Code 탭 컨텍스트 누적 신뢰성과 작업 연속성을 전면 보강한다

이번 커밋은 Code 탭 장기 실행에서 build/file 근거가 너무 빨리 축약되고, 이전 수정 맥락이 다음 LLM 요청에 안정적으로 누적되지 않던 문제를 해결하기 위한 전면 보강을 담는다. 핵심 수정사항: - CodeTaskWorkingSetService를 추가해 최근 생성 디렉터리, 최근 읽기/쓰기 파일, 최신 build/test 진단, 다음 복구 초점을 구조화된 working set으로 유지하고 각 반복 요청에 보조 system context로 주입한다. - AgentQueryContextBuilder와 AgentToolResultBudget에 code profile을 도입해 protected recent window와 tool_result budget을 확장하고 build_run, test_loop, file_read, multi_read, lsp_code_intel, git_tool 같은 고가치 evidence가 기본 탭보다 덜 잘리도록 조정한다. - AgentLoopIterationPreparationService와 AgentLoopLlmRequestPreparationService를 확장해 query-context options와 supplemental messages를 함께 전달하고, AgentLoopService에서는 Code 탭에서 generic session learnings 대신 working set 중심으로 요청을 구성하도록 변경한다. - ChatWindow.UtilityPresentation에서 workspace context 첫 부트스트랩을 강화해 .ax-context.md가 아직 없더라도 첫 요청 시점부터 background generation과 language workflow bootstrap hints가 반영되도록 수정한다. - LlmService.ToolUse에서 historical tool trace sanitization 결과를 assistant flatten/orphan conversion 건수로 요약 로그에 남겨 tool-trace 불변식 문제를 추적 가능하게 만든다. - 관련 테스트를 추가·갱신해 working set 누적, code profile budget, supplemental message 주입, query-context option 전달을 회귀 고정한다. 검증 결과: - dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify_context_reliability_full\\ -p:IntermediateOutputPath=obj\\verify_context_reliability_full\\ : 경고 0 / 오류 0 - dotnet test src/AxCopilot.Tests/AxCopilot.Tests.csproj -c Release -v minimal --filter "AgentQueryContextBuilderTests|AgentToolResultBudgetTests|AgentLoopIterationPreparationServiceTests|AgentLoopLlmRequestPreparationServiceTests|CodeTaskWorkingSetServiceTests|AgentLoopCodeQualityTests" -p:OutputPath=bin\\verify_context_reliability_full_tests\\ -p:IntermediateOutputPath=obj\\verify_context_reliability_full_tests\\ : 통과 150 - dotnet test src/AxCopilot.Tests/AxCopilot.Tests.csproj -c Release -v minimal --filter "AgentLoopE2ETests|AgentMessageInvariantHelperTests" -p:OutputPath=bin\\verify_context_reliability_e2e\\ -p:IntermediateOutputPath=obj\\verify_context_reliability_e2e\\ : 통과 21
2026-04-16 01:45:28 +09:00
parent eb884e9263
commit 0f64bf3f84
17 changed files with 1074 additions and 129 deletions
--- a/README.md
+++ b/README.md
@@ -2380,3 +2380,12 @@ MIT License
 - 검증:
  - `dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify_project_scaffold_layout\\ -p:IntermediateOutputPath=obj\\verify_project_scaffold_layout\\` 경고 0 / 오류 0
  - `dotnet test src/AxCopilot.Tests/AxCopilot.Tests.csproj -c Release -v minimal --filter "IntentGateServiceTests|ProjectScaffoldProfileCatalogTests|SkillServiceRuntimePolicyTests|AgentLoopCodeQualityTests" -p:OutputPath=bin\\verify_project_scaffold_layout_tests\\ -p:IntermediateOutputPath=obj\\verify_project_scaffold_layout_tests\\` 통과 183
+업데이트: 2026-04-16 01:41 (KST)
+- Code 탭 컨텍스트 신뢰성 보강 1차 구현을 반영했습니다. `src/AxCopilot/Services/Agent/CodeTaskWorkingSetService.cs`를 추가해 최근 생성 디렉터리, 최근 읽기/쓰기 파일, 최신 build/test 진단, 다음 복구 초점을 하나의 working set 블록으로 유지하고, 각 반복의 실제 LLM 요청에 보조 system context로 주입합니다.
+- `src/AxCopilot/Services/Agent/AgentQueryContextBuilder.cs`, `AgentToolResultBudget.cs`, `AgentLoopIterationPreparationService.cs`, `AgentLoopLlmRequestPreparationService.cs`를 함께 조정해 Code 탭에서는 더 넓은 protected recent window와 더 큰 tool_result budget을 사용하도록 바꿨습니다. `build_run`, `test_loop`, `file_read`, `multi_read`, `lsp_code_intel`, `git_tool` 같은 고가치 evidence는 기본 탭보다 덜 잘리도록 보호합니다.
+- `src/AxCopilot/Views/ChatWindow.UtilityPresentation.cs`는 `.ax-context.md`가 아직 없더라도 첫 요청 시점에 workspace context 생성을 바로 시작하고, 생성이 완료되기 전에는 언어 워크플로우 힌트를 bootstrap context로 넣도록 바꿨습니다. 덕분에 완전한 빈 작업 폴더에서도 첫 루프부터 최소한의 프로젝트 힌트가 LLM에 전달됩니다.
+- `src/AxCopilot/Services/Agent/AgentLoopService.cs`는 Code 탭에서 generic `session_learnings` 주입을 줄이고, 대신 working set과 query-context diagnostics를 반복마다 `WorkflowLogService.LogTransition(..., \"query_context\", ...)`로 남깁니다. 이제 로그에서 query-view 범위, protected recent 값, supplemental context 수, estimated send token, working-set 요약을 함께 확인할 수 있습니다.
+- `src/AxCopilot/Services/LlmService.ToolUse.cs`는 historical tool-call sanitization 결과를 assistant flatten / orphan conversion 건수로 요약 로그에 남깁니다. 사후 보정은 유지하되, 보정 빈도를 추적할 수 있게 만들어 이후 invariant hardening 후속 작업의 기준선을 확보했습니다.
+- 검증:
+  - `dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify_context_reliability_full\\ -p:IntermediateOutputPath=obj\\verify_context_reliability_full\\` 경고 0 / 오류 0
+  - `dotnet test src/AxCopilot.Tests/AxCopilot.Tests.csproj -c Release -v minimal --filter "AgentQueryContextBuilderTests|AgentToolResultBudgetTests|AgentLoopIterationPreparationServiceTests|AgentLoopLlmRequestPreparationServiceTests|CodeTaskWorkingSetServiceTests|AgentLoopCodeQualityTests" -p:OutputPath=bin\\verify_context_reliability_full_tests\\ -p:IntermediateOutputPath=obj\\verify_context_reliability_full_tests\\` 통과 150
--- a/docs/CODE_CONTEXT_RELIABILITY_PLAN.md
+++ b/docs/CODE_CONTEXT_RELIABILITY_PLAN.md
@@ -247,3 +247,28 @@ AX already has similar mechanisms, but the Code flow still lacks stronger workin
 - better structural consistency for project generation and large edits
 - less drift in long-running Code tasks
 - fewer quality losses caused by broken strings and low-signal context replacements
+
+## Latest Delivery
+
+Updated: 2026-04-16 01:41 (KST)
+
+- Delivered in this pass:
+  - Phase 1 foundation:
+    - `ChatWindow.UtilityPresentation.cs` now bootstraps workspace context generation on first access and returns language-workflow fallback hints while `.ax-context.md` is still being generated.
+    - `AgentLoopService.cs` now records `query_context` workflow transitions with query-window, budget, supplemental-context, and working-set summaries.
+  - Phase 2 foundation:
+    - `CodeTaskWorkingSetService.cs` adds a Code-only structured ledger for:
+      - goal
+      - selected scaffold/profile
+      - created directories
+      - recent reads/writes
+      - latest diagnostics
+      - next repair focus
+    - the working set is injected into each Code request as a supplemental `code_working_set` system message.
+  - Phase 3 foundation:
+    - `AgentToolResultBudget.cs` and `AgentQueryContextBuilder.cs` now expose a `code` query profile with a larger protected-recent window and larger retained budgets for `build_run`, `test_loop`, `process`, `file_read`, `multi_read`, `lsp_code_intel`, and `git_tool`.
+  - Phase 4 observability step:
+    - `LlmService.ToolUse.cs` now logs sanitization counts for flattened assistant tool traces and converted orphan tool messages, so tool-trace repair frequency can be measured per run.
+- Remaining follow-up:
+  - extend pre-request tool-trace validation so the flattening/orphan repair count trends toward zero rather than being logged after repair
+  - replace more mojibake prompt/status strings in active Code execution paths with English equivalents
--- a/docs/DEVELOPMENT.md
+++ b/docs/DEVELOPMENT.md
@@ -1761,3 +1761,46 @@ UI ?遺우쁽????域뱀뮆???귐뗫솯?醫딆춦 ???袁る퓮 ?臾믩씜 ??疫
  - Encoding hygiene and prompt quality cleanup
 - 계획 문서는 `claude-code` 참조 지점(`claw-code/.../src/query.ts`, `history.ts`, `memory-context.md`), AX 적용 위치, 완료 조건, 품질 판정 시나리오를 함께 기록했습니다.
 - 외부 근거로는 Anthropic Claude Code memory docs, OpenAI practical guide to building agents, `SWE-Pruner: Self-Adaptive Context Pruning for Coding Agents`를 반영해 "자동 메모리 계층", "관측 가능성/eval 우선", "task-aware pruning" 원칙을 계획에 녹였습니다.
+
+업데이트: 2026-04-16 01:41 (KST)
+- Code 탭 컨텍스트 신뢰성 보강 1차 구현을 적용했다.
+  - `src/AxCopilot/Services/Agent/CodeTaskWorkingSetService.cs`
+    - Code 전용 working-set 메모리 레이어를 추가했다.
+    - 최근 생성 디렉터리, 최근 읽기/쓰기 파일, 최신 build/test 진단, 다음 복구 초점을 구조화해 유지한다.
+    - `build_run`, `test_loop`, `process`, `file_manage`, `file_write`, `file_edit`, `multi_read` 결과를 바탕으로 현재 작업 연속성을 요약한 `code_working_set` system 메시지를 만든다.
+  - `src/AxCopilot/Services/Agent/AgentLoopService.cs`
+    - Code 탭 실행에서 `CodeTaskWorkingSetService`를 생성하고, 각 도구 실행 뒤 결과를 working set에 기록한다.
+    - Code 탭에서는 generic `session_learnings` 주입을 줄이고, 대신 working set 보조 context를 LLM 요청 직전에 삽입한다.
+    - 각 반복마다 `query_context` 전이 로그를 남겨 query-view 범위, profile, protected recent 값, supplemental context 수, estimated send token, working-set 요약을 관찰 가능하게 만들었다.
+  - `src/AxCopilot/Services/Agent/AgentQueryContextBuilder.cs`
+    - `AgentQueryContextBuildOptions`를 추가해 `default`와 `code` profile을 분리했다.
+    - 결과 객체에 profile, protected recent, tool-result budget 메타를 함께 남긴다.
+  - `src/AxCopilot/Services/Agent/AgentToolResultBudget.cs`
+    - `AgentToolResultBudgetOptions`를 도입했다.
+    - Code profile에서 `build_run`, `test_loop`, `process`, `file_read`, `multi_read`, `lsp_code_intel`, `git_tool` 같은 고가치 evidence의 truncation 한도를 더 크게 잡아 최신 오류와 읽은 파일 근거가 너무 빨리 preview로 축약되지 않게 했다.
+    - truncation marker 문자열은 영어 기준으로 정리했다.
+  - `src/AxCopilot/Services/Agent/AgentLoopIterationPreparationService.cs`
+    - iteration 준비 단계에서 query-context build options를 주입하도록 확장했다.
+  - `src/AxCopilot/Services/Agent/AgentLoopLlmRequestPreparationService.cs`
+    - query view 외에 working set 같은 supplemental messages를 요청 배열에 추가할 수 있게 확장했다.
+    - tool reminder 메시지 문자열을 영어 기준으로 정리했다.
+  - `src/AxCopilot/Views/ChatWindow.UtilityPresentation.cs`
+    - `.ax-context.md`가 아직 없는 첫 요청에서도 workspace context 생성을 즉시 시작한다.
+    - 생성이 완료되기 전에는 `DetectLanguageWorkflowHints(...)` 기반 bootstrap context를 반환해 완전 빈 작업 폴더에서도 첫 루프에 최소 힌트가 포함되도록 보강했다.
+  - `src/AxCopilot/Services/LlmService.ToolUse.cs`
+    - historical tool-call sanitization 결과를 `flattened_assistant`, `converted_orphans` 건수로 요약 로그에 남긴다.
+    - 사후 보정은 유지하면서도 빈도를 추적해 후속 invariant hardening 작업의 기준선을 확보했다.
+- 테스트:
+  - `src/AxCopilot.Tests/Services/CodeTaskWorkingSetServiceTests.cs`
+    - 구조/쓰기 working set 누적, build diagnostic 유지, 성공 build 후 diagnostic clearing을 검증한다.
+  - `src/AxCopilot.Tests/Services/AgentQueryContextBuilderTests.cs`
+    - Code profile 메타데이터 노출을 검증한다.
+  - `src/AxCopilot.Tests/Services/AgentToolResultBudgetTests.cs`
+    - Code mode에서 긴 `build_run` 결과를 더 오래 보존하는지 검증한다.
+  - `src/AxCopilot.Tests/Services/AgentLoopIterationPreparationServiceTests.cs`
+    - iteration 준비 단계가 Code profile query options를 반영하는지 검증한다.
+  - `src/AxCopilot.Tests/Services/AgentLoopLlmRequestPreparationServiceTests.cs`
+    - supplemental messages가 tool reminder 앞에 추가되는지 검증한다.
+- 검증:
+  - `dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify_context_reliability_full\\ -p:IntermediateOutputPath=obj\\verify_context_reliability_full\\` 경고 0 / 오류 0
+  - `dotnet test src/AxCopilot.Tests/AxCopilot.Tests.csproj -c Release -v minimal --filter "AgentQueryContextBuilderTests|AgentToolResultBudgetTests|AgentLoopIterationPreparationServiceTests|AgentLoopLlmRequestPreparationServiceTests|CodeTaskWorkingSetServiceTests|AgentLoopCodeQualityTests" -p:OutputPath=bin\\verify_context_reliability_full_tests\\ -p:IntermediateOutputPath=obj\\verify_context_reliability_full_tests\\` 통과 150
--- a/src/AxCopilot.Tests/Services/AgentLoopIterationPreparationServiceTests.cs
+++ b/src/AxCopilot.Tests/Services/AgentLoopIterationPreparationServiceTests.cs
@@ -46,6 +46,38 @@ public class AgentLoopIterationPreparationServiceTests
            message.Role == "user");
    }

+    [Fact]
+    public void Prepare_ShouldForwardCodeQueryOptions()
+    {
+        var longContent = new string('Z', 2_200);
+        var messages = new List<ChatMessage>
+        {
+            new()
+            {
+                MsgId = "tool-1",
+                Role = "user",
+                Content = $$"""{"type":"tool_result","tool_use_id":"call-build","tool_name":"build_run","content":"{{longContent}}"}"""
+            },
+            new()
+            {
+                MsgId = "assistant-1",
+                Role = "assistant",
+                Content = "recent assistant message"
+            }
+        };
+
+        var result = AgentLoopIterationPreparationService.Prepare(
+            messages,
+            new AgentCommandQueue(),
+            lastToolResultAtUtc: null,
+            lastToolResultToolName: null,
+            utcNow: DateTime.UtcNow,
+            queryOptions: AgentQueryContextBuilder.AgentQueryContextBuildOptions.CreateCodeDefault());
+
+        result.QueryView.ProfileName.Should().Be("code");
+        result.QueryView.ToolResultSoftCharLimit.Should().BeGreaterThan(AgentToolResultBudget.DefaultSoftCharLimit);
+    }
+
    [Fact]
    public void BuildToolResultWaitSummary_ShouldFormatToolNameAndElapsedMilliseconds()
    {
--- a/src/AxCopilot.Tests/Services/AgentLoopLlmRequestPreparationServiceTests.cs
+++ b/src/AxCopilot.Tests/Services/AgentLoopLlmRequestPreparationServiceTests.cs
@@ -55,4 +55,35 @@ public class AgentLoopLlmRequestPreparationServiceTests
        result.InjectedToolReminder.Should().BeFalse();
        result.SendMessages.Should().HaveCount(1);
    }
+
+    [Fact]
+    public void Prepare_ShouldAppendSupplementalMessagesBeforeReminder()
+    {
+        var queryMessages = new List<ChatMessage>
+        {
+            new()
+            {
+                Role = "user",
+                Content = "fix the latest build failure"
+            }
+        };
+        var supplemental = new ChatMessage
+        {
+            Role = "system",
+            MetaKind = "code_working_set",
+            Content = "[code-working-set]\n- Active diagnostic: MC4005 - Themes/ControlStyles.xaml"
+        };
+
+        var result = AgentLoopLlmRequestPreparationService.Prepare(
+            queryMessages,
+            totalToolCalls: 0,
+            forceInitialToolCallEnabled: true,
+            injectPreCallToolReminder: true,
+            noToolCallLoopRetry: 0,
+            supplementalMessages: [supplemental]);
+
+        result.SupplementalMessageCount.Should().Be(1);
+        result.SendMessages[1].MetaKind.Should().Be("code_working_set");
+        result.SendMessages.Last().Content.Should().Contain("[TOOL_REQUIRED]");
+    }
 }
--- a/src/AxCopilot.Tests/Services/AgentQueryContextBuilderTests.cs
+++ b/src/AxCopilot.Tests/Services/AgentQueryContextBuilderTests.cs
@@ -68,4 +68,32 @@ public class AgentQueryContextBuilderTests
            message.QueryPreviewContent != null &&
            message.QueryPreviewContent.Contains("call-synth-view", StringComparison.OrdinalIgnoreCase));
    }
+
+    [Fact]
+    public void Build_ShouldExposeCodeProfileMetadata()
+    {
+        var sourceMessages = new List<ChatMessage>
+        {
+            new()
+            {
+                MsgId = "tool-source-1",
+                Role = "user",
+                Content = """{"type":"tool_result","tool_use_id":"call-code","tool_name":"build_run","content":"short"}"""
+            },
+            new()
+            {
+                MsgId = "tail-1",
+                Role = "assistant",
+                Content = "recent tail"
+            }
+        };
+
+        var result = AgentQueryContextBuilder.Build(
+            sourceMessages,
+            AgentQueryContextBuilder.AgentQueryContextBuildOptions.CreateCodeDefault());
+
+        result.ProfileName.Should().Be("code");
+        result.ProtectedRecentNonSystemMessages.Should().BeGreaterThan(8);
+        result.ToolResultAggregateBudgetChars.Should().BeGreaterThan(AgentToolResultBudget.DefaultAggregateBudgetChars);
+    }
 }
--- a/src/AxCopilot.Tests/Services/AgentToolResultBudgetTests.cs
+++ b/src/AxCopilot.Tests/Services/AgentToolResultBudgetTests.cs
@@ -36,7 +36,10 @@ public class AgentToolResultBudgetTests
            Timestamp = message.Timestamp
        }).ToList();

-        var first = AgentToolResultBudget.Apply(firstWindow, protectedRecentNonSystemMessages: 1, sourceMessages: sourceMessages);
+        var first = AgentToolResultBudget.Apply(
+            firstWindow,
+            protectedRecentNonSystemMessages: 1,
+            sourceMessages: sourceMessages);

        sourceMessages[0].QueryPreviewContent.Should().NotBeNullOrWhiteSpace();
        first.TruncatedCount.Should().Be(1);
@@ -50,24 +53,26 @@ public class AgentToolResultBudgetTests
            Timestamp = message.Timestamp
        }).ToList();

-        var second = AgentToolResultBudget.Apply(secondWindow, protectedRecentNonSystemMessages: 1, sourceMessages: sourceMessages);
+        var second = AgentToolResultBudget.Apply(
+            secondWindow,
+            protectedRecentNonSystemMessages: 1,
+            sourceMessages: sourceMessages);

        second.ReusedPreviewCount.Should().Be(1);
        secondWindow[0].Content.Should().Be(sourceMessages[0].QueryPreviewContent);
    }

    [Fact]
-    public void Apply_ShouldReusePreviewByToolUseIdAcrossClonedMessages()
+    public void Apply_ShouldPreserveLargerBuildResultsInCodeMode()
    {
-        var longContent = new string('B', 1500);
-        var sourceMessages = new List<ChatMessage>
+        var longContent = new string('B', 2_600);
+        var queryView = new List<ChatMessage>
        {
            new()
            {
-                MsgId = "source-tool",
+                MsgId = "tool-build",
                Role = "user",
-                Content = $$"""{"type":"tool_result","tool_use_id":"call-shared","tool_name":"file_read","content":"{{longContent}}"}""",
-                QueryPreviewContent = """{"type":"tool_result","tool_use_id":"call-shared","tool_name":"file_read","content":"preview"}"""
+                Content = $$"""{"type":"tool_result","tool_use_id":"call-build","tool_name":"build_run","content":"{{longContent}}"}"""
            },
            new()
            {
@@ -77,65 +82,19 @@ public class AgentToolResultBudgetTests
            }
        };

-        var queryView = new List<ChatMessage>
-        {
-            new()
-            {
-                MsgId = "rebuilt-tool",
-                Role = "user",
-                Content = $$"""{"type":"tool_result","tool_use_id":"call-shared","tool_name":"file_read","content":"{{longContent}}"}"""
-            },
-            new()
-            {
-                MsgId = "tail-2",
-                Role = "assistant",
-                Content = "recent tail"
-            }
-        };
+        var result = AgentToolResultBudget.Apply(
+            queryView,
+            AgentToolResultBudget.CreateCodeOptions(),
+            sourceMessages: queryView);

-        var result = AgentToolResultBudget.Apply(queryView, protectedRecentNonSystemMessages: 1, sourceMessages: sourceMessages);
-
-        result.ReusedPreviewCount.Should().Be(1);
-        queryView[0].Content.Should().Be(sourceMessages[0].QueryPreviewContent);
+        result.TruncatedCount.Should().Be(0);
+        queryView[0].Content.Should().Contain(longContent[..256]);
    }

    [Fact]
-    public void Apply_ShouldReusePreviewWithinSameWindow_WhenSourceMessagesAreOmitted()
+    public void Apply_ShouldReusePreviewFingerprintAcrossSessions()
    {
-        var longContent = new string('C', 1600);
-        var queryView = new List<ChatMessage>
-        {
-            new()
-            {
-                MsgId = "tool-1",
-                Role = "user",
-                Content = $$"""{"type":"tool_result","tool_use_id":"call-inline","tool_name":"file_read","content":"{{longContent}}"}""",
-                QueryPreviewContent = """{"type":"tool_result","tool_use_id":"call-inline","tool_name":"file_read","content":"preview-inline"}"""
-            },
-            new()
-            {
-                MsgId = "tool-2",
-                Role = "user",
-                Content = $$"""{"type":"tool_result","tool_use_id":"call-inline","tool_name":"file_read","content":"{{longContent}}"}"""
-            },
-            new()
-            {
-                MsgId = "tail-1",
-                Role = "assistant",
-                Content = "recent tail"
-            }
-        };
-
-        var result = AgentToolResultBudget.Apply(queryView, protectedRecentNonSystemMessages: 1);
-
-        result.ReusedPreviewCount.Should().BeGreaterThan(0);
-        queryView[1].QueryPreviewContent.Should().Be(queryView[0].QueryPreviewContent);
-    }
-
-    [Fact]
-    public void Apply_ShouldReuseFingerprintPreviewFromSourceMessages_WhenToolUseIdChangesAcrossSessions()
-    {
-        var longContent = new string('D', 1700);
+        var longContent = new string('C', 1700);
        var sourceMessages = new List<ChatMessage>
        {
            new()
@@ -169,7 +128,10 @@ public class AgentToolResultBudgetTests
            }
        };

-        var result = AgentToolResultBudget.Apply(queryView, protectedRecentNonSystemMessages: 1, sourceMessages: sourceMessages);
+        var result = AgentToolResultBudget.Apply(
+            queryView,
+            protectedRecentNonSystemMessages: 1,
+            sourceMessages: sourceMessages);

        result.ReusedPreviewCount.Should().Be(1);
        queryView[0].Content.Should().Contain("call-replayed");
--- a/src/AxCopilot.Tests/Services/CodeTaskWorkingSetServiceTests.cs
+++ b/src/AxCopilot.Tests/Services/CodeTaskWorkingSetServiceTests.cs
@@ -0,0 +1,92 @@
+using System.Text.Json;
+using AxCopilot.Models;
+using AxCopilot.Services.Agent;
+using FluentAssertions;
+using Xunit;
+
+namespace AxCopilot.Tests.Services;
+
+public class CodeTaskWorkingSetServiceTests
+{
+    [Fact]
+    public void BuildChatMessage_ShouldCaptureStructureAndRecentWrites()
+    {
+        var service = new CodeTaskWorkingSetService(
+            "Create a WPF app",
+            @"E:\code",
+            "WPF MVVM",
+            startedFromEmptyWorkspace: true);
+
+        using var mkdirDoc = JsonDocument.Parse("""{"action":"mkdir","path":"Views"}""");
+        service.RecordToolResult("file_manage", mkdirDoc.RootElement, new ToolResult
+        {
+            Success = true,
+            Output = "created Views"
+        });
+
+        using var writeDoc = JsonDocument.Parse("""{"path":"Views/MainWindow.xaml"}""");
+        service.RecordToolResult("file_write", writeDoc.RootElement, new ToolResult
+        {
+            Success = true,
+            FilePath = @"E:\code\Views\MainWindow.xaml",
+            Output = "wrote MainWindow.xaml"
+        });
+
+        var message = service.BuildChatMessage();
+
+        message.Should().NotBeNull();
+        message!.MetaKind.Should().Be("code_working_set");
+        message.Content.Should().Contain("Structure chosen: Views");
+        message.Content.Should().Contain("Recent writes: Views/MainWindow.xaml");
+    }
+
+    [Fact]
+    public void BuildChatMessage_ShouldCaptureLatestBuildDiagnostics()
+    {
+        var service = new CodeTaskWorkingSetService(
+            "Fix the build",
+            @"E:\code",
+            "WPF MVVM",
+            startedFromEmptyWorkspace: false);
+
+        const string buildOutput = @"E:\code\Themes\ControlStyles.xaml(14,17): error MC4005: 'SelectionTextColor' property does not exist";
+        service.RecordToolResult("build_run", null, new ToolResult
+        {
+            Success = false,
+            Output = buildOutput
+        });
+
+        var message = service.BuildChatMessage();
+
+        message.Should().NotBeNull();
+        message!.Content.Should().Contain("MC4005");
+        message.Content.Should().Contain("Themes/ControlStyles.xaml");
+        message.Content.Should().Contain("Resolve the latest build/test diagnostics");
+    }
+
+    [Fact]
+    public void SuccessfulBuild_ShouldClearActiveDiagnostics()
+    {
+        var service = new CodeTaskWorkingSetService(
+            "Fix the build",
+            @"E:\code",
+            "WPF MVVM",
+            startedFromEmptyWorkspace: false);
+
+        service.RecordToolResult("build_run", null, new ToolResult
+        {
+            Success = false,
+            Output = @"E:\code\App.xaml.cs(10,5): error CS0017: Program has more than one entry point"
+        });
+        service.RecordToolResult("build_run", null, new ToolResult
+        {
+            Success = true,
+            Output = "Build succeeded."
+        });
+
+        var message = service.BuildChatMessage();
+
+        message.Should().NotBeNull();
+        message!.Content.Should().NotContain("CS0017");
+    }
+}
--- a/src/AxCopilot/Services/Agent/AgentLoopContextReliability.cs
+++ b/src/AxCopilot/Services/Agent/AgentLoopContextReliability.cs
@@ -0,0 +1,19 @@
+namespace AxCopilot.Services.Agent;
+
+public partial class AgentLoopService
+{
+    private static AgentQueryContextBuilder.AgentQueryContextBuildOptions CreateQueryContextBuildOptions(bool isCodeTab)
+        => isCodeTab
+            ? AgentQueryContextBuilder.AgentQueryContextBuildOptions.CreateCodeDefault()
+            : AgentQueryContextBuilder.AgentQueryContextBuildOptions.CreateDefault();
+
+    private static string BuildQueryContextDetail(
+        AgentQueryContextWindowResult queryView,
+        AgentLoopLlmRequestPreparationResult llmRequest,
+        CodeTaskWorkingSetService? codeWorkingSet)
+    {
+        var estimatedSendTokens = TokenEstimator.EstimateMessages(llmRequest.SendMessages);
+        var workingSetSummary = codeWorkingSet?.DescribeForLog() ?? "none";
+        return $"{AgentLoopDiagnosticsFormatter.BuildQueryViewSummary(queryView)}, profile={queryView.ProfileName}, protected_recent={queryView.ProtectedRecentNonSystemMessages}, send={llmRequest.SendMessages.Count}, send_tokens={estimatedSendTokens}, supplemental={llmRequest.SupplementalMessageCount}, tool_reminder={llmRequest.InjectedToolReminder}, working_set={workingSetSummary}";
+    }
+}
--- a/src/AxCopilot/Services/Agent/AgentLoopIterationPreparationService.cs
+++ b/src/AxCopilot/Services/Agent/AgentLoopIterationPreparationService.cs
@@ -8,9 +8,8 @@ internal sealed record AgentLoopIterationPreparationResult(
    string? ToolResultWaitSummary);

 /// <summary>
-/// RunAsync 반복 시작 시점의 공통 준비 작업을 묶습니다.
-/// queued command 투영, tool_result 대기 진단, query view 생성 책임을 분리해
-/// AgentLoopService 본체를 orchestration 중심으로 유지합니다.
+/// Performs the common per-iteration preparation work before each LLM request.
+/// This keeps AgentLoopService focused on orchestration.
 /// </summary>
 internal static class AgentLoopIterationPreparationService
 {
@@ -19,10 +18,11 @@ internal static class AgentLoopIterationPreparationService
        AgentCommandQueue pendingCommands,
        DateTime? lastToolResultAtUtc,
        string? lastToolResultToolName,
-        DateTime utcNow)
+        DateTime utcNow,
+        AgentQueryContextBuilder.AgentQueryContextBuildOptions? queryOptions = null)
    {
        var queueProjection = ProjectQueuedCommands(messages, pendingCommands);
-        var queryView = AgentQueryContextBuilder.Build(messages);
+        var queryView = AgentQueryContextBuilder.Build(messages, queryOptions);
        var waitSummary = BuildToolResultWaitSummary(lastToolResultAtUtc, lastToolResultToolName, utcNow);

        return new AgentLoopIterationPreparationResult(queueProjection, queryView, waitSummary);
--- a/src/AxCopilot/Services/Agent/AgentLoopLlmRequestPreparationService.cs
+++ b/src/AxCopilot/Services/Agent/AgentLoopLlmRequestPreparationService.cs
@@ -5,12 +5,12 @@ namespace AxCopilot.Services.Agent;
 internal sealed record AgentLoopLlmRequestPreparationResult(
    List<ChatMessage> SendMessages,
    bool ForceInitialToolCall,
-    bool InjectedToolReminder);
+    bool InjectedToolReminder,
+    int SupplementalMessageCount);

 /// <summary>
-/// query view가 만들어진 뒤 실제 LLM 요청 배열을 조립합니다.
-/// 초기 tool call 강제 여부와 사전 reminder 주입을 한곳에서 결정해
-/// AgentLoopService 본체가 orchestration에 더 집중하도록 분리합니다.
+/// Builds the final LLM request array from the query window and optional
+/// supplemental context blocks.
 /// </summary>
 internal static class AgentLoopLlmRequestPreparationService
 {
@@ -19,25 +19,29 @@ internal static class AgentLoopLlmRequestPreparationService
        int totalToolCalls,
        bool forceInitialToolCallEnabled,
        bool injectPreCallToolReminder,
-        int noToolCallLoopRetry)
+        int noToolCallLoopRetry,
+        IEnumerable<ChatMessage>? supplementalMessages = null)
    {
+        var sendMessages = queryMessages.ToList();
+        var supplementalCount = AppendSupplementalMessages(sendMessages, supplementalMessages);
        var forceInitialToolCall = totalToolCalls == 0 && forceInitialToolCallEnabled;
        if (!forceInitialToolCall
            || !injectPreCallToolReminder
            || noToolCallLoopRetry > 0)
        {
            return new AgentLoopLlmRequestPreparationResult(
-                queryMessages.ToList(),
+                sendMessages,
                forceInitialToolCall,
-                false);
+                false,
+                supplementalCount);
        }

-        var sendMessages = queryMessages.ToList();
        sendMessages.Add(BuildToolReminderMessage());
        return new AgentLoopLlmRequestPreparationResult(
            sendMessages,
            forceInitialToolCall,
-            true);
+            true,
+            supplementalCount);
    }

    internal static ChatMessage BuildToolReminderMessage()
@@ -45,8 +49,26 @@ internal static class AgentLoopLlmRequestPreparationService
        return new ChatMessage
        {
            Role = "user",
-            Content = "[TOOL_REQUIRED] 지금 즉시 <tool_call> 형식으로 도구를 호출하세요. 텍스트만 반환하면 거부됩니다.\n" +
+            Content = "[TOOL_REQUIRED] Emit a valid <tool_call> block right away. A plain-text reply will be rejected.\n" +
                      "Output format:\n<tool_call>\n{\"name\": \"TOOL_NAME\", \"arguments\": {\"param\": \"value\"}}\n</tool_call>"
        };
    }
+
+    private static int AppendSupplementalMessages(List<ChatMessage> sendMessages, IEnumerable<ChatMessage>? supplementalMessages)
+    {
+        if (supplementalMessages == null)
+            return 0;
+
+        var added = 0;
+        foreach (var message in supplementalMessages)
+        {
+            if (message == null || string.IsNullOrWhiteSpace(message.Content))
+                continue;
+
+            sendMessages.Add(message);
+            added++;
+        }
+
+        return added;
+    }
 }
--- a/src/AxCopilot/Services/Agent/AgentLoopService.cs
+++ b/src/AxCopilot/Services/Agent/AgentLoopService.cs
@@ -239,6 +239,7 @@ public partial class AgentLoopService
        var explorationState = runBootstrap.ExplorationState;
        var pathAccessState = runBootstrap.PathAccessState;
        var sessionLearnings = runBootstrap.SessionLearnings;
+        var isCodeTab = string.Equals(ActiveTab, "Code", StringComparison.OrdinalIgnoreCase);
        DateTime? lastToolResultAtUtc = null;
        string? lastToolResultToolName = null;

@@ -299,6 +300,14 @@ public partial class AgentLoopService
        context.InitialUserQuery = userQuery;
        runState.WorkspaceAppearsEmpty = DetectEmptyWorkspace(context.WorkFolder);
        var workspaceWasInitiallyEmpty = runState.WorkspaceAppearsEmpty;
+        var queryContextOptions = CreateQueryContextBuildOptions(isCodeTab);
+        var codeWorkingSet = isCodeTab
+            ? new CodeTaskWorkingSetService(
+                userQuery,
+                context.WorkFolder,
+                explorationState.ScaffoldProfile?.Label,
+                workspaceWasInitiallyEmpty)
+            : null;

        var preferredInitialToolSequence = BuildPreferredInitialToolSequence(
            explorationState,
@@ -454,7 +463,8 @@ public partial class AgentLoopService
                    _pendingCommands,
                    lastToolResultAtUtc,
                    lastToolResultToolName,
-                    DateTime.UtcNow);
+                    DateTime.UtcNow,
+                    queryContextOptions);
                if (!string.IsNullOrWhiteSpace(iterationPreparation.ToolResultWaitSummary))
                {
                    WorkflowLogService.LogTransition(
@@ -520,8 +530,8 @@ public partial class AgentLoopService
                    }
                }

-                // P3: 누적 학습 메시지 주입 (매 반복 갱신)
-                if (sessionLearnings is { Count: > 0 })
+                // Refresh the session learnings block only for non-Code tabs.
+                if (!isCodeTab && sessionLearnings is { Count: > 0 })
                {
                    var learningMsg = sessionLearnings.BuildInjectionMessage();
                    if (learningMsg != null)
@@ -562,12 +572,14 @@ public partial class AgentLoopService
                        EmitEvent(AgentEventType.Error, "", $"{tabLabel} 탭에서 사용 가능한 도구가 없습니다.");
                        return $"⚠ 현재 {tabLabel} 탭에서 사용 가능한 도구가 없어 작업을 진행할 수 없습니다. 탭별 도구 노출 정책을 확인하세요.";
                    }
+                    var workingSetMessage = codeWorkingSet?.BuildChatMessage();
                    var llmRequest = AgentLoopLlmRequestPreparationService.Prepare(
                        queryMessages,
                        totalToolCalls,
                        executionPolicy.ForceInitialToolCall,
                        executionPolicy.InjectPreCallToolReminder,
-                        runState.NoToolCallLoopRetry);
+                        runState.NoToolCallLoopRetry,
+                        workingSetMessage is null ? null : [workingSetMessage]);
                    var forceFirst = llmRequest.ForceInitialToolCall;
                    var sendMessages = llmRequest.SendMessages;

@@ -575,6 +587,12 @@ public partial class AgentLoopService
                    llmCallSw.Restart();
                    var (_, currentModel) = _llm.GetCurrentModelInfo();
                    WorkflowLogService.SetCallContext(_conversationId, _currentRunId, iteration);
+                    WorkflowLogService.LogTransition(
+                        _conversationId,
+                        _currentRunId,
+                        iteration,
+                        "query_context",
+                        BuildQueryContextDetail(queryView, llmRequest, codeWorkingSet));
                    WorkflowLogService.LogLlmRequest(_conversationId, _currentRunId, iteration,
                        currentModel, sendMessages.Count, activeTools.Count, forceFirst);
                    var streamedTextPreview = new StringBuilder();
@@ -1578,8 +1596,10 @@ public partial class AgentLoopService
                    lastToolResultAtUtc = DateTime.UtcNow;
                    lastToolResultToolName = effectiveCall.ToolName;

-                    // P3: 누적 학습 — 도구 결과에서 학습 포인트 추출
-                    sessionLearnings?.TryExtract(effectiveCall.ToolName, result.Output ?? "", result.Success);
+                    // Keep Code runs focused on the current working set instead of generic session learnings.
+                    if (!isCodeTab)
+                        sessionLearnings?.TryExtract(effectiveCall.ToolName, result.Output ?? "", result.Success);
+                    codeWorkingSet?.RecordToolResult(effectiveCall.ToolName, effectiveCall.ToolInput, result);

                    if (!result.Success)
                    {
--- a/src/AxCopilot/Services/Agent/AgentQueryContextBuilder.cs
+++ b/src/AxCopilot/Services/Agent/AgentQueryContextBuilder.cs
@@ -15,18 +15,46 @@ public sealed class AgentQueryContextWindowResult
    public int ReusedToolResultPreviewCount { get; init; }
    public int TokensBeforeBudget { get; init; }
    public int TokensAfterBudget { get; init; }
+    public string ProfileName { get; init; } = "default";
+    public int ProtectedRecentNonSystemMessages { get; init; }
+    public int ToolResultSoftCharLimit { get; init; }
+    public int ToolResultAggregateBudgetChars { get; init; }
 }

 /// <summary>
-/// claude-code의 messagesForQuery처럼, 저장된 전체 대화와 실제 LLM에 보내는 query view를 분리합니다.
+/// Builds the query window that is actually sent to the LLM, similar to
+/// claude-code's messagesForQuery pipeline.
 /// </summary>
 public static class AgentQueryContextBuilder
 {
-    private const int ProtectedRecentNonSystemMessages = 8;
+    public sealed class AgentQueryContextBuildOptions
+    {
+        public string ProfileName { get; init; } = "default";
+        public AgentToolResultBudget.AgentToolResultBudgetOptions ToolResultBudget { get; init; }
+            = AgentToolResultBudget.CreateDefaultOptions();
+
+        public static AgentQueryContextBuildOptions CreateDefault()
+            => new()
+            {
+                ProfileName = "default",
+                ToolResultBudget = AgentToolResultBudget.CreateDefaultOptions(),
+            };
+
+        public static AgentQueryContextBuildOptions CreateCodeDefault()
+            => new()
+            {
+                ProfileName = "code",
+                ToolResultBudget = AgentToolResultBudget.CreateCodeOptions(),
+            };
+    }
+
    private const string PostCompactContextMetaKind = "post_compact_context";

-    public static AgentQueryContextWindowResult Build(IReadOnlyList<ChatMessage> sourceMessages)
+    public static AgentQueryContextWindowResult Build(
+        IReadOnlyList<ChatMessage> sourceMessages,
+        AgentQueryContextBuildOptions? options = null)
    {
+        options ??= AgentQueryContextBuildOptions.CreateDefault();
        if (sourceMessages is IList<ChatMessage> mutableSourceMessages)
            AgentMessageInvariantHelper.PopulateMissingToolResultPreviews(mutableSourceMessages);

@@ -45,6 +73,10 @@ public static class AgentQueryContextBuilder
                ReusedToolResultPreviewCount = 0,
                TokensBeforeBudget = 0,
                TokensAfterBudget = 0,
+                ProfileName = options.ProfileName,
+                ProtectedRecentNonSystemMessages = options.ToolResultBudget.ProtectedRecentNonSystemMessages,
+                ToolResultSoftCharLimit = options.ToolResultBudget.SoftCharLimit,
+                ToolResultAggregateBudgetChars = options.ToolResultBudget.AggregateBudgetChars,
            };
        }

@@ -70,7 +102,7 @@ public static class AgentQueryContextBuilder
            InjectPostCompactContextMessage(windowMessages);

        var tokensBeforeBudget = TokenEstimator.EstimateMessages(windowMessages);
-        var budgetResult = AgentToolResultBudget.Apply(windowMessages, ProtectedRecentNonSystemMessages, sourceMessages: sourceMessages);
+        var budgetResult = AgentToolResultBudget.Apply(windowMessages, options.ToolResultBudget, sourceMessages: sourceMessages);
        var tokensAfterBudget = TokenEstimator.EstimateMessages(windowMessages);

        return new AgentQueryContextWindowResult
@@ -86,6 +118,10 @@ public static class AgentQueryContextBuilder
            ReusedToolResultPreviewCount = budgetResult.ReusedPreviewCount,
            TokensBeforeBudget = tokensBeforeBudget,
            TokensAfterBudget = tokensAfterBudget,
+            ProfileName = options.ProfileName,
+            ProtectedRecentNonSystemMessages = options.ToolResultBudget.ProtectedRecentNonSystemMessages,
+            ToolResultSoftCharLimit = options.ToolResultBudget.SoftCharLimit,
+            ToolResultAggregateBudgetChars = options.ToolResultBudget.AggregateBudgetChars,
        };
    }

@@ -115,7 +151,11 @@ public static class AgentQueryContextBuilder
        }

        var content = message.Content ?? "";
-        return content.StartsWith("[이전 대화 요약", StringComparison.Ordinal)
+        return content.StartsWith("[previous conversation summary", StringComparison.OrdinalIgnoreCase)
+               || content.StartsWith("[session memory compaction", StringComparison.OrdinalIgnoreCase)
+               || content.StartsWith("[previous execution bundle compaction", StringComparison.OrdinalIgnoreCase)
+               || content.StartsWith("[previous compaction boundary merge", StringComparison.OrdinalIgnoreCase)
+               || content.StartsWith("[이전 대화 요약", StringComparison.Ordinal)
               || content.StartsWith("[세션 메모리 압축", StringComparison.Ordinal)
               || content.StartsWith("[이전 실행 묶음 압축", StringComparison.Ordinal)
               || content.StartsWith("[이전 압축 경계 병합", StringComparison.Ordinal);
@@ -219,24 +259,22 @@ public static class AgentQueryContextBuilder
    private static bool TryExtractToolResultToolName(ChatMessage message, out string toolName)
    {
        toolName = "";
-        if (!string.Equals(message.Role, "user", StringComparison.OrdinalIgnoreCase)
-            || string.IsNullOrWhiteSpace(message.Content)
-            || !message.Content.StartsWith("{\"type\":\"tool_result\"", StringComparison.Ordinal))
+        var content = message.Content ?? "";
+        if (!content.StartsWith("{\"type\":\"tool_result\"", StringComparison.Ordinal))
            return false;

        try
        {
-            using var doc = System.Text.Json.JsonDocument.Parse(message.Content);
-            if (doc.RootElement.TryGetProperty("tool_name", out var toolNameEl))
-            {
-                toolName = toolNameEl.GetString() ?? "";
-                return !string.IsNullOrWhiteSpace(toolName);
-            }
+            using var doc = System.Text.Json.JsonDocument.Parse(content);
+            if (!doc.RootElement.TryGetProperty("tool_name", out var toolNameEl))
+                return false;
+
+            toolName = toolNameEl.GetString() ?? "";
+            return !string.IsNullOrWhiteSpace(toolName);
        }
        catch
        {
+            return false;
        }
-
-        return false;
    }
 }
--- a/src/AxCopilot/Services/Agent/AgentToolResultBudget.cs
+++ b/src/AxCopilot/Services/Agent/AgentToolResultBudget.cs
@@ -12,20 +12,61 @@ public sealed class AgentToolResultBudgetResult
 }

 /// <summary>
-/// 오래된 tool_result를 query view와 압축 단계에서 같은 기준으로 줄이기 위한 공용 helper.
+/// Applies a query-time budget to historical tool_result messages without
+/// shrinking the recent active working set more than necessary.
 /// </summary>
 public static class AgentToolResultBudget
 {
    public const int DefaultSoftCharLimit = 900;
    public const int DefaultAggregateBudgetChars = 7_500;

+    private static readonly HashSet<string> s_highValueCodeTools = new(StringComparer.OrdinalIgnoreCase)
+    {
+        "build_run",
+        "test_loop",
+        "process",
+        "shell",
+        "file_read",
+        "multi_read",
+        "lsp_code_intel",
+        "git_tool",
+    };
+
+    public sealed class AgentToolResultBudgetOptions
+    {
+        public string ProfileName { get; init; } = "default";
+        public int ProtectedRecentNonSystemMessages { get; init; } = 8;
+        public int SoftCharLimit { get; init; } = DefaultSoftCharLimit;
+        public int AggregateBudgetChars { get; init; } = DefaultAggregateBudgetChars;
+        public bool PreferDetailedCodeToolResults { get; init; }
+    }
+
+    public static AgentToolResultBudgetOptions CreateDefaultOptions()
+        => new()
+        {
+            ProfileName = "default",
+            ProtectedRecentNonSystemMessages = 8,
+            SoftCharLimit = DefaultSoftCharLimit,
+            AggregateBudgetChars = DefaultAggregateBudgetChars,
+            PreferDetailedCodeToolResults = false,
+        };
+
+    public static AgentToolResultBudgetOptions CreateCodeOptions()
+        => new()
+        {
+            ProfileName = "code",
+            ProtectedRecentNonSystemMessages = 14,
+            SoftCharLimit = 1_400,
+            AggregateBudgetChars = 16_000,
+            PreferDetailedCodeToolResults = true,
+        };
+
    public static AgentToolResultBudgetResult Apply(
        List<ChatMessage> messages,
-        int protectedRecentNonSystemMessages,
-        int softCharLimit = DefaultSoftCharLimit,
-        int aggregateBudgetChars = DefaultAggregateBudgetChars,
+        AgentToolResultBudgetOptions? options = null,
        IReadOnlyList<ChatMessage>? sourceMessages = null)
    {
+        options ??= CreateDefaultOptions();
        var result = new AgentToolResultBudgetResult();
        var previewSourceMessages = sourceMessages ?? messages;
        if (ReferenceEquals(previewSourceMessages, messages))
@@ -47,10 +88,10 @@ public static class AgentToolResultBudget
            .Select(x => x.index)
            .ToList();

-        if (nonSystemIndexes.Count <= protectedRecentNonSystemMessages)
+        if (nonSystemIndexes.Count <= options.ProtectedRecentNonSystemMessages)
            return result;

-        var protectedStart = nonSystemIndexes[Math.Max(0, nonSystemIndexes.Count - protectedRecentNonSystemMessages)];
+        var protectedStart = nonSystemIndexes[Math.Max(0, nonSystemIndexes.Count - options.ProtectedRecentNonSystemMessages)];
        var spentChars = 0;

        for (var i = 0; i < protectedStart; i++)
@@ -87,10 +128,12 @@ public static class AgentToolResultBudget
            }

            spentChars += content.Length;
-            if (content.Length <= softCharLimit && spentChars <= aggregateBudgetChars)
+            var effectiveSoftLimit = GetEffectiveSoftLimit(content, options);
+            var effectiveAggregateLimit = GetEffectiveAggregateLimit(content, options);
+            if (content.Length <= effectiveSoftLimit && spentChars <= effectiveAggregateLimit)
                continue;

-            var truncated = TruncateToolResultJson(content, softCharLimit);
+            var truncated = TruncateToolResultJson(content, effectiveSoftLimit);
            if (string.Equals(truncated, content, StringComparison.Ordinal))
                continue;

@@ -109,6 +152,22 @@ public static class AgentToolResultBudget
        return result;
    }

+    public static AgentToolResultBudgetResult Apply(
+        List<ChatMessage> messages,
+        int protectedRecentNonSystemMessages,
+        int softCharLimit = DefaultSoftCharLimit,
+        int aggregateBudgetChars = DefaultAggregateBudgetChars,
+        IReadOnlyList<ChatMessage>? sourceMessages = null)
+        => Apply(
+            messages,
+            new AgentToolResultBudgetOptions
+            {
+                ProtectedRecentNonSystemMessages = protectedRecentNonSystemMessages,
+                SoftCharLimit = softCharLimit,
+                AggregateBudgetChars = aggregateBudgetChars,
+            },
+            sourceMessages);
+
    public static string TruncateToolResultJson(string json, int softCharLimit = DefaultSoftCharLimit)
    {
        try
@@ -130,7 +189,7 @@ public static class AgentToolResultBudget
            var head = content[..keepHead];
            var tail = keepTail > 0 ? content[^keepTail..] : "";
            var compacted = head +
-                            $"\n...[tool_result 축약: {content.Length:N0}자]...\n" +
+                            $"\n...[tool_result truncated: {content.Length:N0} chars]...\n" +
                            tail;

            return JsonSerializer.Serialize(new
@@ -147,7 +206,7 @@ public static class AgentToolResultBudget
                return json;

            var head = json[..Math.Min(softCharLimit, json.Length)];
-            return head + "...[tool_result 축약]";
+            return head + "...[tool_result truncated]";
        }
    }

@@ -177,6 +236,62 @@ public static class AgentToolResultBudget
        }
    }

+    private static int GetEffectiveSoftLimit(string content, AgentToolResultBudgetOptions options)
+    {
+        if (!options.PreferDetailedCodeToolResults)
+            return options.SoftCharLimit;
+
+        var toolName = ExtractToolName(content);
+        if (string.IsNullOrWhiteSpace(toolName))
+            return options.SoftCharLimit;
+
+        if (string.Equals(toolName, "build_run", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(toolName, "test_loop", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(toolName, "process", StringComparison.OrdinalIgnoreCase))
+        {
+            return Math.Max(options.SoftCharLimit, 3_200);
+        }
+
+        if (string.Equals(toolName, "file_read", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(toolName, "multi_read", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(toolName, "lsp_code_intel", StringComparison.OrdinalIgnoreCase))
+        {
+            return Math.Max(options.SoftCharLimit, 2_400);
+        }
+
+        if (s_highValueCodeTools.Contains(toolName))
+            return Math.Max(options.SoftCharLimit, 1_800);
+
+        return options.SoftCharLimit;
+    }
+
+    private static int GetEffectiveAggregateLimit(string content, AgentToolResultBudgetOptions options)
+    {
+        if (!options.PreferDetailedCodeToolResults)
+            return options.AggregateBudgetChars;
+
+        var toolName = ExtractToolName(content);
+        return s_highValueCodeTools.Contains(toolName)
+            ? Math.Max(options.AggregateBudgetChars, 22_000)
+            : options.AggregateBudgetChars;
+    }
+
+    private static string ExtractToolName(string json)
+    {
+        try
+        {
+            using var doc = JsonDocument.Parse(json);
+            if (doc.RootElement.TryGetProperty("tool_name", out var toolName))
+                return toolName.GetString() ?? "";
+        }
+        catch
+        {
+            // Ignore malformed payloads and fall back to the default budget.
+        }
+
+        return "";
+    }
+
    private static ChatMessage CloneMessage(ChatMessage source, string content)
    {
        return new ChatMessage
--- a/src/AxCopilot/Services/Agent/CodeTaskWorkingSetService.cs
+++ b/src/AxCopilot/Services/Agent/CodeTaskWorkingSetService.cs
@@ -0,0 +1,479 @@
+using System.IO;
+using System.Text;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+using AxCopilot.Models;
+
+namespace AxCopilot.Services.Agent;
+
+internal sealed class CodeTaskWorkingSetService
+{
+    private const int MaxListItems = 6;
+    private static readonly Regex BuildDiagnosticWithFileRegex = new(
+        @"(?<file>(?:[A-Za-z]:)?[^:\r\n]+?\.[A-Za-z0-9]+)\((?<line>\d+)(?:,\d+)?\)\s*:\s*error\s*(?<code>[A-Z]{1,4}\d{3,5})\s*:\s*(?<message>.+)",
+        RegexOptions.Compiled | RegexOptions.IgnoreCase);
+    private static readonly Regex BuildDiagnosticRegex = new(
+        @"error\s*(?<code>[A-Z]{1,4}\d{3,5})\s*:\s*(?<message>.+)",
+        RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+    private readonly object _lock = new();
+    private readonly string _goal;
+    private readonly string _workFolder;
+    private readonly string _scaffoldProfileLabel;
+    private readonly bool _startedFromEmptyWorkspace;
+    private readonly List<string> _createdDirectories = new();
+    private readonly List<string> _recentReads = new();
+    private readonly List<string> _recentWrites = new();
+    private readonly List<CodeDiagnostic> _activeDiagnostics = new();
+    private string _environmentSummary = "";
+    private string _nextFocus = "";
+    private string _lastMutationSummary = "";
+
+    public CodeTaskWorkingSetService(
+        string goal,
+        string? workFolder,
+        string? scaffoldProfileLabel,
+        bool startedFromEmptyWorkspace)
+    {
+        _goal = CollapseWhitespace(goal);
+        _workFolder = workFolder?.Trim() ?? "";
+        _scaffoldProfileLabel = scaffoldProfileLabel?.Trim() ?? "";
+        _startedFromEmptyWorkspace = startedFromEmptyWorkspace;
+    }
+
+    public void RecordToolResult(string toolName, JsonElement? toolInput, ToolResult result)
+    {
+        if (string.IsNullOrWhiteSpace(toolName))
+            return;
+
+        lock (_lock)
+        {
+            TrackEnvironment(toolName, result);
+            TrackDirectories(toolName, toolInput, result);
+            TrackReads(toolName, toolInput, result);
+            TrackWrites(toolName, toolInput, result);
+            TrackDiagnostics(toolName, result);
+            UpdateNextFocus(toolName, result);
+        }
+    }
+
+    public ChatMessage? BuildChatMessage()
+    {
+        string content;
+        lock (_lock)
+        {
+            content = BuildContentCore();
+        }
+
+        if (string.IsNullOrWhiteSpace(content))
+            return null;
+
+        return new ChatMessage
+        {
+            Role = "system",
+            MetaKind = "code_working_set",
+            Content = content,
+            Timestamp = DateTime.Now,
+        };
+    }
+
+    public string DescribeForLog()
+    {
+        lock (_lock)
+        {
+            return $"writes={_recentWrites.Count}, reads={_recentReads.Count}, dirs={_createdDirectories.Count}, diagnostics={_activeDiagnostics.Count}, next={TruncateSingleLine(_nextFocus, 80)}";
+        }
+    }
+
+    private string BuildContentCore()
+    {
+        var lines = new List<string> { "[code-working-set]" };
+
+        if (!string.IsNullOrWhiteSpace(_goal))
+            lines.Add($"- Goal: {TruncateSingleLine(_goal, 220)}");
+        if (!string.IsNullOrWhiteSpace(_workFolder))
+            lines.Add($"- Workspace: {_workFolder}");
+        if (!string.IsNullOrWhiteSpace(_scaffoldProfileLabel))
+            lines.Add($"- Scaffold profile: {_scaffoldProfileLabel}");
+        if (_startedFromEmptyWorkspace)
+            lines.Add("- Initial workspace: empty");
+        if (_createdDirectories.Count > 0)
+            lines.Add("- Structure chosen: " + string.Join(", ", _createdDirectories));
+        if (_recentWrites.Count > 0)
+            lines.Add("- Recent writes: " + string.Join(", ", _recentWrites));
+        if (_recentReads.Count > 0)
+            lines.Add("- Recent reads: " + string.Join(", ", _recentReads));
+        if (!string.IsNullOrWhiteSpace(_environmentSummary))
+            lines.Add("- Environment: " + _environmentSummary);
+
+        foreach (var diagnostic in _activeDiagnostics.Take(2))
+            lines.Add("- Active diagnostic: " + diagnostic.ToSummary());
+
+        if (!string.IsNullOrWhiteSpace(_lastMutationSummary))
+            lines.Add("- Last mutation: " + _lastMutationSummary);
+        if (!string.IsNullOrWhiteSpace(_nextFocus))
+            lines.Add("- Next focus: " + _nextFocus);
+
+        if (lines.Count <= 1)
+            return "";
+
+        lines.Add("- Keep continuity with the listed structure and files unless the latest diagnostics clearly contradict them.");
+        return string.Join("\n", lines);
+    }
+
+    private void TrackEnvironment(string toolName, ToolResult result)
+    {
+        if (!string.Equals(toolName, "dev_env_detect", StringComparison.OrdinalIgnoreCase))
+            return;
+
+        var firstMeaningfulLine = (result.Output ?? "")
+            .Replace("\r\n", "\n", StringComparison.Ordinal)
+            .Split('\n', StringSplitOptions.RemoveEmptyEntries)
+            .Select(CollapseWhitespace)
+            .FirstOrDefault(line => !string.IsNullOrWhiteSpace(line));
+
+        if (!string.IsNullOrWhiteSpace(firstMeaningfulLine))
+            _environmentSummary = TruncateSingleLine(firstMeaningfulLine, 160);
+    }
+
+    private void TrackDirectories(string toolName, JsonElement? toolInput, ToolResult result)
+    {
+        if (!string.Equals(toolName, "file_manage", StringComparison.OrdinalIgnoreCase))
+            return;
+
+        var action = TryGetString(toolInput, "action", "mode", "operation");
+        if (!string.IsNullOrWhiteSpace(action)
+            && !action.Contains("dir", StringComparison.OrdinalIgnoreCase)
+            && !action.Contains("mkdir", StringComparison.OrdinalIgnoreCase)
+            && !action.Contains("folder", StringComparison.OrdinalIgnoreCase))
+        {
+            return;
+        }
+
+        foreach (var candidate in ExtractPathCandidates(toolInput))
+        {
+            if (LooksLikeDirectory(candidate))
+                AddRecentUnique(_createdDirectories, NormalizePath(candidate), MaxListItems);
+        }
+
+        if (!string.IsNullOrWhiteSpace(result.FilePath) && LooksLikeDirectory(result.FilePath))
+            AddRecentUnique(_createdDirectories, NormalizePath(result.FilePath), MaxListItems);
+    }
+
+    private void TrackReads(string toolName, JsonElement? toolInput, ToolResult result)
+    {
+        if (!IsReadOnlyContextTool(toolName))
+            return;
+
+        foreach (var candidate in ExtractPathCandidates(toolInput))
+        {
+            if (LooksLikeFile(candidate))
+                AddRecentUnique(_recentReads, NormalizePath(candidate), MaxListItems);
+        }
+
+        if (!string.IsNullOrWhiteSpace(result.FilePath) && LooksLikeFile(result.FilePath))
+            AddRecentUnique(_recentReads, NormalizePath(result.FilePath), MaxListItems);
+    }
+
+    private void TrackWrites(string toolName, JsonElement? toolInput, ToolResult result)
+    {
+        if (!IsMutatingCodeTool(toolName))
+            return;
+
+        var touchedFiles = new List<string>();
+        foreach (var candidate in ExtractPathCandidates(toolInput))
+        {
+            if (LooksLikeFile(candidate))
+                touchedFiles.Add(NormalizePath(candidate));
+        }
+
+        if (!string.IsNullOrWhiteSpace(result.FilePath) && LooksLikeFile(result.FilePath))
+            touchedFiles.Add(NormalizePath(result.FilePath));
+
+        foreach (var file in touchedFiles.Where(path => !string.IsNullOrWhiteSpace(path)).Distinct(StringComparer.OrdinalIgnoreCase))
+            AddRecentUnique(_recentWrites, file, MaxListItems);
+
+        if (touchedFiles.Count > 0)
+            _lastMutationSummary = "Updated " + string.Join(", ", touchedFiles.Distinct(StringComparer.OrdinalIgnoreCase).Take(3));
+    }
+
+    private void TrackDiagnostics(string toolName, ToolResult result)
+    {
+        if (!IsVerificationTool(toolName))
+            return;
+
+        if (result.Success)
+        {
+            _activeDiagnostics.Clear();
+            return;
+        }
+
+        var diagnostics = ExtractDiagnostics(toolName, result.Output ?? "");
+        if (diagnostics.Count == 0 && !string.IsNullOrWhiteSpace(result.Error))
+            diagnostics = ExtractDiagnostics(toolName, result.Error);
+
+        if (diagnostics.Count == 0)
+        {
+            var fallbackSummary = CollapseWhitespace(result.Error ?? result.Output ?? "");
+            if (!string.IsNullOrWhiteSpace(fallbackSummary))
+            {
+                _activeDiagnostics.Clear();
+                _activeDiagnostics.Add(new CodeDiagnostic(toolName, "", null, "", TruncateSingleLine(fallbackSummary, 180)));
+            }
+            return;
+        }
+
+        _activeDiagnostics.Clear();
+        _activeDiagnostics.AddRange(diagnostics.Take(3));
+    }
+
+    private void UpdateNextFocus(string toolName, ToolResult result)
+    {
+        if (_activeDiagnostics.Count > 0)
+        {
+            _nextFocus = "Resolve the latest build/test diagnostics before creating more files.";
+            return;
+        }
+
+        if (IsMutatingCodeTool(toolName) && result.Success)
+        {
+            _nextFocus = "Verify the recent code changes with build or test before broadening the scope.";
+            return;
+        }
+
+        if (IsReadOnlyContextTool(toolName) && _recentWrites.Count > 0)
+        {
+            _nextFocus = "Use the inspected files to continue from the latest edits instead of restarting exploration.";
+            return;
+        }
+
+        if (string.IsNullOrWhiteSpace(_nextFocus) && _createdDirectories.Count > 0)
+            _nextFocus = "Keep writing into the chosen project structure instead of falling back to flat root files.";
+    }
+
+    private List<CodeDiagnostic> ExtractDiagnostics(string toolName, string text)
+    {
+        var diagnostics = new List<CodeDiagnostic>();
+        if (string.IsNullOrWhiteSpace(text))
+            return diagnostics;
+
+        foreach (Match match in BuildDiagnosticWithFileRegex.Matches(text))
+        {
+            var filePath = NormalizePath(match.Groups["file"].Value);
+            int? lineNumber = int.TryParse(match.Groups["line"].Value, out var parsedLine) ? parsedLine : null;
+            var code = match.Groups["code"].Value.Trim();
+            var message = CollapseWhitespace(match.Groups["message"].Value);
+            diagnostics.Add(new CodeDiagnostic(toolName, filePath, lineNumber, code, message));
+            if (diagnostics.Count >= 3)
+                return DistinctDiagnostics(diagnostics);
+        }
+
+        foreach (Match match in BuildDiagnosticRegex.Matches(text))
+        {
+            var code = match.Groups["code"].Value.Trim();
+            var message = CollapseWhitespace(match.Groups["message"].Value);
+            diagnostics.Add(new CodeDiagnostic(toolName, "", null, code, message));
+            if (diagnostics.Count >= 3)
+                break;
+        }
+
+        return DistinctDiagnostics(diagnostics);
+    }
+
+    private static List<CodeDiagnostic> DistinctDiagnostics(IEnumerable<CodeDiagnostic> diagnostics)
+        => diagnostics
+            .GroupBy(diagnostic => diagnostic.CacheKey, StringComparer.OrdinalIgnoreCase)
+            .Select(group => group.First())
+            .Take(3)
+            .ToList();
+
+    private IEnumerable<string> ExtractPathCandidates(JsonElement? toolInput)
+    {
+        if (toolInput is not { ValueKind: JsonValueKind.Object } input)
+            yield break;
+
+        foreach (var property in input.EnumerateObject())
+        {
+            var propertyName = property.Name;
+            if (property.Value.ValueKind == JsonValueKind.String)
+            {
+                var text = property.Value.GetString() ?? "";
+                if (LooksLikePathProperty(propertyName, text))
+                    yield return text;
+            }
+            else if (property.Value.ValueKind == JsonValueKind.Array)
+            {
+                foreach (var item in property.Value.EnumerateArray())
+                {
+                    if (item.ValueKind != JsonValueKind.String)
+                        continue;
+
+                    var text = item.GetString() ?? "";
+                    if (LooksLikePathProperty(propertyName, text))
+                        yield return text;
+                }
+            }
+        }
+    }
+
+    private static bool LooksLikePathProperty(string propertyName, string value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            return false;
+
+        var loweredName = propertyName.Trim().ToLowerInvariant();
+        if (loweredName.Contains("path", StringComparison.Ordinal)
+            || loweredName.Contains("file", StringComparison.Ordinal)
+            || loweredName.Contains("dir", StringComparison.Ordinal)
+            || loweredName.Contains("folder", StringComparison.Ordinal)
+            || loweredName.Contains("target", StringComparison.Ordinal)
+            || loweredName.Contains("source", StringComparison.Ordinal)
+            || loweredName.Contains("destination", StringComparison.Ordinal))
+        {
+            return true;
+        }
+
+        return value.Contains('\\', StringComparison.Ordinal)
+               || value.Contains('/', StringComparison.Ordinal)
+               || value.Contains('.', StringComparison.Ordinal);
+    }
+
+    private string NormalizePath(string rawPath)
+    {
+        if (string.IsNullOrWhiteSpace(rawPath))
+            return rawPath.Trim();
+
+        var trimmed = rawPath.Trim().Trim('"');
+        try
+        {
+            var candidate = trimmed;
+            if (!Path.IsPathRooted(candidate) && !string.IsNullOrWhiteSpace(_workFolder))
+                candidate = Path.Combine(_workFolder, candidate);
+
+            var normalized = Path.GetFullPath(candidate);
+            if (!string.IsNullOrWhiteSpace(_workFolder))
+            {
+                var root = Path.GetFullPath(_workFolder)
+                    .TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
+                if (normalized.StartsWith(root, StringComparison.OrdinalIgnoreCase))
+                {
+                    var relative = Path.GetRelativePath(root, normalized);
+                    return relative.Replace('\\', '/');
+                }
+            }
+
+            return normalized.Replace('\\', '/');
+        }
+        catch
+        {
+            return trimmed.Replace('\\', '/');
+        }
+    }
+
+    private static bool LooksLikeDirectory(string value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            return false;
+
+        var trimmed = value.Trim().Trim('"').Replace('\\', '/');
+        if (trimmed.EndsWith("/", StringComparison.Ordinal))
+            return true;
+
+        var fileName = Path.GetFileName(trimmed);
+        return !fileName.Contains('.', StringComparison.Ordinal);
+    }
+
+    private static bool LooksLikeFile(string value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            return false;
+
+        var trimmed = value.Trim().Trim('"');
+        var fileName = Path.GetFileName(trimmed);
+        return fileName.Contains('.', StringComparison.Ordinal);
+    }
+
+    private static bool IsMutatingCodeTool(string toolName)
+        => toolName.Contains("file_write", StringComparison.OrdinalIgnoreCase)
+           || toolName.Contains("file_edit", StringComparison.OrdinalIgnoreCase)
+           || toolName.Contains("multi_edit", StringComparison.OrdinalIgnoreCase)
+           || toolName.Contains("apply_patch", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "file_manage", StringComparison.OrdinalIgnoreCase);
+
+    private static bool IsReadOnlyContextTool(string toolName)
+        => string.Equals(toolName, "file_read", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "multi_read", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "grep", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "glob", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "folder_map", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "lsp_code_intel", StringComparison.OrdinalIgnoreCase);
+
+    private static bool IsVerificationTool(string toolName)
+        => string.Equals(toolName, "build_run", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "test_loop", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "process", StringComparison.OrdinalIgnoreCase)
+           || string.Equals(toolName, "shell", StringComparison.OrdinalIgnoreCase);
+
+    private static string? TryGetString(JsonElement? input, params string[] propertyNames)
+    {
+        if (input is not { ValueKind: JsonValueKind.Object } obj)
+            return null;
+
+        foreach (var name in propertyNames)
+        {
+            if (obj.TryGetProperty(name, out var value) && value.ValueKind == JsonValueKind.String)
+                return value.GetString();
+        }
+
+        return null;
+    }
+
+    private static void AddRecentUnique(List<string> list, string value, int maxCount)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            return;
+
+        var existingIndex = list.FindIndex(item => string.Equals(item, value, StringComparison.OrdinalIgnoreCase));
+        if (existingIndex >= 0)
+            list.RemoveAt(existingIndex);
+
+        list.Add(value);
+        if (list.Count > maxCount)
+            list.RemoveRange(0, list.Count - maxCount);
+    }
+
+    private static string CollapseWhitespace(string? value)
+        => Regex.Replace(value ?? "", @"\s+", " ").Trim();
+
+    private static string TruncateSingleLine(string? value, int maxLength)
+    {
+        var collapsed = CollapseWhitespace(value);
+        if (collapsed.Length <= maxLength)
+            return collapsed;
+
+        return collapsed[..maxLength].TrimEnd() + "...";
+    }
+
+    private sealed record CodeDiagnostic(
+        string ToolName,
+        string FilePath,
+        int? LineNumber,
+        string Code,
+        string Message)
+    {
+        public string CacheKey => $"{ToolName}|{FilePath}|{LineNumber}|{Code}|{Message}";
+
+        public string ToSummary()
+        {
+            var parts = new List<string>();
+            if (!string.IsNullOrWhiteSpace(Code))
+                parts.Add(Code);
+            if (!string.IsNullOrWhiteSpace(FilePath))
+                parts.Add(FilePath);
+            if (LineNumber is > 0)
+                parts.Add($"line {LineNumber.Value}");
+            parts.Add(TruncateSingleLine(Message, 140));
+            return string.Join(" - ", parts.Where(part => !string.IsNullOrWhiteSpace(part)));
+        }
+    }
+}
--- a/src/AxCopilot/Services/LlmService.ToolUse.cs
+++ b/src/AxCopilot/Services/LlmService.ToolUse.cs
@@ -906,11 +906,13 @@ public partial class LlmService
            });
        }

-        // ── tool_calls ↔ tool 메시지 쌍 검증 ──
-        // 컨텍스트 압축 후 tool_calls assistant 메시지는 남아있는데
-        // 대응하는 tool result 메시지가 누락되면 vLLM이 400 에러를 반환함.
-        // 깨진 tool_calls 메시지를 일반 assistant 텍스트로 평탄화하여 방지.
-        SanitizeToolCallPairs(msgs);
+        // Validate historical tool-call chains before sending the request.
+        var sanitization = SanitizeToolCallPairs(msgs);
+        if (sanitization.TotalRepairedCount > 0)
+        {
+            LogService.Info(
+                $"[ToolUse] normalized historical tool trace (flattened_assistant={sanitization.FlattenedAssistantCount}, converted_orphans={sanitization.ConvertedOrphanToolCount})");
+        }

        // OpenAI 도구 정의
        var toolDefs = tools.Select(t =>
@@ -1964,15 +1966,20 @@ public partial class LlmService

    // ─── 공통 헬퍼 ─────────────────────────────────────────────────────

-    /// <summary>
-    /// tool_calls가 포함된 assistant 메시지 뒤에 대응하는 tool 메시지가 없으면
-    /// 해당 assistant 메시지를 일반 텍스트로 평탄화합니다.
-    /// 컨텍스트 압축 후 쌍이 깨지는 경우를 방어합니다.
-    /// </summary>
-    private static void SanitizeToolCallPairs(List<object> msgs)
+    private sealed record ToolCallPairSanitizationResult(
+        int FlattenedAssistantCount,
+        int ConvertedOrphanToolCount)
    {
-        // ── 1패스: tool_calls assistant 메시지의 쌍 검증 ──
-        // tool_calls가 있는 assistant 인덱스를 기록하여 2패스에서 고아 tool 판별에 사용
+        public int TotalRepairedCount => FlattenedAssistantCount + ConvertedOrphanToolCount;
+    }
+
+    /// <summary>
+    /// Repairs broken historical tool_call/tool pairs before the request leaves the client.
+    /// </summary>
+    private static ToolCallPairSanitizationResult SanitizeToolCallPairs(List<object> msgs)
+    {
+        var flattenedAssistantCount = 0;
+        var convertedOrphanToolCount = 0;
        var pairedToolIndices = new HashSet<int>();

        for (int i = 0; i < msgs.Count; i++)
@@ -2029,13 +2036,14 @@ public partial class LlmService
                    var jContent = jType.GetProperty("content")?.GetValue(msgs[j]) as string ?? "";
                    msgs[j] = new { role = "user", content = $"[이전 도구 결과]\n{jContent}" };
                    pairedToolIndices.Remove(j);
+                    convertedOrphanToolCount++;
                }

+                flattenedAssistantCount++;
                LogService.Info($"[ToolUse] tool_calls/tool 쌍 불일치 감지 — assistant 메시지를 평탄화 (index={i})");
            }
        }

-        // ── 2패스: 앞에 tool_calls가 없는 고아 tool 메시지를 user로 변환 ──
        for (int i = 0; i < msgs.Count; i++)
        {
            if (pairedToolIndices.Contains(i)) continue;
@@ -2047,8 +2055,11 @@ public partial class LlmService

            var content = msgType.GetProperty("content")?.GetValue(msgs[i]) as string ?? "";
            msgs[i] = new { role = "user", content = $"[이전 도구 결과]\n{content}" };
+            convertedOrphanToolCount++;
            LogService.Info($"[ToolUse] 고아 tool 메시지 감지 — user로 변환 (index={i})");
        }
+
+        return new ToolCallPairSanitizationResult(flattenedAssistantCount, convertedOrphanToolCount);
    }

    /// <summary>ToolProperty를 LLM API용 스키마 객체로 변환. array/enum/items 포함.</summary>
--- a/src/AxCopilot/Views/ChatWindow.UtilityPresentation.cs
+++ b/src/AxCopilot/Views/ChatWindow.UtilityPresentation.cs
@@ -22,7 +22,7 @@ public partial class ChatWindow
    // ─── 프로젝트 문맥 파일 (AGENTS.md) ──────────────────────────────────

    /// <summary>
-    /// P4: 워크스페이스 컨텍스트 자동 생성 파일(.ax-context.md)을 읽어 시스템 프롬프트에 주입합니다.
+    /// Loads the workspace context file and kicks off bootstrap generation on first use.
    /// </summary>
    private static string LoadWorkspaceContext(string? workFolder)
    {
@@ -32,13 +32,32 @@ public partial class ChatWindow
        if (!(app?.SettingsService?.Settings.Llm.EnableAutoWorkspaceContext ?? true))
            return "";

+        var ensureTask = Services.Agent.WorkspaceContextGenerator.EnsureContextAsync(workFolder);
        var content = Services.Agent.WorkspaceContextGenerator.LoadContext(workFolder);
-        if (string.IsNullOrEmpty(content)) return "";
+        if (string.IsNullOrEmpty(content))
+        {
+            try
+            {
+                if (ensureTask.Wait(TimeSpan.FromMilliseconds(180)))
+                    content = ensureTask.Result;
+            }
+            catch
+            {
+                // Keep the prompt builder non-blocking when background generation fails.
+            }
+        }

-        // 비동기 자동 생성 트리거 (파일이 아직 없을 때)
-        _ = Task.Run(() => Services.Agent.WorkspaceContextGenerator.EnsureContextAsync(workFolder));
+        if (!string.IsNullOrEmpty(content))
+            return $"\n## Workspace Context (auto-detected)\n{content}\n";

-        return $"\n## Workspace Context (auto-detected)\n{content}\n";
+        var workflowHints = Services.Agent.WorkspaceContextGenerator.DetectLanguageWorkflowHints(workFolder);
+        if (workflowHints.Count == 0)
+            return "";
+
+        var hintLines = string.Join("\n", workflowHints.Select(hint => $"- {hint}"));
+        return "\n## Workspace Context (bootstrap)\n- Background workspace context generation started.\n" +
+               hintLines +
+               "\n";
    }

    /// <summary>