Setting up the Advanced Cross-Contract Calls Project

Let's set up the project environment with the main contract and test contracts.

Obtaining the Project

git clone https://github.com/near-examples/cross-contract-calls
cd cross-contract-calls

Choose your language:

JavaScript

cd contract-advanced-ts
npm install

Rust

cd contract-advanced-rs
cargo check

Project Structure

├── tests/                    # Test environment
│   └── external-contracts/   # Pre-compiled contracts
│       ├── counter.wasm      # Simple counter
│       ├── guest-book.wasm   # Message storage
│       └── hello-near.wasm   # Greeting contract
├── src/                      # Main contract code
│   ├── batch_actions.*       # Batch operations
│   ├── multiple_contracts.*  # Parallel execution
│   └── similar_contracts.*   # Same-type calls
└── README.md

Test Contracts Overview

Hello NEAR Contract

• get_greeting() - Returns current greeting
• set_greeting(message: string) - Updates greeting

Counter Contract

• get_num() - Returns current count
• increment() - Increases by 1
• decrement() - Decreases by 1

Guest Book Contract

• add_message(text: string) - Adds message
• get_messages() - Returns all messages

Building the Contract

JavaScript

npm run build
# Output: build/cross_contract.wasm

Rust

cargo near build
# Output: target/wasm32-unknown-unknown/release/cross_contract.wasm

Running Tests

Verify everything works:

JavaScript

npm test

Rust

cargo test

Expected output:

✓ Test batch actions
✓ Test multiple contracts  
✓ Test similar contracts

Contract Initialization

The main contract needs external contract addresses:

JavaScript

@NearBindgen({})
export class CrossContractCall {
  hello_account: AccountId;
  counter_account: AccountId;
  guestbook_account: AccountId;

  @initialize({})
  init({
    hello_account,
    counter_account,
    guestbook_account,
  }: {
    hello_account: AccountId;
    counter_account: AccountId;
    guestbook_account: AccountId;
  }) {
    this.hello_account = hello_account;
    this.counter_account = counter_account;
    this.guestbook_account = guestbook_account;
  }
}

Rust

#[near_bindgen]
impl Contract {
    #[init]
    pub fn init(
        hello_account: AccountId,
        counter_account: AccountId,
        guestbook_account: AccountId,
    ) -> Self {
        Self {
            hello_account,
            counter_account,
            guestbook_account,
        }
    }
}

Deploy Your Contract

# Create your account
near account create-account sponsor-by-faucet-service xcc.YOUR_NAME.testnet autogenerate-new-keypair save-to-keychain network-config testnet create

# Deploy with initialization
near contract deploy xcc.YOUR_NAME.testnet use-file ./build/cross_contract.wasm with-init-call init json-args '{
  "hello_account":"hello.near-examples.testnet",
  "counter_account":"counter.near-examples.testnet",
  "guestbook_account":"guestbook.near-examples.testnet"
}' prepaid-gas '100.0 Tgas' attached-deposit '0 NEAR' network-config testnet sign-with-keychain send

Now let's explore batch actions in the next chapter!