# 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
```
<details><summary>example output</summary>
```commandline
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)
```
</details>
To get further info on any command, run `help` followed by the subcommand, e.g.
```
cargo run --release -- help keygen
```
<details><summary>example output</summary>
```commandline
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
```
</details>
### 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 $HOME/.client_keys
```
## Interacting with a local node
Many client commands require sending HTTP requests and receiving responses. To do this with a local node running on the
same machine, follow the instructions in
[the `nctl` README](https://github.com/casper-network/casper-node/tree/dev/utils/nctl#readme) to set up a local test
network.
Ensure the network has fully started before running client commands. This can be determined by running
`nctl-view-node-peers` and checking each node has connections to all others.
For client commands requiring a node address (specified via the `--node-address` or `-n` arg), the default value is
`http://localhost:7777`, which is the address for a real network node. The `--node-address=http://localhost:11101`
argument must be included for the address of the first node of a testnet started via `nctl`.
### Transfer funds between purses
The testnet will be set up so that the nodes each have an initial balance of tokens in their main purses. Let's say we
want to create a new purse under the public key we just created (in the "Generate asymmetric signing keys" section). We
can do this by creating a new deploy which will transfer funds between two purses once executed. The simplest way to
achieve this is via the `transfer` subcommand.
First, set the contents of the `public_key_hex` file to a variable. We'll use this as the target account:
```
PUBLIC_KEY=$(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
```
<details><summary>example output</summary>
```commandline
{
"jsonrpc": "2.0",
"result": {
"api_version": "1.0.0",
"deploy_hash": "c42210759368a07a1b1ff4f019f7e77e7c9eaf2961b8c9dfc4237ea2218246c9"
},
"id": 2564730065
}
```
</details>
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
```
<details><summary>example output</summary>
```commandline
{
"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
}
```
</details>
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
```
<details><summary>example output</summary>
```commandline
{
"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
}
```
</details>
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
```
<details><summary>example output</summary>
```commandline
{
"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
}
```
</details>
### 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
```
<details><summary>example output</summary>
```commandline
{
"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
}
```
</details>
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
```
<details><summary>example output</summary>
```commandline
{
"jsonrpc": "2.0",
"result": {
"api_version": "1.0.0",
"balance_value": "1234567"
},
"id": 4193583276
}
```
</details>
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](LICENSE).