Make a simple multisig contract with fift

advanced level

This information is very low-level. Could be hard to understand for newcomers and designed for advanced people who want to understand fift. The use of fift is not required in everyday tasks.

💡 Overview

This tutorial help you learn how to deploy your multisig contract.
Recall, that (n, k)-multisig contract is a multisignature wallet with n private keys holders, which accepts requests to send messages if the request (aka order, query) collects at least k signatures of the holders.

Based on original multisig contract code and updates by akifoq:

• original TON Blockchain multisig-code.fc
• akifoq/multisig with fift libraries to work with multisig.

starter tip

For anyone new with multisig: What is Multisig Technology? (video)

📖 What you'll learn

• How to create and customize a simple multisig wallet.
• How to deploy multisig wallet using lite-client.
• How to sign request and send it in message to the blockchain.

⚙ Set your environment

Before we begin our journey, check and prepare your environment.

• Install func, fift, lite-client binaries and fiftlib from the Installation section.
• Clone repository and open its directory in CLI.

git clone https://github.com/akifoq/multisig.git
cd ~/multisig

🚀 Let's get started!

1. Compile the code to fift.
2. Prepare multisig owners keys.
3. Deploy your contract.
4. Interact with deployed multisig wallet in blockchain.

Compile the contract

Compile the contract to Fift with:

func -o multisig-code.fif -SPA stdlib.fc multisig-code.fc

Prepare multisig owners keys

Create participants keys

To create a key you need to run:

fift -s new-key.fif $KEY_NAME$

• Where KEY_NAME is the name of the file where the private key will be written.

For example:

fift -s new-key.fif multisig_key

We'll receive a file multisig_key.pk with private key inside.

Collect public keys

Also, the script will issue a public key in the format:

Public key = Pub5XqPLwPgP8rtryoUDg2sadfuGjkT4DLRaVeIr08lb8CB5HW

Anything after "Public key = " needs to be saved somewhere!

Let's store in file keys.txt. One Public Key per line, it's important.

Deploy your contract

Deploy via lite-client

After creating all the keys, you need to collect the public keys into a text file keys.txt.

For example:

PubExXl3MdwPVuffxRXkhKN1avcGYrm6QgJfsqdf4dUc0an7/IA
PubH821csswh8R1uO9rLYyP1laCpYWxhNkx+epOkqwdWXgzY4

After that, you need to run:

fift -s new-multisig.fif 0 $WALLET_ID$ wallet $KEYS_COUNT$ ./keys.txt

• $WALLET_ID$ - the wallet number assigned for current key. It is recommended to use a unique $WALLET_ID$ for each new wallet with the same key.
• $KEYS_COUNT$ - the number of keys needed for confirmation, usually equal to the number of public keys

wallet_id explained

It's possible to create many wallets with the same keys (Alice key, Bob key). What to do if Alice and Bob already have treasure? That's why $WALLET_ID$ is crucial here.

The script will output something like:

new wallet address = 0:4bbb2660097db5c72dd5e9086115010f0f8c8501e0b8fef1fe318d9de5d0e501

(Saving address to file wallet.addr)

Non-bounceable address (for init): 0QBLuyZgCX21xy3V6QhhFQEPD4yFAeC4_vH-MY2d5dDlAbel

Bounceable address (for later access): kQBLuyZgCX21xy3V6QhhFQEPD4yFAeC4_vH-MY2d5dDlAepg

(Saved wallet creating query to file wallet-create.boc)

info

If you have "public key must be 48 characters long" error, please make sure your keys.txt has unix type word wrap - LF. For example, word wrap can be changed via Sublime text editor.

tip

Bounceable address is better to keep - this is the address of the wallet.

Activate your contract

You need to send some TON to our newly generated treasure. For example 0.5 TON. You can send testnet coins via @testgiver_ton_bot.

After that, you need to run lite-client:

lite-client -C global.config.json

Where get global.config.json?

You can get fresh config file global.config.json for mainnet or testnet.

After starting lite-client, it's best to run the time command in lite-client console to make sure the connection was successful:

time

Okay, lite-client is works!

After you need to deploy the wallet. run the command:

sendfile ./wallet-create.boc

After that, the wallet will be ready to work within a minute.

Interact with multisig wallet

Create a request

First you need to create a message request:

fift -s create-msg.fif $ADDRESS$ $AMOUNT$ $MESSAGE$

• $ADDRESS$ - address where to send coins
• $AMOUNT$ - number of coins
• $MESSAGE$ - name of file for compiled message.

For example:

fift -s create-msg.fif EQApAj3rEnJJSxEjEHVKrH3QZgto_MQMOmk8l72azaXlY1zB 0.1 message

tip

To add comment for your transaction, use -C comment attribute. To get more information, run create-msg.fif file without parameters.

Choose a wallet

Next you need to choose a wallet to send a coins from:

fift -s create-order.fif $WALLET_ID$ $MESSAGE$ -t $AWAIT_TIME$

Where

• $WALLET_ID$ — is an ID of wallet backed by this multisig contract.
• $AWAIT_TIME$ — Time in seconds that smart contract will await signs from multisig wallet's owners for request.
• $MESSAGE$ — here is a name of message boc-file created on the previous step.

info

If time equals $AWAIT_TIME$ passed before the request signs, the request becomes expired. As usual, $AWAIT_TIME$ equals a couple of hours (7200 seconds)

For example:

fift -s create-order.fif 0 message -t 7200

Ready file will be saved in order.boc

info

order.boc needs to be shared with key holders, they have to sign it.

Sign your part

To sign, you need to do:

fift -s add-signature.fif $KEY$ $KEY_INDEX$

• $KEY$ - name of the file containing the private key to sign, without extension.
• $KEY_INDEX$ - index of the given key in keys.txt (zero-based)

For example, for our multisig_key.pk file:

fift -s add-signature.fif multisig_key 0

Create a message

After everyone has signed the order, it needs to be turned into a message for the wallet and signed again with the following command:

fift -s create-external-message.fif wallet $KEY$ $KEY_INDEX$

In this case, will be enough only one sign of wallet's owner. The idea is that you can't attack a contract with invalid signatures.

For example:

fift -s create-external-message.fif wallet multisig_key 0

Send sign to TON Blockchain

After that, you need to start the light client again:

lite-client -C global.config.json

And after finally, we want to send our sign! Just run:

sendfile wallet-query.boc

If everyone else signed the request, it will be completed!

You did it, ha-ha! 🚀🚀🚀

What's next?

• Read more about multisig wallets in TON from akifoq