diff --git a/packages/agent-core-v2/src/contextMemory/contextMemoryService.ts b/packages/agent-core-v2/src/contextMemory/contextMemoryService.ts
index fbf5f9006..ae942a36d 100644
--- a/packages/agent-core-v2/src/contextMemory/contextMemoryService.ts
+++ b/packages/agent-core-v2/src/contextMemory/contextMemoryService.ts
@@ -81,6 +81,7 @@ export class ContextMemoryService extends Disposable implements IContextMemory {
 
   private applySplice(record: WireRecord<'context.splice'>): void {
     const messages = [...record.messages];
+    this.history.splice(record.start, record.deleteCount, ...messages);
     for (const message of messages) {
       this.replayBuilder.push({ type: 'message', message });
     }
diff --git a/packages/agent-core-v2/src/llmRequester/llmRequesterService.ts b/packages/agent-core-v2/src/llmRequester/llmRequesterService.ts
index f77555ffc..3f1bce0d3 100644
--- a/packages/agent-core-v2/src/llmRequester/llmRequesterService.ts
+++ b/packages/agent-core-v2/src/llmRequester/llmRequesterService.ts
@@ -144,7 +144,9 @@ export class LLMRequesterService implements ILLMRequester {
         usage,
         model: usageModel,
       });
-      this.usage.record(usageModel, usage, request.usageContext);
+      if (request.usageContext === undefined) {
+        this.usage.record(usageModel, usage);
+      }
       queue.push({
         type: 'finish',
         providerFinishReason: result.finishReason ?? undefined,
diff --git a/packages/agent-core-v2/src/loop/turn-step.ts b/packages/agent-core-v2/src/loop/turn-step.ts
index ab6b621a3..8571860ac 100644
--- a/packages/agent-core-v2/src/loop/turn-step.ts
+++ b/packages/agent-core-v2/src/loop/turn-step.ts
@@ -131,13 +131,14 @@ export async function executeLoopStep(deps: ExecuteLoopStepDeps): Promise<{
   let effectiveStopReason: LoopStepStopReason =
     stopTurnAfterUsage && stopReason === 'tool_use' ? 'end_turn' : stopReason;
   if (effectiveStopReason === 'tool_use') {
-    const toolResults = await toolExecutor.execute(response.toolCalls, {
-      signal,
-      turnId,
-      stepNumber: currentStep,
-      dispatchEvent,
-      onProgress: (toolCallId, update) => {
-        void dispatchEvent({ type: 'tool.progress', toolCallId, update });
+      const toolResults = await toolExecutor.execute(response.toolCalls, {
+        signal,
+        turnId,
+        stepNumber: currentStep,
+        stepUuid,
+        dispatchEvent,
+        onProgress: (toolCallId, update) => {
+          void dispatchEvent({ type: 'tool.progress', toolCallId, update });
       },
     });
     if (toolResults.some((r) => r.stopTurn === true)) {
diff --git a/packages/agent-core-v2/src/toolExecutor/toolExecutor.ts b/packages/agent-core-v2/src/toolExecutor/toolExecutor.ts
index f6e57647b..f6beaba38 100644
--- a/packages/agent-core-v2/src/toolExecutor/toolExecutor.ts
+++ b/packages/agent-core-v2/src/toolExecutor/toolExecutor.ts
@@ -9,6 +9,7 @@ export interface ToolExecutorExecuteOptions {
   readonly signal?: AbortSignal;
   readonly turnId?: string;
   readonly stepNumber?: number;
+  readonly stepUuid?: string;
   readonly dispatchEvent?: LoopEventDispatcher | undefined;
   readonly onProgress?: ((toolCallId: string, update: ToolUpdate) => void) | undefined;
 }
diff --git a/packages/agent-core-v2/src/toolExecutor/toolExecutorService.ts b/packages/agent-core-v2/src/toolExecutor/toolExecutorService.ts
index 3f6f03c7d..6d83b28ec 100644
--- a/packages/agent-core-v2/src/toolExecutor/toolExecutorService.ts
+++ b/packages/agent-core-v2/src/toolExecutor/toolExecutorService.ts
@@ -476,7 +476,7 @@ async function dispatchToolCall(
     uuid: call.toolCall.id,
     turnId: options.turnId ?? '',
     step: options.stepNumber ?? 0,
-    stepUuid: '',
+    stepUuid: options.stepUuid ?? '',
     toolCallId: call.toolCall.id,
     name: call.toolName,
     args,
diff --git a/packages/agent-core-v2/test/contextMemory/context.test.ts b/packages/agent-core-v2/test/contextMemory/context.test.ts
index a9179084c..9fd7e6365 100644
--- a/packages/agent-core-v2/test/contextMemory/context.test.ts
+++ b/packages/agent-core-v2/test/contextMemory/context.test.ts
@@ -1,13 +1,12 @@
 import type { Message } from '@moonshot-ai/kosong';
 import { describe, expect, it } from 'vitest';
 
-import { estimateTokensForMessages } from '../../../src/utils/tokens';
-import { testAgent } from './harness';
-import {
-  project,
-  renderNotificationXml,
-  type ContextMessage,
-} from '../../../src/services/agent';
+import { estimateTokensForMessages } from '#/_base/utils/tokens';
+import { project } from '#/contextProjector';
+import type { ContextMessage } from '#/contextMemory';
+import { renderNotificationXml } from '#/contextMemory/notification-xml';
+
+import { testAgent } from '../harness';
 
 describe('Agent context', () => {
   it('stores prompt origins without leaking them to LLM projection', () => {
diff --git a/packages/agent-core-v2/test/loop/basic.test.ts b/packages/agent-core-v2/test/loop/basic.test.ts
index 5607296c8..b848b90aa 100644
--- a/packages/agent-core-v2/test/loop/basic.test.ts
+++ b/packages/agent-core-v2/test/loop/basic.test.ts
@@ -1,14 +1,14 @@
 import type { ToolCall } from '@moonshot-ai/kosong';
 import { expect, it } from 'vitest';
 
-import { FLAG_DEFINITIONS, FlagResolver } from '../../../src/flags';
-import { testAgent } from './harness';
+import { IFlagService } from '#/flag';
+
+import { testAgent } from '../harness';
 
 it('creates an independent agent with a scoped experimental flag resolver', () => {
-  const flags = new FlagResolver({}, FLAG_DEFINITIONS);
   const ctx = testAgent({
-    experimentalFlags: flags,
   });
+  const flags = ctx.get(IFlagService);
 
   expect(flags.enabled('micro_compaction')).toBe(true);
 });
diff --git a/packages/agent-core-v2/test/usage/usage.test.ts b/packages/agent-core-v2/test/usage/usage.test.ts
index 75d03b276..fda33e7c0 100644
--- a/packages/agent-core-v2/test/usage/usage.test.ts
+++ b/packages/agent-core-v2/test/usage/usage.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest';
 
-import { testAgent } from './harness';
+import { testAgent } from '../harness';
 
 describe('Agent usage', () => {
   it('accumulates usage by model', () => {