# Vextorium DEX Swap Quote (Base/Uniswap v3)

> Vextorium DEX Swap Quote (Base/Uniswap v3) is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-15).

Returns an on-chain swap quote on Base using Uniswap v3 QuoterV2, providing output amount, unit price, best pool fee tier, and gas estimate — without executing any trade.

## Facts

- Endpoint: POST https://api.vextorium.com/v1/dex-swap-quote?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-dex-swap-quote-base-uniswap-v3-15708f22
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BK0y8hF_yypsYsg5EC2Ql

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 vextorium-dex-swap-quote-base-uniswap-v3-15708f22 -d '<json body>'
```

Example prompt: How much USDC would I get if I swap 1 WETH on Base right now? Use Uniswap v3 to find the best pool fee tier and give me the output amount and unit price.

## When to prefer this

Use this endpoint when you need a real on-chain swap price from Uniswap v3 on the Base network before deciding whether to execute a trade. It checks all four fee tiers (0.01%, 0.05%, 0.3%, 1%) and returns the best one. Prefer this over off-chain price feeds when you need DEX-accurate output amounts and pool routing. It is read-only so it is safe to call without financial risk.

## Known failure modes

- Unsupported token symbol or invalid contract address returns an error
- No liquidity in any fee tier for the requested pair returns null or error
- Amount of zero or negative input is rejected
- Network or RPC issues may cause timeout or empty response
- Very large amounts may hit liquidity limits and return inaccurate quotes

## How this service works

558 pay-per-call data APIs for AI agents: Solana and EVM on-chain data, tokenized stocks, DeFi, Hyperliquid, economy and official statistics, FX, validation, web and developer tools. Pay in USDC via x402.

## Output

Returns a JSON object with the output token symbol and amount you would receive, the unit price (e.g. USDC per WETH), and the best pool fee percentage (e.g. 0.05 for the 0.05% tier). No trade is executed; this is a read-only quote from Uniswap v3 QuoterV2 on Base.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "amount": {
   "type": "number",
   "description": "Input amount in token units"
  },
  "token_in": {
   "type": "string",
   "description": "Token to sell: WETH (or ETH), USDC, USDT, DAI, cbBTC, or a Base token contract address"
  },
  "token_out": {
   "type": "string",
   "description": "Token to buy: WETH (or ETH), USDC, USDT, DAI, cbBTC, or a Base token contract address"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "output": {
   "token": "USDC",
   "amount": 2688.58
  },
  "unit_price": 2688.58,
  "best_pool_fee_pct": 0.05
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-dex-swap-quote-base-uniswap-v3-15708f22/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)