Gas API

Get gas prices, estimate transaction costs, and track historical gas data across all supported EVM chains.

Endpoints

Get Current Gas Prices

GET /v1/blockchain/{chain}/gas

Returns current gas prices for EVM chains.

Request

curl -H "X-API-Key: YOUR_KEY" \
  https://api.axol.io/api/v1/blockchain/ethereum/gas

Response

{
  "success": true,
  "data": {
    "chain": "ethereum",
    "block_number": 19500000,
    "timestamp": "2026-01-15T10:30:00Z",
    "slow": 20,
    "standard": 25,
    "fast": 30,
    "instant": 40,
    "base_fee": 18,
    "suggested_tip": {
      "slow": 2,
      "standard": 7,
      "fast": 12,
      "instant": 22
    }
  },
  "metadata": {
    "cached": true,
    "cache_ttl": 3
  }
}

Supported Chains

• ethereum
• polygon
• arbitrum
• optimism
• base
• gnosis
• avalanche

---

Get Gas History

GET /v1/blockchain/{chain}/gas/history

Returns historical gas data.

Query Parameters

Parameter	Type	Description
hours	int	Hours of history (default 24, max 168)
resolution	string	Data resolution (1m, 5m, 15m, 1h)

Response

{
  "success": true,
  "data": {
    "chain": "ethereum",
    "history": [
      {
        "timestamp": "2026-01-15T09:00:00Z",
        "avg_gas": 25,
        "min_gas": 18,
        "max_gas": 45,
        "base_fee": 20
      },
      {
        "timestamp": "2026-01-15T10:00:00Z",
        "avg_gas": 28,
        "min_gas": 20,
        "max_gas": 50,
        "base_fee": 22
      }
    ]
  }
}

---

Compare Gas Across Chains

GET /v1/gas/compare

Compare gas prices across multiple chains.

Query Parameters

Parameter	Type	Description
chains	string	Comma-separated chain list

Response

{
  "success": true,
  "data": {
    "timestamp": "2026-01-15T10:30:00Z",
    "prices": {
      "ethereum": {"fast": 30, "usd_per_transfer": 2.50},
      "polygon": {"fast": 100, "usd_per_transfer": 0.02},
      "arbitrum": {"fast": 0.1, "usd_per_transfer": 0.15},
      "optimism": {"fast": 0.001, "usd_per_transfer": 0.08},
      "base": {"fast": 0.001, "usd_per_transfer": 0.05}
    },
    "cheapest": "base",
    "eth_price_usd": 3000
  }
}

---

Estimate Gas

POST /v1/gas/estimate

Estimate gas for a transaction.

Request

{
  "chain": "ethereum",
  "from": "0x123...",
  "to": "0x456...",
  "value": "1000000000000000000",
  "data": "0x..."
}

Response

{
  "success": true,
  "data": {
    "gas_limit": 21000,
    "estimated_cost": {
      "slow": {
        "gas_gwei": 20,
        "total_eth": "0.00042",
        "total_usd": "1.26"
      },
      "fast": {
        "gas_gwei": 30,
        "total_eth": "0.00063",
        "total_usd": "1.89"
      }
    }
  }
}

---

Code Examples

Python - Gas Tracker

import requests
from dataclasses import dataclass

@dataclass
class GasPrice:
    slow: float
    standard: float
    fast: float
    instant: float
    base_fee: float

class GasTracker:
    def __init__(self, api_key: str):
        self.api_key = api_key
        self.base_url = "https://api.axol.io/api/v1"

    def get_gas(self, chain: str) -> GasPrice:
        response = requests.get(
            f"{self.base_url}/blockchain/{chain}/gas",
            headers={"X-API-Key": self.api_key}
        )
        data = response.json()["data"]
        return GasPrice(
            slow=data["slow"],
            standard=data["standard"],
            fast=data["fast"],
            instant=data["instant"],
            base_fee=data["base_fee"]
        )

    def find_cheapest_chain(self, chains: list[str]) -> tuple[str, float]:
        response = requests.get(
            f"{self.base_url}/gas/compare",
            headers={"X-API-Key": self.api_key},
            params={"chains": ",".join(chains)}
        )
        data = response.json()["data"]
        return data["cheapest"], data["prices"][data["cheapest"]]["fast"]

# Usage
tracker = GasTracker(api_key="YOUR_KEY")

# Get Ethereum gas
eth_gas = tracker.get_gas("ethereum")
print(f"ETH Fast: {eth_gas.fast} gwei")

# Find cheapest L2
cheapest, price = tracker.find_cheapest_chain(
    ["arbitrum", "optimism", "base", "polygon"]
)
print(f"Cheapest: {cheapest} at {price} gwei")

TypeScript - Gas Alert

interface GasAlert {
  chain: string;
  threshold: number;
  callback: (price: number) => void;
}

class GasMonitor {
  private apiKey: string;
  private baseUrl = 'https://api.axol.io/api/v1';
  private alerts: GasAlert[] = [];
  private intervalId?: NodeJS.Timeout;

  constructor(apiKey: string) {
    this.apiKey = apiKey;
  }

  addAlert(chain: string, threshold: number, callback: (price: number) => void) {
    this.alerts.push({ chain, threshold, callback });
  }

  async checkGas(chain: string): Promise<number> {
    const response = await fetch(
      `${this.baseUrl}/blockchain/${chain}/gas`,
      { headers: { 'X-API-Key': this.apiKey } }
    );
    const data = await response.json();
    return data.data.fast;
  }

  start(intervalMs = 10000) {
    this.intervalId = setInterval(async () => {
      for (const alert of this.alerts) {
        const price = await this.checkGas(alert.chain);
        if (price <= alert.threshold) {
          alert.callback(price);
        }
      }
    }, intervalMs);
  }

  stop() {
    if (this.intervalId) {
      clearInterval(this.intervalId);
    }
  }
}

// Usage
const monitor = new GasMonitor(process.env.AXOL_API_KEY!);

monitor.addAlert('ethereum', 25, (price) => {
  console.log(`ETH gas is low: ${price} gwei - time to transact!`);
});

monitor.start();

---

Best Practices

1. Choose the Right Tier

Use Case	Recommended Tier
Time-sensitive arbitrage	instant
Normal DeFi operations	fast
Regular transfers	standard
Non-urgent batch operations	slow

2. Monitor Base Fee Trends

history = requests.get(
    f"{BASE_URL}/blockchain/ethereum/gas/history",
    params={"hours": 24, "resolution": "1h"}
)

# Find typical low-gas periods
for entry in history.json()["data"]["history"]:
    if entry["avg_gas"] < 20:
        print(f"Low gas at {entry['timestamp']}")

3. Use L2s for Cost Savings

Compare costs before choosing a chain:

comparison = tracker.find_cheapest_chain([
    "ethereum", "arbitrum", "optimism", "base", "polygon"
])

if comparison["cheapest"] != "ethereum":
    print(f"Save money by using {comparison['cheapest']}")

---

See Also

• Oracle API - MEV-focused gas oracle
• Unified Pattern - API structure
• Supported Chains - Chain list