@stacks/connect

🐎 Getting Started

1. Add the dependency

Add the @stacks/connect dependency to your project using your favorite package manager. Some options below

npm install @stacks/connect
pnpm install @stacks/connect
yarn add @stacks/connect

2. Creating AppConfig and UserSession

Add a reusable UserSession instance to your project. This will allow your website to store authentication state in localStorage.

/* ./userSession.js */
import { AppConfig, UserSession } from '@stacks/connect';

const appConfig = new AppConfig(['store_write', 'publish_data']);
export const userSession = new UserSession({ appConfig }); // we will use this export from other files

3. Interacting with the wallet

• "Connect" aka authentication (showConnect)
• Sending STX (openSTXTransfer)
• Sending transactions with post-conditions (openSTXTransfer)
  • Post-Condition Modes
• Calling Smart-Contracts (openContractCall)

"Connect" aka authentication (showConnect)

Connecting the wallet is a very simple form of authentication. This process gives the web-app information about a wallet account (selected by the user).

The snippet below lets your web-app trigger the wallet to open and authenticate an account. If no wallet is installed, an informational modal will be displayed in the web-app.

import { showConnect } from '@stacks/connect';
import { userSession } from './userSession';

const myAppName = 'My Stacks Web-App'; // shown in wallet pop-up
const myAppIcon = window.location.origin + '/my_logo.png'; // shown in wallet pop-up

showConnect({
  userSession, // `userSession` from previous step, to access storage
  appDetails: {
    name: myAppName,
    icon: myAppIcon,
  },
  onFinish: () => {
    window.location.reload(); // WHEN user confirms pop-up
  },
  onCancel: () => {
    console.log('oops'); // WHEN user cancels/closes pop-up
  },
});

Sending STX (openSTXTransfer)

Sending STX tokens is also possible through web-apps interacting with a user's wallet.

The snippet below will open the wallet to confirm and broadcast a smart-contract transaction. Here, we are sending 10000 micro-STX tokens to a recipient address.

import { openSTXTransfer } from '@stacks/connect';
import { StacksTestnet } from '@stacks/network';
import { AnchorMode, PostConditionMode } from '@stacks/transactions';
import { userSession } from './userSession';

openSTXTransfer({
  network: new StacksTestnet(), // which network to use; use `new StacksMainnet()` for mainnet
  anchorMode: AnchorMode.Any, // which type of block the tx should be mined in

  recipient: 'ST39MJ145BR6S8C315AG2BD61SJ16E208P1FDK3AK', // which address we are sending to
  amount: 10000, // tokens, denominated in micro-STX
  memo: 'Nr. 1337', // optional; a memo to help identify the tx

  postConditionMode: PostConditionMode.Deny, // whether the tx should fail when unexpected assets are transferred
  postConditions: [], // for an example using post-conditions, see next example

  onFinish: response => {
    // WHEN user confirms pop-up
    console.log(response.txid); // the response includes the txid of the transaction
  },
  onCancel: () => {
    // WHEN user cancels/closes pop-up
    console.log('User canceled');
  },
});

Sending transactions with post-conditions (openSTXTransfer)

Consider the example above. Using post-conditions, a feature of the Stacks blockchain, we can ensure something happened after a transaction. Here, we could ensure that the recipient indeed receives a certain amount of STX.

import {
  PostConditionMode,
  FungibleConditionCode,
  makeStandardSTXPostCondition,
} from '@stacks/transactions';

// this post-condition ensures that our recipient receives at least 5000 tokens
const myPostCondition = makeStandardSTXPostCondition(
  'ST39MJ145BR6S8C315AG2BD61SJ16E208P1FDK3AK', // address of recipient
  FungibleConditionCode.GreaterEqual, // comparator
  5000 // relative amount to previous balance
);

// passing to `openSTXTransfer` options, e.g. modifying our previous example ...
  postConditionMode: PostConditionMode.Deny, // whether the tx should fail when unexpected assets are transferred
  postConditions: [ myPostCondition ],
// ...

For more examples on constructing different kinds of post-conditions read the Post-Conditions Guide of Stacks.js.

Post-Condition Modes

If post-conditions postConditions: [ ... ] are specified, they will ALWAYS be checked by blockchain nodes. If ANY conditions fails, the transaction will fail.

The Post-Condition Mode only relates to transfers of assets, which were not specified in the postConditions.

• PostConditionMode.Deny will fail the transaction if any unspecified assets are transferred
• PostConditionMode.Allow will allow unspecified assets to be transferred
• In both cases, all postConditions will be checked

Calling Smart-Contracts (openContractCall)

Calling smart-contracts lets users interact with the blockchain through transactions.

The snippet below will open the wallet to confirm and broadcast a smart-contract transaction. Here, we are passing our pick Alice to an imaginary deployed voting smart-contract.

import { openContractCall } from '@stacks/connect';
import { StacksTestnet } from '@stacks/network';
import { AnchorMode, PostConditionMode, stringUtf8CV } from '@stacks/transactions';
import { userSession } from './userSession';

const pick = stringUtf8CV('Alice');

openContractCall({
  network: new StacksTestnet(),
  anchorMode: AnchorMode.Any, // which type of block the tx should be mined in

  contractAddress: 'ST39MJ145BR6S8C315AG2BD61SJ16E208P1FDK3AK',
  contractName: 'example-contract',
  functionName: 'vote',
  functionArgs: [pick],

  postConditionMode: PostConditionMode.Deny,
  postConditions: [],

  onFinish: response => {
    // WHEN user confirms pop-up
  },
  onCancel: () => {
    // WHEN user cancels/closes pop-up
  },
});

🤔 Pitfalls

• Connect can currently not set manual nonces, since this is not supported by wallets.
• For some projects it might be necessary to also install the regenerator-runtime package. npm install --save-dev regenerator-runtime. This is a build issue of @stacks/connect and we are working on a fix.

📚 Option Glossary

A glossary of the most common options of openSTXTransfer and openContractCall

openSTXTransfer Required

	Description	Type	Example
recipient	The recipient (STX principal) address	string	'ST39MJ145BR6S8C315AG2BD61SJ16E208P1FDK3AK'
amount	The amount (in micro-STX) to transfer	Integer (e.g. number, bigint)	10000

openContractCall Required

	Description	Type	Example
contractAddress	The (STX contract) address of the smart contract	string	'ST39MJ145BR6S8C315AG2BD61SJ16E208P1FDK3AK'
contractName	The contract name	string	'example-contract'
functionName	The contract function name	string	'vote'
functionArgs	The contract function arguments	Array of Clarity Values	[], [uintCV(100)]

Optional

	Default	Description	Type	Example
network	Mainnet	The network to broadcast the transaction to	StacksNetwork	new StacksMainnet()
anchorMode	Any	The type of block the transaction should be mined in	AnchorMode Enum	AnchorMode.OnChainOnly
memo	Empty ''	The memo field (used for additional data)	string	'a memo'
fee	Handled by Wallet	The transaction fee (the wallet will estimate fees as well)	Integer (e.g. number, bigint)	1000
onFinish	No-op	The callback function to run after broadcasting the transaction	Function (receiving response)
onCancel	No-op	The callback function to run after the user cancels/closes the wallet	Function