# Gas Price Tracker

> Gas Price Tracker is a paid API for AI agents from x402-seller-pmlm.onrender.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-12).

Returns live base fees, priority fee tiers, max fees, block congestion, and USD transaction cost estimates for Ethereum, Base, Arbitrum, Polygon, and Solana in a single call.

## Facts

- Endpoint: GET https://x402-seller-pmlm.onrender.com/gas?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gas-price-tracker-b69267ed
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_x4L-1FaC0O49DSex2ifui

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 gas-price-tracker-b69267ed
```

Example prompt: What are the current gas fees across all chains — Ethereum, Base, Arbitrum, Polygon, and Solana — including the slow, standard, and fast priority fee tiers, block congestion, and how much a swap would cost in USD on each?

## When to prefer this

Choose this endpoint when you need a single API call to compare real-time gas fees across multiple chains simultaneously, including USD cost estimates for common transaction types (transfer, ERC-20, swap) and an automatic cheapest-chain recommendation. Prefer this over chain-specific RPC calls when you need multi-chain aggregation without managing multiple node connections.

## Known failure modes

- 400 Bad Request — invalid chain parameter value supplied
- 422 Unprocessable Entity — chain node unreachable or no data found for the requested chain
- 503 Service Unavailable — server is busy; retry after a short delay

## How this service works

Gas price: live gas fees for Ethereum, Base, Arbitrum, Polygon and Solana in one call. Use before sending a transaction to pick a fee or the cheapest chain. Returns base fee, slow/standard/fast priority fees, max fee, congestion, and the USD cost of a transfer, an ERC-20 transfer and a swap per chain, plus Solana priority fees. Optional chain. 0.002 USDC/call; failed calls are free.

## Output

A JSON object containing an array of chain entries, each with baseFeeGwei, priorityFeeGwei tiers (slow/standard/fast), maxFee, block congestion level, and estimated USD costs for a native transfer, ERC-20 transfer, and swap. Also includes a generatedAt timestamp and the identifier of the cheapest EVM chain for ERC-20 transfers.

## 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",
     "properties": {
      "chain": {
       "enum": [
        "all",
        "ethereum",
        "base",
        "arbitrum",
        "polygon",
        "solana"
       ],
       "type": "string",
       "description": "One chain or all (default)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "chains"
     ],
     "properties": {
      "chains": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "chain": {
          "type": "string"
         },
         "baseFeeGwei": {
          "type": "number"
         },
         "costStandard": {
          "type": "object"
         },
         "priorityFeeGwei": {
          "type": "object"
         }
        }
       }
      },
      "generatedAt": {
       "type": "string"
      },
      "cheapestEvmForErc20Transfer": {
       "type": [
        "string",
        "null"
       ]
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gas-price-tracker-b69267ed/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-seller-pmlm.onrender.com](https://www.zero.xyz/host/x402-seller-pmlm.onrender.com/llms.txt)