PublicDataProvider
For the complete documentation index, see llms.txt
Midnight.js API Reference v4.0.4
Midnight.js API Reference / @midnight-ntwrk/midnight-js-types / PublicDataProvider
Interface: PublicDataProvider
Interface for a public data service. This service retrieves public data from the blockchain. TODO: Add timeouts or retry limits to 'watchFor' queries.
Methods
contractStateObservable()
contractStateObservable(
address,config):Observable<ContractState>
Creates a stream of contract states. The observable emits a value every time a state is either created or updated at the given address. Waits indefinitely for matching data to appear.
Parameters
address
string
The address of the contract of interest.
config
The configuration for the observable.
Returns
Observable<ContractState>
queryContractState()
queryContractState(
contractAddress,config?):Promise<ContractState|null>
Retrieves the on-chain state of a contract. If no block hash or block height are provided, the contract state at the address in the latest block is returned. Immediately returns null if no matching data is found.
Parameters
contractAddress
string
The address of the contract of interest.
config?
BlockHeightConfig | BlockHashConfig
The configuration of the query.
If undefined returns the latest states.
Returns
Promise<ContractState | null>
queryDeployContractState()
queryDeployContractState(
contractAddress):Promise<ContractState|null>
Retrieves the contract state included in the deployment of the contract at the given contract address. Immediately returns null if no matching data is found.
Parameters
contractAddress
string
The address of the contract of interest.
Returns
Promise<ContractState | null>
queryUnshieldedBalances()
queryUnshieldedBalances(
contractAddress,config?):Promise<UnshieldedBalances|null>
Retrieves the unshielded balances associated with a specific contract address.
Parameters
contractAddress
string
The address of the contract of interest.
config?
BlockHeightConfig | BlockHashConfig
The configuration of the query.
If undefined returns the latest states.
Returns
Promise<UnshieldedBalances | null>
queryZSwapAndContractState()
queryZSwapAndContractState(
contractAddress,config?):Promise<[ZswapChainState,ContractState,LedgerParameters] |null>
Retrieves the zswap chain state (token balances), the contract state of the contract at the given address, and the ledger parameters in effect on the associated block. Both states are retrieved in a single query to ensure consistency between the two. Immediately returns null if no matching data is found.
Parameters
contractAddress
string
The address of the contract of interest.
config?
BlockHeightConfig | BlockHashConfig
The configuration of the query.
If undefined returns the latest states.
Returns
Promise<[ZswapChainState, ContractState, LedgerParameters] | null>
unshieldedBalancesObservable()
unshieldedBalancesObservable(
address,config):Observable<UnshieldedBalances>
Retrieves an observable that tracks the unshielded balances for a specific contract address.
Parameters
address
string
The contract address for which unshielded balances are being observed.
config
The configuration object for observing contract state changes.
Returns
Observable<UnshieldedBalances>
An observable that emits the unshielded balances for the provided address.
watchForContractState()
watchForContractState(
contractAddress):Promise<ContractState>
Retrieves the contract state of the contract with the given address. Waits indefinitely for matching data to appear.
Parameters
contractAddress
string
The address of the contract of interest.
Returns
Promise<ContractState>
watchForDeployTxData()
watchForDeployTxData(
contractAddress):Promise<FinalizedTxData>
Retrieves data of the deployment transaction for the contract at the given contract address.
IMPORTANT: This method waits indefinitely until the deployment transaction appears on the blockchain. It will never timeout or reject unless an error occurs.
Custom implementations MUST maintain this indefinite waiting behavior to ensure consistency across all PublicDataProvider implementations. Do not implement timeouts in this method.
Parameters
contractAddress
string
The address of the contract of interest.
Returns
Promise<FinalizedTxData>
A promise that resolves with finalized transaction data when the deployment appears on-chain. The promise never rejects due to timeout.
watchForTxData()
watchForTxData(
txId):Promise<FinalizedTxData>
Retrieves data of the transaction containing the call or deployment with the given identifier.
IMPORTANT: This method waits indefinitely until the transaction appears on the blockchain. It will never timeout or reject unless an error occurs.
Custom implementations MUST maintain this indefinite waiting behavior to ensure consistency across all PublicDataProvider implementations. Do not implement timeouts in this method.
Applications using this method should be aware that:
- The promise will not resolve until the transaction appears on-chain
- If a transaction is invalid and never appears, this will never return
- Consider using application-level timeouts or cancellation mechanisms if needed
Parameters
txId
string
The identifier of the call or deployment of interest.
Returns
Promise<FinalizedTxData>
A promise that resolves with finalized transaction data when the transaction appears on-chain. The promise never rejects due to timeout.
watchForUnshieldedBalances()
watchForUnshieldedBalances(
contractAddress):Promise<UnshieldedBalances>
Monitors for any unshielded balances associated with a specific contract address.
Parameters
contractAddress
string
The address of the contract to monitor for unshielded balances.
Returns
Promise<UnshieldedBalances>
A promise that resolves to the detected unshielded balances.