Babylon Genesis Smart Contracts Deployment Guide

This guide walks you through deploying a smart contract on the Babylon Genesis blockchain. The example contract we'll deploy is a storage contract that allows saving data with Bitcoin timestamps and verifying Bitcoin finalization status.

Prerequisites

Before starting, ensure you have installed:

• Rust - Required for building the CosmWASM contract and CLI tool
• Docker - Used for contract optimization

Detailed Deployment Steps

1. Repository Setup

First, clone this repository containing the Babylon smart contract code. The repository includes submodules for Babylon core and contract dependencies.

Clone and update the submodules:

git submodule update --init --recursive

This command initializes and fetches all necessary submodule code: babylond binary and storage_contract. It might take a few minutes to complete as close to 1GB of data will be downloaded.

2. Babylond CLI Installation

The Babylond CLI is your primary tool for interacting with the Babylon Genesis blockchain.

Verify your Rust installation first:

cargo --version
# Expected output similar to:
cargo 1.84.1 (66221abde 2024-11-19)

Build and install the CLI:

cd babylon
make install

Verify the installation:

babylond version
# Should output a version hash similar to:
main-112821536b0ada40aa29e34b53206f56c61bf631

3. Environment Configuration

Load network-specific variables:

# For Phase 2 testnet (Babylon Genesis)
source env-phase2-testnet.sh

# OR for Phase 3 devnet
source env-phase3-devnet.sh

These files set crucial variables:

• $homeDir: Babylond configuration directory
• $chainId: Network identifier
• $feeToken: Token used for transaction fees
• $key: Your wallet name
• $nodeUrl: RPC endpoint
• $apiUrl: REST API endpoint

Verify the configuration:

echo $homeDir, $chainId, $feeToken, $key, $nodeUrl, $apiUrl

# Expected output:
/Users/<your_username>/.babylond, bbn-test-6, ubbn, test-key, https://babylon-testnet-rpc.polkachu.com, https://babylon-testnet-api.polkachu.com

4. Wallet Management

Create a New Wallet

Create a test wallet using the local keyring:

babylond keys add test-key --keyring-backend=test

This command:

• Creates a new key pair named test-key
• Stores it in the test keyring
• Outputs the address and recovery phrase
• IMPORTANT: Save the mnemonic phrase securely for recovery using --restore command

Verify the wallet:

babylond keys list --keyring-backend=test
# Expected output:
- address: bbn1y7h7nmxpwlfuj8m72qa0uwc8nqflzgragve5zv
  name: test-key
  pubkey: '{"@type":"/cosmos.crypto.secp256k1.PubKey","key":"Aw48YzsPg4bPhToeAfBM/sIL+nmgi7oxPjJ8sQXVl0lW"}'
  type: local

Fund Your Wallet

You need test tokens (tBABY) to deploy contracts. Get them through:

Xangle Babylon Genesis Testnet Faucet:

1. Visit Xangle Faucet
2. Create an account
3. Request test tokens with wallet you just created above

Verify your balance:

babylond query bank balances $(babylond keys show $key -a --keyring-backend=test) --node=$nodeUrl

Expected output should show some tBABY tokens.

5. Contract Building

Verify Docker

The build process uses Docker for consistent environments:

docker run hello-world

Build Contract

Navigate to the contract directory and build:

cd storage-contract
cargo run-script optimize

This creates an optimized WASM file in the artifacts directory.

6. Contract Deployment Process

Step 1: Store Contract Code

Upload the WASM file to the blockchain:

babylond tx wasm store ./artifacts/storage_contract-aarch64.wasm \
--from=$key \
--gas=auto \
--gas-prices=0.002$feeToken \
--gas-adjustment=1.3 \
--chain-id="$chainId" \
-b=sync \
--yes \
--keyring-backend=test \
--log_format=json \
--home=$homeDir \
--node=$nodeUrl

Key parameters explained:

• --gas=auto: Automatically estimates required gas
• --gas-prices=0.002$feeToken: Sets the gas price to gas = autoCalculation x 0.002ubbn
• --gas-adjustment=1.3: Adds 30% to estimated gas for safety so gas = autoCalculation x 0.002ubbn x 1.3
• -b=sync: Waits for transaction to be broadcast
• --yes: Automatically confirms the transaction

Step 2: Get Contract Code ID

After storing, get the unique code identifier:

codeID=$(babylond query wasm list-code \
--node $nodeUrl \
-o json \
| jq \
--arg ADDR "$(babylond keys show $key -a --keyring-backend=test)" \
'.code_infos[] | select(.creator==$ADDR).code_id | tonumber')

This command filters contracts against your wallet address to find the one you just uploaded.

Step 3: Instantiate Contract

Create a new instance of the contrac using tx wasm instantiate command:

babylond tx wasm instantiate $codeID '{}' \
--from=$key \
--no-admin \
--label="storage_contract" \
--gas=auto \
--gas-prices=0.002$feeToken \
--gas-adjustment=1.3 \
--chain-id="$chainId" \
-b=sync \
--yes \
--keyring-backend=test \
--log_format=json \
--home=$homeDir \
--node=$nodeUrl

Parameters explained:

• '{}': Empty initialization parameters for the storage_contract
• --no-admin: Creates contract without admin privileges
• --label: Human-readable identifier

Get the contract's address and store it in a variable:

contractAddress=$(babylond query wasm list-contract-by-code $codeID \
--node=$nodeUrl \
-o json \
| jq -r '.contracts[0]')

7. Contract Interaction

Save Data

To store data in the contract using tx wasm execute command:

# Your data to store
data="This is example plain-text data"

# Convert to hex format (required by contract)
hexData=$(echo -n "$data" | xxd -ps -c0)

# Create the execution message for the save_data function
executeMsg="{\"save_data\":{\"data\":\"$hexData\"}}"

# Send transaction via `tx wasm execute` command
babylond tx wasm execute $contractAddress "$executeMsg" \
--from=$key \
--gas=auto \
--gas-prices=0.002$feeToken \
--gas-adjustment=1.3 \
--chain-id="$chainId" \
-b=sync \
--yes \
--keyring-backend=test \
--log_format=json \
--home=$homeDir \
--node=$nodeUrl

Query Data

To retrieve stored data using query wasm contract command:

# Create hash of original data for verification
hashedData=$(echo -n "$data" | sha256sum | cut -f1 -d' ')

# Prepare query message
quer

As a reault you should see the following output with data store and finalized status and btc_timestamp information:

{
  "data": {
    "finalized": false,
    "latest_finalized_epoch": "644",
    "data": {
      "data": "54686973206973206578616d706c6520706c61696e2d746578742064617461",
      "btc_height": "234328",
      "btc_timestamp": "1738908922",
      "saved_at_btc_epoch": "658"
    }
  }
}