@lido-sdk/fetch

⚠️DEPRECATION WARNING⚠️

This project is being slowly deprecated and may not receive further updates. Check out modern Lido SDK to access latest functionality. It is actively maintained and is built for interacting with Lido Protocol.

Fetchers

Fetchers for Lido Finance projects. Part of Lido JS SDK

• Install
• Fetch
• Fetch With Fallbacks
• Fetch RPC
  • Options
• Helpers
  • getInfuraRPCUrl
  • getAlchemyRPCUrl

Install

yarn add @lido-sdk/fetch

Fetch

node-fetch package NPM, Github

import { fetch } from '@lido-sdk/fetch';

const response = await fetch('https://example.com');
const result = await response.json();

Fetch With Fallbacks

Source

A wrapper over fetch which takes an array of URLs instead of a single URL. If a request throws an exception, it takes the following URL from the array and repeats the request to it.

import { fetchWithFallbacks } from '@lido-sdk/fetch';

const urls = ['https://example.com', 'https://fallback.com'];

const response = await fetchWithFallbacks(urls);
const result = await response.json();

Fetch RPC

Source

A wrapper over fetchWithFallbacks, which is useful as a backend part of proxying RPC requests from frontend to API provider.

import { fetchRPC } from '@lido-sdk/fetch';

const options = {
  urls: [
    'http://your_rpc_server.url',
    (chainId) => `http://your_rpc_server.url/?chainId=${chainId}`,
  ],
  providers: {
    infura: 'INFURA_API_KEY',
    alchemy: 'ALCHEMY_API_KEY',
  },
};

const rpc = async (req, res) => {
  // chainId and body from request
  const chainId = Number(req.query.chainId);
  const body = JSON.stringify(req.body);

  const response = await fetchRPC(chainId, { body, ...options });
  const result = await response.json();

  res.json(result);
};

Options

Options extend RequestInit interface with the urls and providers. urls have priority over providers.

import { CHAINS } from '@lido-sdk/constants';
import { RequestInit } from 'node-fetch';

interface FetchRPCOptions extends RequestInit {
  providers?: {
    infura?: string;
    alchemy?: string;
  };
  urls?: Array<string, (chainId: CHAINS) => string>;
}

Helpers

Source

getInfuraRPCUrl

Returns infura endpoint for API key and chainId

import { getInfuraRPCUrl } from '@lido-sdk/fetch';
import { CHAINS } from '@lido-sdk/constants';

const url = getInfuraRPCUrl(CHAINS.Mainnet, 'YOUR_API_KEY');
console.log(url); // https://mainnet.infura.io/v3/YOUR_API_KEY

getAlchemyRPCUrl

Returns alchemy endpoint for API key and chainId

import { getAlchemyRPCUrl } from '@lido-sdk/fetch';
import { CHAINS } from '@lido-sdk/constants';

const url = getAlchemyRPCUrl(CHAINS.Mainnet, 'YOUR_API_KEY');
console.log(url); // https://eth-mainnet.alchemyapi.io/v2/YOUR_API_KEY