# On-Chain USD Spot Price Lookup (Chainlink / Base DEX)

> On-Chain USD Spot Price Lookup (Chainlink / Base DEX) is a paid API for AI agents from webtools402.176-109-107-191.sslip.io, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Returns the current USD spot price of a token using Chainlink price feeds or the most-liquid Base DEX pool computed from on-chain state.

## Facts

- Endpoint: GET https://webtools402.176-109-107-191.sslip.io/price
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/on-chain-usd-spot-price-lookup-chainlink-base-dex-80e7750a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5epgVHLrEUJ-ySWtQ9IaA

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 on-chain-usd-spot-price-lookup-chainlink-base-dex-80e7750a
```

Example prompt: What's the current on-chain USD spot price of AERO? Use Chainlink or the Base DEX pool to look it up.

## When to prefer this

Use this endpoint when you need a trustworthy, on-chain-derived USD spot price for a token — especially for tokens in the Base ecosystem or those with Chainlink feeds — rather than relying on a centralized exchange API or off-chain aggregator. Ideal for DeFi agents, portfolio trackers, or any workflow that requires verifiable price data sourced from public blockchain state.

## Known failure modes

- Unsupported or unknown token symbol returns an error or empty result
- Token not listed on Chainlink or any liquid Base DEX pool may have no price available
- Network issues or RPC node latency may delay or fail the on-chain lookup
- Malformed token symbol parameter returns a validation error

## How this service works

On-chain USD spot price of a token from Chainlink feeds or the most-liquid Base DEX pool (computed from public chain state).

## Output

The current USD spot price of the requested token, sourced from Chainlink price feeds or the most-liquid Base DEX pool, derived from live on-chain state.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "token"
     ],
     "properties": {
      "token": {
       "type": "string",
       "description": "Symbol to price. Crypto e.g. ETH, BTC, SOL, XRP, DEGEN. Stablecoin e.g. USDT, USDC, USDe. Forex e.g. EUR, GBP, JPY. Metal e.g. XAU (gold), XAG (silver)."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/on-chain-usd-spot-price-lookup-chainlink-base-dex-80e7750a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from webtools402.176-109-107-191.sslip.io](https://www.zero.xyz/host/webtools402.176-109-107-191.sslip.io/llms.txt)