currentUser

The main current user service for managing user authentication and authorization in Flow applications. This service provides a complete interface for wallet connections, user sessions, transaction signing, and user data management. It handles the complexity of connecting to various FCL-compatible wallets, managing authentication state, and providing authorization functions for transaction signing.

The currentUser service is configured for web platforms and uses the browser's localStorage by default for session persistence. It integrates with Flow's discovery service to enable wallet selection and supports both authentication and re-authentication flows.

This service is reactive and provides subscription capabilities to monitor authentication state changes in real-time. All wallet interactions are handled through FCL's standardized protocols, ensuring compatibility with the Flow ecosystem.

Returns an object with the following methods:

_10

{

_10

authenticate, // Authenticates the user via FCL-compatible wallets

_10

unauthenticate, // Logs out the current user and clears session data

_10

authorization, // Produces authorization details for transaction signing

_10

signUserMessage, // Signs arbitrary messages with the user's wallet

_10

subscribe, // Subscribes to authentication state changes

_10

snapshot, // Returns the current user object snapshot

_10

resolveArgument // Resolves the current user as a transaction argument

_10

}

Import

You can import the entire package and access the function:

_10

import * as fcl from "@onflow/fcl"

_10

_10

fcl.currentUser()

Or import directly the specific function:

_10

import { currentUser } from "@onflow/fcl"

_10

_10

currentUser()

Usage

_36

// Basic authentication flow

_36

import * as fcl from "@onflow/fcl"

_36

_36

// Configure FCL

_36

fcl.config({

_36

"accessNode.api": "https://rest-testnet.onflow.org",

_36

"discovery.wallet": "https://fcl-discovery.onflow.org/testnet/authn",

_36

"flow.network": "testnet"

_36

})

_36

_36

// Authenticate user

_36

const user = await fcl.currentUser.authenticate()

_36

console.log("User authenticated:", user.addr)

_36

_36

// Check authentication status

_36

const currentUser = await fcl.currentUser.snapshot()

_36

if (currentUser.loggedIn) {

_36

console.log("User is logged in:", currentUser.addr)

_36

}

_36

_36

// Subscribe to authentication state changes

_36

import * as fcl from "@onflow/fcl"

_36

_36

const unsubscribe = fcl.currentUser.subscribe((user) => {

_36

if (user.loggedIn) {

_36

console.log("User logged in:", user.addr)

_36

document.getElementById("login-btn").style.display = "none"

_36

document.getElementById("logout-btn").style.display = "block"

_36

} else {

_36

console.log("User logged out")

_36

document.getElementById("login-btn").style.display = "block"

_36

document.getElementById("logout-btn").style.display = "none"

_36

}

_36

})

_36

// Clean up subscription when component unmounts

_36

window.addEventListener("beforeunload", () => unsubscribe())

Returns

_10

export interface CurrentUserService extends CurrentUserServiceApi {

_10

(): CurrentUserServiceApi

_10

}

A CurrentUserService object

---