account.
getAccountBalances
Get the balance info of an account.
Parameters:
accountId
: account idsubAccountId
: optional, the id of the subaccount; null if the query requests the balance of all subaccounts.
getAccountOrderSlots
Get the order slot of an account.
Parameters
accountId
: account idsubAccountId
: optional, the id of the subaccount; null if the query requests the balance of all subaccounts.