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UNDER THE HOOD

Anatomy of a Transaction: What Happens Between the Click and the Confirmation

You hit "confirm" and then stare at a spinner for ten seconds. We break down what happens in those seconds, why you pay a fee, and what every field in the transaction details actually means.

Between clicking "confirm" and seeing "done," a few seconds pass in which a surprising amount happens. Once you know what, two things that annoy people most stop being a mystery: why it sometimes takes a while, and why you pay a fee even for a failed transaction.

A Transaction Is a Signed Command, Not a Transfer of Money

You're not moving coins around like files. You create an instruction — "send this much from address A to address B" — and sign it with your private key. The key itself never leaves your device; the signature is mathematical proof that the command came from whoever holds it. The network verifies it and updates the state.

That's exactly why signing is such a sensitive act. You're signing the content, not the intent. If a scam site slips you a command that reads "allow me to manage all of your USDC" and you click through it, the network will dutifully carry out exactly what you signed.

Walk the Path Yourself

Set a fee and send the transaction. You'll see where it waits and why the fee is worth paying:

Transaction path the fee changes the wait in line
  1. Signature Your wallet signs the instruction with your private key. The key never leaves your device.
  2. Mempool The transaction waits in the queue of unprocessed ones. This is where the fee decides the order.
  3. In a Block A validator included it in a block. From this moment it's in the chain.
  4. Confirmed More blocks pile up on top of it. The more there are, the harder it is to move the history.
waiting on you

The Fee: Who Gets It and For What

Every operation on the network costs computational work, measured in units called gasA unit of computational cost. A plain transfer costs 21,000 gas, a complex trade through a contract can easily cost ten times that.. How much gas an operation consumes is fixed. How much you pay per unit is an auction — and when the network is busy, whoever bids more wins.

Which gives us the unpleasant rule: you pay the fee for the work done, not for success. If a transaction fails halfway through, the work already happened and the network charges you for it anyway. That's why it's worth sending a small test amount first with any new contract.

On Polygon it's fortunately pocket change While on Ethereum a fee can spike to tens of dollars at peak times, on Polygon it usually sits in the range of cents. You still need a little POL on the address, though — without it, not even the cheapest transaction goes through.

Take It Apart, Piece by Piece

Open a transaction in a block explorer and a table of fields spills out at you. Click any of them and we'll tell you what it means:

Transaction autopsy click a field

When a Transaction Gets Stuck

Sometimes a transaction just hangs in the mempool and nothing happens — you offered too little and the queue keeps skipping it. The fix is in the nonce field: you send a new transaction with the same nonce, but a higher fee. The network only processes one of them, and the old one quietly falls away. In a wallet this is called "speed up" or "cancel," and that's exactly what it does.

A consequence of the same rule: transactions from one address are processed in nonce order. If the one numbered 42 is stuck, number 43 can't go through, no matter how much it's willing to pay.

How Many Confirmations Are Enough

Once a transaction is in a block, it's technically gone through. But shortly after it's included, the network can still reshuffle the last few blocks (reorgA situation where the network settles between two competing ends of the chain proposed at nearly the same time, and discards one of them. It only affects the last few blocks — deep history is never touched.), so you wait for more blocks to build on top of it. Small amounts only need a handful of confirmations; large ones wait for finality — the point at which reversing it would cost an attacker more than they'd gain.

What matters for us is that this whole process is public at every stage. We see a shark's transaction the moment it lands in the mempool — that is, before it's even in a block. That's where the head start PolyTips runs on comes from.

The most dangerous transaction is the boring one An "approve" doesn't transfer a single cent, so it looks harmless. Meanwhile it hands a contract the right to move your tokens — sometimes with no limit, and forever. Only approve where you actually intend to trade, and revoke old approvals every so often.

What to Take Away

  • A transaction is a signed command. You're signing content, not intent — read what you're clicking through.
  • You pay the fee for the work, even when the transaction fails. Test with a small amount.
  • nonce determines the order. Beat a stuck transaction with a new one using the same nonce and a higher fee.
  • In a block = it happened. Confirmations on top of it = it's not moving now.
  • "Approve" is the quietest and most dangerous transaction you'll ever sign.

That covers the basics: the market, the wallet, the chain, and the transaction. The rest is patience — and watching where the big money flows.