README.md

casper-client

A client 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:

cd client
cargo run --release -- help

example output

Casper client 0.1.0
A client for interacting with the Casper network

USAGE:
    casper-client [SUBCOMMAND]

FLAGS:
    -h, --help
            Prints help information

    -V, --version
            Prints version information


SUBCOMMANDS:
    put-deploy               Creates a new deploy and sends it to the network for execution
    make-deploy              Constructs a deploy and outputs it to a file or stdout. As a file, the deploy can
                             subsequently be signed by other parties and sent to a node, or signed with the sign-
                             deploy subcommand
    sign-deploy              Cryptographically signs a deploy and appends signature to existing approvals
    send-deploy              Sends a deploy to the network for execution
    transfer                 Transfers funds between purses
    get-deploy               Retrieves a stored deploy
    get-block                Retrieves a block
    list-deploys             Gets the list of all deploy hashes from a given block
    get-balance              Retrieves a stored balance
    get-global-state-hash    Retrieves a global state hash
    query-state              Retrieves a stored value from global state
    keygen                   Generates account key files in the given directory
    generate-completion      Generates a shell completion script
    help                     Prints 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 ["public_key_hex", "secret_key.pem", "public_key.pem"].
"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               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 to send HTTP requests and receive 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:50101, which should match the address of the first node of a testnet started via nctl, and thus can usually be omitted.

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 \
    --secret-key=../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=10000

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 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 --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,
        "global_state_hash": "c79f4c9a017532fe265593d86d3917581479fd1601093e16d17ec90aeaa63b83",
        "height": 987,
        "parent_hash": "ffb95eac42eae1112d37797a1ecc67860e88a9364c44845cb7a96eb426dca502",
        "proposer": "015b7723f1d9499fa02bd17dfe4e1315cfe1660a071e27ab1f29d6ceb6e2abcd73",
        "random_bit": true,
        "timestamp": "2020-10-15T13:23:48.352Z"
      },
      "proofs": [
        "0104df3fe39567d22a48b68c4b046dadf5af6552c45b1a93613c89a65caa98b12a4564ba1a794e77787eb3d37c19617ca344f2a304387a0364fee0e8f89da2da0d"
      ]
    }
  },
  "id": 3484548969
}

The global_state_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.

Query the global state

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

cargo run --release -- query-state \
    --global-state-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.

Get the balance of a purse

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

cargo run --release -- get-balance \
    --global-state-hash=242666f5959e6a51b7a75c23264f3cb326eecd6bec6dbab147f5801ec23daed6 \
    --purse-uref=uref-09480c3248ef76b603d386f3f4f8a5f87f597d4eaffd475433f861af187ab5db-007

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-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.