Sei API Quickstart

To use the Sei API you’ll need to create a free Alchemy account first!

Introduction

Sei is a high-performance blockchain designed for decentralized finance (DeFi) applications. It offers fast transaction speeds, scalability, and a developer-friendly environment, making it an ideal platform for deploying DeFi applications and services.

What is the Sei API?

The Sei API allows developers to interact with the Sei network through a collection of JSON-RPC methods. Given its compatibility with standard blockchain APIs, developers familiar with other blockchain JSON-RPC APIs will find working with Sei intuitive and straightforward.

Getting Started Instructions

1. Choose a Package Manager (npm or yarn)

Your first step involves selecting a package manager, which will be crucial for managing your project’s dependencies. The choice between npm and yarn depends on your personal preference or project requirements.

2. Set Up Your Project

To kickstart your project, open your terminal and execute the following commands:

mkdir sei-api-quickstart
cd sei-api-quickstart
npm init --yes

This creates a new directory named sei-api-quickstart and initializes a Node.js project within it.

3. Make Your First Request

For making API requests, we’ll use Axios, a widely-used HTTP client. Install Axios with the following command:

$
npm install axios
>
# Or with yarn
>
# yarn add axios

Next, create an index.js file in your project directory. Paste the following code to send a request to the Sei network:

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const axios = require('axios');
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const url = `https://sei-mainnet.g.alchemy.com/v2/${yourAPIKey}`;
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const payload = {
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  jsonrpc: '2.0',
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  id: 1,
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  method: 'sei_getBlockNumber',
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  params: []
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};
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axios.post(url, payload)
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  .then(response => {
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    console.log('Block Number:', response.data.result);
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  })
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  .catch(error => {
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    console.error(error);
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  });

Remember to replace yourAPIKey with your actual Alchemy API key that you can get from your Alchemy dashboard.

4. Run Your Script

To execute your script and make a request to the Sei network, run:

$
node index.js

You should see the current block number on Sei (in hexadecimal format) outputted to your console:

$
Block Number: 0x6d68e

Next Steps

Well done! You’ve just made your first request to the Sei API. With this foundation, you can dive deeper into the array of JSON-RPC methods available on Sei and start building your dApps on it!