TAC SDK (Python)

Python SDK for TON <-> TAC cross-chain operations. Repository: https://github.com/TacBuild/python-tac-sdk

ETH <-> TON Bridge Helpers

See the dedicated helper docs: helpers/README.md

Installation

pip install tac-sdk

Prerequisities

1. Create .env out of .env.example and populate it with necessary data;
2. Fund your TAC wallet (the one which corresponds to EVM_PRIVATE_KEY) on the TAC chain with WTAC to pay fees. You can use https://bridge.tac.build/; Addresses on TAC and ETH chains are equal for the same EVM_PRIVATE_KEY.
3. Go to WTAC address https://explorer.tac.build/token/0xB63B9f0eb4A6E6f191529D71d4D88cc8900Df2C9 and connect your wallet EVM_PRIVATE_KEY. Navigate to Contract > Read/Write contract > Write > approve. Set spender to be composer address (currently 0xC1313fD7ca98a85E8a0A3398739801f6653d456b) and your value. As of Feb 2026 bridge tx on TAC chain costs ~120-150 WTAC. If you happen to reach allowance limit, your bridge txs start to fail. You can increase allowance with higher value;
4. For cbBTC. Go to https://etherscan.io/token/0xcbb7c0000ab88b473b1f5afd9ef808440eed33bf and connect your wallet EVM_PRIVATE_KEY. Navigate to Contract > Write as Proxy. Set spender to be cbBTC OFT adapter on ETH chain (0x59Ea2825d8Ad7D60cC6Aa77FFbDD0E89c0fBF539) and the value of cbBTC you expect to bridge in upcoming future;
5. For WETH. Go to https://etherscan.io/token/0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2 and connect your wallet EVM_PRIVATE_KEY. Navigate to Contract > Write as Proxy. Set spender to be WETH OFT adapter on ETH chain (0xf211D3B40A74632162F45F4d42A461b663694a9D) and the value of WETH you expect to bridge in upcoming future.

Quick start

import asyncio
from sdk.tac_sdk import TacSdk
from structs.struct import Network, SDKParams


async def main() -> None:
    sdk = await TacSdk.create(SDKParams(network=Network.TESTNET))
    token = await sdk.getFT("EQBLi0v_y-KiLlT1VzQJmmMbaoZnLcMAHrIEmzur13dwOmM1")
    print(token.address)


asyncio.run(main())