# x402helper.xyz Swap Price Quote

> x402helper.xyz Swap Price Quote is a paid API for AI agents from x402helper.xyz, paid per call via x402, $0.013/call, status unknown (last checked 2026-11-07).

Returns a price quote for swapping one ERC-20 token for another on Base via a micropayment-gated endpoint costing $0.013 USDC per call.

## Facts

- Endpoint: GET https://x402helper.xyz/89e509/swap/price?utm_source=zero.xyz
- Price: $0.013/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-07
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402helper-xyz-swap-price-quote-9177a56f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fEkTK9OQQLJqySI-4wGUM

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 x402helper-xyz-swap-price-quote-9177a56f
```

Example prompt: What's the current swap price to sell 1 WETH (1000000000000000000 raw units) for USDC on Base, with a maximum slippage of 50 basis points?

## When to prefer this

Use this endpoint when you need a real-time swap price quote for ERC-20 token pairs on Base network and are operating in an x402 micropayment-enabled agent environment. Prefer this over manual DEX aggregator queries when your agent already handles USDC micropayments via x402 protocol and needs a simple GET-based quote with OFAC compliance built in.

## Known failure modes

- Invalid or unsupported tokenIn/tokenOut symbol or address returns an error
- amountIn not provided as a raw integer string causes parsing failure
- Slippage exceeds 5000 bps (50%) triggers validation error
- OFAC screening failure blocks the request
- Payment of 0.013 USDC not included or rejected causes 402 Payment Required response
- Network or liquidity issues may return empty or zero quotes

## How this service works

X402 micropayments server — AI agents pay USDC for OFAC screening, rates, and billing verification.

## Output

A JSON object with a success flag and a result object containing the swap price quote, including the expected output token amount for the given input amount and token pair on Base network.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "tokenIn",
      "tokenOut",
      "amountIn"
     ],
     "properties": {
      "tokenIn": {
       "type": "string",
       "default": null,
       "description": "Sell token: a supported symbol (WETH, USDC, AERO, ...) or a 0x ERC-20 address on Base."
      },
      "amountIn": {
       "type": "string",
       "default": null,
       "description": "Sell amount in RAW atomic units of tokenIn (e.g. 1 WETH = 1000000000000000000). Integer as string."
      },
      "tokenOut": {
       "type": "string",
       "default": null,
       "description": "Buy token: a supported symbol or a 0x ERC-20 address on Base."
      },
      "slippageBps": {
       "type": "integer",
       "default": null,
       "description": "Max slippage in basis points (50 = 0.5%). Default 50, max 5000."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {},
  "success": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402helper-xyz-swap-price-quote-9177a56f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402helper.xyz](https://www.zero.xyz/host/x402helper.xyz/llms.txt)