# DEX Swap Price Quote (UniswapV2 on Base/Ethereum)

> DEX Swap Price Quote (UniswapV2 on Base/Ethereum) is a paid API for AI agents from x402.professorsausages.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Returns an indicative UniswapV2 swap quote — amount out, realized price, and price impact — for any token pair using live on-chain reserves on Base or Ethereum.

## Facts

- Endpoint: GET https://x402.professorsausages.com/swap-quote/quote/:chain/:tokenIn/:tokenOut
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dex-swap-price-quote-uniswapv2-on-base-ethereum-26fa058b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_F_9iDue4UHY6ATOY66aNW

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability dex-swap-price-quote-uniswapv2-on-base-ethereum-26fa058b
```

Example prompt: What's the UniswapV2 swap quote on Base if I trade 1000 USDC for WETH right now — give me the amount out, the realized price, and the price impact percentage.

## When to prefer this

Use this endpoint when you need a fast, live, on-chain UniswapV2 price quote without executing a trade — ideal for pre-trade estimation, slippage checks, or displaying indicative swap rates on Base or Ethereum. Prefer it over centralized exchange price feeds when you specifically need DEX pool pricing with price impact. Not suitable for Uniswap V3, V4, or other DEX protocols.

## Known failure modes

- No UniswapV2 pool exists for the token pair — returns found=false with a reason string
- Invalid or unrecognized token address/symbol — may return found=false or HTTP error
- Unsupported chain specified — API returns an error
- Payment not included or insufficient — HTTP 402 returned before quote is served
- RPC or on-chain data unavailability — potential timeout or server error

## How this service works

DEX swap price quote — indicative UniswapV2 amount-out, price & price-impact for any token pair from live on-chain reserves on Base/Ethereum

## Output

On success (found=true): amountOut in human units, realized price (tokenOut per tokenIn), price_impact_pct, the UniswapV2 pair address, block height the reserves were read at, fee_pct (0.3%), and a disclaimer. On failure (found=false): the reason the pair couldn't be quoted, plus the chain's WETH address for routing hints.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dex-swap-price-quote-uniswapv2-on-base-ethereum-26fa058b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.professorsausages.com](https://www.zero.xyz/host/x402.professorsausages.com/llms.txt)