Chainlink Developers

Welcome to the Chainlink documentation site. You'll find comprehensive guides and documentation to help you start working with Chainlink as quickly as possible, as well as support if you get stuck. Click here for an introductory walkthrough on how to create a Chainlink request on the Ropsten test network!

Building on Chainlink? Click here to get started!

Get Started

Contract creators are developers who build smart contracts with the goal of connecting them to off-chain data sources.

Getting started


You can start creating your contracts now! Start with Create a Chainlinked Project or the Example Walkthrough.

We strongly recommend you deploy first to testnets before deploying to Ethereum mainnet. Chainlink provides a practical developer environment on Ropsten, Rinkeby and Kovan.

You will also want to consider what kind of data and what data source you want to use.

Choosing a Data Source


There are two categories of data sources available to you:

  1. Reference Data - Aggregated data from many sources
  2. Request & Receive Data - Request specific data from API endpoints

Reference Data

Reference data contracts are updated by a network on independent Chainlink nodes. They aggregate results from many sources and make that data available in a single place.

Visit Using Reference Data for more information.

This type of data source is great for immediately using data in your smart contract without waiting to receive a response back to your contract. We have provided a list of reference data: Reference Data Contracts

Request & Receive

Request & receive describes the scheme in which your contract requests data from an oracle and the oracle sends the data back to your contract, triggering a custom function which does something with the data.

Visit our Example Walkthrough which allows you to fetch the price of ETHUSD and use it in your contract.

This type of data source is great for connecting to any API and bringing its data on-chain. We have provided lists of ready-made data sources available: Chainlinks (Testnet) and Chainlinks (Ethereum Mainnet)

Updated 19 days ago


What's Next

We'll discuss the ChainLink framework used to customize your contracts.

Create a Chainlinked Project
Example Walkthrough

Overview


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