JavaScript/TypeScript

Saiba mais sobre como usar JavaScript e TypeScript com Infura.

Guias

Ethers.js: How to get the ETH and ERC-20 token balance of an address at a particular timestamp

In this short tutorial, we'll look at how to retrieve the balance of an ETH or ERC-20 token at a particular timestamp with Ethers.js.

Web3.js: How to keep WebSocket subscriptions alive and reconnect on failures

Smart contracts are an essential part of the Ethereum ecosystem. Smart contracts emit so-called events when something meaningful happens within the smart contract that should be communicated to dapps and other smart contracts.

Ethers.js: How to retrieve the balance of an ERC-20 token

In this short tutorial we'll look at how to retrieve the balance of an ERC-20 token with Ethers.js.

Web3.js: How to Retrieve the Balance of an ERC-20 Token

Almost all tokens deployed on Ethereum follow the same specification: ERC-20.

Ethers.js: How to send batch requests with Infura

In this guide we'll write a simple script using Ethers.js and Infura for sending batch requests.

Web3.js: How to send batch requests with Infura

This tutorial makes use of Web3.js v1.x.x. Not all functionality might work with Web3.js v4.

Axios: How to send an EIP-1559 raw transaction in JavaScript

In general the Javascript libraries like Ethers.js or Web3.js have build in methods to sign and send a raw transaction but there might be situations where you'd want interact with the Ethereum API via plain JSON-RPC requests.

Ethers.js: How to send EIP-1559 transactions

Ethers can send EIP-1559 transactions without any extra configuration. It will use a maxPriorityFeePerGas of 1.5 Gwei by default, starting with v5.6.0. Here's a simple script that would send such a transaction:

Ethers.js: How to send ERC-20 Tokens

In this post we will explore how to transfer an ERC-20 token from one address to another with ethers.js. Ethers is a JavaScript library that can send an EIP-1559 transaction without the need to manually specify gas properties. It will determine the gasLimit and use a maxPriorityFeePerGas of 1.5 Gwei by default, starting with v5.6.0. Also, if you use a signer class it can manage the nonce for you.

Web3.js: How to send ERC-20 tokens

This tutorial makes use of Web3.js v1.x.x. Not all functionality might work with Web3.js v4.

Web3.js How to subscribe to pending transactions using web3.subscribe

This tutorial makes use of Web3.js v1.x.x. Not all functionality might work with Web3.js v4.

Web3.js: How to track ERC-20 token transfers

You can programmatically track ERC-20 token transfers using Web3.js and some ABI and event tracking magic.

Web3.js: How to track NFT (ERC-721/1155) transfers and mints

This tutorial makes use of Web3.js v1.x.x. Not all functionality might work with Web3.js v4.

React.js and Ethers.js: Demo of using the `InfuraProvider` vs the MetaMask wallet `Web3Provider`

This guide covers how to connect to Ethereum using the Ethers.js InfuraProvider and the Web3Provider which injects a web3 wallet, in this case MetaMask.

Aprender

Ethers provider behaviour when hitting the API key daily limit

When the daily API key limit is being hit, an API request to Infura should return: “exceeded project daily request limit”.