### Install OAuth Plugins

Source: https://limenauth.dev/blog/introducing-limen

Install the necessary OAuth plugins for Limen using go get.

```go
go get github.com/thecodearcher/limen/plugins/oauth
go get github.com/thecodearcher/limen/plugins/oauth-google
```

--------------------------------

### Install Limen and Dependencies

Source: https://limenauth.dev/blog/introducing-limen

Install the Limen core library, the SQL adapter, and the credential-password plugin. Ensure you have Go 1.25+ installed.

```go
go get github.com/thecodearcher/limen
go get github.com/thecodearcher/limen/adapters/sql
go get github.com/thecodearcher/limen/plugins/credential-password
```

--------------------------------

### Initialize Limen with Base URL and Password Plugin

Source: https://limenauth.dev/

This example demonstrates initializing Limen with a specific BaseURL, a database adapter, and the password credential plugin. It's useful for setting up authentication in a client-server environment where the base URL is known.

```go
package main

import (...) 

func main() {
  auth, err := limen.New(&limen.Config{
    BaseURL:  "http://localhost:8080",
    Database: adapter.New(db),
    Plugins: []limen.Plugin{
      credentialpassword.New(),
    },
  })
  if err != nil {
    log.Fatal(err)
  }

  mux := http.NewServeMux()
  mux.Handle("/api/auth/", auth.Handler())
}
```

--------------------------------

### Install Limen Dependencies

Source: https://limenauth.dev/docs/installation

Add the core Limen library, a database adapter (GORM in this example), and the credential-password authentication plugin to your project.

```bash
go get github.com/thecodearcher/limen
go get github.com/thecodearcher/limen/adapters/gorm
go get github.com/thecodearcher/limen/plugins/credential-password
go get gorm.io/gorm gorm.io/driver/postgres
```

--------------------------------

### Install Two-Factor Authentication Plugin

Source: https://limenauth.dev/blog/introducing-limen

Install the two-factor authentication plugin for Limen using go get.

```go
go get github.com/thecodearcher/limen/plugins/two-factor
```

--------------------------------

### Run Limen Application

Source: https://limenauth.dev/docs/installation

Start your Go application to begin using Limen for user authentication.

```bash
go run main.go
```

--------------------------------

### Wire Up Limen Core with PostgreSQL

Source: https://limenauth.dev/blog/introducing-limen

Set up the main Go application to initialize Limen with a PostgreSQL database adapter and the credential-password plugin. This example demonstrates basic configuration including database connection, session secret, and plugin registration.

```go
package main

import (
	"database/sql"
	"log"
	"net/http"
	"os"

	_ "github.com/lib/pq"

	"github.com/thecodearcher/limen"
	sqladapter "github.com/thecodearcher/limen/adapters/sql"
	credentialpassword "github.com/thecodearcher/limen/plugins/credential-password"
)

func main() {
	db, err := sql.Open("postgres", os.Getenv("DATABASE_URL"))
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	auth, err := limen.New(&limen.Config{
		BaseURL:  "http://localhost:8080",
		Database: sqladapter.NewPostgreSQL(db),
		Secret:   []byte(os.Getenv("LIMEN_SECRET")), // 32 bytes
		Plugins: []limen.Plugin{
			credentialpassword.New(),
		},
	})
	if err != nil {
		log.Fatal(err)
	}

	mux := http.NewServeMux()
	mux.Handle("/api/auth/", auth.Handler())

	log.Println("listening on :8080")
	log.Fatal(http.ListenAndServe(":8080", mux))
}
```

--------------------------------

### Create Limen Instance and Get Handler

Source: https://limenauth.dev/docs/installation

Instantiate Limen with the configuration and retrieve the HTTP handler to be mounted in your server.

```go
auth, err := limen.New(config)
if err != nil {
	log.Fatalf("Failed to create limen: %v", err)
}

handler := auth.Handler()
```

--------------------------------

### Add Custom User Fields with Limen Schema System

Source: https://limenauth.dev/blog/introducing-limen

Extend the user schema in Limen to include custom fields like 'display_name' without forking the core. This example shows how to define a required 'display_name' field.

```go
limen.WithSchemaUser(
	limen.WithUserAdditionalFields(func(ctx *limen.AdditionalFieldsContext) (map[string]any, error) {
		if ctx.IsEmpty("display_name") {
			return nil, limen.NewLimenError("display_name is required", http.StatusBadRequest, nil)
		}
		return map[string]any{
			"display_name": ctx.GetBodyValue("display_name"),
		},
	}),
)
```

--------------------------------

### Initialize GORM Database Adapter

Source: https://limenauth.dev/docs/installation

Open a database connection using GORM and wrap it with the Limen GORM adapter to enable database interactions.

```go
package main

import (
	"log"

	gormadapter "github.com/thecodearcher/limen/adapters/gorm"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

func main() {
	dsn := "host=localhost user=postgres password=postgres dbname=myapp port=5432 sslmode=disable"
	gormdb, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
	if err != nil {
		log.Fatalf("Failed to open database: %v", err)
	}

	adapter := gormadapter.New(gormdb)
}
```

--------------------------------

### Configure Limen with Plugins

Source: https://limenauth.dev/docs/installation

Build the limen.Config object, specifying the base URL, database adapter, and desired authentication plugins like credential-password.

```go
import (
	"github.com/thecodearcher/limen"
	credentialpassword "github.com/thecodearcher/limen/plugins/credential-password"
)

config := &limen.Config{
	BaseURL:       "http://localhost:8080",
	Database:      adapter,
	Plugins: []limen.Plugin{
		credentialpassword.New(),
	},
}
```

--------------------------------

### Initialize Limen Authentication with Password Plugin

Source: https://limenauth.dev/

This snippet shows how to initialize Limen with a configuration that includes a database adapter and the password credential plugin. It then sets up a basic HTTP handler for authentication routes.

```go
package main

func main() {
	auth, err := limen.New(
    &limen.Config{
		Database: adapter.New(db),
		Plugins: []limen.Plugin{
        credentialpassword.New(),
      }
    }
  )

	if err != nil {
		log.Fatal(err)
	}

	mux := http.NewServeMux()
	mux.Handle("/api/auth/", auth.Handler())
}
```

--------------------------------

### Enable Limen CLI for Migrations

Source: https://limenauth.dev/docs/installation

Add the CLI configuration to your Limen config to enable the CLI for generating database migrations.

```go
&limen.Config{
    //... other config options ...
    CLI: &limen.CLIConfig{
			Enabled: true,
		},
    //... other config options ...
	}
```

--------------------------------

### Set Up Environment Variable for Secret Key

Source: https://limenauth.dev/docs/installation

Create a .env file and add the LIMEN_SECRET variable with a 32-character signing secret for encryption.

```env
LIMEN_SECRET=your-32-byte-signing-secret-here!
```

--------------------------------

### Generate Database Migrations with Limen CLI

Source: https://limenauth.dev/docs/installation

Use the Limen CLI to generate SQL migration files based on your database schema and driver.

```bash
limen generate migrations --driver postgres --dsn "host=localhost user=postgres password=postgres dbname=myapp port=5432 sslmode=disable"
```

--------------------------------

### User Signup with Credential Password

Source: https://limenauth.dev/blog/introducing-limen

This snippet shows the JSON payload for signing up a user using the credential-password endpoint. It requires the email and password for the new user.

```json
{ "email": "ada@example.com", "password": "correct-horse-battery" }
```

--------------------------------

### Configure Google OAuth in Limen

Source: https://limenauth.dev/blog/introducing-limen

Integrate Google OAuth into your Limen application by adding the oauth-google plugin. Ensure GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET are set in your environment or passed explicitly.

```go
import (
	"github.com/thecodearcher/limen/plugins/oauth"
	oauthgoogle "github.com/thecodearcher/limen/plugins/oauth-google"
)

auth, _ := limen.New(&limen.Config{
	// ... BaseURL, Database, Secret ...
	Plugins: []limen.Plugin{
		credentialpassword.New(),
		oauth.New(oauth.WithProviders(
			oauthgoogle.New(),
		)),
	},
})
```

--------------------------------

### Protect a Route with Limen Session

Source: https://limenauth.dev/blog/introducing-limen

Demonstrates how to retrieve and use the user session to protect an API route. The `auth.GetSession(r)` method can be used in any handler or middleware that has access to the `http.Request`.

```go
mux.HandleFunc("GET /api/me", func(w http.ResponseWriter, r *http.Request) {
	session, err := auth.GetSession(r)
	if err != nil || session == nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}
	// session.User and session.Session are fully typed
	json.NewEncoder(w).Encode(session.User)
})
```

--------------------------------

### Enable Two-Factor Authentication in Limen

Source: https://limenauth.dev/blog/introducing-limen

Add the two-factor plugin to your Limen configuration to enable TOTP authenticator enrollment and backup code generation for users.

```go
import twofactor "github.com/thecodearcher/limen/plugins/two-factor"

Plugins: []limen.Plugin{
	credentialpassword.New(),
	oauth.New( /* ... */ ),
	twofactor.New(),
},
```

--------------------------------

### User Signin with Credential Password

Source: https://limenauth.dev/blog/introducing-limen

This snippet shows the JSON payload for signing in a user using the credential-password endpoint. It requires the user's email or username and their password.

```json
{ "credential": "ada@example.com", "password": "correct-horse-battery" }
```

--------------------------------

### Mount Limen Handler in HTTP Server

Source: https://limenauth.dev/docs/installation

Register the Limen HTTP handler with your HTTP multiplexer, typically under an authentication-related path.

```go
mux := http.NewServeMux()
mux.Handle("/auth/", handler)
log.Fatal(http.ListenAndServe(":8080", mux))
```

--------------------------------

### Limen OAuth Endpoints

Source: https://limenauth.dev/blog/introducing-limen

Limen automatically exposes API endpoints for OAuth flows. These endpoints handle authorization, callback, token exchange, and user profile fetching.

```text
GET  /api/auth/oauth/google/authorize?callback_url=https://yourapp.com/callback
GET  /api/auth/oauth/google/callback
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.