How to Create Email Sign-In Links Without Sign-Up in Go

Introduction Creating email sign-in links in Firebase can be a straightforward process when all settings are correctly configured. However, when the Enable create (sign-up) option is disabled in the Firebase console, you may encounter an ADMIN_ONLY_OPERATION error while trying to generate email auth links using the Golang Admin SDK. This article will guide you through understanding the implications of this setting, how to address the error, and whether it’s possible to generate these links without allowing user sign-ups. Understanding the ADMIN_ONLY_OPERATION Error When working with Firebase Authentication, certain operations are only permitted if the user sign-up is enabled. Specifically, if you have disabled the Enable create (sign-up) option, Firebase restricts operations that might create new accounts. When you attempt to create a sign-in link using the EmailSignInLink method, Firebase checks your settings and throws an ADMIN_ONLY_OPERATION error if it determines that account creation is not allowed. This is due to Firebase's mechanism to ensure that the appropriate user actions are managed correctly, which safeguards against unintended account creation. Thus, the error indicates your current configuration is disallowing this function. Step-by-Step: Manage Email Sign-In Links in Go To effectively utilize Firebase Email Sign-In Links with the Admin SDK, follow these steps: Step 1: Install the Firebase Admin SDK for Go To use the Firebase Admin SDK, you need to install it if you haven't already: go get firebase.google.com/go Step 2: Initialize Firebase Admin SDK Before making any calls to the Admin SDK, ensure you initialize it correctly: package main import ( "context" "firebase.google.com/go/auth" "firebase.google.com/go"] "log" "os" "firebase.google.com/go" ) func main() { // Initialize a Firebase App opt := option.WithCredentialsFile("path/to/serviceAccountKey.json") app, err := firebase.NewApp(context.Background(), nil, opt) if err != nil { log.Fatalf("error initializing app: %v", err) } // Create an Auth client client, err := app.Auth(context.Background()) if err != nil { log.Fatalf("error getting Auth client: %v", err) } } Step 3: Creating ActionCodeSettings To build your action code settings: actionCodeSettings := auth.ActionCodeSettings{ URL: "https://example.firebaseapp.com", HandleCodeInApp: true, IOSBundleID: "com.example.ios", } Step 4: Generate the Sign-In Link Here's where the error occurs if the Enable create (sign-up) option is disabled: link, reqErr := client.EmailSignInLink(context.Background(), email, &actionCodeSettings) if reqErr != nil { log.Fatalf("error creating sign-in link: %v", reqErr) } At this point, if the sign-up feature is disabled, the ADMIN_ONLY_OPERATION error is thrown, indicating you are unable to create a sign-in link without allowing account creation. Possible Workarounds Currently, Firebase does not provide a direct way to bypass the need for enabling account creation for generating email sign-in links. Here are a few alternative approaches you might consider: Option 1: Enable Account Creation Temporarily If generating the sign-in link is essential for your application’s authentication flow, you may need to temporarily enable the Enable create (sign-up) option while performing this action. After generating the link, you can disable it again, but this is not recommended due to security and user experience issues. Option 2: Using Custom Authentication Consider implementing a custom authentication system where you handle email sign-in links separately from Firebase's native methods, particularly if your application can manage user state and authentication independently. Frequently Asked Questions 1. Can I generate a sign-in link without sign-up enabled? No, if sign-up is disabled, Firebase prevents the generation of email sign-in links for security reasons. 2. How does enabling sign-up impact my app? Enabling sign-up allows new users to create accounts and impacts your app's user authentication flows. 3. Are there security implications of enabling sign-up? There can be, as this setting allows anyone with an email address to create an account. Ensure you implement email verification and other security measures. Conclusion Generating email sign-in links using the Firebase Admin SDK in Go requires enabling the Enable create (sign-up) option to avoid the ADMIN_ONLY_OPERATION error. Unfortunately, there are currently no available methods to bypass this requirement without risking application functionality and security. Always assess the security implications of your authentication decisions to maintain a secure user environment.

May 12, 2025 - 17:03

Introduction

Creating email sign-in links in Firebase can be a straightforward process when all settings are correctly configured. However, when the Enable create (sign-up) option is disabled in the Firebase console, you may encounter an ADMIN_ONLY_OPERATION error while trying to generate email auth links using the Golang Admin SDK. This article will guide you through understanding the implications of this setting, how to address the error, and whether it’s possible to generate these links without allowing user sign-ups.

Understanding the ADMIN_ONLY_OPERATION Error

When working with Firebase Authentication, certain operations are only permitted if the user sign-up is enabled. Specifically, if you have disabled the Enable create (sign-up) option, Firebase restricts operations that might create new accounts. When you attempt to create a sign-in link using the EmailSignInLink method, Firebase checks your settings and throws an ADMIN_ONLY_OPERATION error if it determines that account creation is not allowed.

This is due to Firebase's mechanism to ensure that the appropriate user actions are managed correctly, which safeguards against unintended account creation. Thus, the error indicates your current configuration is disallowing this function.

Step-by-Step: Manage Email Sign-In Links in Go

To effectively utilize Firebase Email Sign-In Links with the Admin SDK, follow these steps:

Step 1: Install the Firebase Admin SDK for Go

To use the Firebase Admin SDK, you need to install it if you haven't already:

go get firebase.google.com/go

Step 2: Initialize Firebase Admin SDK

Before making any calls to the Admin SDK, ensure you initialize it correctly:

package main

import (
    "context"
    "firebase.google.com/go/auth"
    "firebase.google.com/go"]
    "log"
    "os"
    "firebase.google.com/go"
)

func main() {
    // Initialize a Firebase App
    opt := option.WithCredentialsFile("path/to/serviceAccountKey.json")
    app, err := firebase.NewApp(context.Background(), nil, opt)
    if err != nil {
        log.Fatalf("error initializing app: %v", err)
    }

    // Create an Auth client
    client, err := app.Auth(context.Background())
    if err != nil {
        log.Fatalf("error getting Auth client: %v", err)
    }
}

Step 3: Creating ActionCodeSettings

To build your action code settings:

actionCodeSettings := auth.ActionCodeSettings{
    URL:             "https://example.firebaseapp.com",
    HandleCodeInApp: true,
    IOSBundleID:     "com.example.ios",
}

Step 4: Generate the Sign-In Link

Here's where the error occurs if the Enable create (sign-up) option is disabled:

link, reqErr := client.EmailSignInLink(context.Background(), email, &actionCodeSettings)
if reqErr != nil {
    log.Fatalf("error creating sign-in link: %v", reqErr)
}

At this point, if the sign-up feature is disabled, the ADMIN_ONLY_OPERATION error is thrown, indicating you are unable to create a sign-in link without allowing account creation.

Possible Workarounds

Currently, Firebase does not provide a direct way to bypass the need for enabling account creation for generating email sign-in links. Here are a few alternative approaches you might consider:

Option 1: Enable Account Creation Temporarily

If generating the sign-in link is essential for your application’s authentication flow, you may need to temporarily enable the Enable create (sign-up) option while performing this action. After generating the link, you can disable it again, but this is not recommended due to security and user experience issues.

Option 2: Using Custom Authentication

Consider implementing a custom authentication system where you handle email sign-in links separately from Firebase's native methods, particularly if your application can manage user state and authentication independently.

Frequently Asked Questions

1. Can I generate a sign-in link without sign-up enabled?
No, if sign-up is disabled, Firebase prevents the generation of email sign-in links for security reasons.

2. How does enabling sign-up impact my app?
Enabling sign-up allows new users to create accounts and impacts your app's user authentication flows.

3. Are there security implications of enabling sign-up?
There can be, as this setting allows anyone with an email address to create an account. Ensure you implement email verification and other security measures.

Conclusion

Generating email sign-in links using the Firebase Admin SDK in Go requires enabling the Enable create (sign-up) option to avoid the ADMIN_ONLY_OPERATION error. Unfortunately, there are currently no available methods to bypass this requirement without risking application functionality and security. Always assess the security implications of your authentication decisions to maintain a secure user environment.