# Vextorium Multi-Chain Gas Price Comparator

> Vextorium Multi-Chain Gas Price Comparator is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-13).

Returns real-time gas prices and estimated USD transaction costs (native transfer, ERC-20 transfer, swap) across Base, Ethereum, Arbitrum, Optimism, and Polygon, plus the cheapest chain for swaps.

## Facts

- Endpoint: POST https://api.vextorium.com/gas-comparar-pago?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-multi-chain-gas-price-comparator-5ebcd5f3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5NKKA8iPyieFkN_HcgS7X

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-multi-chain-gas-price-comparator-5ebcd5f3 -d '<json body>'
```

Example prompt: What are the current gas prices and USD transaction costs for a native transfer, ERC-20 transfer, and a swap across Base, Ethereum, Arbitrum, Optimism, and Polygon — and which chain is cheapest for swapping right now?

## When to prefer this

Prefer this endpoint when you need a single call to compare gas costs across all five major EVM chains simultaneously, including USD-denominated estimates for common transaction types. Ideal for agents helping users decide which chain to use before executing a DeFi operation, or for building gas dashboards. Not suitable if you need historical gas data, per-contract estimates, or chains beyond Base, Ethereum, Arbitrum, Optimism, and Polygon.

## Known failure modes

- Upstream RPC or gas oracle unavailability may cause null values for specific chains
- Polygon swap/token transfer costs may return null if POL price is unavailable
- Gas price data may be slightly stale if upstream nodes are lagging
- Network congestion spikes can cause estimates to be outdated within seconds of fetching

## How this service works

Gas price right now on Base, Ethereum, Arbitrum, Optimism and Polygon, with the estimated USD cost of a native transfer, an ERC-20 transfer and a swap on each, and the cheapest chain.

## Output

A JSON object with per-chain data including: network name, native token, gas price in gwei, estimated USD cost of a swap, ERC-20 token send, and native transfer; plus the name of the cheapest chain for swaps and current USD prices of native tokens (ETH, POL). A note clarifies that L2 chains incur an additional L1 data fee not included in the estimates.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "required": [],
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": [
      "object",
      "null"
     ],
     "properties": {
      "nota": {
       "type": [
        "string",
        "null"
       ]
      },
      "redes": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": [
         "null",
         "object"
        ],
        "properties": {
         "red": {
          "type": [
           "null",
           "string"
          ]
         },
         "nativo": {
          "type": [
           "null",
           "string"
          ]
         },
         "gas_gwei": {
          "type": [
           "null",
           "number"
          ]
         },
         "swap_usd": {
          "type": [
           "null",
           "number"
          ]
         },
         "envio_token_usd": {
          "type": [
           "null",
           "number"
          ]
         },
         "transferencia_usd": {
          "type": [
           "null",
           "number"
          ]
         }
        }
       }
      },
      "mas_barata_swap": {
       "type": [
        "string",
        "null"
       ]
      },
      "precios_nativos_usd": {
       "type": [
        "object",
        "null"
       ],
       "properties": {
        "eth": {
         "type": [
          "number",
          "null"
         ]
        },
        "pol": {}
       }
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "nota": "En los L2 (Base, Arbitrum, Optimism) se suma una pequeña tarifa de datos a L1 que no se incluye aquí.",
  "redes": [
   {
    "red": "base",
    "nativo": "ETH",
    "gas_gwei": 0.006008,
    "swap_usd": 0.00293,
    "envio_token_usd": 0.00106,
    "transferencia_usd": 0.00034
   },
   {
    "red": "ethereum",
    "nativo": "ETH",
    "gas_gwei": 0.902926,
    "swap_usd": 0.44,
    "envio_token_usd": 0.15889,
    "transferencia_usd": 0.05133
   },
   {
    "red": "arbitrum",
    "nativo": "ETH",
    "gas_gwei": 0.020012,
    "swap_usd": 0.00975,
    "envio_token_usd": 0.00352,
    "transferencia_usd": 0.00114
   },
   {
    "red": "optimism",
    "nativo": "ETH",
    "gas_gwei": 0.001004,
    "swap_usd": 0.00049,
    "envio_token_usd": 0.00018,
    "transferencia_usd": 0.00006
   },
   {
    "red": "polygon",
    "nativo": "POL",
    "gas_gwei": 277.023823,
    "swap_usd": null,
    "envio_token_usd": null,
    "transferencia_usd": null
   }
  ],
  "mas_barata_swap": "optimism",
  "precios_nativos_usd": {
   "eth": 2707.22696629,
   "pol": null
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-multi-chain-gas-price-comparator-5ebcd5f3/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)