contract-ts

Count on NEAR Contract

The smart contract exposes methods to interact with a counter stored in the NEAR network.

val: number = 0;

@view
// Public read-only method: Returns the counter value.
get_num(): number {
  return this.val
}

@call
// Public method: Increment the counter.
increment() {
  this.val += 1;
  near.log(`Increased number to ${this.val}`)
}

@call
// Public method: Decrement the counter.
decrement() {
  this.val -= 1;
  near.log(`Decreased number to ${this.val}`)
}

@call
// Public method - Reset to zero.
reset() {
  this.val = 0;
  near.log(`Reset counter to zero`)
}

Quickstart

1. Make sure you have installed node.js >= 16.
2. Install the NEAR CLI

1. Build and Deploy the Contract

You can automatically compile and deploy the contract in the NEAR testnet by running:

npm run deploy

Once finished, check the ~/.near-credentials/testnet directory to find the address in which the contract was deployed:

cat ~/.near-credentials/testnet/counter-62af7c90-3.testnet.json
# e.g. {"account_id":"counter-62af7c90-3.testnet","public_key":"ed25519:59wcVk2q2tkibZLH6SRAFuPf2RRvNPDRTzdgnRSqHV7b","private_key":"ed25519:*****"}

2. Get the Counter

get_num is a read-only method (aka view method).

View methods can be called for free by anyone, even people without a NEAR account!

# Use near-cli to get the counter value
near view <dev-account> get_num

3. Modify the Counter

increment, decrement and reset change the contract's state, for which they are call methods.

Call methods can only be invoked using a NEAR account, since the account needs to pay GAS for the transaction.

# Use near-cli to set increment the counter
near call <dev-account> increment --accountId <dev-account>

Tip: If you would like to call increment using your own account, first login into NEAR using:

# Use near-cli to login your NEAR account
near login

and then use the logged account to sign the transaction: --accountId <your-account>.