diff --git a/api/api.go b/api/api.go
index 543e7566..a2702208 100644
--- a/api/api.go
+++ b/api/api.go
@@ -2,6 +2,7 @@ package api
 
 import (
 	"errors"
+	"strings"
 
 	"github.com/go-skynet/LocalAI/internal"
 	"github.com/go-skynet/LocalAI/pkg/assets"
@@ -83,6 +84,26 @@ func App(opts ...AppOption) (*fiber.App, error) {
 	// Default middleware config
 	app.Use(recover.New())
 
+	// Auth middleware checking if API key is valid. If no API key is set, no auth is required.
+	auth := func(c *fiber.Ctx) error {
+		if options.apiKey != "" {
+			authHeader := c.Get("Authorization")
+			if authHeader == "" {
+				return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"message": "Authorization header missing"})
+			}
+			authHeaderParts := strings.Split(authHeader, " ")
+			if len(authHeaderParts) != 2 || authHeaderParts[0] != "Bearer" {
+				return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"message": "Invalid Authorization header format"})
+			}
+
+			apiKey := authHeaderParts[1]
+			if apiKey != options.apiKey {
+				return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"message": "Invalid API key"})
+			}
+		}
+		return c.Next()
+	}
+
 	if options.preloadJSONModels != "" {
 		if err := ApplyGalleryFromString(options.loader.ModelPath, options.preloadJSONModels, cm, options.galleries); err != nil {
 			return nil, err
@@ -109,42 +130,42 @@ func App(opts ...AppOption) (*fiber.App, error) {
 	applier := newGalleryApplier(options.loader.ModelPath)
 	applier.start(options.context, cm)
 
-	app.Get("/version", func(c *fiber.Ctx) error {
+	app.Get("/version", auth, func(c *fiber.Ctx) error {
 		return c.JSON(struct {
 			Version string `json:"version"`
 		}{Version: internal.PrintableVersion()})
 	})
 
-	app.Post("/models/apply", applyModelGallery(options.loader.ModelPath, cm, applier.C, options.galleries))
-	app.Get("/models/available", listModelFromGallery(options.galleries, options.loader.ModelPath))
-	app.Get("/models/jobs/:uuid", getOpStatus(applier))
+	app.Post("/models/apply", auth, applyModelGallery(options.loader.ModelPath, cm, applier.C, options.galleries))
+	app.Get("/models/available", auth, listModelFromGallery(options.galleries, options.loader.ModelPath))
+	app.Get("/models/jobs/:uuid", auth, getOpStatus(applier))
 
 	// openAI compatible API endpoint
 
 	// chat
-	app.Post("/v1/chat/completions", chatEndpoint(cm, options))
-	app.Post("/chat/completions", chatEndpoint(cm, options))
+	app.Post("/v1/chat/completions", auth, chatEndpoint(cm, options))
+	app.Post("/chat/completions", auth, chatEndpoint(cm, options))
 
 	// edit
-	app.Post("/v1/edits", editEndpoint(cm, options))
-	app.Post("/edits", editEndpoint(cm, options))
+	app.Post("/v1/edits", auth, editEndpoint(cm, options))
+	app.Post("/edits", auth, editEndpoint(cm, options))
 
 	// completion
-	app.Post("/v1/completions", completionEndpoint(cm, options))
-	app.Post("/completions", completionEndpoint(cm, options))
-	app.Post("/v1/engines/:model/completions", completionEndpoint(cm, options))
+	app.Post("/v1/completions", auth, completionEndpoint(cm, options))
+	app.Post("/completions", auth, completionEndpoint(cm, options))
+	app.Post("/v1/engines/:model/completions", auth, completionEndpoint(cm, options))
 
 	// embeddings
-	app.Post("/v1/embeddings", embeddingsEndpoint(cm, options))
-	app.Post("/embeddings", embeddingsEndpoint(cm, options))
-	app.Post("/v1/engines/:model/embeddings", embeddingsEndpoint(cm, options))
+	app.Post("/v1/embeddings", auth, embeddingsEndpoint(cm, options))
+	app.Post("/embeddings", auth, embeddingsEndpoint(cm, options))
+	app.Post("/v1/engines/:model/embeddings", auth, embeddingsEndpoint(cm, options))
 
 	// audio
-	app.Post("/v1/audio/transcriptions", transcriptEndpoint(cm, options))
-	app.Post("/tts", ttsEndpoint(cm, options))
+	app.Post("/v1/audio/transcriptions", auth, transcriptEndpoint(cm, options))
+	app.Post("/tts", auth, ttsEndpoint(cm, options))
 
 	// images
-	app.Post("/v1/images/generations", imageEndpoint(cm, options))
+	app.Post("/v1/images/generations", auth, imageEndpoint(cm, options))
 
 	if options.imageDir != "" {
 		app.Static("/generated-images", options.imageDir)
@@ -163,8 +184,8 @@ func App(opts ...AppOption) (*fiber.App, error) {
 	app.Get("/readyz", ok)
 
 	// models
-	app.Get("/v1/models", listModels(options.loader, cm))
-	app.Get("/models", listModels(options.loader, cm))
+	app.Get("/v1/models", auth, listModels(options.loader, cm))
+	app.Get("/models", auth, listModels(options.loader, cm))
 
 	return app, nil
 }
diff --git a/api/options.go b/api/options.go
index 923288ac..41ef62b8 100644
--- a/api/options.go
+++ b/api/options.go
@@ -23,6 +23,7 @@ type Option struct {
 	preloadJSONModels               string
 	preloadModelsFromPath           string
 	corsAllowOrigins                string
+	apiKey                          string
 
 	galleries []gallery.Gallery
 
@@ -167,3 +168,9 @@ func WithImageDir(imageDir string) AppOption {
 		o.imageDir = imageDir
 	}
 }
+
+func WithApiKey(apiKey string) AppOption {
+	return func(o *Option) {
+		o.apiKey = apiKey
+	}
+}
diff --git a/main.go b/main.go
index fc1dea09..118364c3 100644
--- a/main.go
+++ b/main.go
@@ -110,6 +110,11 @@ func main() {
 				EnvVars: []string{"UPLOAD_LIMIT"},
 				Value:   15,
 			},
+			&cli.StringFlag{
+				Name:    "api-key",
+				Usage:   "API Key to enable API authentication. When this is set, all the requests must be authenticated with this API key.",
+				EnvVars: []string{"API_KEY"},
+			},
 		},
 		Description: `
 LocalAI is a drop-in replacement OpenAI API which runs inference locally.
@@ -145,7 +150,9 @@ For a list of compatible model, check out: https://localai.io/model-compatibilit
 				api.WithThreads(ctx.Int("threads")),
 				api.WithBackendAssets(backendAssets),
 				api.WithBackendAssetsOutput(ctx.String("backend-assets-path")),
-				api.WithUploadLimitMB(ctx.Int("upload-limit")))
+				api.WithUploadLimitMB(ctx.Int("upload-limit")),
+				api.WithApiKey(ctx.String("api-key")),
+			)
 			if err != nil {
 				return err
 			}