Validate all block parameters are defined in workflow (#4464)

skyvern/forge/sdk/workflow/exceptions.py

@@ -119,7 +119,11 @@ class InvalidFileType(BaseWorkflowHTTPException):
         )
 
 
-class WorkflowParameterMissingRequiredValue(BaseWorkflowHTTPException):
+class WorkflowDefinitionValidationException(BaseWorkflowHTTPException):
+    """Base exception for workflow definition validation errors."""
+
+
+class WorkflowParameterMissingRequiredValue(WorkflowDefinitionValidationException):
     def __init__(self, workflow_parameter_type: str, workflow_parameter_key: str, required_value: str) -> None:
         super().__init__(
             f"Missing required value for workflow parameter. Workflow parameter type: {workflow_parameter_type}. workflow_parameter_key: {workflow_parameter_key}. Required value: {required_value}",
@@ -127,6 +131,25 @@ class WorkflowParameterMissingRequiredValue(BaseWorkflowHTTPException):
         )
 
 
+class WorkflowDefinitionHasUndefinedParameters(WorkflowDefinitionValidationException):
+    def __init__(self, undefined_parameters: dict[str, list[str]]) -> None:
+        # Format: {"block_label": ["param1", "param2"]}
+        error_details = []
+        for block_label, params in undefined_parameters.items():
+            params_str = ", ".join(f"'{p}'" for p in params)
+            error_details.append(f"  - Block '{block_label}' references undefined parameter(s): {params_str}")
+
+        error_message = (
+            f"Workflow definition has blocks that reference undefined parameters:\n"
+            f"{chr(10).join(error_details)}\n\n"
+            f"Make sure to define all parameters in the workflow parameters list before using them in blocks."
+        )
+        super().__init__(
+            error_message,
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+        )
+
+
 class InvalidWaitBlockTime(SkyvernException):
     def __init__(self, max_sec: int) -> None:
         super().__init__(f"Invalid wait time for wait block, it should be a number between 0 and {max_sec}.")