# Crypto Swap Quote (Base Chain)

> Crypto Swap Quote (Base Chain) is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-31).

Returns a multi-venue aggregated swap quote for two tokens on Base, including route, price, gas cost, slippage, and an optional ready-to-sign transaction calldata.

## Facts

- Endpoint: GET https://kr-x402-mvp.kgy5612.workers.dev/v1/crypto/swap-quote?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crypto-swap-quote-base-chain-6f12e87c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0TRJMAWEC6oFn-W2VCdrh

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 crypto-swap-quote-base-chain-6f12e87c
```

Example prompt: Get me a swap quote for 10 USDC to WETH on Base — use my wallet 0xAbCd1234...5678 and a slippage of 50 bps so I can see if the fill looks good and get the calldata ready to sign.

## When to prefer this

Use this endpoint when an AI agent needs to price or execute a token swap on Base chain without managing API keys, wants multi-venue aggregated quotes (not just a single DEX), needs gas cost estimates in USD, wants a human-readable verdict on fill quality, or needs ready-to-sign calldata for a specific wallet. Prefer over raw DEX APIs when you want aggregated routing, cost analysis, and agent-friendly guidance in one call. Especially suited for pay-per-call agent workflows via x402 USDC micropayments.

## Known failure modes

- Unsupported token symbol or invalid 0x address returns an error or empty route
- No liquidity found for the pair on Base returns an error or null route
- Invalid amount format (non-numeric) causes a validation error
- Missing required parameters (from, to, amount) returns a 400-level error
- Payment not settled via x402 returns a 402 Payment Required response
- Wallet address fails regex validation (not a valid 0x address) returns a schema error

## How this service works

Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.

## Output

Returns a JSON object with both token details (symbol, address, decimals), number of hops, chain, effective price, route array, router address and label, source aggregator, gas cost in USD, L1 fee in USD, minimum output amount, amount out (human units), amount out USD, net out USD, cost percentage, verdict (e.g. GOOD), and human-readable guidance. If a wallet address is provided, also includes ready-to-sign calldata and allowance/balance checks.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "from",
      "to",
      "amount"
     ],
     "properties": {
      "to": {
       "type": "string",
       "examples": [
        "WETH"
       ],
       "description": "Token out: symbol or 0x address"
      },
      "from": {
       "type": "string",
       "examples": [
        "USDC"
       ],
       "description": "Token in: symbol (USDC, ETH, WETH, cbBTC, DAI, USDbC, AERO, DEGEN, BRETT, VIRTUAL) or 0x address"
      },
      "amount": {
       "type": "string",
       "examples": [
        "10"
       ],
       "description": "Amount of token in, human units (e.g. 10 = 10 USDC)"
      },
      "wallet": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Optional sender/recipient: returns ready-to-sign tx + allowance/balance check"
      },
      "slippage_bps": {
       "type": "integer",
       "maximum": 2000,
       "minimum": 1,
       "description": "Slippage tolerance in bps (default 50 = 0.5%)"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "to": {
   "symbol": "WETH",
   "address": "0x4200000000000000000000000000000000000006",
   "decimals": 18
  },
  "from": {
   "symbol": "USDC",
   "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
   "decimals": 6
  },
  "hops": 1,
  "chain": "base",
  "price": 2224.6,
  "route": [
   "pmm-2"
  ],
  "router": "0x6131b5fae19ea4f9d964eac0408e4408b66337b5",
  "source": "kyberswap",
  "gas_usd": 0.0319,
  "min_out": 0.00447272,
  "verdict": "GOOD",
  "cost_pct": -0.73,
  "guidance": "Good fill. Pass wallet= for ready-to-sign calldata; verify it with /crypto/decode-calldata before signing.",
  "amount_in": 10,
  "amount_out": 0.0044952,
  "l1_fee_usd": 0.0015,
  "net_out_usd": 10.0153,
  "router_label": "KyberSwap MetaAggregation Router v2",
  "slippage_bps": 50,
  "amount_in_usd": 9.976,
  "amount_out_usd": 10.0487
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crypto-swap-quote-base-chain-6f12e87c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kr-x402-mvp.kgy5612.workers.dev](https://www.zero.xyz/host/kr-x402-mvp.kgy5612.workers.dev/llms.txt)