Bitcoin Forum

Hello, I am a newbie, I can code, how can I use the taproot upgrade to code a smart contract involving BTC and not Eth?

That depends on what you want to accomplish.  Bitcoin Script is not Turing Complete, so depending on what you want to do, it may or may not be possible.

It would be great if you're being specific about what do you want to do and how much do you know about Bitcoin? Assuming  you're not too familiar with Bitcoin script/protocol, but just want to look around you could try Minsc (https://min.sc (https://min.sc)). But if you want interact with Bitcoin script directly and looking for introduction material, check https://blockgeeks.com/guides/best-bitcoin-script-guide/ (https://blockgeeks.com/guides/best-bitcoin-script-guide/). Take note it's somehow outdated and doesn't cover Taproot.

Unfortunately people have been misled to think "smart contract" is the same as "token creation capability" whereas "smart contract" has a wider meaning. Essentially ever since the first bitcoin transaction we have been using "smart contracts" in bitcoin, usually in their simplest form but with the ability to create more complex ones such as the HTLC ones used for second layer.
However, bitcoin doesn't and will probably never have the "token creation capability", at least not in the same sense as token creation platforms such as ethereum have. You can use Omni layer to create tokens (which is what Tether/USDT started with).

Thankfully...

Can you imagine what would happen to the mempool, network load and fees if someone created a Bitcoin version of "CrypoKitties" :o :-\ ::)

The taproot upgrade isn't meant to introduce token creation. However, it can be used to:

• Improve your privacy. The transactions which open lightning channels won't seem differently in the block chain. Also, with MAST and Schnorr signatures, it can obfuscate the final destination. it can make indistinguishable M-of-N addresses from 1-of-1.
• Make big transactions' fees lower such as the ones with multi-sig.

If you're a newbie, I would recommend you to start learning (https://learnmeabitcoin.com/).

What do you mean by that?
The "destination" is the outputs of the transaction, how can you obfuscate the outputs by using Schnorr signatures or MAST? The only thing that gets obfuscated is the "details" of the "signature", like a multi sig not looking any different than a single sig while the destination remains the same, the same address and the same amount obvious for anyone to see.

Sorry, that's what I meant! Not the destination. It just makes indistinguishable multi-sig transactions.