Usually the seller takes on short-term price fluctuation risk.

Buyer initiates purchase, and the seller gives them a window of x minutes to send y btc to an address, where the price of the service is denominated in btc as of the trading price at that moment.

If at least 1 transaction doesn't show up on the btc network in the x minutes, that transaction times out.

If at least 1 does, then the seller waits for w confirmations to take place before the payment is recognized as valid, where w is set to their tolerance. I've seen as low as 3 and as high as 7.

At times that bad with the lightning network?

There's a thing called a stablecoin :)

So what? If you want to send someone $10 as crypto a centralized stablecoin works perfectly.

USDC/USDT is centralized as in a central entity is trading it in a way to keep the peg at $1.

It is not centralized as in a central entity needs to approve your transaction.

Explain how Fei is centralised.

I don't know about "Fei" in particular, but stablecoins generally fall into two categories:

1. Relies on some central entity to buy/sell it as to peg/back it to another asset.

2. Relies on some central observer to sign exchange rates so that the system can automatically adjust its reward system.

I'm guessing it's the latter. But feel free to explain to me how it isn't centralized if you think you have a case for it.

It relies on both those things, but both are decentralized. The first is handled by arbitragers who can mint/redeem it for other decentralized assets (it is fully collateralized by a treasury of decentralized assets).

The oracle is handled by Chainlink which is decentralized.

No offense, but I highly doubt that.

>The first is handled by arbitragers who can mint/redeem it for other decentralized assets (it is fully collateralized by a treasury of decentralized assets).

Sure, but the parameters of this mint/reward system are a function of the exchange rate, are they not? Even then, those decentralized assets are either other stablecoins, or non-stablecoins. If it's backed by stablecoins, then it's centralized. If it's backed by non-stablecoins, then it's non-stable.

>The oracle is handled by Chainlink which is decentralized.

You can't have a decentralized oracle in any meaningful way, it is like what truthcoin tried to do. I admittedly have no idea how chain-link works, but I am pretty certain that it is not decentralized. It is almost a truism that members of distributed system cannot verify arbitrary facts about the outside world (for example, exchange rates) without having trusted oracle/oracles. You can try to make the system reliant on many different oracles, but that is similar to classical consensus and there's no distributed way to prevent them from colluding. It is essentially the problem with proof-of-stake.

If you ask me, Fei looks like yet another ponzi system like USDT/LUNA. Why are stablecoin owners always rewarded for merely holding?

You've made a lot of assumptions that aren't true. Highly recommend actually researching them.

You can absolutely have price oracles of crypto assets without any interaction offchain, as you can use uniswap market prices and if they differ from any other exchanges arbitragers will make a profit by fixing that difference. But that is another oracle that is different from chainlink.

Chainlink is decentralized. It could possibly be attacked with enough effort and money to destabilize things but that is a totally different threat vector than the government restricting trading to services it doesn't like or censoring users.

Fei is backed only by decentralized assets.

UST was backed by nothing which is why it collapsed, Fei is over collateralized. You don't get any rewards for holding Fei.

I don't think this addresses my main points.

Uniswap is only between cryptocurrencies. As I said earlier, those cryptocurrencies are either other stablecoins, or non-stablecoins. If it's backed by stablecoins, then it's centralized. If it's backed by non-stablecoins, then it's non-stable.

Chainlink is, from what I understand, a truthcoin-like system where oracles put down collateral. It is fundamentally a broken system because whatever group with the majority of the collateral just wins. What is stopping a government that can censor users and restrict trading from forcing oracles to collude and report false information?

You keep repeating that non-stablecoins make it non-stable but it doesn't actually make any sense. Fei is a stablecoin using non-stable assets, that is stable. All you need is a treasury bigger than outstanding debt. You're going to have to present better evidence than that.

I addressed your comment on Chainlink already, yes it could come under pressure or attack which would destabilize the network. This could be used to break many things, but it's not a vector for censorship / centralization because it has nothing to do with Fei's use as a currency and definitely doesn't make Fei centralised.

If it's backed by bitcoin for example, and you're trying to peg it to USD, then the spending power of your treasury in USD will depend on the price of bitcoin and the peg will just break when the price of bitcoin falls too far.

Fei's reward system is controlled by whichever party controls the oracles. You can outsource the oracles to a proof-of-stake-like system on chainlink, but that doesn't get rid of the fundamental problem.