Swapping
A swap on OpenProp fills against one quoter's book: a ladder of up to five price levels on each side of the quoter's mid price. You get the quoted prices, walked from the best level outward, and nothing worse than the minimum you set.
Swap in the app
- Open Books. Each row shows a book's state, mid, best bid and ask and how old its quote is.
- Select a book to open it. The ladder drawing shows each level's price and size.
- Choose Sell SOL or Buy SOL and enter the amount you pay.
- Read the preview: the output, the average price and the levels it walks. The preview runs the same rules the program runs, at the current quote and reference price.
- Select Swap and approve in your wallet.
The swap sets a minimum output 1% below the preview. If the quote moves before your transaction lands and the output would be smaller, the swap fails as a whole and your assets stay where they were.
What the program checks
Before any level fills, the program checks the book and the pair:
| Check | A fill needs |
|---|---|
| Fresh quote | The quote written within the last 2 slots |
| Inside band | The quoted mid inside the band around the reference price |
| Skew limit | The book's inventory skew within its limit after the fill |
| Loss window | The book inside its hourly (0.5%) and epoch (2%) loss limits |
| Breaker | The pair not halted |
If a check fails, the swap is rejected and the app shows which one. Try another book, or wait a moment for the quoter to post a fresh quote.
Partial fills
A book's ladder has finite depth, and its skew limit caps how far one fill can move its inventory. If your input is larger than the book can take, the program fills what it can and transfers only the input it used; the rest never leaves your wallet. Your minimum output applies to what is filled. For a large order, split it across books or check the depth first.
Prices and costs
- No swap fee. The quoter's spread is the price; the program adds nothing on top.
- Network fees are the Solana base fee and a small priority fee, paid in SOL.
- Native SOL. Selling SOL wraps exactly the amount you sell in a temporary account inside the transaction; buying SOL unwraps what you receive. Both close the temporary account, so its rent comes back.
Swapping through aggregators
Each OpenProp book is a market for routers. OpenProp ships an adapter for Jupiter's AMM interface that quotes a book with the same rule crate the program executes; a book that would fail a check returns no route. Where a router lists OpenProp, its quotes come from the same books, and the program checks every fill the same way.
Common questions
Why did my swap fail with a stale quote? Quotes are valid for 2 slots. If your transaction landed later than that and the quoter had not updated, the book could not fill. Retrying usually finds a fresh quote.
Why is the pair halted? The reference price moved more than 3% within 150 slots, aged past 10 slots, or its two sources disagreed. Swaps resume 50 slots after the condition clears. Incidents shows the cause.
Can I choose a different minimum? Through the API, yes: minAmountOutAtomic is yours to set. The app sets it 1% below its preview.