Implement LLM router (#95)

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

@@ -0,0 +1,48 @@
+from skyvern.exceptions import SkyvernException
+
+
+class BaseLLMError(SkyvernException):
+    pass
+
+
+class MissingLLMProviderEnvVarsError(BaseLLMError):
+    def __init__(self, llm_key: str, missing_env_vars: list[str]) -> None:
+        super().__init__(f"Environment variables {','.join(missing_env_vars)} are required for LLMProvider {llm_key}")
+
+
+class EmptyLLMResponseError(BaseLLMError):
+    def __init__(self, response: str) -> None:
+        super().__init__(f"LLM response content is empty: {response}")
+
+
+class InvalidLLMResponseFormat(BaseLLMError):
+    def __init__(self, response: str) -> None:
+        super().__init__(f"LLM response content is not a valid JSON: {response}")
+
+
+class DuplicateCustomLLMProviderError(BaseLLMError):
+    def __init__(self, llm_key: str) -> None:
+        super().__init__(f"Custom LLMProvider {llm_key} is already registered")
+
+
+class DuplicateLLMConfigError(BaseLLMError):
+    def __init__(self, llm_key: str) -> None:
+        super().__init__(f"LLM config with key {llm_key} is already registered")
+
+
+class InvalidLLMConfigError(BaseLLMError):
+    def __init__(self, llm_key: str) -> None:
+        super().__init__(f"LLM config with key {llm_key} is not a valid LLMConfig")
+
+
+class LLMProviderError(BaseLLMError):
+    def __init__(self, llm_key: str) -> None:
+        super().__init__(f"Error while using LLMProvider {llm_key}")
+
+
+class NoProviderEnabledError(BaseLLMError):
+    def __init__(self) -> None:
+        super().__init__(
+            "At least one LLM provider must be enabled. Run setup.sh and follow through the LLM provider setup, or "
+            "update the .env file (check out .env.example to see the required environment variables)."
+        )