go-ethereum/docs/tools/clef/apis.md

title	description
Clef APIs	Reference documentation for the Clef APIs

Clef uses two separate APIs. The external API is an untrusted set of JSON-RPC methods that can be called by a user. The internal API is a set of JSON-RPC methods that can be called by a UI. The UI could be Clef's native command line interface or a custom UI.

External API

Clef listens to HTTP requests on http.addr:http.port (or to IPC on ipcpath), with the same JSON-RPC standard as Geth. The messages are expected to be JSON-RPC 2.0 standard.

Some of these JSON-RPC calls require user interaction in the Clef terminal. Responses may be delayed significantly or may never be received if a user fails to respond to a confirmation request.

The External API is untrusted: it does not accept credentials, nor does it expect that requests have any authority.

See the external API changelog for up to date information about changes to this API.

The External API encoding is as follows:

• number: positive integers that are hex encoded
• data: hex encoded data
• string: ASCII string

All hex encoded values must be prefixed with 0x.

Methods

account_new

Create new password protected account

The signer will generate a new private key, encrypt it according to web3 keystore spec and store it in the keystore directory. The client is responsible for creating a backup of the keystore. If the keystore is lost there is no method of retrieving lost accounts.

Arguments

None

Result

• address [string]: account address that is derived from the generated key

Sample call

{
  "id": 0,
  "jsonrpc": "2.0",
  "method": "account_new",
  "params": []
}

Response

{
  "id": 0,
  "jsonrpc": "2.0",
  "result": "0xbea9183f8f4f03d427f6bcea17388bdff1cab133"
}

account_list

List available accounts

List all accounts that this signer currently manages

Arguments

None

Result

• array with account records:
  • account.address [string]: account address that is derived from the generated key

Sample call

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "account_list"
}

Response

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": [
    "0xafb2f771f58513609765698f65d3f2f0224a956f",
    "0xbea9183f8f4f03d427f6bcea17388bdff1cab133"
  ]
}

account_signTransaction

Sign transactions

Signs a transaction and responds with the signed transaction in RLP-encoded and JSON forms. Supports both legacy and EIP-1559-style transactions.

Arguments

1. transaction object (legacy):
   • from [address]: account to send the transaction from
   • to [address]: receiver account. If omitted or 0x, will cause contract creation.
   • gas [number]: maximum amount of gas to burn
   • gasPrice [number]: gas price
   • value [number:optional]: amount of Wei to send with the transaction
   • data [data:optional]: input data
   • nonce [number]: account nonce
2. transaction object (1559):
   • from [address]: account to send the transaction from
   • to [address]: receiver account. If omitted or 0x, will cause contract creation.
   • gas [number]: maximum amount of gas to burn
   • maxPriorityFeePerGas [number]: maximum priority fee per unit of gas for the transaction
   • maxFeePerGas [number]: maximum fee per unit of gas for the transaction
   • value [number:optional]: amount of Wei to send with the transaction
   • data [data:optional]: input data
   • nonce [number]: account nonce
3. method signature [string:optional]
   • The method signature, if present, is to aid decoding the calldata. Should consist of methodname(paramtype,...), e.g. transfer(uint256,address). The signer may use this data to parse the supplied calldata, and show the user. The data, however, is considered totally untrusted, and reliability is not expected.

Result

• raw [data]: signed transaction in RLP encoded form
• tx [json]: signed transaction in JSON form

Sample call (legacy)

{
  "id": 2,
  "jsonrpc": "2.0",
  "method": "account_signTransaction",
  "params": [
    {
      "from": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db",
      "gas": "0x55555",
      "gasPrice": "0x1234",
      "input": "0xabcd",
      "nonce": "0x0",
      "to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
      "value": "0x1234"
    }
  ]
}

Response

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "raw": "0xf88380018203339407a565b7ed7d7a678680a4c162885bedbb695fe080a44401a6e4000000000000000000000000000000000000000000000000000000000000001226a0223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20ea02aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663",
    "tx": {
      "nonce": "0x0",
      "gasPrice": "0x1234",
      "gas": "0x55555",
      "to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
      "value": "0x1234",
      "input": "0xabcd",
      "v": "0x26",
      "r": "0x223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20e",
      "s": "0x2aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663",
      "hash": "0xeba2df809e7a612a0a0d444ccfa5c839624bdc00dd29e3340d46df3870f8a30e"
    }
  }
}

Sample call (1559)

{
  "id": 2,
  "jsonrpc": "2.0",
  "method": "account_signTransaction",
  "params": [
    {
      "from": "0xd1a9C60791e8440AEd92019a2C3f6c336ffefA27",
      "to": "0x8A8eAFb1cf62BfBeb1741769DAE1a9dd47996192",
      "gas": "0x33333",
      "maxPriorityFeePerGas": "0x174876E800",
      "maxFeePerGas": "0x174876E800",
      "nonce": "0x0",
      "value": "0x10",
      "data": "0x4401a6e40000000000000000000000000000000000000000000000000000000000000012"
    }
  ]
}

Response

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "raw": "0x02f891018085174876e80085174876e80083033333948a8eafb1cf62bfbeb1741769dae1a9dd4799619210a44401a6e40000000000000000000000000000000000000000000000000000000000000012c080a0c8b59180c6e0c154284402b52d772f1afcf8ec2d245cf75bfb3212ebe676135ba02c660aaebf92d5e314fc2ba4c70f018915d174c3c1fc6e4e38d00ebf1a5bb69f",
    "tx": {
      "type": "0x2",
      "nonce": "0x0",
      "gasPrice": null,
      "maxPriorityFeePerGas": "0x174876e800",
      "maxFeePerGas": "0x174876e800",
      "gas": "0x33333",
      "value": "0x10",
      "input": "0x4401a6e40000000000000000000000000000000000000000000000000000000000000012",
      "v": "0x0",
      "r": "0xc8b59180c6e0c154284402b52d772f1afcf8ec2d245cf75bfb3212ebe676135b",
      "s": "0x2c660aaebf92d5e314fc2ba4c70f018915d174c3c1fc6e4e38d00ebf1a5bb69f",
      "to": "0x8a8eafb1cf62bfbeb1741769dae1a9dd47996192",
      "chainId": "0x1",
      "accessList": [],
      "hash": "0x8e096eb11ea89aa83900e6816fb182ff0adb2c85d270998ca2dd2394ec6c5a73"
    }
  }
}

Sample call with ABI-data

{
  "id": 67,
  "jsonrpc": "2.0",
  "method": "account_signTransaction",
  "params": [
    {
      "from": "0x694267f14675d7e1b9494fd8d72fefe1755710fa",
      "gas": "0x333",
      "gasPrice": "0x1",
      "nonce": "0x0",
      "to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
      "value": "0x0",
      "data": "0x4401a6e40000000000000000000000000000000000000000000000000000000000000012"
    },
    "safeSend(address)"
  ]
}

Response

{
  "jsonrpc": "2.0",
  "id": 67,
  "result": {
    "raw": "0xf88380018203339407a565b7ed7d7a678680a4c162885bedbb695fe080a44401a6e4000000000000000000000000000000000000000000000000000000000000001226a0223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20ea02aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663",
    "tx": {
      "nonce": "0x0",
      "gasPrice": "0x1",
      "gas": "0x333",
      "to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
      "value": "0x0",
      "input": "0x4401a6e40000000000000000000000000000000000000000000000000000000000000012",
      "v": "0x26",
      "r": "0x223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20e",
      "s": "0x2aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663",
      "hash": "0xeba2df809e7a612a0a0d444ccfa5c839624bdc00dd29e3340d46df3870f8a30e"
    }
  }
}

Bash example:

> curl -H "Content-Type: application/json" -X POST --data '{"jsonrpc":"2.0","method":"account_signTransaction","params":[{"from":"0x694267f14675d7e1b9494fd8d72fefe1755710fa","gas":"0x333","gasPrice":"0x1","nonce":"0x0","to":"0x07a565b7ed7d7a678680a4c162885bedbb695fe0", "value":"0x0", "data":"0x4401a6e40000000000000000000000000000000000000000000000000000000000000012"},"safeSend(address)"],"id":67}' http://localhost:8550/

{"jsonrpc":"2.0","id":67,"result":{"raw":"0xf88380018203339407a565b7ed7d7a678680a4c162885bedbb695fe080a44401a6e4000000000000000000000000000000000000000000000000000000000000001226a0223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20ea02aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663","tx":{"nonce":"0x0","gasPrice":"0x1","gas":"0x333","to":"0x07a565b7ed7d7a678680a4c162885bedbb695fe0","value":"0x0","input":"0x4401a6e40000000000000000000000000000000000000000000000000000000000000012","v":"0x26","r":"0x223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20e","s":"0x2aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663","hash":"0xeba2df809e7a612a0a0d444ccfa5c839624bdc00dd29e3340d46df3870f8a30e"}}}

account_signData

Sign data

Signs a chunk of data and returns the calculated signature.

Arguments

• content type [string]: type of signed data
  • text/validator: hex data with custom validator defined in a contract
  • application/clique: clique headers
  • text/plain: simple hex data validated by account_ecRecover
• account [address]: account to sign with
• data [object]: data to sign

Result

• calculated signature [data]

Sample call

{
  "id": 3,
  "jsonrpc": "2.0",
  "method": "account_signData",
  "params": ["data/plain", "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db", "0xaabbccdd"]
}

Response

{
  "id": 3,
  "jsonrpc": "2.0",
  "result": "0x5b6693f153b48ec1c706ba4169960386dbaa6903e249cc79a8e6ddc434451d417e1e57327872c7f538beeb323c300afa9999a3d4a5de6caf3be0d5ef832b67ef1c"
}

account_signTypedData

Sign data

Signs a chunk of structured data conformant to EIP-712 and returns the calculated signature.

Arguments

• account [address]: account to sign with
• data [object]: data to sign

Result

• calculated signature [data]

Sample call

{
  "id": 68,
  "jsonrpc": "2.0",
  "method": "account_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!"
      }
    }
  ]
}

Response

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c"
}

account_ecRecover

Recover the signing address

Derive the address from the account that was used to sign data with content type text/plain and the signature.

Arguments

• data [data]: data that was signed
• signature [data]: the signature to verify

Result

• derived account [address]

Sample call

{
  "id": 4,
  "jsonrpc": "2.0",
  "method": "account_ecRecover",
  "params": [
    "0xaabbccdd",
    "0x5b6693f153b48ec1c706ba4169960386dbaa6903e249cc79a8e6ddc434451d417e1e57327872c7f538beeb323c300afa9999a3d4a5de6caf3be0d5ef832b67ef1c"
  ]
}

Response

{
  "id": 4,
  "jsonrpc": "2.0",
  "result": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db"
}

account_version

Get external API version

Get the version of the external API used by Clef.

Arguments

None

Result

• external API version [string]

Sample call

{
  "id": 0,
  "jsonrpc": "2.0",
  "method": "account_version",
  "params": []
}

Response

{
  "id": 0,
  "jsonrpc": "2.0",
  "result": "6.0.0"
}

Internal (UI) API

Clef has one native console-based UI, for operation without any standalone tools. However, there is also an API to communicate with an external UI. To enable that UI, the signer needs to be started with the --stdio-ui option, which allocates stdin / stdout for the UI API.

The internal API methods need to be implemented by a UI listener. By starting the signer with the switch --stdio-ui-test, the signer will invoke all known methods, and expect the UI to respond with denials. This can be used during development to ensure that the API is (at least somewhat) correctly implemented.

All methods in this API use object-based parameters, so that there can be no mixup of parameters: each piece of data is accessed by key.

An example (insecure) proof-of-concept external UI has been implemented in pythonsigner.py.

The model is as follows:

• The user starts the UI app (pythonsigner.py).
• The UI app starts clef with --stdio-ui, and listens to the process output for confirmation-requests.
• clef opens the external HTTP API.
• When the signer receives requests, it sends a JSON-RPC request via stdout.
• The UI app prompts the user accordingly, and responds to clef.
• clef signs (or not), and responds to the original request.

See the ui API changelog for information about changes to this API.

NOTE A slight deviation from json standard is in place: every request and response should be confined to a single line. Whereas the json specification allows for linebreaks, linebreaks should not be used in this communication channel, to make things simpler for both parties.

Methods

ApproveTx / ui_approveTx

Invoked when there's a transaction for approval.

Sample call

Here's a method invocation:

curl -i -H "Content-Type: application/json" -X POST --data '{"jsonrpc":"2.0","method":"account_signTransaction","params":[{"from":"0x694267f14675d7e1b9494fd8d72fefe1755710fa","gas":"0x333","gasPrice":"0x1","nonce":"0x0","to":"0x07a565b7ed7d7a678680a4c162885bedbb695fe0", "value":"0x0", "data":"0x4401a6e40000000000000000000000000000000000000000000000000000000000000012"},"safeSend(address)"],"id":67}' http://localhost:8550/

Results in the following invocation on the UI:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "ui_approveTx",
  "params": [
    {
      "transaction": {
        "from": "0x0x694267f14675d7e1b9494fd8d72fefe1755710fa",
        "to": "0x0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
        "gas": "0x333",
        "gasPrice": "0x1",
        "value": "0x0",
        "nonce": "0x0",
        "data": "0x4401a6e40000000000000000000000000000000000000000000000000000000000000012",
        "input": null
      },
      "call_info": [
        {
          "type": "WARNING",
          "message": "Invalid checksum on to-address"
        },
        {
          "type": "Info",
          "message": "safeSend(address: 0x0000000000000000000000000000000000000012)"
        }
      ],
      "meta": {
        "remote": "127.0.0.1:48486",
        "local": "localhost:8550",
        "scheme": "HTTP/1.1"
      }
    }
  ]
}

The same method invocation, but with invalid data:

curl -i -H "Content-Type: application/json" -X POST --data '{"jsonrpc":"2.0","method":"account_signTransaction","params":[{"from":"0x694267f14675d7e1b9494fd8d72fefe1755710fa","gas":"0x333","gasPrice":"0x1","nonce":"0x0","to":"0x07a565b7ed7d7a678680a4c162885bedbb695fe0", "value":"0x0", "data":"0x4401a6e40000000000000002000000000000000000000000000000000000000000000012"},"safeSend(address)"],"id":67}' http://localhost:8550/

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "ui_approveTx",
  "params": [
    {
      "transaction": {
        "from": "0x0x694267f14675d7e1b9494fd8d72fefe1755710fa",
        "to": "0x0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
        "gas": "0x333",
        "gasPrice": "0x1",
        "value": "0x0",
        "nonce": "0x0",
        "data": "0x4401a6e40000000000000002000000000000000000000000000000000000000000000012",
        "input": null
      },
      "call_info": [
        {
          "type": "WARNING",
          "message": "Invalid checksum on to-address"
        },
        {
          "type": "WARNING",
          "message": "Transaction data did not match ABI-interface: WARNING: Supplied data is stuffed with extra data. \nWant 0000000000000002000000000000000000000000000000000000000000000012\nHave 0000000000000000000000000000000000000000000000000000000000000012\nfor method safeSend(address)"
        }
      ],
      "meta": {
        "remote": "127.0.0.1:48492",
        "local": "localhost:8550",
        "scheme": "HTTP/1.1"
      }
    }
  ]
}

One which has missing to, but with no data:

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "ui_approveTx",
  "params": [
    {
      "transaction": {
        "from": "",
        "to": null,
        "gas": "0x0",
        "gasPrice": "0x0",
        "value": "0x0",
        "nonce": "0x0",
        "data": null,
        "input": null
      },
      "call_info": [
        {
          "type": "CRITICAL",
          "message": "Tx will create contract with empty code!"
        }
      ],
      "meta": {
        "remote": "signer binary",
        "local": "main",
        "scheme": "in-proc"
      }
    }
  ]
}

ApproveListing / ui_approveListing

Invoked when a request for account listing has been made.

Sample call

{
  "jsonrpc": "2.0",
  "id": 5,
  "method": "ui_approveListing",
  "params": [
    {
      "accounts": [
        {
          "url": "keystore:///home/bazonk/.ethereum/keystore/UTC--2017-11-20T14-44-54.089682944Z--123409812340981234098123409812deadbeef42",
          "address": "0x123409812340981234098123409812deadbeef42"
        },
        {
          "url": "keystore:///home/bazonk/.ethereum/keystore/UTC--2017-11-23T21-59-03.199240693Z--cafebabedeadbeef34098123409812deadbeef42",
          "address": "0xcafebabedeadbeef34098123409812deadbeef42"
        }
      ],
      "meta": {
        "remote": "signer binary",
        "local": "main",
        "scheme": "in-proc"
      }
    }
  ]
}

ApproveSignData / ui_approveSignData

Sample call

{
  "jsonrpc": "2.0",
  "id": 4,
  "method": "ui_approveSignData",
  "params": [
    {
      "address": "0x123409812340981234098123409812deadbeef42",
      "raw_data": "0x01020304",
      "messages": [
        {
          "name": "message",
          "value": "\u0019Ethereum Signed Message:\n4\u0001\u0002\u0003\u0004",
          "type": "text/plain"
        }
      ],
      "hash": "0x7e3a4e7a9d1744bc5c675c25e1234ca8ed9162bd17f78b9085e48047c15ac310",
      "meta": {
        "remote": "signer binary",
        "local": "main",
        "scheme": "in-proc"
      }
    }
  ]
}

ApproveNewAccount / ui_approveNewAccount

Invoked when a request for creating a new account has been made.

Sample call

{
  "jsonrpc": "2.0",
  "id": 4,
  "method": "ui_approveNewAccount",
  "params": [
    {
      "meta": {
        "remote": "signer binary",
        "local": "main",
        "scheme": "in-proc"
      }
    }
  ]
}

ShowInfo / ui_showInfo

The UI should show the info (a single message) to the user. Does not expect response.

Sample call

{
  "jsonrpc": "2.0",
  "id": 9,
  "method": "ui_showInfo",
  "params": ["Tests completed"]
}

ShowError / ui_showError

The UI should show the error (a single message) to the user. Does not expect response.

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "ui_showError",
  "params": ["Something bad happened!"]
}

OnApprovedTx / ui_onApprovedTx

OnApprovedTx is called when a transaction has been approved and signed. The call contains the return value that will be sent to the external caller. The return value from this method is ignored - the reason for having this callback is to allow the ruleset to keep track of approved transactions.

When implementing rate-limited rules, this callback should be used.

TLDR; Use this method to keep track of signed transactions, instead of using the data in ApproveTx.

Example call:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "ui_onApprovedTx",
  "params": [
    {
      "raw": "0xf88380018203339407a565b7ed7d7a678680a4c162885bedbb695fe080a44401a6e4000000000000000000000000000000000000000000000000000000000000001226a0223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20ea02aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663",
      "tx": {
        "nonce": "0x0",
        "gasPrice": "0x1",
        "gas": "0x333",
        "to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
        "value": "0x0",
        "input": "0x4401a6e40000000000000000000000000000000000000000000000000000000000000012",
        "v": "0x26",
        "r": "0x223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20e",
        "s": "0x2aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663",
        "hash": "0xeba2df809e7a612a0a0d444ccfa5c839624bdc00dd29e3340d46df3870f8a30e"
      }
    }
  ]
}

OnSignerStartup / ui_onSignerStartup

This method provides the UI with information about what API version the signer uses (both internal and external) as well as build-info and external API, in k/v-form.

Example call:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "ui_onSignerStartup",
  "params": [
    {
      "info": {
        "extapi_http": "http://localhost:8550",
        "extapi_ipc": null,
        "extapi_version": "2.0.0",
        "intapi_version": "1.2.0"
      }
    }
  ]
}

OnInputRequired / ui_onInputRequired

Invoked when Clef requires user input (e.g. a password).

Example call:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "ui_onInputRequired",
  "params": [
    {
      "title": "Account password",
      "prompt": "Please enter the password for account 0x694267f14675d7e1b9494fd8d72fefe1755710fa",
      "isPassword": true
    }
  ]
}