Welcome to Tact

Tact is a new programming language for TON blockchain that is focused on efficiency and simplicity. It is designed to be easy to learn and use, and to be a good fit for smart contracts. Tact is a statically typed language with a simple syntax and a powerful type system.

Getting started from template

To get started, you can use the template project. It contains a simple contract that can be deployed to the TON blockchain, example of implementing unit tests and helper functions for contract deployment.

To create a project from template, just create a new repository from the template project: https://github.com/ton-core/tact-template (opens in a new tab).

Getting started from scratch

Tact is distributed via npm package manager and is meant to be installed to typescript/javascript projects:

yarn add tact

Then you need to create a tact.config.json file in the root of your project. It should contain the following:

{
    "projects": [{
        "name": "sample",
        "path": "./sources/contract.tact",
        "output": "./sources/output"
    }]
}

Add an example contract to ./sources/contract.tact:

import "@stdlib/deploy";
 
message Add {
    amount: Int as uint32;
}
 
contract SampleTactContract with Deployable {
 
    owner: Address;
    counter: Int as uint32;
 
    init(owner: Address) {
        self.owner = owner;
        self.counter = 0;
    }
 
    fun add(v: Int) {
        
        // Check sender
        let ctx: Context = context();
        require(ctx.sender == self.owner, "Invalid sender");
        
        // Update counter
        self.counter = (self.counter + v);
    }
 
    receive(msg: Add) {
        self.add(msg.amount);
    }
 
    receive("increment") {
        self.add(1);
    }
 
    get fun counter(): Int {
        return self.counter;
    }
}

Add a build script to package.json:

{
    "scripts": {
        "build": "tact --config ./tact.config.json",
    }
}

Now you can run yarn build and get the compiled contract in ./sources/output folder.