--- description: Use for signing execution layer payloads sidebar_position: 1 --- > For AI agents: a documentation index is available at [/llms.txt](/llms.txt). Append `.md` to any documentation URL to get the markdown source. # Web3Signer JSON-RPC API import Tabs from '@theme/Tabs'; import TabItem from '@theme/TabItem'; :::note - All JSON-RPC HTTP examples use the default host and port endpoint `http://127.0.0.1:8545`. - The examples use Besu, but you can use any Ethereum execution client. ::: ## `eth_accounts` Returns the account address with which Web3Signer is signing transactions. Returns multiple accounts if multiple signers are configured. ### Parameters None ### Returns `Array of data` - Account address with which Web3Signer is signing transactions ```bash curl -X POST --data '{"jsonrpc":"2.0","method":"eth_accounts","params":[],"id":1}' http://127.0.0.1:8545 ``` ```json { "jsonrpc": "2.0", "id": 1, "result": ["0xfe3b557e8fb62b89f4916b721be55ceb828dbd73"] } ``` ## `eth_sign` Calculates an Ethereum specific signature using `sign(keccak256("\x19Ethereum Signed Message:\n" + len(message) + message)))."` Adds a prefix to the message that makes the calculated signature recognizable as an Ethereum specific signature. This prevents malicious dapps from signing arbitrary data (for example, a transaction) and using the signature to impersonate the victim. ### Parameters `DATA` - 20-byte account address `DATA` - Data string to sign ### Returns `DATA` - Signature ```bash curl -X POST --data '{"jsonrpc":"2.0","method":"eth_sign","params":["0x78e6e236592597c09d5c137c2af40aecd42d12a2", "0x2eadbe1f"], "id":1}' http://127.0.0.1:8545 ``` ```json { "jsonrpc": "2.0", "id": 1, "result": "0xa6122e277f46fea78f3e97d3354a03ad20b2296733dfefbadc7305c80e70ce9826d44f12ab5aa488689744657491c70d3b654d7f60f8f50beefac9abcf02a4cf1b" } ``` ## `eth_signTransaction` Signs a transaction that you can submit to Besu at a later time using [`eth_sendRawTransaction`](https://besu.hyperledger.org/public-networks/reference/api#eth_sendrawtransaction). ### Parameters Transaction object: | Key | Type | Required/Optional | Value | | --- | :-- | --- | --- | | `from` | Data, 20 bytes | Required | Address of the sender. | | `to` | Data, 20 bytes | Optional for contract creation | Address of the receiver. `null` if this is a contract creation transaction. | | `gas` | Quantity | Optional | Gas provided by the sender. The default is `90000`. | | `gasPrice` | Quantity | Optional | Gas price provided by the sender in Wei. The default is `0`. Used only in non [EIP-1559] transactions. | | `maxPriorityFeePerGas` | Quantity | Optional | Maximum fee, in Wei, the sender is willing to pay above the base fee. Used only in [EIP-1559] transactions. | | `maxFeePerGas` | Quantity | Optional | Maximum total fee (base fee + priority fee), in Wei, the sender is willing to pay. Used only in [EIP-1559] transactions. | | `nonce` | Quantity | Optional | Number of transactions made by the sender before this one. | | `value` | Quantity | Optional | Value transferred in Wei. | | `data` | Quantity | Optional | Compiled contract code or hash of the invoked method signature and encoded parameters. | ### Returns `result` : `data` - The signed transaction object. ```bash curl -X POST --data '{"jsonrpc":"2.0","method":"eth_signTransaction","params":[{"from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73","to": "0xd46e8dd67c5d32be8058bb8eb970870f07244567","gas": "0x7600","gasPrice": "0x9184e72a000","value": "0x9184e72a", "nonce":"0x46"}], "id":1}' http://127.0.0.1:8545 ``` ```json { "jsonrpc": "2.0", "id": 1, "result": "0xa3f20717a250c2b0b729b7e5becbff67fdaef7e0699da4de7ca5895b02a170a12d887fd3b17bfdce3481f10bea41f45ba9f709d39ce8325427b57afcfc994cee1b" } ``` ## `eth_signTypedData` `eth_signTypedData` is the same as `ethsign` except a typed data structure is specified as the object to be signed instead of a data string. Calculates an Ethereum specific signature using `sign(keccak256("\x19Ethereum Signed Message:\n" + len(message) + message)))."` Adds a prefix to the message that makes the calculated signature recognizable as an Ethereum specific signature. This prevents malicious dapps from signing arbitrary data (for example, a transaction) and using the signature to impersonate the victim. The JSON schema for the typed data structure to sign is: ```json { type: 'object', properties: { types: { type: 'object', properties: { EIP712Domain: {type: 'array'}, }, additionalProperties: { type: 'array', items: { type: 'object', properties: { name: {type: 'string'}, type: {type: 'string'} }, required: ['name', 'type'] } }, required: ['EIP712Domain'] }, primaryType: {type: 'string'}, domain: {type: 'object'}, message: {type: 'object'} }, required: ['types', 'primaryType', 'domain', 'message'] } ``` ### Parameters `DATA` - 20-byte account address `TYPEDDATA` - Typed data structure to sign ### Returns `DATA` - Signature ```bash curl -X POST --data '{"jsonrpc":"2.0","method":"eth_signTypedData","params":["0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826", {"types":{"EIP712Domain":[{"name":"name","type":"string"},{"name":"version","type":"string"},{"name":"chainId","type":"uint256"},{"name":"verifyingContract","type":"address"}],"Person":[{"name":"name","type":"string"},{"name":"wallet","type":"address"}],"Mail":[{"name":"from","type":"Person"},{"name":"to","type":"Person"},{"name":"contents","type":"string"}]},"primaryType":"Mail","domain":{"name":"Ether Mail","version":"1","chainId":1,"verifyingContract":"0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"},"message":{"from":{"name":"Cow","wallet":"0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826"},"to":{"name":"Bob","wallet":"0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB"},"contents":"Hello, Bob!"}}],"id":1}' ``` ```json { "jsonrpc": "2.0", "id": 1, "result": "0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c" } ``` ## `eth_sendTransaction` Creates and signs a transaction using the signing key. Web3Signer submits the signed transaction to Besu using [`eth_sendRawTransaction`](https://besu.hyperledger.org/public-networks/reference/api#eth_sendrawtransaction). ### Parameters Transaction object: | Key | Type | Required/Optional | Value | | --- | :-- | --- | --- | | `from` | Data, 20 bytes | Required | Address of the sender. | | `to` | Data, 20 bytes | Optional for contract creation | Address of the receiver. `null` if this is a contract creation transaction. | | `gas` | Quantity | Optional | Gas provided by the sender. The default is `90000`. | | `gasPrice` | Quantity | Optional | Gas price provided by the sender in Wei. The default is `0`. Used only in non [EIP-1559] transactions. | | `maxPriorityFeePerGas` | Quantity | Optional | Maximum fee, in Wei, the sender is willing to pay above the base fee. Used only in [EIP-1559] transactions. | | `maxFeePerGas` | Quantity | Optional | Maximum total fee (base fee + priority fee), in Wei, the sender is willing to pay. Used only in [EIP-1559] transactions. | | `nonce` | Quantity | Optional | Number of transactions made by the sender before this one. | | `value` | Quantity | Optional | Value transferred in Wei. | | `data` | Quantity | Optional | Compiled contract code or hash of the invoked method signature and encoded parameters. | :::tip Submitting a transaction with the same nonce as a pending transaction and a higher gas price replaces the pending transaction with the new one. ::: ### Returns `result` : `data` - 32-byte transaction hash ```bash curl -X POST --data '{"jsonrpc":"2.0","method":"eth_sendTransaction","params":[{"from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73","to": "0xd46e8dd67c5d32be8058bb8eb970870f07244567","gas": "0x7600","gasPrice": "0x9184e72a000","value": "0x9184e72a"}], "id":1}' http://127.0.0.1:8545 ``` ```json { "jsonrpc": "2.0", "id": 1, "result": "0x6052dd2131667ef3e0a0666f2812db2defceaec91c470bb43de92268e8306778" } ``` [EIP-1559]: https://eips.ethereum.org/EIPS/eip-1559