You do not run a DEX. You transfer to a counter. The counter makes the exchange. The result returns to the same account.
Tap Swap in many Canton wallets, and what you are asked to do is not to sign a DEX transaction. What you are asked to do is simpler and that is exactly why people coming from Solana or Ethereum find it strange.
On Uniswap or Jupiter, the reflex is already muscle memory: approve, tap Swap, and the wallet signs a transaction to a public contract. On Canton Network, that reflex often stalls. Canton is not EVM. Its basic unit is a party. Its settlement model is delivery-versus-payment. Many wallets can send tokens, but they cannot or only with difficulty sign a full DvP transaction.
If a DEX forced the Ethereum model, retail users would be filtered out at the first door. OneSwap does not force the user to learn institutional settlement. It adapts to wallets that can only make a plain transfer. The official documentation says this directly.
https://docs.oneswap.cc/introduction
The counter, not the button.
The integrator flow works like this. An app or backend calls createSwap. OneSwap returns a depositParty a Canton party ID and a deadline. The user sends the input token to that party. It is a normal transfer. The wallet does not sign a swap.
https://docs.oneswap.cc/guides/swaps
Once the deposit is visible on the ledger, the protocol does the work. The swap is executed atomically: the exchange happens all at once, or it does not happen at all. The output is sent back to the party that funded the deposit. OneSwap calls this return-to-sender. There is no destination address field. There is no destination that can be typed wrong.
https://docs.oneswap.cc/guides/swaps
This distinction needs to be made early. This is the swap face for apps that attach through the SDK. The oneswap.cc V2 interface is a different surface. The core idea is the same the user does not have to assemble a DvP transaction but the way in is different. The retail screen on the official site is not always identical to this deposit-party flow.
The guarantee is not in the signature.
Many people instinctively feel a trade is only safe if they sign every step. On OneSwap, the user’s signature stops at the transfer. The protocol is what executes settlement.
The docs call that execution custodial and atomic. That means the asset is held temporarily during the settlement cycle, then leaves again as the output token or as a refund. This is not a centralized-exchange deposit that waits for you to withdraw. The guarantees sit in three places: an atomic swap, a refund if the swap fails or the amount is off, and an output that always returns to the sender.
https://docs.oneswap.cc/guides/swaps
Without holding the asset for that short cycle, a wallet that can only make a plain transfer cannot complete DvP. That is the trade-off. Hiding it is more dangerous than writing it down.
The deposit rules are strict because the system refuses to guess.
The deposited amount must fall within 1 percent of the requested amount. Outside that band, the funds are returned. One user identity on the integrator side may have only one open swap at a time. The deposit window is 60 minutes. After that deadline, nothing happens. Pairs with no direct pool are not routed automatically; they are usually split into two swaps through an intermediate asset, often CC.
https://docs.oneswap.cc/guides/swaps
Because the user only has to transfer, this mechanism can be embedded almost anywhere. Without that foundation, talk of an SDK or of apps attaching on top of it sounds like an announcement without context.
The button moves into other apps.
Loop embeds the SDK in the wallet; the user sees a price and sends, without needing to understand DvP. CantonNews does the same on a news site: the user stays on the original page, and OneSwap is the settlement rail.
https://cantonnews.org/oneswap-goes-live-inside-loop-wallet-as-first-sdk-integration
https://x.com/Oneswapcc/status/2089728838754611572
The SDK here is not an add-on. It is the reason a mechanism that “feels strange” can be used by people who never open oneswap.cc.
At its foundation, OneSwap is closer to a swap-settlement engine than to a classic DEX button. You transfer to the counter. The counter makes the exchange. If the exchange fails, your money comes back.
Sources
1. OneSwap Docs Introduction.
https://docs.oneswap.cc/introduction
2. OneSwap Docs Swaps.
https://docs.oneswap.cc/guides/swaps
3. CantonNews OneSwap Goes Live Inside Loop Wallet as First SDK Integration. https://cantonnews.org/oneswap-goes-live-inside-loop-wallet-as-first-sdk-integration
4. OneSwap announcement that swap is live inside CantonNews, 18 August 2026. https://x.com/Oneswapcc/status/2089728838754611572
