Extensions
The extensions step is where a coin's market stops being a default and becomes a configuration. It is one screen, and it is the part of the form worth spending time on, because nothing here can be changed once the coin exists.
The path a swap takes
The step opens on the execution path: the five stops a swap travels through, in order. Three of them are yours to fill, two are fixed.
Reading it left to right is reading the order of execution on every single trade:
- Transaction. A trader sends a swap. Nothing of yours runs yet.
- Fee. Your fee calculators are asked what this swap costs, in the order you added them, each seeing the answer the previous one gave. The last answer is what the trader pays.
- Swap. The trade executes and the fee is split. This stop is the protocol's and cannot be configured.
- Observer. Your observers are told the swap settled, and what fee it paid. They can record and act; they are too late to change anything about the trade.
- Fee recipient. Your side of the fee lands at its destination: a payout address, or a contract that acts on the money — a staking vault, a buyback, a splitter.
Two of the five are fixed, which is the point: whatever you assemble, a trade still arrives and still executes.
What else the screen shows
The catalog. A grid of modules grouped by the stop they run on, searchable and filterable by family. Each card carries what the module does; selecting one adds it to the pool.
The pool panel. Everything selected so far, and the settings of whichever module is being tuned. This is where a module's values are entered — the steps of a fee curve, the length of a window, the share going to a vault.
The slot counters. Four fee modules and four observers per coin, one recipient. The counters on the path show what is used as modules are added.
The families
| Family | The question it answers | Documented in |
|---|---|---|
| Fee calculators | what does this swap cost? | Fee calculators |
| Observers | what happens because this swap happened? | Observers |
| Fee recipients | where does the creator's income go, and what happens to it there? | Fee recipients |
The staking vault is one of them: it is a recipient module, added from this screen like any other, with one setting — the percentage of the creator's own income that goes to the people staking the coin. See Staking vault.
Order matters
Fee modules run in the order they were added, each seeing what the previous one decided, so the order is part of the configuration. Observers run in their own order and share one gas budget per swap, which means a module placed early can leave less for the ones behind it.
The form arrives on a working arrangement, and leaving it alone is the right answer for most coins. The default order is the one the protocol recommends, it produces a standard market, and it cannot be revisited once the coin exists. Reorder it only if you can say what the new sequence does differently — a module that ends up in the wrong place does not fail loudly, it simply makes a market you did not intend, permanently.
Where to read more
The whole of Programmable markets documents this step: what each family can and cannot do, one page per module in the catalog, the safety constraints the hook enforces, and worked examples of several modules running together.