The 'Clarity - Stacks Labs' extension as it appears in Visual Studio Code.
;; Simple Message Board Contract
;; This contract allows users to read and post messages for a fee in sBTC.
;; Define contract owner
(define-constant CONTRACT_OWNER tx-sender)
;; Define error codes
(define-constant ERR_NOT_ENOUGH_SBTC (err u1004))
(define-constant ERR_NOT_CONTRACT_OWNER (err u1005))
(define-constant ERR_BLOCK_NOT_FOUND (err u1003))
;; Define a map to store messages
;; Each message has an ID, content, author, and Bitcoin block height timestamp
(define-map messages
uint
{
message: (string-utf8 280),
author: principal,
time: uint,
}
)
;; Counter for total messages
(define-data-var message-count uint u0)
;; Public function to add a new message for 1 satoshi of sBTC
;; @format-ignore
(define-public (add-message (content (string-utf8 280)))
(let ((id (+ (var-get message-count) u1)))
(try! (restrict-assets? contract-caller
((with-ft 'SM3VDXK3WZZSA84XXFKAFAF15NNZX32CTSG82JFQ4.sbtc-token "sbtc-token" u1))
(unwrap!
;; Charge 1 satoshi of sBTC from the caller
(contract-call? 'SM3VDXK3WZZSA84XXFKAFAF15NNZX32CTSG82JFQ4.sbtc-token
transfer u1 contract-caller current-contract none
)
ERR_NOT_ENOUGH_SBTC
)
))
;; Store the message with current Bitcoin block height
(map-set messages id {
message: content,
author: contract-caller,
time: burn-block-height,
})
;; Update message count
(var-set message-count id)
;; Emit event for the new message
(print {
event: "[Stacks Dev Quickstart] New Message",
message: content,
id: id,
author: contract-caller,
time: burn-block-height,
})
;; Return the message ID
(ok id)
)
)
(try! (restrict-assets? contract-caller
((with-ft 'SM3VDXK3WZZSA84XXFKAFAF15NNZX32CTSG82JFQ4.sbtc-token "sbtc-token" u1))
(unwrap!
;; Charge 1 satoshi of sBTC from the caller
(contract-call? 'SM3VDXK3WZZSA84XXFKAFAF15NNZX32CTSG82JFQ4.sbtc-token
transfer u1 contract-caller current-contract none
)
ERR_NOT_ENOUGH_SBTC
)
))
;; Return the message ID
(ok id)
;; Withdraw function for contract owner to withdraw accumulated sBTC
(define-public (withdraw-funds)
(begin
(asserts! (is-eq tx-sender CONTRACT_OWNER) (err u1005))
(let ((balance (unwrap-panic (contract-call? 'SM3VDXK3WZZSA84XXFKAFAF15NNZX32CTSG82JFQ4.sbtc-token
get-balance current-contract
))))
(if (> balance u0)
(contract-call? 'SM3VDXK3WZZSA84XXFKAFAF15NNZX32CTSG82JFQ4.sbtc-token
transfer balance current-contract CONTRACT_OWNER none
)
(ok false)
)
)
)
)
;; Read-only function to get a message by ID
(define-read-only (get-message (id uint))
(map-get? messages id)
)
;; Read-only function to get message author
(define-read-only (get-message-author (id uint))
(get author (map-get? messages id))
)
;; Read-only function to get message count at a specific Stacks block height
(define-read-only (get-message-count-at-block (block uint))
(ok (at-block
(unwrap! (get-stacks-block-info? id-header-hash block) ERR_BLOCK_NOT_FOUND)
(var-get message-count)
))
)
import { Cl, ClarityType } from "@stacks/transactions";
import { describe, expect, it } from "vitest";
const accounts = simnet.getAccounts();
const deployer = accounts.get("deployer")!;
const address1 = accounts.get("wallet_1")!;
describe("example tests", () => {
let content = "Hello Stacks Devs!"
it("allows user to add a new message", () => {
let currentBurnBlockHeight = simnet.burnBlockHeight;
let confirmation = simnet.callPublicFn(
"stacks-dev-quickstart-message-board",
"add-message",
[Cl.stringUtf8(content)],
address1
)
const messageCount = simnet.getDataVar("stacks-dev-quickstart-message-board", "message-count");
expect(confirmation.result).toHaveClarityType(ClarityType.ResponseOk);
expect(confirmation.result).toBeOk(messageCount);
expect(confirmation.events[1].data.value).toBeTuple({
author: Cl.standardPrincipal(address1),
event: Cl.stringAscii("[Stacks Dev Quickstart] New Message"),
id: messageCount,
message: Cl.stringUtf8(content),
time: Cl.uint(currentBurnBlockHeight),
});
});
it("allows contract owner to withdraw funds", () => {
simnet.callPublicFn(
"stacks-dev-quickstart-message-board",
"add-message",
[Cl.stringUtf8(content)],
address1
)
simnet.mineEmptyBurnBlocks(2);
let confirmation = simnet.callPublicFn(
"stacks-dev-quickstart-message-board",
"withdraw-funds",
[],
deployer
)
expect(confirmation.result).toBeOk(Cl.bool(true));
expect(confirmation.events[0].event).toBe("ft_transfer_event")
expect(confirmation.events[0].data).toMatchObject({
amount: '1',
asset_identifier: 'SM3VDXK3WZZSA84XXFKAFAF15NNZX32CTSG82JFQ4.sbtc-token::sbtc-token',
recipient: deployer,
sender: `${deployer}${".stacks-dev-quickstart-message-board"}`,
})
})
});
[network]
name = "testnet"
stacks_node_rpc_address = "https://api.testnet.hiro.so"
deployment_fee_rate = 10
[accounts.deployer]
mnemonic = "<YOUR TESTNET MNEMONIC>"
derivation = "m/44'/5757'/0'/0/0"
import { connect, disconnect } from '@stacks/connect'
import type { GetAddressesResult } from '@stacks/connect/dist/types/methods'
import { useState } from 'react'
function App() {
let [isConnected, setIsConnected] = useState<boolean>(false)
let [walletInfo, setWalletInfo] = useState<any>(null)
let [bns, setBns] = useState<string>('')
async function connectWallet() {
let connectionResponse: GetAddressesResult = await connect()
let bnsName = await getBns(connectionResponse.addresses[2].address)
setIsConnected(true)
setWalletInfo(connectionResponse)
setBns(bnsName)
}
async function disconnectWallet() {
disconnect();
}
async function getBns(stxAddress: string) {
let response = await fetch(`https://api.bnsv2.com/testnet/names/address/${stxAddress}/valid`)
let data = await response.json()
return data.names[0].full_name
}
return (
<>
<h3>Stacks Dev Quickstart Message Board</h3>
{isConnected ? (
<button onClick={disconnectWallet}>{
bns ? bns : walletInfo.addresses[2].address
}</button>
) : (
<button onClick={connectWallet}>connect wallet</button>
)}
</>
)
}
The Stacks Connect wallet selector modal
import { request } from '@stacks/connect'
import type { TransactionResult } from '@stacks/connect/dist/types/methods'
import { Cl, Pc } from '@stacks/transactions'
import { useState } from 'react'
function App() {
// ...
let [content, setContent] = useState<string>('')
async function addMessage() {
let postCond_1 = Pc.principal('ST11V9ZN6E6VG72SHMAVM9GDE30VD3VGW5Q1W9WX3')
.willSendEq(1)
.ft('ST1F7QA2MDF17S807EPA36TSS8AMEFY4KA9TVGWXT.sbtc-token', 'sbtc-token')
let result: TransactionResult = await request('stx_callContract', {
contract: 'ST11V9ZN6E6VG72SHMAVM9GDE30VD3VGW5Q1W9WX3.stacks-dev-quickstart-message-board',
functionName: 'add-message',
functionArgs: [Cl.stringUtf8(content)],
network: 'testnet',
postConditions: [postCond_1],
postConditionMode: 'deny',
sponsored: false
})
setContent('')
}
return (
<>
// ...
<span className='input-container'>
<button onClick={addMessage}>add-message</button>
<input type="text" onChange={e => setContent(e.target.value)}/>
</span>
</>
)
}
// ...
import type { ClarityValue } from '@stacks/connect/dist/types/methods'
import { Cl, fetchCallReadOnlyFunction } from '@stacks/transactions'
function App() {
// ...
async function getMessageCountAtBlock() {
let response = await fetch('https://api.testnet.hiro.so/v2/info', {
headers: {
"x-api-key": "<HIRO_API_KEY>"
}
})
let data = await response.json()
let stacksBlockHeight = data.stacks_tip_height
let result: ClarityValue = await fetchCallReadOnlyFunction({
contractAddress: 'ST11V9ZN6E6VG72SHMAVM9GDE30VD3VGW5Q1W9WX3',
contractName: 'stacks-dev-quickstart-message-board',
functionName: 'get-message-count-at-block',
functionArgs: [Cl.uint(stacksBlockHeight)],
network: 'testnet',
senderAddress: 'ST11V9ZN6E6VG72SHMAVM9GDE30VD3VGW5Q1W9WX3',
})
}
// ...