> For the complete documentation index, see [llms.txt](https://ston-fi.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ston-fi.gitbook.io/docs/developer-section/dex/sdk/v2.md).

# v2 (latest)

The remaining sections of the documentation will demonstrate specific examples of the DEX usage:

* [perform a swap operation](/docs/developer-section/dex/sdk/v2/swap.md)
* [provide liquidity](/docs/developer-section/dex/sdk/v2/provide-liquidity.md)
* [refund liquidity](/docs/developer-section/dex/sdk/v2/refund-liquidity.md)
* [burn liquidity tokens](/docs/developer-section/dex/sdk/v2/burn-lp-tokens.md)
* [withdraw fee from vault](/docs/developer-section/dex/sdk/v2/vault-operations.md)

## Referral Fees

DEX v2 stores each swap's referral portion in a dedicated `Vault` contract (one per `referrer × token` pair). The fee percentage can be set between **0.01 % and 1 %** and must be withdrawn later by the referrer.

Inspect vault balances and history using the Stats & Vaults REST API:

* `GET /v1/wallets/{addr_str}/fee_vaults` – lists all known vaults per referrer
* `GET /v1/stats/fee_accruals` – shows all operations leading to fee accrual for the referrer, filterable by period
* `GET /v1/stats/fee_withdrawals` – lists withdrawals from the referrer's vaults by period
* `GET /v1/stats/fees` – returns aggregated referral fee information, for example total accrued USD value

See the Omniston [referral fees guide](/docs/developer-section/omniston/referral-fees.md#referral-fees-with-dex-v2) (note: although the guide is Omniston-oriented, the referenced paragraph explains DEX V2 referral fees in detail). Full API documentation is available in the [Swagger UI](https://api.ston.fi/swagger-ui/#/).