Quote API

Get the best available swap quote for a token pair. The API finds the optimal route across V2 and V3 pools, including multi-hop paths.

GET /api/v1/quote

Parameters

Parameter	Type	Required	Description
`tokenIn`	`string`	Yes	Input token address
`tokenOut`	`string`	Yes	Output token address
`amountIn`	`string`	Conditional	Input amount in raw units (required when `tradeType=0`)
`amountOut`	`string`	Conditional	Output amount in raw units (required when `tradeType=1`)
`tradeType`	`string`	No	`0` = Exact Input (default), `1` = Exact Output

For native KAS, use the WKAS address, not the zero address.

Response

{
  "tokenIn": "0xb190...",
  "tokenOut": "0x3ac3...",
  "amountIn": "1000000000000000000",
  "amountOut": "1007249042881810956",
  "tradeType": 0,
  "route": {
    "path": ["0xb190...", "0x3ac3..."],
    "protocol": "v2",
    "hops": 1,
    "fees": [0]
  },
  "priceImpact": 0.3,
  "gasCost": "100000",
  "executionPrice": 1.007249
}

Field	Description
`amountIn`	Input amount (user-specified for Exact Input, calculated for Exact Output)
`amountOut`	Output amount (calculated for Exact Input, user-specified for Exact Output)
`route.path`	Ordered list of token addresses in the swap path
`route.protocol`	`"v2"`, `"v3"`, or `"mixed"`
`route.hops`	Number of pools in the path
`route.fees`	Fee tier for each hop (0 for V2, 100/500/3000/10000 for V3)
`priceImpact`	Estimated price impact as a percentage
`gasCost`	Estimated gas cost
`executionPrice`	Output per input ratio

Examples

# I want to sell 1 token — how much do I get?
curl "https://dex.kasplex.org/swap-api/api/v1/quote?\
tokenIn=0xB190a6A7fC2873f1Abf145279eD664348d5Ef630&\
tokenOut=0x3Ac3B30b7f18AEFD4590D7FE4d9C5944aaeB7220&\
amountIn=1000000000000000000&\
tradeType=0"

# I want to buy 1 token — how much do I need?
curl "https://dex.kasplex.org/swap-api/api/v1/quote?\
tokenIn=0xB190a6A7fC2873f1Abf145279eD664348d5Ef630&\
tokenOut=0x3Ac3B30b7f18AEFD4590D7FE4d9C5944aaeB7220&\
amountOut=1000000000000000000&\
tradeType=1"

Multi-Hop Routes

When no direct pool exists or a multi-hop path provides better pricing, the API returns a multi-hop route:

{
  "route": {
    "path": ["0xb190...", "0x0baf...", "0x3ac3..."],
    "protocol": "mixed",
    "hops": 2,
    "fees": [0, 500]
  }
}

This means: token A → (V2 pool) → intermediate token → (V3 0.05% pool) → token B.