diff --git a/packages/core/src/context/graph/toGraph.test.ts b/packages/core/src/context/graph/toGraph.test.ts
index 5f16e0cdf4..9f221339bf 100644
--- a/packages/core/src/context/graph/toGraph.test.ts
+++ b/packages/core/src/context/graph/toGraph.test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { describe, it, expect } from 'vitest';
+import { describe, it, expect, vi } from 'vitest';
 import { ContextGraphBuilder } from './toGraph.js';
 import type { Content } from '@google/genai';
 import type { BaseConcreteNode } from './types.js';
@@ -38,6 +38,8 @@ describe('ContextGraphBuilder', () => {
     });
 
     it('should generate completely deterministic graph structure and UUIDs across JSON serialization cycles', () => {
+      vi.spyOn(Date, 'now').mockReturnValue(0);
+
       const complexHistory: Content[] = [
         { role: 'user', parts: [{ text: 'Step 1: complex analysis' }] },
         {
@@ -86,11 +88,14 @@ describe('ContextGraphBuilder', () => {
       nodes1.forEach((node, index) => {
         expect(node.id).toBeDefined();
         expect(node.id).toBe(nodes2[index].id);
+        expect(node.timestamp).toBe(0);
         if ('turnId' in node) {
           expect(node.turnId).toBeDefined();
           expect(node.turnId).toBe((nodes2[index] as BaseConcreteNode).turnId);
         }
       });
+
+      vi.restoreAllMocks();
     });
   });
 });
diff --git a/packages/core/src/context/graph/toGraph.ts b/packages/core/src/context/graph/toGraph.ts
index f47aa8c7ee..8bf9459789 100644
--- a/packages/core/src/context/graph/toGraph.ts
+++ b/packages/core/src/context/graph/toGraph.ts
@@ -62,6 +62,26 @@ function isFunctionResponsePart(
   );
 }
 
+function isExecutableCodePart(
+  part: Part,
+): part is Part & { executableCode: { code: string } } {
+  return (
+    typeof part.executableCode === 'object' &&
+    part.executableCode !== null &&
+    typeof part.executableCode.code === 'string'
+  );
+}
+
+function isCodeExecutionResultPart(
+  part: Part,
+): part is Part & { codeExecutionResult: { outcome: string; output: string } } {
+  return (
+    typeof part.codeExecutionResult === 'object' &&
+    part.codeExecutionResult !== null &&
+    typeof part.codeExecutionResult.output === 'string'
+  );
+}
+
 /**
  * Generates a stable ID for an object reference using a WeakMap.
  * Falls back to content-based hashing for Part-like objects to ensure
@@ -116,6 +136,16 @@ export function getStableId(
       )
       .digest('hex');
     id = `resp_h_${contentHash}_${turnSalt}_${partIdx}`;
+  } else if (isExecutableCodePart(part)) {
+    contentHash = createHash('sha256')
+      .update(`exec:${part.executableCode.code}`)
+      .digest('hex');
+    id = `exec_${contentHash}_${turnSalt}_${partIdx}`;
+  } else if (isCodeExecutionResultPart(part)) {
+    contentHash = createHash('sha256')
+      .update(`result:${part.codeExecutionResult.output}`)
+      .digest('hex');
+    id = `result_${contentHash}_${turnSalt}_${partIdx}`;
   }
 
   if (contentHash) {
@@ -194,7 +224,7 @@ export class ContextGraphBuilder {
             apiId || getStableId(part, this.nodeIdentityMap, turnSalt, partIdx);
           const node: ConcreteNode = {
             id,
-            timestamp: 0, // Using 0 for deterministic structural equality. Actual time is applied by orchestrator.
+            timestamp: Date.now(),
             type: isFunctionResponsePart(part)
               ? NodeType.TOOL_EXECUTION
               : NodeType.USER_PROMPT,
@@ -215,7 +245,7 @@ export class ContextGraphBuilder {
             apiId || getStableId(part, this.nodeIdentityMap, turnSalt, partIdx);
           const node: ConcreteNode = {
             id,
-            timestamp: 0, // Using 0 for deterministic structural equality. Actual time is applied by orchestrator.
+            timestamp: Date.now(),
             type: isFunctionCallPart(part)
               ? NodeType.TOOL_EXECUTION
               : NodeType.AGENT_THOUGHT,