> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mayan.finance/llms.txt
> Use this file to discover all available pages before exploring further.

# Integrate the Swap API

> Build a cross-chain swap from scratch.

Most integrations should use the [SDK](/build/sdk), which builds the transaction for you on every supported chain.

Go directly to the API when you are working in a language the SDK does not cover, running quotes on a backend that never touches a wallet, or building the transaction yourself for another reason. This page covers the API surface and what you are responsible for once you skip the SDK.

## What you implement yourself

Four things the SDK would otherwise handle:

* Building the transaction for each source chain, including Solana instructions and Sui Move calls
* ERC20 allowance against the Forwarder contract, or an EIP-2612 permit
* Encoding the referrer addresses and verifying they match the quote
* Reading route-specific fields off the quote and branching on `type`

## Get a quote

```bash theme={null}
curl 'https://price-api.mayan.finance/v3/quote?amountIn=100&fromToken=0xb97ef9ef8734c71904d8002f8b6bc66dd9c48a6e&fromChain=avalanche&toToken=0x0000000000000000000000000000000000000000&toChain=solana&slippageBps=300&gasDrop=0&swift=true&mctp=true&fastMctp=true&wormhole=true'
```

The full parameter list is on the [Quote API](/integration/quote-api) page. The ones that matter most:

| Param                                   | Notes                                                               |
| --------------------------------------- | ------------------------------------------------------------------- |
| `amountIn64`                            | Base units. `amountIn` takes a human-readable number instead.       |
| `slippageBps`                           | Basis points, max 500.                                              |
| `swift`, `mctp`, `fastMctp`, `wormhole` | Enable or disable route families. Omit to allow all.                |
| `fullList`                              | `true` returns every option, unsorted. Default returns at most two. |
| `apiKey`                                | Raises the per-IP rate limit.                                       |
| `destinationAddress`                    | Improves accuracy, and is required for deposit addresses.           |

## Read the quote

The response is `{ quotes: [...], minimumSdkVersion: [...] }`. For each quote:

| Field                         | Use                                                                                                                  |
| ----------------------------- | -------------------------------------------------------------------------------------------------------------------- |
| `type`                        | `SWIFT`, `MCTP`, `FAST_MCTP`, or `WH`. Determines which contract you interact with.                                  |
| `expectedAmountOut`           | Display this to the user.                                                                                            |
| `minAmountOut`                | The floor.                                                                                                           |
| `minReceived`                 | The floor after relayer fees are deducted.                                                                           |
| `etaSeconds` / `clientEta`    | Estimated settlement, in seconds and as a display string.                                                            |
| `deadline64`                  | After this, the order can no longer be filled and becomes refundable.                                                |
| `swiftAuctionMode`            | Swift only. `3` means [Guaranteed Price](/features/guaranteed-price): the user receives exactly `expectedAmountOut`. |
| `protocolBps` / `referrerBps` | Fees applied to this quote.                                                                                          |
| `swiftMayanContract`          | Swift only. The contract to send to.                                                                                 |
| `gasless`                     | Whether this quote executes without source-chain gas.                                                                |

<Warning>
  Do not assume every quote in the array is the same route type. Check `type` on the specific quote you selected before building anything.
</Warning>

## Approve the input token

For an ERC20 input on EVM, approve the Mayan Forwarder contract for at least `effectiveAmountIn64` before sending the swap. The address is in `forwarderAddress` on the quote request, and documented on [Forwarder Contract](/integration/forwarder-contract).

Tokens supporting [EIP-2612](https://eips.ethereum.org/EIPS/eip-2612) can use a permit signature instead, which saves the user a transaction.

Native inputs need no approval.

## Send the transaction

The contract and calldata depend on `type`. Read the route page for the one you are using:

* [Swift](/architecture/swift), the default for most pairs
* [MCTP and Fast MCTP](/architecture/mctp), built around Circle's CCTP
* [Wormhole Swap](/architecture/wh-swap)

<Note>
  `getSwapFromEvmTxPayload` returns the payload without sending it, and its `_forwarder` object gives you the method name and parameters for a contract-level call. See [manual transaction building](/build/sdk/manual-transactions).
</Note>

## Track it

Poll the [Explorer API](/integration/explorer-api) with the source transaction hash and read `clientStatus`.

```bash theme={null}
curl 'https://explorer-api.mayan.finance/v3/swap/trx/{sourceTxHash}'
```

`INPROGRESS`, `COMPLETED`, or `REFUNDED`. See [Track Transactions](/build/track-transactions) for handling each state.

## Supported chains and tokens

* `GET https://sia.mayan.finance/v10/init` returns every supported chain, with `originActive` and `destinationActive` telling you which direction each supports.
* `GET https://price-api.mayan.finance/v3/tokens?chain=solana` returns the whitelisted token list. Drop `chain` for all chains. Any token with a contract address is routable, whitelisted or not, given liquidity.

The API does not return a documented error-code enum. The [SDK](/build/sdk) handles quote and execution failures for you, so if you can use it, use it.