Quickstart

Here is a list of commands for developers who already meet the prerequisites and want to quickly send a sample contract to the Testnet. Consult the complete documentation for context and additional help.

Prerequisites

1. You have installed Rust. Verify the installation with this command: rustup --version. Restart the shell if needed.
2. You have installed cmake. Verify the installation with this command: cmake --version.
   • On Ubuntu, you can follow this guide.
   • On MacOS, use this command: brew install cmake.
3. You have an integrated development environment (IDE). On Windows, you will need to download the C++ build developer tools, without which you cannot install cargo-casper.
4. You have download Git.

Steps

5. Install Cargo Casper with this command:

   cargo install cargo-casper

6. Install the Casper client:

   cargo install casper-client

   If you have issues installing the casper-client, you may need additional libraries.

   • On MacOS:

     brew install pkg-config
     brew install openssl

   • On Ubuntu:

     sudo apt-get install pkg-config
     sudo apt-get install openssl
     sudo apt-get install libssl-dev

   Note: Make sure you also have the development packages of openssl installed. For example, libssl-dev on Ubuntu or openssl-devel on Fedora.

7. Test the casper-client by querying a node on the network and getting the latest state root hash.

   casper-client get-state-root-hash --node-address http://65.21.235.219:7777

8. Set up a Casper Account.

9. Clone a simple counter contract or download it from GitHub:

   git clone https://github.com/casper-ecosystem/counter

10. Navigate to the folder and prepare the dependencies to build the contract:

cd counter
make prepare

11. Build the contract and tests:

make test

12. Install the contract on Testnet using the casper-client's put-deploy command. Replace the secret key with your path. Record the deploy hash from the output.

casper-client put-deploy \
--node-address [NODE_ADDRESS] \
--chain-name casper-test \
--secret-key [YOUR_PATH_TO_SECRET_KEY_FILE] \
--payment-amount 30000000000 \
--session-path contracts/counter-v1/target/wasm32-unknown-unknown/release/counter-v1.wasm

13. Check the deploy status given the deploy hash from the previous command:

casper-client get-deploy --node-address [NODE_ADDRESS] [DEPLOY_HASH]

14. Get the latest state root hash:

casper-client get-state-root-hash --node-address [NODE_ADDRESS]

15. Open the deploy tab of the account on the Testnet to see the deploy details.

• As an alternative to step 15, check your account using the command line:

casper-client query-global-state \
--node-address [NODE_ADDRESS] \
--state-root-hash [STATE_ROOT_HASH] \
--key [PATH_TO_PUBLIC_KEY]

• As another alternative, use the account hash for the --key argument. To get the account hash, look at the account details on the block explorer, or run this command:

casper-client account-address --public-key [PATH_TO_PUBLIC_KEY]

Then, query the blockchain using the account hash:

casper-client query-global-state \
--node-address [NODE_ADDRESS] \
--state-root-hash [STATE_ROOT_HASH] \
--key [ACCOUNT_HASH]

16. Now, you can play with the smart contract and increment the value it manages from 0 to 1. First, let's make sure the value is 0. Look at the "parsed" value returned in the output. An expected example output is shown below.

casper-client query-global-state \
--node-address [NODE_ADDRESS] \
--state-root-hash [STATE_ROOT_HASH] \
--key [ACCOUNT_HASH] \
-q "counter/count"

Example output:

{
    "id": 8523290678829319485,
    "jsonrpc": "2.0",
    "result": {
        "api_version": "1.4.6",
        "block_header": null,
        "merkle_proof": "[85716 hex chars]",
        "stored_value": {
            "CLValue": {
                "bytes": "01000000",
                "cl_type": "I32",
                "parsed": 0
            }
        }
    }
}

17. Now increment the count value by calling the entry point counter_inc.

casper-client put-deploy \
--node-address [NODE_ADDRESS] \
--chain-name [CHAIN_NAME] \
--secret-key [PATH_TO_YOUR_KEY] \
--payment-amount 100000000 \
--session-name "counter" \
--session-entry-point "counter_inc"

18. Get the NEW state root hash, to get the latest snapshot of the blockchain state – this is EXTREMELY IMPORTANT!

casper-client get-state-root-hash --node-address [NODE_ADDRESS]

19. Query the state of the network.

casper-client query-state \
--node-address [NODE_ADDRESS] \
--state-root-hash [STATE_ROOT_HASH] \
--key [ACCOUNT_HASH] \
-q "counter/count"

If everything went according to plan, the value should be 1. Look at the "parsed" value below.

{
    "id": 8523290678829319485,
    "jsonrpc": "2.0",
    "result": {
        "api_version": "1.4.6",
        "block_header": null,
        "merkle_proof": "[85716 hex chars]",
        "stored_value": {
            "CLValue": {
                "bytes": "01000000",
                "cl_type": "I32",
                "parsed": 1
            }
        }
    }
}

You have successfully invoked a contract on the Casper Testnet to increment a value from 0 to 1. Now you have all the infrastructure required to work with more meaningful contracts.