createHttpHandler
createHttpHandler(
client
):RequestListener
<typeofIncomingMessage
, typeofServerResponse
>
/**
- Creates a Node.js http handler for handling JSON-RPC requests with Ethereumjs EVM
- Any unimplemented methods will be proxied to the given proxyUrl
- This handler works for any server that supports the Node.js http module
Parameters
• client
• client._tevm: object
& EIP1193Events
& object
& Eip1193RequestProvider
& TevmActionsApi
& object
• client.account: undefined
The Account of the Client.
• client.batch?
Flags for batch settings.
• client.batch.multicall?: boolean
| object
Toggle to enable eth_call
multicall aggregation.
• client.cacheTime: number
Time (in ms) that cached data will remain in memory.
• client.call
Executes a new message call immediately without submitting a transaction to the network.
- Docs: https://viem.sh/docs/actions/public/call
- JSON-RPC Methods:
eth_call
Example
• client.ccipRead?: false
| object
CCIP Read configuration.
• client.chain: undefined
Chain for the client.
• client.createBlockFilter
Creates a Filter to listen for new block hashes that can be used with getFilterChanges
.
- Docs: https://viem.sh/docs/actions/public/createBlockFilter
- JSON-RPC Methods:
eth_newBlockFilter
Example
• client.createContractEventFilter
Creates a Filter to retrieve event logs that can be used with getFilterChanges
or getFilterLogs
.
Example
• client.createEventFilter
Creates a Filter
to listen for new events that can be used with getFilterChanges
.
- Docs: https://viem.sh/docs/actions/public/createEventFilter
- JSON-RPC Methods:
eth_newFilter
Example
• client.createPendingTransactionFilter
Creates a Filter to listen for new pending transaction hashes that can be used with getFilterChanges
.
- Docs: https://viem.sh/docs/actions/public/createPendingTransactionFilter
- JSON-RPC Methods:
eth_newPendingTransactionFilter
Example
• client.estimateContractGas
Estimates the gas required to successfully execute a contract write function call.
Remarks
Internally, uses a Public Client to call the estimateGas
action with ABI-encoded data
.
Example
• client.estimateFeesPerGas
Returns an estimate for the fees per gas for a transaction to be included in the next block.
Example
• client.estimateGas
Estimates the gas necessary to complete a transaction without submitting it to the network.
- Docs: https://viem.sh/docs/actions/public/estimateGas
- JSON-RPC Methods:
eth_estimateGas
Example
• client.estimateMaxPriorityFeePerGas
Returns an estimate for the max priority fee per gas (in wei) for a transaction to be included in the next block.
Example
• client.extend
• client.getBalance
Returns the balance of an address in wei.
- Docs: https://viem.sh/docs/actions/public/getBalance
- JSON-RPC Methods:
eth_getBalance
Remarks
You can convert the balance to ether units with formatEther
.
Example
• client.getBlobBaseFee
Returns the base fee per blob gas in wei.
- Docs: https://viem.sh/docs/actions/public/getBlobBaseFee
- JSON-RPC Methods:
eth_blobBaseFee
Example
• client.getBlock
Returns information about a block at a block number, hash, or tag.
- Docs: https://viem.sh/docs/actions/public/getBlock
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/blocks/fetching-blocks
- JSON-RPC Methods:
- Calls
eth_getBlockByNumber
forblockNumber
&blockTag
. - Calls
eth_getBlockByHash
forblockHash
.
- Calls
Example
• client.getBlockNumber
Returns the number of the most recent block seen.
- Docs: https://viem.sh/docs/actions/public/getBlockNumber
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/blocks/fetching-blocks
- JSON-RPC Methods:
eth_blockNumber
Example
• client.getBlockTransactionCount
Returns the number of Transactions at a block number, hash, or tag.
- Docs: https://viem.sh/docs/actions/public/getBlockTransactionCount
- JSON-RPC Methods:
- Calls
eth_getBlockTransactionCountByNumber
forblockNumber
&blockTag
. - Calls
eth_getBlockTransactionCountByHash
forblockHash
.
- Calls
Example
• client.getBytecode
Retrieves the bytecode at an address.
- Docs: https://viem.sh/docs/contract/getBytecode
- JSON-RPC Methods:
eth_getCode
Example
• client.getChainId
Returns the chain ID associated with the current network.
- Docs: https://viem.sh/docs/actions/public/getChainId
- JSON-RPC Methods:
eth_chainId
Example
• client.getContractEvents
Returns a list of event logs emitted by a contract.
- Docs: https://viem.sh/docs/actions/public/getContractEvents
- JSON-RPC Methods:
eth_getLogs
Example
• client.getEnsAddress
Gets address for ENS name.
- Docs: https://viem.sh/docs/ens/actions/getEnsAddress
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/ens
Remarks
Calls resolve(bytes, bytes)
on ENS Universal Resolver Contract.
Since ENS names prohibit certain forbidden characters (e.g. underscore) and have other validation rules, you likely want to normalize ENS names with UTS-46 normalization before passing them to getEnsAddress
. You can use the built-in normalize
function for this.
Example
• client.getEnsAvatar
Gets the avatar of an ENS name.
- Docs: https://viem.sh/docs/ens/actions/getEnsAvatar
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/ens
Remarks
Calls getEnsText
with key
set to 'avatar'
.
Since ENS names prohibit certain forbidden characters (e.g. underscore) and have other validation rules, you likely want to normalize ENS names with UTS-46 normalization before passing them to getEnsAddress
. You can use the built-in normalize
function for this.
Example
• client.getEnsName
Gets primary name for specified address.
- Docs: https://viem.sh/docs/ens/actions/getEnsName
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/ens
Remarks
Calls reverse(bytes)
on ENS Universal Resolver Contract to “reverse resolve” the address to the primary ENS name.
Example
• client.getEnsResolver
Gets resolver for ENS name.
- Docs: https://viem.sh/docs/ens/actions/getEnsResolver
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/ens
Remarks
Calls findResolver(bytes)
on ENS Universal Resolver Contract to retrieve the resolver of an ENS name.
Since ENS names prohibit certain forbidden characters (e.g. underscore) and have other validation rules, you likely want to normalize ENS names with UTS-46 normalization before passing them to getEnsAddress
. You can use the built-in normalize
function for this.
Example
• client.getEnsText
Gets a text record for specified ENS name.
- Docs: https://viem.sh/docs/ens/actions/getEnsResolver
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/ens
Remarks
Calls resolve(bytes, bytes)
on ENS Universal Resolver Contract.
Since ENS names prohibit certain forbidden characters (e.g. underscore) and have other validation rules, you likely want to normalize ENS names with UTS-46 normalization before passing them to getEnsAddress
. You can use the built-in normalize
function for this.
Example
• client.getFeeHistory
Returns a collection of historical gas information.
- Docs: https://viem.sh/docs/actions/public/getFeeHistory
- JSON-RPC Methods:
eth_feeHistory
Example
• client.getFilterChanges
Returns a list of logs or hashes based on a Filter since the last time it was called.
- Docs: https://viem.sh/docs/actions/public/getFilterChanges
- JSON-RPC Methods:
eth_getFilterChanges
Remarks
A Filter can be created from the following actions:
Depending on the type of filter, the return value will be different:
- If the filter was created with
createContractEventFilter
orcreateEventFilter
, it returns a list of logs. - If the filter was created with
createPendingTransactionFilter
, it returns a list of transaction hashes. - If the filter was created with
createBlockFilter
, it returns a list of block hashes.
Examples
• client.getFilterLogs
Returns a list of event logs since the filter was created.
- Docs: https://viem.sh/docs/actions/public/getFilterLogs
- JSON-RPC Methods:
eth_getFilterLogs
Remarks
getFilterLogs
is only compatible with event filters.
Example
• client.getGasPrice
Returns the current price of gas (in wei).
- Docs: https://viem.sh/docs/actions/public/getGasPrice
- JSON-RPC Methods:
eth_gasPrice
Example
• client.getLogs
Returns a list of event logs matching the provided parameters.
- Docs: https://viem.sh/docs/actions/public/getLogs
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/filters-and-logs/event-logs
- JSON-RPC Methods:
eth_getLogs
Example
• client.getProof
Returns the account and storage values of the specified account including the Merkle-proof.
- Docs: https://viem.sh/docs/actions/public/getProof
- JSON-RPC Methods:
- Calls
eth_getProof
- Calls
Example
• client.getStorageAt
Returns the value from a storage slot at a given address.
- Docs: https://viem.sh/docs/contract/getStorageAt
- JSON-RPC Methods:
eth_getStorageAt
Example
• client.getTransaction
Returns information about a Transaction given a hash or block identifier.
- Docs: https://viem.sh/docs/actions/public/getTransaction
- Example: https://stackblitz.com/github/wevm/viem/tree/main/examples/transactions/fetching-transactions
- JSON-RPC Methods:
eth_getTransactionByHash
Example
• client.getTransactionConfirmations
Returns the number of blocks passed (confirmations) since the transaction was processed on a block.
- Docs: https://viem.sh/docs/actions/public/getTransactionConfirmations
- Example: https://stackblitz.com/github/wevm/viem/tree/main/examples/transactions/fetching-transactions
- JSON-RPC Methods:
eth_getTransactionConfirmations
Example
• client.getTransactionCount
Returns the number of Transactions an Account has broadcast / sent.
- Docs: https://viem.sh/docs/actions/public/getTransactionCount
- JSON-RPC Methods:
eth_getTransactionCount
Example
• client.getTransactionReceipt
Returns the Transaction Receipt given a Transaction hash.
- Docs: https://viem.sh/docs/actions/public/getTransactionReceipt
- Example: https://stackblitz.com/github/wevm/viem/tree/main/examples/transactions/fetching-transactions
- JSON-RPC Methods:
eth_getTransactionReceipt
Example
• client.key: string
A key for the client.
• client.multicall
Similar to readContract
, but batches up multiple functions on a contract in a single RPC call via the multicall3
contract.
Example
• client.name: string
A name for the client.
• client.pollingInterval: number
Frequency (in ms) for polling enabled actions & events. Defaults to 4_000 milliseconds.
• client.prepareTransactionRequest
Prepares a transaction request for signing.
Examples
• client.readContract
Calls a read-only function on a contract, and returns the response.
- Docs: https://viem.sh/docs/contract/readContract
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/contracts/reading-contracts
Remarks
A “read-only” function (constant function) on a Solidity contract is denoted by a view
or pure
keyword. They can only read the state of the contract, and cannot make any changes to it. Since read-only methods do not change the state of the contract, they do not require any gas to be executed, and can be called by any user without the need to pay for gas.
Internally, uses a Public Client to call the call
action with ABI-encoded data
.
Example
• client.request: EIP1193RequestFn
<[object
, object
, object
, object
, object
]>
Request function wrapped with friendly error handling
• client.sendRawTransaction
Sends a signed transaction to the network
- Docs: https://viem.sh/docs/actions/wallet/sendRawTransaction
- JSON-RPC Method:
eth_sendRawTransaction
Example
• client.simulateContract
Simulates/validates a contract interaction. This is useful for retrieving return data and revert reasons of contract write functions.
- Docs: https://viem.sh/docs/contract/simulateContract
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/contracts/writing-to-contracts
Remarks
This function does not require gas to execute and does not change the state of the blockchain. It is almost identical to readContract
, but also supports contract write functions.
Internally, uses a Public Client to call the call
action with ABI-encoded data
.
Example
• client.tevmCall: CallHandler
• client.tevmContract: ContractHandler
• client.tevmDeploy: DeployHandler
• client.tevmDumpState: DumpStateHandler
• client.tevmForkUrl?: string
• client.tevmGetAccount: GetAccountHandler
• client.tevmLoadState: LoadStateHandler
• client.tevmMine: MineHandler
• client.tevmReady
• client.tevmScript: ScriptHandler
• client.tevmSetAccount: SetAccountHandler
• client.transport: TransportConfig
<string
, EIP1193RequestFn
> & Record
<string
, any
>
The RPC transport
• client.type: string
The type of client.
• client.uid: string
A unique ID for the client.
• client.uninstallFilter
Destroys a Filter that was created from one of the following Actions:
-
JSON-RPC Methods:
eth_uninstallFilter
Example
• client.verifyMessage
Verify that a message was signed by the provided address.
Compatible with Smart Contract Accounts & Externally Owned Accounts via ERC-6492.
• client.verifySiweMessage
Verifies EIP-4361 formatted message was signed.
Compatible with Smart Contract Accounts & Externally Owned Accounts via ERC-6492.
• client.verifyTypedData
Verify that typed data was signed by the provided address.
• client.waitForTransactionReceipt
Waits for the Transaction to be included on a Block (one confirmation), and then returns the Transaction Receipt. If the Transaction reverts, then the action will throw an error.
- Docs: https://viem.sh/docs/actions/public/waitForTransactionReceipt
- Example: https://stackblitz.com/github/wevm/viem/tree/main/examples/transactions/sending-transactions
- JSON-RPC Methods:
- Polls
eth_getTransactionReceipt
on each block until it has been processed. - If a Transaction has been replaced:
- Calls
eth_getBlockByNumber
and extracts the transactions - Checks if one of the Transactions is a replacement
- If so, calls
eth_getTransactionReceipt
.
- Calls
- Polls
Remarks
The waitForTransactionReceipt
action additionally supports Replacement detection (e.g. sped up Transactions).
Transactions can be replaced when a user modifies their transaction in their wallet (to speed up or cancel). Transactions are replaced when they are sent from the same nonce.
There are 3 types of Transaction Replacement reasons:
repriced
: The gas price has been modified (e.g. differentmaxFeePerGas
)cancelled
: The Transaction has been cancelled (e.g.value === 0n
)replaced
: The Transaction has been replaced (e.g. differentvalue
ordata
)
Example
• client.watchBlockNumber
Watches and returns incoming block numbers.
- Docs: https://viem.sh/docs/actions/public/watchBlockNumber
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/blocks/watching-blocks
- JSON-RPC Methods:
- When
poll: true
, callseth_blockNumber
on a polling interval. - When
poll: false
& WebSocket Transport, uses a WebSocket subscription viaeth_subscribe
and the"newHeads"
event.
- When
Example
• client.watchBlocks
Watches and returns information for incoming blocks.
- Docs: https://viem.sh/docs/actions/public/watchBlocks
- Examples: https://stackblitz.com/github/wevm/viem/tree/main/examples/blocks/watching-blocks
- JSON-RPC Methods:
- When
poll: true
, callseth_getBlockByNumber
on a polling interval. - When
poll: false
& WebSocket Transport, uses a WebSocket subscription viaeth_subscribe
and the"newHeads"
event.
- When
Example
• client.watchContractEvent
Watches and returns emitted contract event logs.
Remarks
This Action will batch up all the event logs found within the pollingInterval
, and invoke them via onLogs
.
watchContractEvent
will attempt to create an Event Filter and listen to changes to the Filter per polling interval, however, if the RPC Provider does not support Filters (e.g. eth_newFilter
), then watchContractEvent
will fall back to using getLogs
instead.
Example
• client.watchEvent
Watches and returns emitted Event Logs.
- Docs: https://viem.sh/docs/actions/public/watchEvent
- JSON-RPC Methods:
- RPC Provider supports
eth_newFilter
:- Calls
eth_newFilter
to create a filter (called on initialize). - On a polling interval, it will call
eth_getFilterChanges
.
- Calls
- RPC Provider does not support
eth_newFilter
:- Calls
eth_getLogs
for each block between the polling interval.
- Calls
- RPC Provider supports
Remarks
This Action will batch up all the Event Logs found within the pollingInterval
, and invoke them via onLogs
.
watchEvent
will attempt to create an Event Filter and listen to changes to the Filter per polling interval, however, if the RPC Provider does not support Filters (e.g. eth_newFilter
), then watchEvent
will fall back to using getLogs
instead.
Example
• client.watchPendingTransactions
Watches and returns pending transaction hashes.
- Docs: https://viem.sh/docs/actions/public/watchPendingTransactions
- JSON-RPC Methods:
- When
poll: true
- Calls
eth_newPendingTransactionFilter
to initialize the filter. - Calls
eth_getFilterChanges
on a polling interval.
- Calls
- When
poll: false
& WebSocket Transport, uses a WebSocket subscription viaeth_subscribe
and the"newPendingTransactions"
event.
- When
Remarks
This Action will batch up all the pending transactions found within the pollingInterval
, and invoke them via onTransactions
.
Example
Returns
RequestListener
<typeof IncomingMessage
, typeof ServerResponse
>
Example
Source
packages/server/src/createHttpHandler.js:31