[Feature] Add support for Mistral API (#1194)

Co-authored-by: Deven Patel <deven298@yahoo.com>

embedchain/llm/mistralai.py

@@ -0,0 +1,52 @@
+import os
+from typing import Optional
+
+from embedchain.config import BaseLlmConfig
+from embedchain.helpers.json_serializable import register_deserializable
+from embedchain.llm.base import BaseLlm
+
+
+@register_deserializable
+class MistralAILlm(BaseLlm):
+    def __init__(self, config: Optional[BaseLlmConfig] = None):
+        super().__init__(config)
+        if not self.config.api_key and "MISTRAL_API_KEY" not in os.environ:
+            raise ValueError("Please set the MISTRAL_API_KEY environment variable or pass it in the config.")
+
+    def get_llm_model_answer(self, prompt):
+        return MistralAILlm._get_answer(prompt=prompt, config=self.config)
+
+    @staticmethod
+    def _get_answer(prompt: str, config: BaseLlmConfig):
+        try:
+            from langchain_core.messages import HumanMessage, SystemMessage
+            from langchain_mistralai.chat_models import ChatMistralAI
+        except ModuleNotFoundError:
+            raise ModuleNotFoundError(
+                "The required dependencies for MistralAI are not installed."
+                'Please install with `pip install --upgrade "embedchain[mistralai]"`'
+            ) from None
+
+        api_key = config.api_key or os.getenv("MISTRAL_API_KEY")
+        client = ChatMistralAI(mistral_api_key=api_key)
+        messages = []
+        if config.system_prompt:
+            messages.append(SystemMessage(content=config.system_prompt))
+        messages.append(HumanMessage(content=prompt))
+        kwargs = {
+            "model": config.model or "mistral-tiny",
+            "temperature": config.temperature,
+            "max_tokens": config.max_tokens,
+            "top_p": config.top_p,
+        }
+
+        # TODO: Add support for streaming
+        if config.stream:
+            answer = ""
+            for chunk in client.stream(**kwargs, input=messages):
+                answer += chunk.content
+            return answer
+        else:
+            response = client.invoke(**kwargs, input=messages)
+            answer = response.content
+            return answer