How long do decentralized swap routers keep logs of my trades

07 September 2026

They do not keep logs of your trades at all. A decentralized swap router is a smart contract, not a company, and it has no memory, no database, and no operator checking a dashboard.

What actually exists is the blockchain itself. Every swap you make through a router is recorded permanently on the ledger - Ethereum, Polygon, or whatever chain the router lives on. That record is not a “log” in the usual sense. It is a transaction, part of the chain’s history, and it stays there for as long as that chain exists. No one deletes it. No one can delete it, short of a catastrophic network rewrite, which does not happen in practice.

So the honest answer has two parts. The router keeps nothing, because it has no storage. The blockchain keeps everything, because that is its design. If you are asking about a specific router’s front-end website - the interface you clicked through - that is a different matter. The site may keep server logs, analytics cookies, or IP addresses, but those are not “logs of your trades” in the way you mean. Those are web traffic records, and their retention period is set by whoever runs the site. It could be days, months, or years. There is no standard. Some sites keep nothing. Others keep everything for compliance reasons. You cannot know without asking them, and many will not tell you.

The key distinction is between the trade itself and your interaction with the interface. The trade is a blockchain transaction. It is public, permanent, and has no expiry. Your interaction with the website - which wallet you used, what time you clicked, what IP address you came from - is not part of the blockchain. That data lives on servers you do not control, and its lifespan is a mystery to you.

Why does this matter for tax time? Because the blockchain record is your evidence, and it never goes away. The screenshot you take today is just a convenience. The underlying transaction hash will still resolve on a block explorer in five years, or ten, or fifty. But that only helps if you know the hash. If you relied on the router’s website to show you your history, and that website disappears or changes its privacy policy, you lose that convenience permanently. The chain still holds the data. You just have to find it another way.

A common mistake is assuming a router “clears” old trades. It does not. There is no purge. There is no archive. The transaction sits in a block, and that block sits in the chain, and the chain grows forward forever. What you might be confusing is the front-end’s display. A website might only show the last hundred trades you made through it. That is a UI limitation, not a deletion. The trades are still on-chain.

For practical purposes, treat the blockchain as permanent and the website as temporary. If you need a record for tax time, the blockchain is your source of truth. But the blockchain does not tell you why you traded, what your cost basis was at that moment, or whether the swap was part of a taxable event. That is the paperwork you keep yourself. The hub page - “Which swap records to keep for tax time” - covers exactly that, and it is worth reading before you assume the chain gives you everything.

One more thing to note. Some routers are upgradeable, or they get replaced by new versions. The old contract still holds its history, but the new contract starts fresh. Your old trades are still on-chain, just under a different address. Do not panic if the router you used last year has a new version. The old transactions are not gone. They are just older.

So, to answer the question directly: the router keeps zero logs, the blockchain keeps them forever, and the website’s logs are unknown and out of your hands. Save your transaction hashes, save your timestamps, and save your own notes. That is the only record you control. The chain will not forget, but it will not remind you either.

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