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

# Contracts

Zest Protocol Stacks Swap runs on open Clarity smart contracts deployed on Stacks mainnet. The contracts fall into three groups.

## Router Contracts (`zr-*`)

The routers execute swaps. Each route, whether a single pool, multi-hop, or split across DEXes, runs through one router contract in a single atomic transaction. Every router enforces the same guarantees:

* **Measured output**: the amount received is measured from what the pools actually delivered, never estimated
* **Minimum received**: if the measured output is below the minimum in the signed transaction, the swap reverts
* **Deadline**: a swap that confirms too late reverts instead of executing on stale prices
* **No custody**: routers hold zero user funds between swaps. Input is pulled from the wallet and output is delivered to the wallet within the same transaction.

On a Stacks explorer, a swap appears as a call to a contract with a name like `zr-a-0` and a function like `r-xs`. This identifies the router and the specific route shape the swap used.

## Adapter Contracts

Each supported DEX has an adapter, a thin contract that translates the router's uniform swap interface into that DEX's own pool interface. Adapters are stateless and never hold a balance between swaps.

| Adapter                        | Platform        | Pool Type                              |
| ------------------------------ | --------------- | -------------------------------------- |
| `alex-adapter-1`               | ALEX            | Weighted AMM (amm-v2)                  |
| `arkadiko-adapter-1`           | Arkadiko        | Classic (constant-product)             |
| `bitflow-adapter`              | Bitflow         | Classic (XYK)                          |
| `stableswap-adapter`           | Bitflow / Velar | StableSwap                             |
| `dlmm-adapter`                 | Bitflow         | Concentrated liquidity (DLMM)          |
| `velar-adapter`                | Velar           | Classic (univ2)                        |
| `velar-stableswap-adapter`     | Velar           | Curve-style StableSwap                 |
| `stacking-dao-receipt-adapter` | Stacking DAO    | stSTX and stSTXbtc protocol conversion |

## Contract Addresses

All contracts are deployed under the Zest Protocol Stacks Swap deployer address on Stacks mainnet: `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST`.

| Contract            | Address                                                                                                                                                        |
| ------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Routers             | `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.``zr-*`                                                                                                             |
| ALEX Adapter        | `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.alex-adapter-1`                                                                                                     |
| Arkadiko Adapter    | `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.arkadiko-adapter-1`                                                                                                 |
| Bitflow Adapter     | `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.bitflow-adapter`                                                                                                    |
| Stableswap Adapter  | `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.stableswap-adapter`                                                                                                 |
| DLMM Adapter        | `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.dlmm-adapter`                                                                                                       |
| Velar Adapters      | <p><code>SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.velar-adapter</code><br><code>SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.velar-stableswap-adapter</code></p> |
| StackingDAO Adapter | `SP3EWCDA3V8HCP64CSETSNYXZ25WC4AJ95EC0ZEST.stacking-dao-receipt-adapter`                                                                                       |