some more skeleton

src/photools3/llm_session.py

@@ -1,13 +1,31 @@
+from openai import OpenAI
+from openai.types.chat import ChatCompletion
 
-from photools3.models import LlmRequest, LlmResponse
+from photools3.models import LlmRequest
+from photools3.settings import Settings
+
+settings = Settings()
 
 
 class LlmSession:
-    def __init__(self):
-        ...
+    base_url: str = str(settings.llm_api_base_url)
+    api_key: str = settings.llm_api_key
 
-    def prompt(self, request: LlmRequest) -> LlmResponse:
-        ...
+    def __init__(self, system_prompt: str):
+        self._models: list = []
 
-    def close(self):
-        ...
+        self.system_prompt = system_prompt
+
+        self.client = OpenAI(
+            base_url=self.base_url,
+            api_key=self.api_key,
+        )
+
+    @property
+    def models(self):
+        if not self._models:
+            self._models = self.client.models.list().data
+        return self._models
+
+    def call_raw(self, request: LlmRequest) -> ChatCompletion:
+        return self.client.chat.completions.create(**request.model_dump())

src/photools3/models.py

@@ -1,8 +1,28 @@
-from pydantic import BaseModel
+from typing import Literal
+
+from pydantic import BaseModel, model_validator
 
 
 class LlmRequest(BaseModel):
-    ...
+    model_id: int
+    messages: list[LlmRequestMessage]
+    temperature: float | None = None
 
-class LlmResponse(BaseModel):
-    ...
+
+class LlmRequestMessage(BaseModel):
+    role: Literal["system", "user"]
+    content: list[LlmMessageContent]
+
+
+class LlmMessageContent(BaseModel):
+    type: Literal["text", "image_url"]
+    text: str | None = None
+    image_url: str | None = None
+
+    @model_validator(mode="after")
+    def _type_matches_content(self):
+        if self.type == "text" and self.text is None:
+            raise ValueError("text must be set when type is 'text'")
+        if self.type == "image_url" and self.image_url is None:
+            raise ValueError("image_url must be set when type is 'image_url'")
+        return self

src/photools3/settings.py

@@ -0,0 +1,9 @@
+from pydantic_core import Url
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env")
+
+    llm_api_base_url: Url
+    llm_api_key: str