Feature/graphql table query (#486)

* Tech spec

* Object query service for Cassandra

* Gateway support for objects-query

* GraphQL query utility

* Filters, ordering

trustgraph-base/trustgraph/api/flow.py

@@ -383,3 +383,46 @@ class FlowInstance:
             input
         )
 
+    def objects_query(
+            self, query, user="trustgraph", collection="default",
+            variables=None, operation_name=None
+    ):
+
+        # The input consists of a GraphQL query and optional variables
+        input = {
+            "query": query,
+            "user": user,
+            "collection": collection,
+        }
+
+        if variables:
+            input["variables"] = variables
+
+        if operation_name:
+            input["operation_name"] = operation_name
+
+        response = self.request(
+            "service/objects",
+            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 the GraphQL response structure
+        result = {}
+        
+        if "data" in response:
+            result["data"] = response["data"]
+            
+        if "errors" in response and response["errors"]:
+            result["errors"] = response["errors"]
+            
+        if "extensions" in response and response["extensions"]:
+            result["extensions"] = response["extensions"]
+            
+        return result
+

trustgraph-base/trustgraph/messaging/__init__.py

@@ -21,6 +21,7 @@ from .translators.embeddings_query import (
     DocumentEmbeddingsRequestTranslator, DocumentEmbeddingsResponseTranslator,
     GraphEmbeddingsRequestTranslator, GraphEmbeddingsResponseTranslator
 )
+from .translators.objects_query import ObjectsQueryRequestTranslator, ObjectsQueryResponseTranslator
 
 # Register all service translators
 TranslatorRegistry.register_service(
@@ -107,6 +108,12 @@ TranslatorRegistry.register_service(
     GraphEmbeddingsResponseTranslator()
 )
 
+TranslatorRegistry.register_service(
+    "objects-query", 
+    ObjectsQueryRequestTranslator(), 
+    ObjectsQueryResponseTranslator()
+)
+
 # Register single-direction translators for document loading
 TranslatorRegistry.register_request("document", DocumentTranslator())
 TranslatorRegistry.register_request("text-document", TextDocumentTranslator())

trustgraph-base/trustgraph/messaging/translators/__init__.py

@@ -17,3 +17,4 @@ from .embeddings_query import (
     DocumentEmbeddingsRequestTranslator, DocumentEmbeddingsResponseTranslator,
     GraphEmbeddingsRequestTranslator, GraphEmbeddingsResponseTranslator
 )
+from .objects_query import ObjectsQueryRequestTranslator, ObjectsQueryResponseTranslator

trustgraph-base/trustgraph/messaging/translators/objects_query.py

@@ -0,0 +1,79 @@
+from typing import Dict, Any, Tuple, Optional
+from ...schema import ObjectsQueryRequest, ObjectsQueryResponse
+from .base import MessageTranslator
+import json
+
+
+class ObjectsQueryRequestTranslator(MessageTranslator):
+    """Translator for ObjectsQueryRequest schema objects"""
+    
+    def to_pulsar(self, data: Dict[str, Any]) -> ObjectsQueryRequest:
+        return ObjectsQueryRequest(
+            user=data.get("user", "trustgraph"),
+            collection=data.get("collection", "default"),
+            query=data.get("query", ""),
+            variables=data.get("variables", {}),
+            operation_name=data.get("operation_name", None)
+        )
+    
+    def from_pulsar(self, obj: ObjectsQueryRequest) -> Dict[str, Any]:
+        result = {
+            "user": obj.user,
+            "collection": obj.collection,
+            "query": obj.query,
+            "variables": dict(obj.variables) if obj.variables else {}
+        }
+        
+        if obj.operation_name:
+            result["operation_name"] = obj.operation_name
+            
+        return result
+
+
+class ObjectsQueryResponseTranslator(MessageTranslator):
+    """Translator for ObjectsQueryResponse schema objects"""
+    
+    def to_pulsar(self, data: Dict[str, Any]) -> ObjectsQueryResponse:
+        raise NotImplementedError("Response translation to Pulsar not typically needed")
+    
+    def from_pulsar(self, obj: ObjectsQueryResponse) -> Dict[str, Any]:
+        result = {}
+        
+        # Handle GraphQL response data
+        if obj.data:
+            try:
+                result["data"] = json.loads(obj.data)
+            except json.JSONDecodeError:
+                result["data"] = obj.data
+        else:
+            result["data"] = None
+        
+        # Handle GraphQL errors
+        if obj.errors:
+            result["errors"] = []
+            for error in obj.errors:
+                error_dict = {
+                    "message": error.message
+                }
+                if error.path:
+                    error_dict["path"] = list(error.path)
+                if error.extensions:
+                    error_dict["extensions"] = dict(error.extensions)
+                result["errors"].append(error_dict)
+        
+        # Handle extensions
+        if obj.extensions:
+            result["extensions"] = dict(obj.extensions)
+        
+        # Handle system-level error
+        if obj.error:
+            result["error"] = {
+                "type": obj.error.type,
+                "message": obj.error.message
+            }
+            
+        return result
+    
+    def from_response_with_completion(self, obj: ObjectsQueryResponse) -> Tuple[Dict[str, Any], bool]:
+        """Returns (response_dict, is_final)"""
+        return self.from_pulsar(obj), True

trustgraph-base/trustgraph/schema/services/__init__.py

@@ -8,4 +8,5 @@ from .config import *
 from .library import *
 from .lookup import *
 from .nlp_query import *
-from .structured_query import *
+from .structured_query import *
+from .objects_query import *

trustgraph-base/trustgraph/schema/services/objects_query.py

@@ -0,0 +1,28 @@
+from pulsar.schema import Record, String, Map, Array
+
+from ..core.primitives import Error
+from ..core.topic import topic
+
+############################################################################
+
+# Objects Query Service - executes GraphQL queries against structured data
+
+class GraphQLError(Record):
+    message = String()
+    path = Array(String())       # Path to the field that caused the error
+    extensions = Map(String())   # Additional error metadata
+
+class ObjectsQueryRequest(Record):
+    user = String()              # Cassandra keyspace (follows pattern from TriplesQueryRequest)
+    collection = String()        # Data collection identifier (required for partition key)
+    query = String()             # GraphQL query string
+    variables = Map(String())    # GraphQL variables
+    operation_name = String()    # Operation to execute for multi-operation documents
+
+class ObjectsQueryResponse(Record):
+    error = Error()              # System-level error (connection, timeout, etc.)
+    data = String()              # JSON-encoded GraphQL response data
+    errors = Array(GraphQLError()) # GraphQL field-level errors
+    extensions = Map(String())   # Query metadata (execution time, etc.)
+
+############################################################################