By the end you will know the layer most people actually touch: the machines that drive the other machines, what each one optimizes, and the commission it takes for the wheel.
Think of the last trip you booked. You did not call the airline, the hotel and the transfer desk one by one; something assembled the trip while you tapped once. Money works the same way. Almost nobody hand-drives every machine they use.
And by now you know the machines: pools, ranges, loans, receipts. The concentrated liquidity checkpoint was honest about it: running a range well is a job. This lesson is about the layer that does the job for you, and what it charges for the wheel.
You could book every flight, hotel and transfer yourself. The travel agent knows the routes, watches the prices, moves fast, and takes a commission you mostly never itemize. DeFi grew the same profession: machines that drive the other machines.
This is the layer most people actually touch. Three agents work the desk: one runs your money, one shops your trades, one takes your order and finds its own way there. Meet them one at a time.
Agent one, function first: many depositors pool money into one shared strategy, and the strategy runs itself. It re-centers ranges, harvests rewards, compounds them back in, rotates to better pastures: the exact babysitting the concentrated liquidity checkpoint priced in sweat. The name: a vault.
Yearn is the ancestor: the protocol that turned yield strategies into a deposit box, and the pattern is everywhere now. You hand over the itinerary planning. The agent flies your money for you.
So who is paying here? You are, twice. A management fee taken from the balance, a performance fee taken from the yield: the commission is skimmed before the return ever reaches you. No trickery in that. Agents work for commission everywhere on earth.
The honest comparison is never fee versus free. It is fee versus what the job costs you: hours of watching, gas on every re-center, mistakes at 3am. For most depositors the agent is cheaper. The point is knowing you hired one.
Agent two works the swap desk. You ask for a trade; instead of walking into one pool, it shops every pool in the city and hands you one quote. Function first: a route shopper. The name: an aggregator, and 1inch is the classic.
Here is the puzzle. Sometimes its quote beats the biggest pool's own price for the same swap. Place your bet before the machine opens.
Here is your swap from the inside. One click on your side of the counter; behind it, the order fans out into hops across pools you never chose and never see. Tap each station to walk the route the agent booked.
Write the trip down and the pattern shows itself. You asked for an outcome. What ran was an itinerary: three legs, three venues, chosen by the agent. The itinerary was good this time. You did not read it, and you almost never will.
Hold that feeling. It is the whole convenience layer in one line: you buy the outcome and stop reading the route. The newest machines take that bargain to its logical end.
The newest model flips the paperwork. Instead of signing a route, you sign the outcome: at least this much out, or nothing at all. Specialized fillers compete for your order and find their own way there. Function first: outcome-signing. The name: intents, the CoW Swap style of trading.
Who is paying whom? The filler keeps whatever its cleverness earns above your floor. You trade the upside of a perfect route for a guaranteed worst case. The agent stopped charging a commission and started keeping the change.
Every agent's bill has three lines. Fees you see: listed, honest, easy to compare. Spreads you do not: the quiet gap between the perfect fill and yours. And the third line: delegation. The vault's strategy is now your strategy, and you have not read it.
Not a villain story: an unread itinerary story. The agent can be wrong, lazy, or conflicted, and the plan is in their handwriting. Two vaults will now make the point with one number.
The reading skill, then. For any convenience layer, any wrapper, any one-click anything, ask three questions. What does it optimize? What does it charge, visible and invisible? And what job did I just delegate without noticing?
One test before the map. If every layer takes a cut, surely the insiders go without them. Find the edge of the lens.
Zoom out. Vaults run your money, aggregators shop your trades, intents take your destination and keep the change. Under all three sit the pools, loans and receipts you already know by name. You have now met every machine on the floor.
Last stop of Act 2: what happens when the machines snap together, and one position quietly stands on four of them at once. Next: the money legos.