casper-client

A client library and binary for interacting with the Casper network.

Running the client

The client runs in one of several modes, each mode performing a single action. To see all available commands:

cargo run --release -- help

example output

Casper client 2.0.0
A client for interacting with the Casper network

USAGE:
    casper-client [SUBCOMMAND]

OPTIONS:
    -h, --help       Print help information
    -V, --version    Print version information

SUBCOMMANDS:
    put-deploy               Create a deploy and send it to the network for execution
    make-deploy              Create a deploy and output it to a file or stdout. As a file, the
                                 deploy can subsequently be signed by other parties using the
                                 'sign-deploy' subcommand and then sent to the network for execution
                                 using the 'send-deploy' subcommand
    sign-deploy              Read a previously-saved deploy from a file, cryptographically sign
                                 it, and output it to a file or stdout
    send-deploy              Read a previously-saved deploy from a file and send it to the
                                 network for execution
    transfer                 Transfer funds between purses
    make-transfer            Create a transfer deploy and output it to a file or stdout. As a
                                 file, the deploy can subsequently be signed by other parties using
                                 the 'sign-deploy' subcommand and then sent to the network for
                                 execution using the 'send-deploy' subcommand
    get-deploy               Retrieve a deploy from the network
    get-block                Retrieve a block from the network
    get-block-transfers      Retrieve all transfers for a block from the network
    list-deploys             Retrieve the list of all deploy hashes in a given block
    get-state-root-hash      Retrieve a state root hash at a given block
    get-era-info             Retrieve era information from the network
    query-global-state       Retrieve a stored value from the network
    query-balance            Retrieve a purse's balance from the network
    get-dictionary-item      Retrieve a stored value from a dictionary
    get-account              Retrieve account information from the network
    get-auction-info         Retrieve the bids and validators as of either a specific block (by
                                 height or hash), or the most recently added block
    get-validator-changes    Retrieve status changes of active validators
    get-peers                Retrieve network identity and address of each of the specified
                                 node's peers
    get-node-status          Retrieve status of the specified node
    get-chainspec            Retrieve the chainspec of the network (to print the full TOML, run
                                 with '-vv')
    list-rpcs                List all currently supported RPCs
    keygen                   Generate account key files in the given directory
    account-address          Generate an account hash from a given public key
    generate-completion      Generate a shell completion script
    help                     Print this message or the help of the given subcommand(s)

To get further info on any command, run help followed by the subcommand, e.g.

cargo run --release -- help keygen

example output

casper-client-keygen 
Generates account key files in the given directory. Creates ["secret_key.pem", "public_key.pem", "public_key_hex"].
"public_key_hex" contains the hex-encoded key's bytes with the hex-encoded algorithm tag prefixed

USAGE:
    casper-client keygen [FLAGS] [OPTIONS] [PATH]

FLAGS:
    -f, --force      If this flag is passed, any existing output files will be overwritten. Without this flag, if any
                     output file exists, no output files will be generated and the command will fail
    -h, --help       Prints help information
    -V, --version    Prints version information

OPTIONS:
    -a, --algorithm <STRING>    The type of keys to generate [default: Ed25519]  [possible values: Ed25519, secp256k1]

ARGS:
    <PATH>    Path to output directory where key files will be created. If the path doesn't exist, it will be
              created. If not set, the current working directory will be used

Generate asymmetric signing keys

Some commands require the use of a secret key for signing data. To generate a secret and public key pair:

cargo run --release -- keygen $HOME/.client_keys

Interacting with a local node

Many client commands require sending HTTP requests and receiving responses. To do this with a local node running on the same machine, follow the instructions in the nctl README to set up a local test network.

Ensure the network has fully started before running client commands. This can be determined by running nctl-view-node-peers and checking each node has connections to all others.

For client commands requiring a node address (specified via the --node-address or -n arg), the default value is http://localhost:7777, which is the address for a real network node. The --node-address=http://localhost:11101 argument must be included for the address of the first node of a testnet started via nctl.

Transfer funds between purses

The testnet will be set up so that the nodes each have an initial balance of tokens in their main purses. Let's say we want to create a new purse under the public key we just created (in the "Generate asymmetric signing keys" section). We can do this by creating a new deploy which will transfer funds between two purses once executed. The simplest way to achieve this is via the transfer subcommand.

First, set the contents of the public_key_hex file to a variable. We'll use this as the target account:

PUBLIC_KEY=$(cat $HOME/.client_keys/public_key_hex)

Then execute the transfer subcommand. We'll specify that we want to transfer 1,234,567 tokens from the main purse of node 3, and that we'll pay a maximum of 10,000 tokens to execute this deploy:

cargo run --release -- transfer \
    --node-address=http://localhost:11101 \
    --secret-key=../casper-node/utils/nctl/assets/net-1/nodes/node-3/keys/secret_key.pem \
    --amount=1234567 \
    --target-account=$PUBLIC_KEY \
    --chain-name=casper-net-1 \
    --payment-amount=3000000000

example output

{
  "jsonrpc": "2.0",
  "result": {
    "api_version": "1.0.0",
    "deploy_hash": "c42210759368a07a1b1ff4f019f7e77e7c9eaf2961b8c9dfc4237ea2218246c9"
  },
  "id": 2564730065
}

The deploy_hash in the response is worth noting, as it can be used to identify this deploy.

Get details of a deploy

To see information about a deploy sent to the network via transfer, put-deploy, or send-deploy, you can use get-deploy, along with the deploy hash printed after executing one of these subcommands.

For example, to see if our previous transfer command generated a deploy which was executed by the network:

cargo run --release -- get-deploy --node-address=http://localhost:11101 c42210759368a07a1b1ff4f019f7e77e7c9eaf2961b8c9dfc4237ea2218246c9

example output

{
  "jsonrpc": "2.0",
  "result": {
    "api_version": "1.0.0",
    "deploy": {
      "approvals": [
        {
          "signature": "0140850c4f74aaad24894ce2d0e3efb64f599633fad4e280f39529dbd062ab49ca6a1f0bd6f20a8cddeab68e95ae5ea416a5b2ae3a02a0bc7a714c2915106e1c09",
          "signer": "015b7723f1d9499fa02bd17dfe4e1315cfe1660a071e27ab1f29d6ceb6e2abcd73"
        }
      ],
      "hash": "c42210759368a07a1b1ff4f019f7e77e7c9eaf2961b8c9dfc4237ea2218246c9",
      "header": {
        "account": "015b7723f1d9499fa02bd17dfe4e1315cfe1660a071e27ab1f29d6ceb6e2abcd73",
        "body_hash": "c66f1040f8f2aeafee73b7c0811e00fd6eb63a6a5992d7cc0f967e14704dd35b",
        "chain_name": "casper-net-1",
        "dependencies": [],
        "gas_price": 10,
        "timestamp": "2020-10-15T13:23:45.355Z",
        "ttl": "1h"
      },
      "payment": {
        "ModuleBytes": {
          "args": "0100000006000000616d6f756e740300000002102708",
          "module_bytes": ""
        }
      },
      "session": {
        "Transfer": {
          "args": "0200000006000000616d6f756e74040000000387d612080600000074617267657420000000018189fd2d42c36d951f9803e595795a3a0fc07aa999c88a28d286c7cbf338940f0320000000"
        }
      }
    },
    "execution_results": [
      {
        "block_hash": "80a09df67f45bfb290c8f36021daf2fb898587a48fa0e4f7c506202ae8f791b8",
        "result": {
          "cost": "0",
          "effect": {
            "operations": {
              "account-hash-018189fd2d42c36d951f9803e595795a3a0fc07aa999c88a28d286c7cbf33894": "Write",
              "hash-09480c3248ef76b603d386f3f4f8a5f87f597d4eaffd475433f861af187ab5db": "Write",
              "hash-d46e35465520ef9f868be3f26eaded1585dd66ac410706bab4b7adf92bdf528a": "Read",
              "hash-ea274222cc975e4daec2cced17a0270df7c282e865115d98f544a35877af5271": "Add",
              "uref-09480c3248ef76b603d386f3f4f8a5f87f597d4eaffd475433f861af187ab5db-000": "Write",
              "uref-8e7893be4b33bc5eacde4dd684b030593200364a211b8566ed9458ccbafbcde9-000": "Write",
              "uref-b645152645faa6c3f7708fd362a118296f7f4d39dc065c120877d13b6981cd67-000": "Write"
            },
            "transforms": {
              "account-hash-018189fd2d42c36d951f9803e595795a3a0fc07aa999c88a28d286c7cbf33894": "WriteAccount",
              "hash-09480c3248ef76b603d386f3f4f8a5f87f597d4eaffd475433f861af187ab5db": {
                "WriteCLValue": {
                  "bytes": "02b645152645faa6c3f7708fd362a118296f7f4d39dc065c120877d13b6981cd6707",
                  "cl_type": "Key"
                }
              },
              "hash-d46e35465520ef9f868be3f26eaded1585dd66ac410706bab4b7adf92bdf528a": "Identity",
              "hash-ea274222cc975e4daec2cced17a0270df7c282e865115d98f544a35877af5271": {
                "AddKeys": {
                  "uref-09480c3248ef76b603d386f3f4f8a5f87f597d4eaffd475433f861af187ab5db-000": "uref-b645152645faa6c3f7708fd362a118296f7f4d39dc065c120877d13b6981cd67-007"
                }
              },
              "uref-09480c3248ef76b603d386f3f4f8a5f87f597d4eaffd475433f861af187ab5db-000": {
                "WriteCLValue": {
                  "bytes": "",
                  "cl_type": "Unit"
                }
              },
              "uref-8e7893be4b33bc5eacde4dd684b030593200364a211b8566ed9458ccbafbcde9-000": {
                "WriteCLValue": {
                  "bytes": "087929775d78456301",
                  "cl_type": "U512"
                }
              },
              "uref-b645152645faa6c3f7708fd362a118296f7f4d39dc065c120877d13b6981cd67-000": {
                "WriteCLValue": {
                  "bytes": "0387d612",
                  "cl_type": "U512"
                }
              }
            }
          },
          "error_message": null
        }
      }
    ]
  },
  "id": 592430140
}

The block_hash in the response's execution_results is worth noting, as it can be used to identify the block in which the deploy is included. If the deploy was successfully received and parsed by the node, but failed to execute, the error_message in execution_results may provide useful information.

Get details of a Block

To see information about a Block created by the network, you can use get-block. For example:

cargo run --release -- get-block \
    --node-address=http://localhost:11101 \
    --block-hash=80a09df67f45bfb290c8f36021daf2fb898587a48fa0e4f7c506202ae8f791b8

example output

{
  "jsonrpc": "2.0",
  "result": {
    "api_version": "1.0.0",
    "block": {
      "body": null,
      "hash": "80a09df67f45bfb290c8f36021daf2fb898587a48fa0e4f7c506202ae8f791b8",
      "header": {
        "accumulated_seed": "e8c65524331dc950d9065c289deb05458d3f9d8beba15e663a5418f5a6c7bed5",
        "body_hash": "0e5751c026e543b2e8ab2eb06099daa1d1e5df47778f7787faab45cdf12fe3a8",
        "deploy_hashes": [
          "c42210759368a07a1b1ff4f019f7e77e7c9eaf2961b8c9dfc4237ea2218246c9"
        ],
        "era_end": null,
        "era_id": 89,
        "state_root_hash": "c79f4c9a017532fe265593d86d3917581479fd1601093e16d17ec90aeaa63b83",
        "height": 987,
        "parent_hash": "ffb95eac42eae1112d37797a1ecc67860e88a9364c44845cb7a96eb426dca502",
        "proposer": "015b7723f1d9499fa02bd17dfe4e1315cfe1660a071e27ab1f29d6ceb6e2abcd73",
        "random_bit": true,
        "timestamp": "2020-10-15T13:23:48.352Z"
      },
      "proofs": [
        "0104df3fe39567d22a48b68c4b046dadf5af6552c45b1a93613c89a65caa98b12a4564ba1a794e77787eb3d37c19617ca344f2a304387a0364fee0e8f89da2da0d"
      ]
    }
  },
  "id": 3484548969
}

The state_root_hash in the response's header is worth noting, as it can be used to identify the state root hash for the purposes of querying the global state.

Get all Transfers contained in a Block

To retrieve all Transfer transactions processed in a Block created by the network, you can use get-block-transfers. For example:

cargo run --release -- get-block-transfers \
    --node-address=http://localhost:11101 \
    --block-hash=80a09df67f45bfb290c8f36021daf2fb898587a48fa0e4f7c506202ae8f791b8

example output

{
  "jsonrpc": "2.0",
  "result": {
    "api_version": "1.0.0",
    "block_hash": "80a09df67f45bfb290c8f36021daf2fb898587a48fa0e4f7c506202ae8f791b8",
    "transfers": [
      {
        "amount": "100000000",
        "deploy_hash": "ab87c5f2c0f6f331bf488703676fb0c68f897282dfbb8e085752f220a3dfc25e",
        "from": "account-hash-1ace33e66142d5a0679ba5507ef75b9c09888d1567e86100d1db535fa819a962",
        "gas": "0",
        "id": null,
        "source": "uref-21f7316e72d1baa7b706a9083077d643665ad3a56673c594db9762ceac4f3788-007",
        "target": "uref-c5eb9788156b53c9a599dfb5e591c6399580b491c72086a6bc028dd18fdfcb2d-004"
      }
    ]
  },
  "id": 7229488934468542904
}

Query the global state

To view data stored to global state after executing a deploy, you can use query-global-state. For example, to see the value stored under our new account's public key:

cargo run --release -- query-global-state \
    --node-address=http://localhost:11101 \
    --state-root-hash=242666f5959e6a51b7a75c23264f3cb326eecd6bec6dbab147f5801ec23daed6 \
    --key=$PUBLIC_KEY

example output

{
  "jsonrpc": "2.0",
  "result": {
    "api_version": "1.0.0",
    "stored_value": {
      "Account": {
        "account_hash": "018189fd2d42c36d951f9803e595795a3a0fc07aa999c88a28d286c7cbf33894",
        "action_thresholds": {
          "deployment": 1,
          "key_management": 1
        },
        "associated_keys": [
          {
            "account_hash": "018189fd2d42c36d951f9803e595795a3a0fc07aa999c88a28d286c7cbf33894",
            "weight": 1
          }
        ],
        "main_purse": "uref-09480c3248ef76b603d386f3f4f8a5f87f597d4eaffd475433f861af187ab5db-007",
        "named_keys": {}
      }
    }
  },
  "id": 3649040235
}

This yields details of the newly-created account object, including the URef of the account's main purse.

Query the balance of a purse

This can be done via query-balance. For example, to get the balance of the main purse of our newly-created account:

cargo run --release -- query-balance \
    --node-address=http://localhost:11101 \
    --state-root-hash=242666f5959e6a51b7a75c23264f3cb326eecd6bec6dbab147f5801ec23daed6 \
    --purse-identifier=account-hash-f7196ed0f4a4aa2aae02daa8f0bdad39ed3098c028979db4f96c3c25670a8240

example output

{
  "jsonrpc": "2.0",
  "result": {
    "api_version": "1.0.0",
    "balance_value": "1234567"
  },
  "id": 4193583276
}

Note that the system mint contract is required to retrieve the balance of any given purse. If you execute a query-global-state specifying a purse URef as the --key argument, you'll find that the actual value stored there is a unit value (). This makes the get-balance subcommand particularly useful.

---

Client library

The lib directory contains source for the client library, which may be called directly rather than through the CLI binary. The CLI app casper-client makes use of this library to implement its functionality.

---

License

Licensed under the Apache License Version 2.0.