> For the complete documentation index, see [llms.txt](https://docs.butane.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.butane.dev/use-butane/swap.md).

# Swap

Swap synthetics with the treasury reserves or redeemable CDPs.

**Swap** exchanges a synthetic with the assets that back it.

1. Open **Swap**.
2. Choose the synthetic, the asset to pay or receive, and the direction.
3. Enter the amount to pay. The app calculates what you receive.
4. Check the route, the amounts, the available capacity and any fee.
5. Select **Swap** and sign the transaction.

<figure><img src="https://2611713366-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FsKoaKdI1o97UnvYVMfiL%2Fuploads%2Fgit-blob-41b0578c5f02172d3d7ba9e4bf9a968fd8277837%2Fv2-swap.png?alt=media" alt="Butane Swap page"><figcaption><p>Swapping a synthetic on the Swap page.</p></figcaption></figure>

## Routes

Buying a synthetic goes through the treasury at the market's fixed conversion rate, with no fee. Selling a synthetic can take one of two routes. When both are available, the app uses the one that pays more.

### Via treasury reserves

The treasury route exchanges with reserve assets held by the Butane treasury. Each market defines which reserve assets it accepts and a fixed conversion rate for each, so the quote has no slippage.

Selling to the treasury may incur a redemption fee, which is added to the synthetic you pay. A swap can only use reserves the treasury holds, shown as **Treasury capacity**.

### Via redeemable positions

The positions route redeems against CDPs whose rate cap is below the market rate and pays out their collateral. It is available when the asset you receive is collateral in those CDPs. See [Redeem](/use-butane/liquidate-and-redeem.md#redeem).