Quick Swap API

The Quick Swap API allows you to perform cross-chain or same-chain token swaps in a single call, returning both the best route and all the transactions required to complete it. This API is perfect for dApps, wallets, checkouts, or DeFi flows where simplicity and speed are essential.

Endpoint: GET /quick-swap

/quick-swap
    ?fromChainId=
    &fromAssetAddress=
    &toChainId=
    &toAssetAddress=
    &inputAmountDisplay=
    &userWalletAddress=
    &recipient=

Query Parameters

Field	Type	Description
fromChainId*	string	Source blockchain identifier
fromAssetAddress*	string	Token address on source chain
toChainId*	string	Destination blockchain identifier
toAssetAddress*	string	Token address on destination chain
inputAmountDisplay*	string	Human-readable input amount (e.g., "1.5") Note: Either inputAmountDisplay or inputAmount should be passed
inputAmount*	string	Input amount in decimal units Note: Either inputAmountDisplay or inputAmount should be passed
userWalletAddress*	string	User's wallet address
recipient	string	Final recipient of the tokens. If not provided userWalletAddress is used by default
slippage	number	Slippage tolerance in basis points (100 = 1%)
solanaOptions	SolanaOptions	Solana-specific parameters
evmOptions	EvmOptions	EVM-specific parameters
skipChecks	boolean	Skip validation checks
include	string	Comma-separated list of providers to include
exclude	string	Comma-separated list of providers to exclude

Solana Options

Field	Type	Description
solanaPriorityFee	number | PriorityLevel	Priority fee in micro lamports or priority level
solanaJitoTip	number | PriorityLevel	Jito MEV tip in lamports or priority level

EVM Options

Field	Type	Description
evmPriorityFee	number | PriorityLevel	Priority fee in wei or priority level

PriorityLevel = 'low' | 'medium' | 'high' | 'ultra' | 'degen'

Response

The Quick Swap endpoint returns a simplified response containing both the selected route and ready-to-execute transaction data.

Field	Type	Description
route	Route	The selected route for the swap (null if no suitable route)
txn	TxnData[]	Array of transaction data ready for execution (null if error)
error	string	Error message if the swap cannot be completed

Route Object

The route object contains the same structure as returned by the /quotes endpoint, including:

• from/to: Source and destination token details

• inputAmount/outputAmount: Input and output amounts in wei/native units

• inputAmountDisplay/outputAmountDisplay: Human-readable amounts

• provider: Liquidity provider used

• estimatedTimeInSeconds: Estimated execution time

• steps: Transaction steps (limited to simple swaps only)

• fee: Fee breakdown

Transaction Data Array

The txn array contains 1-2 transaction objects ready for execution:

1. Approval Transaction (if required): ERC20 token approval for non-native tokens

2. Swap Transaction: The actual swap transaction

Each transaction object includes:

• txnEvm: EVM transaction data (from, to, data, value, gasPrice, gasLimit)

• txnSol: Solana transaction data (base64 encoded transaction)

• networkType: "evm" or "sol"

• routeId/stepId: Identifiers for tracking

Limitations

The Quick Swap endpoint is designed for simple swaps only and has the following restrictions:

• Only supports single-step swaps (no complex multi-hop routes)

• Automatically uses recommended providers only

• Routes with more than 2 steps (approval + swap) will be rejected

• Cross-chain swaps are supported but must be single-step

Example

Request:

https://api2.blockend.com/v1/quick-swap
?fromChainId=1
&fromAssetAddress=0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
&toChainId=1
&toAssetAddress=0xA0b86a33E6417aE4bbBd449c8E87C2E2e20E84DE
&inputAmountDisplay=0.1
&userWalletAddress=0x17e7c3DD600529F34eFA1310f00996709FfA8d5c
&slippage=100

Response:

{
  "status": "success",
  "data": {
    "route": {
      "routeId": "01J2WB1NY6MD3F25CJTTB01D8F",
      "from": {
        "networkType": "evm",
        "chainId": "1",
        "address": "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
        "decimals": 18,
        "name": "Ethereum",
        "symbol": "ETH",
        "isNative": true,
        "lastPrice": 3480.62
      },
      "to": {
        "networkType": "evm",
        "chainId": "1",
        "address": "0xA0b86a33E6417aE4bbBd449c8E87C2E2e20E84DE",
        "decimals": 18,
        "name": "USDC",
        "symbol": "USDC",
        "isNative": false,
        "lastPrice": 1.002
      },
      "inputAmount": "100000000000000000",
      "inputAmountDisplay": "0.1",
      "outputAmount": "348062000000",
      "outputAmountDisplay": "348.062",
      "provider": "1inch",
      "estimatedTimeInSeconds": 30,
      "steps": [{
        "stepId": "01J2WB1NY64MKVCM8FM994WMZV",
        "stepType": "swap",
        "from": { /* token details */ },
        "to": { /* token details */ },
        "inputAmount": "100000000000000000",
        "outputAmount": "348062000000"
      }]
    },
    "txn": [{
      "id": "txn_123",
      "routeId": "01J2WB1NY6MD3F25CJTTB01D8F",
      "stepId": "01J2WB1NY64MKVCM8FM994WMZV",
      "networkType": "evm",
      "txnType": "on-chain",
      "txnEvm": {
        "from": "0x17e7c3DD600529F34eFA1310f00996709FfA8d5c",
        "to": "0x1111111254eeb25477b68fb85ed929f73a960582",
        "value": "100000000000000000",
        "data": "0x7c025200000000000000000000000000...",
        "gasPrice": "20000000000",
        "gasLimit": "150000"
      }
    }]
  }
}

Error Responses

The endpoint may return the following error scenarios:

• No routes found: When no suitable swap routes are available

• Route too complex: When the optimal route requires multiple steps

• Failed to compute transaction data: When transaction data cannot be generated

{
  "status": "success",
  "data": {
    "route": null,
    "txn": null,
    "error": "No routes found"
  }
}

This endpoint is perfect for applications that need simple, one-click swap functionality without the complexity of managing separate quote and transaction creation flows.