Structured query support (#492)

* Tweak the structured query schema

* Structure query service

* Gateway support for nlp-query and structured-query

* API support

* Added CLI

* Update tests

* More tests

trustgraph-base/trustgraph/api/flow.py

@@ -426,3 +426,62 @@ class FlowInstance:
             
         return result
 
+    def nlp_query(self, question, max_results=100):
+        """
+        Convert a natural language question to a GraphQL query.
+        
+        Args:
+            question: Natural language question
+            max_results: Maximum number of results to return (default: 100)
+            
+        Returns:
+            dict with graphql_query, variables, detected_schemas, confidence
+        """
+        
+        input = {
+            "question": question,
+            "max_results": max_results
+        }
+        
+        response = self.request(
+            "service/nlp-query",
+            input
+        )
+        
+        # Check for system-level error
+        if "error" in response and response["error"]:
+            error_type = response["error"].get("type", "unknown")
+            error_message = response["error"].get("message", "Unknown error")
+            raise ProtocolException(f"{error_type}: {error_message}")
+        
+        return response
+
+    def structured_query(self, question):
+        """
+        Execute a natural language question against structured data.
+        Combines NLP query conversion and GraphQL execution.
+        
+        Args:
+            question: Natural language question
+            
+        Returns:
+            dict with data and optional errors
+        """
+        
+        input = {
+            "question": question
+        }
+        
+        response = self.request(
+            "service/structured-query",
+            input
+        )
+        
+        # Check for system-level error
+        if "error" in response and response["error"]:
+            error_type = response["error"].get("type", "unknown")
+            error_message = response["error"].get("message", "Unknown error")
+            raise ProtocolException(f"{error_type}: {error_message}")
+        
+        return response
+