Implement LLM router (#95)

skyvern/forge/sdk/api/llm/models.py

@@ -0,0 +1,32 @@
+from dataclasses import dataclass
+from typing import Any, Awaitable, Protocol
+
+from skyvern.forge.sdk.models import Step
+from skyvern.forge.sdk.settings_manager import SettingsManager
+
+
+@dataclass(frozen=True)
+class LLMConfig:
+    model_name: str
+    required_env_vars: list[str]
+    supports_vision: bool
+
+    def get_missing_env_vars(self) -> list[str]:
+        missing_env_vars = []
+        for env_var in self.required_env_vars:
+            env_var_value = getattr(SettingsManager.get_settings(), env_var, None)
+            if not env_var_value:
+                missing_env_vars.append(env_var)
+
+        return missing_env_vars
+
+
+class LLMAPIHandler(Protocol):
+    def __call__(
+        self,
+        prompt: str,
+        step: Step | None = None,
+        screenshots: list[bytes] | None = None,
+        parameters: dict[str, Any] | None = None,
+    ) -> Awaitable[dict[str, Any]]:
+        ...