> ## Documentation Index
> Fetch the complete documentation index at: https://docs.b3os.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Uniswap V4 Swap Quote

Get a live Uniswap V4 swap quote and its fill-vs-spot price impact for a token pair and size, without executing or moving funds. Use it to check whether a buy/swap is feasible before building it.

![Uniswap V4 Swap Quote logo](https://ai-icon.b3.fun/logo/ethereum)
Catalog action EVM Onchain

Get a live Uniswap V4 swap quote and its fill-vs-spot price impact for a token pair and size, without executing or moving funds. Use it to check whether a buy/swap is feasible before building it.


## At a Glance

| Field | Value |
| --- | --- |
| Action ID | `v4-swap-quote` |
| Category | EVM Onchain |
| Connector | Not required |
| Requires gas | No |
| Funds movement | None declared |
| Tags | `blockchain`, `evm`, `dex`, `swap`, `defi`, `quote`, `read` |

## Payload Schema

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `tokenIn` | `string` | Yes | Input token address to sell. Use 0x0000000000000000000000000000000000000000 for native ETH. |
| `tokenOut` | `string` | Yes | Output token address to receive. Use 0x0000000000000000000000000000000000000000 for native ETH. |
| `amountIn` | `string` | Yes | Exact input amount to price, in the token's smallest unit \(wei\). |
| `chainId` | `number` | Yes | Chain to quote on. V4 swaps are single-chain only. |
| `maxHops` | `number` | No | Maximum number of pool hops the auto-router may use. Default: 2. Capped at 2 for v1. |

## Result Schema

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `amountOut` | `string` | Yes | Quoted output amount for the exact input, in the output token's smallest unit \(wei\). NOT slippage-adjusted. |
| `priceImpactBps` | `number` | Yes | Fill-vs-spot price impact of the best route, in basis points \(1000 = 10%\). 0 when the quote meets or beats the pool's spot price. |
| `route` | `array` | Yes | The best route: 1 entry for a direct swap, 2 entries for a hub-token hop. |
| `tokenOutSymbol` | `string \| null` | No | Display symbol of tokenOut \(null when the metadata lookup fails\) — lets a consumer render the quoted amount without a second lookup. |
| `tokenOutDecimals` | `number \| null` | No | Decimals of tokenOut \(null when the metadata lookup fails\); pairs with tokenOutSymbol. |

## Examples

**Workflow node**

```json
{
  "type": "v4-swap-quote",
  "payload": {
    "tokenIn": "0x0000000000000000000000000000000000000000",
    "tokenOut": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amountIn": "300000000000000",
    "chainId": 8453
  },
  "children": []
}
```
  **Test with API**

```bash
curl -X POST "https://api.b3os.org/v1/actions/v4-swap-quote/test" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "inputs": {
    "tokenIn": "0x0000000000000000000000000000000000000000",
    "tokenOut": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amountIn": "300000000000000",
    "chainId": 8453
  }
}'
```

**Use expressions for dynamic values**

Payload fields can use workflow expressions such as `{{$trigger.body.amount}}`, `{{$nodes.fetch.result.price}}`, and `{{$props.asset}}` when the value should come from a trigger, prior node, or reusable workflow prop.