Enable API request forwarding

For Avalanche (C-Chain) JSON-RPC methods, you can request failover protection by adding the failover header to your API request using cURL, Web3.js, Ethers.js, or any other language of your choice.

For more information about this feature, including our partner and their privacy information, see Failover protection.

info

Avalanche (C-Chain) failover support is available on Mainnet only.

Request

In the code tabs, the eth_blockNumber method is used as an example.

cURL

curl https://avalanche-mainnet.infura.io/v3/YOUR-API-KEY \
    -X POST \
    -H "Enable-Failover: true" \
    -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params": [],"id":1}'

Web3.js

const { Web3 } = require('web3');
const https = require('https');

const options = {
    headers: {
        "Enable-Failover": "true",
    },
};

const provider = new https.Agent(options);

const web3 = new Web3(new Web3.providers.HttpProvider('https://avalanche-mainnet.infura.io/v3/YOUR-API-KEY', { agent: provider }));

web3.eth.getBlockNumber().then(console.log);

Ethers.js

const ethers = require('ethers');
const fetch = require('node-fetch');

class InfuraJsonRpcProvider extends ethers.providers.JsonRpcProvider {
    constructor(network, apiKey) {
        super(network, apiKey);
        this.fetchFunc = async (url, json, processFunc) => {
            const response = await fetch(url, {
                method: 'POST',
                body: json.body,
                headers: {
                    'Content-Type': 'application/json',
                    'Enable-Failover': 'true'
                }
            });

            const text = await response.text();
            const fetchJsonResponse = {
                jsonrpc: json.jsonrpc,
                id: json.id,
                result: JSON.parse(text).result,
                error: JSON.parse(text).error
            };

            return processFunc(fetchJsonResponse);
        };
    }
}

const provider = new InfuraJsonRpcProvider('https://avalanche-mainnet.infura.io/v3/YOUR-API-KEY');

provider.getBlockNumber().then((blockNumber) => {
    console.log(blockNumber);
});