feat(tts): add Elevenlabs and OpenAI TTS compatibility layer (#1834)

* feat(elevenlabs): map elevenlabs API support to TTS

This allows elevenlabs Clients to work automatically with LocalAI by
supporting the elevenlabs API.

The elevenlabs server endpoint is implemented such as it is wired to the
TTS endpoints.

Fixes: https://github.com/mudler/LocalAI/issues/1809

* feat(openai/tts): compat layer with openai tts

Fixes: #1276

* fix: adapt tts CLI

core/backend/tts.go

@@ -29,7 +29,7 @@ func generateUniqueFileName(dir, baseName, ext string) string {
 	}
 }
 
-func ModelTTS(backend, text, modelFile string, loader *model.ModelLoader, appConfig *config.ApplicationConfig, backendConfig config.BackendConfig) (string, *proto.Result, error) {
+func ModelTTS(backend, text, modelFile, voice string, loader *model.ModelLoader, appConfig *config.ApplicationConfig, backendConfig config.BackendConfig) (string, *proto.Result, error) {
 	bb := backend
 	if bb == "" {
 		bb = model.PiperBackend
@@ -44,12 +44,12 @@ func ModelTTS(backend, text, modelFile string, loader *model.ModelLoader, appCon
 		model.WithAssetDir(appConfig.AssetsDestination),
 		model.WithLoadGRPCLoadModelOpts(grpcOpts),
 	})
-	piperModel, err := loader.BackendLoader(opts...)
+	ttsModel, err := loader.BackendLoader(opts...)
 	if err != nil {
 		return "", nil, err
 	}
 
-	if piperModel == nil {
+	if ttsModel == nil {
 		return "", nil, fmt.Errorf("could not load piper model")
 	}
 
@@ -57,25 +57,31 @@ func ModelTTS(backend, text, modelFile string, loader *model.ModelLoader, appCon
 		return "", nil, fmt.Errorf("failed creating audio directory: %s", err)
 	}
 
-	fileName := generateUniqueFileName(appConfig.AudioDir, "piper", ".wav")
+	fileName := generateUniqueFileName(appConfig.AudioDir, "tts", ".wav")
 	filePath := filepath.Join(appConfig.AudioDir, fileName)
 
 	// If the model file is not empty, we pass it joined with the model path
 	modelPath := ""
 	if modelFile != "" {
-		if bb != model.TransformersMusicGen {
-			modelPath = filepath.Join(loader.ModelPath, modelFile)
-			if err := utils.VerifyPath(modelPath, appConfig.ModelPath); err != nil {
+		// If the model file is not empty, we pass it joined with the model path
+		// Checking first that it exists and is not outside ModelPath
+		// TODO: we should actually first check if the modelFile is looking like
+		// a FS path
+		mp := filepath.Join(loader.ModelPath, modelFile)
+		if _, err := os.Stat(mp); err == nil {
+			if err := utils.VerifyPath(mp, appConfig.ModelPath); err != nil {
 				return "", nil, err
 			}
+			modelPath = mp
 		} else {
 			modelPath = modelFile
 		}
 	}
 
-	res, err := piperModel.TTS(context.Background(), &proto.TTSRequest{
+	res, err := ttsModel.TTS(context.Background(), &proto.TTSRequest{
 		Text:  text,
 		Model: modelPath,
+		Voice: voice,
 		Dst:   filePath,
 	})
 

core/http/api.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/go-skynet/LocalAI/core/http/endpoints/elevenlabs"
 	"github.com/go-skynet/LocalAI/core/http/endpoints/localai"
 	"github.com/go-skynet/LocalAI/core/http/endpoints/openai"
 
@@ -21,6 +22,24 @@ import (
 	"github.com/gofiber/fiber/v2/middleware/recover"
 )
 
+func readAuthHeader(c *fiber.Ctx) string {
+	authHeader := c.Get("Authorization")
+
+	// elevenlabs
+	xApiKey := c.Get("xi-api-key")
+	if xApiKey != "" {
+		authHeader = "Bearer " + xApiKey
+	}
+
+	// anthropic
+	xApiKey = c.Get("x-api-key")
+	if xApiKey != "" {
+		authHeader = "Bearer " + xApiKey
+	}
+
+	return authHeader
+}
+
 func App(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *config.ApplicationConfig) (*fiber.App, error) {
 	// Return errors as JSON responses
 	app := fiber.New(fiber.Config{
@@ -94,10 +113,12 @@ func App(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *confi
 			return c.Next()
 		}
 
-		authHeader := c.Get("Authorization")
+		authHeader := readAuthHeader(c)
 		if authHeader == "" {
 			return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"message": "Authorization header missing"})
 		}
+
+		// If it's a bearer token
 		authHeaderParts := strings.Split(authHeader, " ")
 		if len(authHeaderParts) != 2 || authHeaderParts[0] != "Bearer" {
 			return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"message": "Invalid Authorization header format"})
@@ -111,7 +132,6 @@ func App(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *confi
 		}
 
 		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"message": "Invalid API key"})
-
 	}
 
 	if appConfig.CORS {
@@ -147,6 +167,11 @@ func App(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *confi
 	app.Get("/models/jobs/:uuid", auth, modelGalleryEndpointService.GetOpStatusEndpoint())
 	app.Get("/models/jobs", auth, modelGalleryEndpointService.GetAllStatusEndpoint())
 
+	app.Post("/tts", auth, localai.TTSEndpoint(cl, ml, appConfig))
+
+	// Elevenlabs
+	app.Post("/v1/text-to-speech/:voice-id", auth, elevenlabs.TTSEndpoint(cl, ml, appConfig))
+
 	// openAI compatible API endpoint
 
 	// chat
@@ -181,7 +206,7 @@ func App(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *confi
 
 	// audio
 	app.Post("/v1/audio/transcriptions", auth, openai.TranscriptEndpoint(cl, ml, appConfig))
-	app.Post("/tts", auth, localai.TTSEndpoint(cl, ml, appConfig))
+	app.Post("/v1/audio/speech", auth, localai.TTSEndpoint(cl, ml, appConfig))
 
 	// images
 	app.Post("/v1/images/generations", auth, openai.ImageEndpoint(cl, ml, appConfig))

core/http/endpoints/elevenlabs/tts.go

@@ -0,0 +1,55 @@
+package elevenlabs
+
+import (
+	"github.com/go-skynet/LocalAI/core/backend"
+	"github.com/go-skynet/LocalAI/core/config"
+	fiberContext "github.com/go-skynet/LocalAI/core/http/ctx"
+	"github.com/go-skynet/LocalAI/pkg/model"
+
+	"github.com/go-skynet/LocalAI/core/schema"
+	"github.com/gofiber/fiber/v2"
+	"github.com/rs/zerolog/log"
+)
+
+func TTSEndpoint(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *config.ApplicationConfig) func(c *fiber.Ctx) error {
+	return func(c *fiber.Ctx) error {
+
+		input := new(schema.ElevenLabsTTSRequest)
+		voiceID := c.Params("voice-id")
+
+		// Get input data from the request body
+		if err := c.BodyParser(input); err != nil {
+			return err
+		}
+
+		modelFile, err := fiberContext.ModelFromContext(c, ml, input.ModelID, false)
+		if err != nil {
+			modelFile = input.ModelID
+			log.Warn().Msgf("Model not found in context: %s", input.ModelID)
+		}
+
+		cfg, err := cl.LoadBackendConfigFileByName(modelFile, appConfig.ModelPath,
+			config.LoadOptionDebug(appConfig.Debug),
+			config.LoadOptionThreads(appConfig.Threads),
+			config.LoadOptionContextSize(appConfig.ContextSize),
+			config.LoadOptionF16(appConfig.F16),
+		)
+		if err != nil {
+			modelFile = input.ModelID
+			log.Warn().Msgf("Model not found in context: %s", input.ModelID)
+		} else {
+			if input.ModelID != "" {
+				modelFile = input.ModelID
+			} else {
+				modelFile = cfg.Model
+			}
+		}
+		log.Debug().Msgf("Request for model: %s", modelFile)
+
+		filePath, _, err := backend.ModelTTS(cfg.Backend, input.Text, modelFile, voiceID, ml, appConfig, *cfg)
+		if err != nil {
+			return err
+		}
+		return c.Download(filePath)
+	}
+}

core/http/endpoints/localai/tts.go

@@ -46,7 +46,7 @@ func TTSEndpoint(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfi
 			cfg.Backend = input.Backend
 		}
 
-		filePath, _, err := backend.ModelTTS(cfg.Backend, input.Input, modelFile, ml, appConfig, *cfg)
+		filePath, _, err := backend.ModelTTS(cfg.Backend, input.Input, modelFile, input.Voice, ml, appConfig, *cfg)
 		if err != nil {
 			return err
 		}

core/schema/elevenlabs.go

@@ -0,0 +1,6 @@
+package schema
+
+type ElevenLabsTTSRequest struct {
+	Text    string `json:"text" yaml:"text"`
+	ModelID string `json:"model_id" yaml:"model_id"`
+}

core/schema/localai.go

@@ -17,5 +17,6 @@ type BackendMonitorResponse struct {
 type TTSRequest struct {
 	Model   string `json:"model" yaml:"model"`
 	Input   string `json:"input" yaml:"input"`
+	Voice   string `json:"voice" yaml:"voice"`
 	Backend string `json:"backend" yaml:"backend"`
 }