Using Beam Shaders

Why DAppnet?

Beam consists of three public networks:

1. DAppnet: a testing sandbox that produces a pseudo-mining block every 15 seconds.
2. Testnet: produces genuine mining blocks but is mostly a testing site before Mainnet deployment.
3. Mainnet: the living Beam network with real assets.

Install DAppnet wallet

The latest version of the Beam DAppnet Wallet is on our website.

When installing DAppnet, choose the default settings to operate the local node (required) to run Beam Shader contracts. Create a new wallet (save the seed phrase).

Beam Shaders require the use of the integrated node found in the DAppnet Wallet and must remain open for this tutorial.

Withdraw from the Faucet

All DAppnet transactions (including Beam Shader deployment) contain transaction fees that are paid in Beam coins, and require a positive wallet balance.

Launch My DApp Store and find the Faucet Application .

Launch Faucet >>> Get your first Beam >>> Confirm, and Beam coins will deposit into your wallet after the next mining block.

Configuring your CLI wallet

Beam shaders are deployed via CLI wallet which can be found on our website. This tutorial uses Windows Command Prompt, but users can substitute Mac and Linux commands if desired.

Create a shader folder in your hard drive, and transfer CLI wallet archive. The shader folder should contain two files: two files: the CLI wallet archive and wallet config file.

For this tutorial, we will use our DAppnet's wallet.db(for testing purposes only. This practice is not recommended with wallets containing real assets).

Copy wallet.db from DAppnet Wallet

Beam wallets store wallet metadata (transaction history, balance, etc) locally on your hard drive in the wallet.db file.

Locate your DAppnet wallet.db in the %LOCALAPPDATA%\Beam Wallet folder. Transfer the wallet.db in the same shader folder.

Refer to our Desktop Wallet guide for wallet.db file location for macOS and Linux operating systems.

Configure CLI wallet settings

One more crucial step before running Shader contracts involves configuring the CLI wallet settings to simplify and shorten commands.

To connect CLI wallet's to the built-in node, first edit the config file using text editor (such as Visual Studio Code) and enter the following:

log_level=debug
pass=<your wallet password>
node_addr=127.0.0.1:10005
wallet_path=wallet.db

The config file should resemble the following:

################################################################################
# General options:
################################################################################

# log level [info|debug|verbose]
log_level=debug

# file log level [info|debug|verbose]
# file_log_level=debug

# old logs cleanup period (days)
# log_cleanup_days=5

################################################################################
# Wallet options:
################################################################################

# password for the wallet
pass=123

# phrase to generate secret key according to BIP-39.
# seed_phrase=

# address of node
node_addr=127.0.0.1:10005

# path to wallet file
wallet_path=wallet.db

# command to execute [new_addr|send|receive|listen|init|info|export_miner_key|export_owner_key|generate_phrase]
# command=listen

The testing environment is ready to deploy Shaders, all that remains is selecting the Shader contract.

Choosing a Shader application

The Dappnet Blockchain Explorer (see Contracts tab) contains a list of Shader contract applications ready for testing.

For the purposes of this tutorial, we will select the Vault Shader application (copy the Vault Contract ID -- we will use this later).

At thid time, the list of available contracts is DAppnet. The majority of deployed contracts don't contain a contract description. These features will be adjusted with future iterations of DAppnet.

Please download the Vault application Shader from our Beam repository. The Shader contract will not respond to CLI commands without the precompiled source code.

Download app.wasm and copy it to your shader folder. Note: if you are testing several applications, create a folder for each Shader application so each application contains a separate app.wasm file.

Running Shader commands

Open as command line interface and change directory to the location of the CLI wallet executable.

First, print the contract API with the following command:

beam-wallet-dappnet.exe shader --shader_app_file vault\app.wasm

Note, we have provided only a single parameter (--shader_app_file) since it's assume all other parameters are set in the config file and a separate path to the application Shader is found in the shader folder (with the Vault contract).

The output should resemble the following (debug logs are found in this example):

Copy the Shader output (see below) into your text editor, (following JSON format).

 {
     "roles":
     {
         "manager":
         {
             "create":
             {},
             "destroy":
             {
                 "cid": "ContractID"
             },
             "view":
             {},
             "view_logs":
             {
                 "cid": "ContractID"
             },
             "view_accounts":
             {
                 "cid": "ContractID"
             },
             "view_account":
             {
                 "cid": "ContractID",
                 "pubKey": "PubKey"
             }
         },
         "my_account":
         {
             "view":
             {
                 "cid": "ContractID"
             },
             "get_key":
             {
                 "cid": "ContractID"
             },
             "get_proof":
             {
                 "cid": "ContractID",
                 "aid": "AssetID"
             },
             "deposit":
             {
                 "cid": "ContractID",
                 "pkForeign": "PubKey",
                 "bCoSigner": "uint32_t",
                 "amount": "Amount",
                 "aid": "AssetID"
             },
             "withdraw":
             {
                 "cid": "ContractID",
                 "pkForeign": "PubKey",
                 "bCoSigner": "uint32_t",
                 "amount": "Amount",
                 "aid": "AssetID",
                 "amountCoSigner": "Amount"
             }
         }
     }
 }

The Vault contract API (as retrieved from the Vault Shader contract) separates the API actions into roles, (manager , my_account) following semantic structure.

The view_accounts method will list all Vault accounts present and were we can can plug the Valut Shader (found in the DAppnet explorer) contract ID into the view_accounts parameter.

d9c5d1782b2d2b6f733486be480bb0d8bcf34d5fdc63bbac996ed76af541cc14

Enter the following command:

beam-wallet-dappnet.exe shader --shader_app_file vault\app.wasm --shader_args=cid=d9c5d1782b2d2b6f733486be480bb0d8bcf34d5fdc63bbac996ed76af541cc14,role=manager,action=view_accounts

The output should resemble the following:

In the above example, there are currently no accounts within the contract. To create an account, utilize deposit method and deposit one Beam coin with the following command:

beam-wallet-dappnet.exe shader --shader_app_file vault\app.wasm --shader_args="cid=d9c5d1782b2d2b6f733486be480bb0d8bcf34d5fdc63bbac996ed76af541cc14,role=my_account,action=deposit,amount=100000000"

Note: amount is set in Groth, which is $$1^10-8$$ of Beam.

The above action creates and sends the transaction to the network (so it will take a moment). When completed, the output should resemble the following:

The response generated (see below) clarfies the API response:

To confirm the transaction was successful, re-enter the accounts command:

The response generated confirms a new account is identified by your wallet public key and has a balance of one Beams. To get aquainted with the API function, try depositing and withdrawing Beam's into your account. Users can also attempt to retrieve Beam's from a seperate account (spoiler: it won't work).

To learn how to code your own Shader application contract and deploy it chain, please refer to our Shader SDK tutorial.