diff --git a/ontocast/agent/check_chunks.py b/ontocast/agent/check_chunks.py
index 4d1059c..779b29d 100644
--- a/ontocast/agent/check_chunks.py
+++ b/ontocast/agent/check_chunks.py
@@ -60,6 +60,7 @@ def check_chunks_empty(state: AgentState) -> AgentState:
         state.current_chunk = state.chunks.pop(0)
         state.node_visits = defaultdict(int)
         state.status = Status.FAILED
+        # TODO use method for easier tracing
     else:
         state.current_chunk = Chunk(
             text="",
diff --git a/ontocast/onto/state.py b/ontocast/onto/state.py
index ace523b..8bf4289 100644
--- a/ontocast/onto/state.py
+++ b/ontocast/onto/state.py
@@ -5,11 +5,7 @@
 from pydantic import ConfigDict, Field
 
 from ontocast.onto.chunk import Chunk
-from ontocast.onto.constants import (
-    CHUNK_NULL_IRI,
-    DEFAULT_DOMAIN,
-    ONTOLOGY_NULL_IRI,
-)
+from ontocast.onto.constants import CHUNK_NULL_IRI, DEFAULT_DOMAIN, ONTOLOGY_NULL_IRI
 from ontocast.onto.context import AgentContext, AgentType, ContextManager
 from ontocast.onto.enum import FailureStage, Status, WorkflowNode
 from ontocast.onto.model import BasePydanticModel, Suggestions
@@ -167,6 +163,8 @@ class AgentState(BasePydanticModel):
         default=None,
     )
 
+    graph_uri_override: str | None = Field(default=None)
+
     source_url: str | None = Field(
         description="Source URL from JSON input file (for provenance tracking)",
         default=None,
@@ -578,6 +576,12 @@ def doc_namespace(self):
         """
         return iri2namespace(self.doc_iri, ontology=False)
 
+    @property
+    def graph_uri(self):
+        if self.graph_uri_override is not None:
+            return self.graph_uri_override
+        return self.doc_namespace
+
     @property
     def ontology_id(self):
         """Get the document namespace.
diff --git a/ontocast/toolbox.py b/ontocast/toolbox.py
index c82b364..15ed991 100644
--- a/ontocast/toolbox.py
+++ b/ontocast/toolbox.py
@@ -22,9 +22,7 @@
 from ontocast.tool.llm import LLMTool
 from ontocast.tool.ontology_manager import OntologyManager
 from ontocast.tool.sparql import SPARQLTool
-from ontocast.tool.triple_manager.core import (
-    TripleStoreManager,
-)
+from ontocast.tool.triple_manager.core import TripleStoreManager
 
 logger = logging.getLogger(__name__)
 
@@ -193,7 +191,7 @@ def serialize(self, state: AgentState) -> None:
             self.filesystem_manager.serialize(state.current_ontology)
             self.filesystem_manager.serialize(
                 state.aggregated_facts,
-                graph_uri=state.doc_namespace,
+                graph_uri=state.graph_uri,
             )
         if (
             self.triple_store_manager is not None
@@ -203,7 +201,7 @@ def serialize(self, state: AgentState) -> None:
             self.triple_store_manager.serialize(state.current_ontology)
             self.triple_store_manager.serialize(
                 state.aggregated_facts,
-                graph_uri=state.doc_namespace,
+                graph_uri=state.graph_uri,
             )
 
     async def initialize(self) -> None: