:gem: [Feature] New ChatAPIApp: Enable fastapi for openai format api call

apis/chat_api.py

@@ -0,0 +1,82 @@
+import uvicorn
+from fastapi import FastAPI
+from pydantic import BaseModel, Field
+from sse_starlette.sse import EventSourceResponse
+from utils.logger import logger
+from networks.message_streamer import MessageStreamer
+from messagers.message_composer import MessageComposer
+
+
+class ChatAPIApp:
+    def __init__(self):
+        self.app = FastAPI(
+            docs_url="/",
+            title="HuggingFace LLM API",
+            swagger_ui_parameters={"defaultModelsExpandDepth": -1},
+            version="1.0",
+        )
+        self.setup_routes()
+
+    def get_available_models(self):
+        self.available_models = [
+            {
+                "id": "mixtral-8x7b",
+                "description": "Mixtral-8x7B: https://huggingface.co/mistralai/Mixtral-8x7B-Instruct-v0.1",
+            },
+        ]
+        return self.available_models
+
+    class ChatCompletionsPostItem(BaseModel):
+        model: str = Field(
+            default="mixtral-8x7b",
+            description="(str) `mixtral-8x7b`",
+        )
+        messages: list = Field(
+            default=[{"role": "user", "content": "Hello, who are you?"}],
+            description="(list) Messages",
+        )
+        temperature: float = Field(
+            default=0.01,
+            description="(float) Temperature",
+        )
+        max_tokens: int = Field(
+            default=32000,
+            description="(int) Max tokens",
+        )
+        stream: bool = Field(
+            default=True,
+            description="(bool) Stream",
+        )
+
+    def chat_completions(self, item: ChatCompletionsPostItem):
+        streamer = MessageStreamer(model=item.model)
+        composer = MessageComposer(model=item.model)
+        composer.merge(messages=item.messages)
+        return EventSourceResponse(
+            streamer.chat(
+                prompt=composer.merged_str,
+                temperature=item.temperature,
+                max_new_tokens=item.max_tokens,
+                stream=item.stream,
+                yield_output=True,
+            ),
+            media_type="text/event-stream",
+        )
+
+    def setup_routes(self):
+        for prefix in ["", "/v1"]:
+            self.app.get(
+                prefix + "/models",
+                summary="Get available models",
+            )(self.get_available_models)
+
+            self.app.post(
+                prefix + "/chat/completions",
+                summary="Chat completions in conversation session",
+            )(self.chat_completions)
+
+
+app = ChatAPIApp().app
+
+if __name__ == "__main__":
+    uvicorn.run("__main__:app", host="0.0.0.0", port=23333, reload=True)