TTS/STT: Integrated Sarvam STT and TTS (#621)

Co-authored-by: Prajna Prayas <gituprajna20@gmail.com>

Author: rajagopalmotivate

backend/app/core/providers.py

@@ -13,6 +13,7 @@ class Provider(str, Enum):
     AWS = "aws"
     LANGFUSE = "langfuse"
     GOOGLE = "google"
+    SARVAMAI = "sarvamai"
 
 
 @dataclass
@@ -32,6 +33,7 @@ class ProviderConfig:
         required_fields=["secret_key", "public_key", "host"]
     ),
     Provider.GOOGLE: ProviderConfig(required_fields=["api_key"]),
+    Provider.SARVAMAI: ProviderConfig(required_fields=["api_key"]),
 }
 
 

backend/app/models/llm/request.py

@@ -22,7 +22,7 @@ class TextLLMParams(SQLModel):
         description="Reasoning configuration or instructions",
     )
     temperature: float | None = Field(
-        default=None,
+        default=0.1,
         ge=0.0,
         le=2.0,
     )
@@ -35,17 +35,18 @@ class TextLLMParams(SQLModel):
 
 class STTLLMParams(SQLModel):
     model: str
-    instructions: str
+    instructions: str | None = None
     input_language: str | None = None
     output_language: str | None = None
     response_format: Literal["text"] | None = Field(
         None,
         description="Currently supports text type",
     )
     temperature: float | None = Field(
-        default=0.2,
+        default=None,
         ge=0.0,
         le=2.0,
+        description="Temperature parameter (not supported by all STT providers)",
     )
 
 
@@ -190,7 +191,7 @@ class NativeCompletionConfig(SQLModel):
     Supports any LLM provider's native API format.
     """
 
-    provider: Literal["openai-native", "google-native"] = Field(
+    provider: Literal["openai-native", "google-native", "sarvamai-native"] = Field(
         ...,
         description="Native provider type (e.g., openai-native)",
     )
@@ -210,8 +211,8 @@ class KaapiCompletionConfig(SQLModel):
     Supports multiple providers: OpenAI, Claude, Gemini, etc.
     """
 
-    provider: Literal["openai", "google"] = Field(
-        ..., description="LLM provider (openai)"
+    provider: Literal["openai", "google", "sarvamai"] = Field(
+        ..., description="LLM provider (openai, google, sarvamai)"
     )
 
     type: Literal["text", "stt", "tts"] = Field(

backend/app/services/llm/mappers.py

@@ -142,12 +142,98 @@ def map_kaapi_to_google_params(kaapi_params: dict) -> tuple[dict, list[str]]:
     return google_params, warnings
 
 
+def map_kaapi_to_sarvam_params(kaapi_params: dict) -> tuple[dict, list[str]]:
+    """Map Kaapi-abstracted parameters to SarvamAI API parameters.
+
+    Handles both STTLLMParams and TTSLLMParams.
+
+    STTLLMParams: model, instructions, input_language, output_language, response_format, temperature
+    TTSLLMParams: model, voice, language, response_format
+
+    Args:
+        kaapi_params: Dictionary with standardized Kaapi parameters
+
+    Returns:
+        Tuple of:
+        - Dictionary of SarvamAI API parameters
+        - List of warnings for unsupported parameters
+    """
+    sarvam_params = {}
+    warnings = []
+
+    # Model is required for all completion types
+    model = kaapi_params.get("model")
+    if not model:
+        return {}, ["Missing required 'model' parameter"]
+    sarvam_params["model"] = model
+
+    # Determine if STT or TTS based on presence of specific params
+    voice = kaapi_params.get("voice")
+    input_language = kaapi_params.get("input_language")
+
+    if voice is not None:
+        # TTS mode - map TTSLLMParams
+        sarvam_params["speaker"] = voice
+
+        language = kaapi_params.get("language")
+        if not language:
+            return {}, ["Missing required 'language' parameter for TTS"]
+        sarvam_params["target_language_code"] = language
+
+        response_format = kaapi_params.get("response_format")
+        if response_format:
+            # Map audio format to SarvamAI codec
+            format_mapping = {"mp3": "mp3", "wav": "wav", "ogg": "ogg"}
+            sarvam_params["output_audio_codec"] = format_mapping.get(
+                response_format, "wav"
+            )
+
+    elif input_language is not None or kaapi_params.get("output_language") is not None:
+        # STT mode - map STTLLMParams
+        output_language = kaapi_params.get("output_language")
+        transcription_mode = "transcribe"
+
+        if input_language == "auto":
+            sarvam_params["language_code"] = "unknown"
+        elif input_language:
+            sarvam_params["language_code"] = input_language
+
+        if output_language is None:
+            output_language = input_language
+
+        if output_language == "en-IN" and input_language != output_language:
+            transcription_mode = "translate"
+
+        sarvam_params["mode"] = transcription_mode
+
+        # Warn about unsupported STT parameters
+        instructions = kaapi_params.get("instructions")
+        if instructions:
+            warnings.append(
+                "Parameter 'instructions' is not supported by SarvamAI STT and was ignored"
+            )
+
+        temperature = kaapi_params.get("temperature")
+        if temperature is not None:
+            warnings.append(
+                "Parameter 'temperature' is not supported by SarvamAI STT and was ignored"
+            )
+
+        response_format = kaapi_params.get("response_format")
+        if response_format:
+            warnings.append(
+                "Parameter 'response_format' is not supported by SarvamAI STT and was ignored"
+            )
+
+    return sarvam_params, warnings
+
+
 def transform_kaapi_config_to_native(
     kaapi_config: KaapiCompletionConfig,
 ) -> tuple[NativeCompletionConfig, list[str]]:
     """Transform Kaapi completion config to native provider config with mapped parameters.
 
-    Supports OpenAI and Google AI providers.
+    Supports OpenAI,Google AI and Sarvam AI providers.
 
     Args:
         kaapi_config: KaapiCompletionConfig with abstracted parameters
@@ -175,4 +261,13 @@ def transform_kaapi_config_to_native(
             warnings,
         )
 
+    if kaapi_config.provider == "sarvamai":
+        mapped_params, warnings = map_kaapi_to_sarvam_params(kaapi_config.params)
+        return (
+            NativeCompletionConfig(
+                provider="sarvamai-native", params=mapped_params, type=kaapi_config.type
+            ),
+            warnings,
+        )
+
     raise ValueError(f"Unsupported provider: {kaapi_config.provider}")

backend/app/services/llm/providers/registry.py

@@ -6,6 +6,7 @@
 from app.services.llm.providers.base import BaseProvider
 from app.services.llm.providers.oai import OpenAIProvider
 from app.services.llm.providers.gai import GoogleAIProvider
+from app.services.llm.providers.sai import SarvamAIProvider
 
 logger = logging.getLogger(__name__)
 
@@ -16,13 +17,15 @@ class LLMProvider:
     # Future constants for native providers:
     # CLAUDE_NATIVE = "claude-native"
     GOOGLE_NATIVE = "google-native"
+    SARVAMAI_NATIVE = "sarvamai-native"
 
     _registry: dict[str, type[BaseProvider]] = {
         OPENAI_NATIVE: OpenAIProvider,
         OPENAI: OpenAIProvider,
         # Future native providers:
         # CLAUDE_NATIVE: ClaudeProvider,
         GOOGLE_NATIVE: GoogleAIProvider,
+        SARVAMAI_NATIVE: SarvamAIProvider,
     }
 
     @classmethod