FCL: Flow Client Library

Making secure web applications powered by the Flow Blockchain

Flow Client Library (FCL) enables applications to easily integrate with all FCL-compatible wallets and other services (e.g. (Coming Soon) profiles, private information, notifications). This offers developers a strong foundation to compose their apps with existing building blocks. It’s currently supported for browser applications, and will be extended to other platforms.

With FCL, you can:

• Integrate all compatible wallets without any custom code or code injection
• Authenticate users
• Query the Flow Blockchain
• Send transactions (e.g. initializing resources, sending assets, purchasing, etc.)
• Sign transactions through wallet integration avoiding key management

With FCL, you will eventually be able to:

• Personally sign data via FCL Compatible Wallets
• Request Additional User info like Emails

Status

• Last Updated: Mar 2nd 2021
• Stable: Yes
• Risk of Breaking Change: Low

The things that exists probably won't be changing much externally, we will be adding new functionality in the near future.

Install

npm install --save @onflow/fcl @onflow/types

Getting Started

For a detailed guide explaining how to use @onflow/fcl to interact with Flow please see the Flow App Quick Start

Having trouble with something? Reach out to us on Discord, we are more than happy to help.

WalletConnect Deeplinks

This package uses wc-redirect as the deeplink path for WalletConnect redirects (e.g., myapp://wc-redirect). When a wallet approves a connection or transaction, it redirects back to your app using this path.

If you're using Expo Router, you may want to intercept this path to prevent unwanted navigation. See @onflow/react-native-sdk README for details.