> ## 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 Swap Quote

Get a live Uniswap swap quote across V2/V3/V4 pools for a token pair and size, without executing or moving funds. Routes through the same hosted Uniswap Trading API as `uniswap-swap`, so a plan-time quote and the runtime swap can never disagree on whether a route exists. Use it to check whether a buy/swap is feasible before building it.

![Uniswap Swap Quote logo](https://cdn.b3.fun/b3os-icons/uniswap.svg)
Catalog action EVM Onchain

Get a live Uniswap swap quote across V2/V3/V4 pools for a token pair and size, without executing or moving funds. Routes through the same hosted Uniswap Trading API as `uniswap-swap`, so a plan-time quote and the runtime swap can never disagree on whether a route exists. Use it to check whether a buy/swap is feasible before building it.


## At a Glance

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

## Payload Schema

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `tokenIn` | `string` | Yes | Input token address to price. Use 0x0000000000000000000000000000000000000000 for native ETH. |
| `tokenOut` | `string` | Yes | Output token address to price. 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. Uniswap Trading API routing is single-chain only. |

## Result Schema

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `amountOut` | `string` | Yes | Quoted output amount for the exact input, in the output token's smallest unit \(wei\). "0" when noRoute is true. |
| `route` | `array` | Yes | Route steps the Trading API's best quote used — passed through as-is from the API response, since its shape varies by routing engine and pool version \(v2/v3/v4\). Empty when noRoute is true. |
| `routing` | `string` | Yes | Routing engine the Trading API used for the best quote \(e.g. "CLASSIC"\). "NONE" when noRoute is true. |
| `noRoute` | `boolean` | Yes | True when the Trading API found no route for this pair/size on any pool version. Read this instead of treating a caught error as the block signal — matches how the caddie feasibility gate consumes this action. |
| `tokenOutSymbol` | `string \| null` | No | Display symbol of tokenOut — lets a consumer render the quoted amount without a second lookup. Null when the metadata lookup fails, or when noRoute is true. |
| `tokenOutDecimals` | `number \| null` | No | Decimals of tokenOut, pairs with tokenOutSymbol. Null when the metadata lookup fails, or when noRoute is true. |
| `priceImpactBps` | `number \| null` | No | Fill-vs-spot price impact in basis points \(positive = worse/loss\), from the Trading API's percent priceImpact × 100. Null when noRoute is true, or when the quote omitted a numeric price impact. The caddie swap-feasibility gate reads this to classify the swap. |

## Examples

**Workflow node**

```json
{
  "type": "uniswap-swap-quote",
  "payload": {
    "tokenIn": "0x0000000000000000000000000000000000000000",
    "tokenOut": "0x6330D8C3178a418788dF01a47479c0ce7CCF450b",
    "amountIn": "300000000000000",
    "chainId": 4663
  },
  "children": []
}
```
  **Test with API**

```bash
curl -X POST "https://api.b3os.org/v1/actions/uniswap-swap-quote/test" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "inputs": {
    "tokenIn": "0x0000000000000000000000000000000000000000",
    "tokenOut": "0x6330D8C3178a418788dF01a47479c0ce7CCF450b",
    "amountIn": "300000000000000",
    "chainId": 4663
  }
}'
```

**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.