Integration-Automation · JE-Chen · Jun 21, 2026 · Jun 21, 2026
diff --git a/README.md b/README.md
@@ -13,6 +13,7 @@
 
 ## Table of Contents
 
+- [What's new (2026-06-21) — Text Diff, Patch & Three-Way Merge](#whats-new-2026-06-21--text-diff-patch--three-way-merge)
 - [What's new (2026-06-21) — Calendar Recurrence Rules (RRULE)](#whats-new-2026-06-21--calendar-recurrence-rules-rrule)
 - [What's new (2026-06-21) — Statistics & A/B Significance](#whats-new-2026-06-21--statistics--ab-significance)
 - [What's new (2026-06-21) — Full-Text Search (BM25)](#whats-new-2026-06-21--full-text-search-bm25)
@@ -119,6 +120,12 @@
 
 ---
 
+## What's new (2026-06-21) — Text Diff, Patch & Three-Way Merge
+
+Apply and merge text diffs. Full reference: [`docs/source/Eng/doc/new_features/v67_features_doc.rst`](docs/source/Eng/doc/new_features/v67_features_doc.rst).
+
+- **`unified_diff` / `apply_unified` / `three_way_merge`** (`AC_unified_diff`, `AC_apply_unified`, `AC_three_way_merge`): `difflib` *generates* a unified diff but the stdlib can't *apply* one, and there was no three-way merge. This adds the missing applier (walks `@@` hunks, verifies context, raises on mismatch) and a line-based three-way merge (non-overlapping edits combine cleanly; overlapping ones emit `<<<<<<<` conflict markers). Complements `json_patch` (structured JSON); pure-stdlib `difflib`.
+
 ## What's new (2026-06-21) — Calendar Recurrence Rules (RRULE)
 
 Schedule "every 2nd Tuesday". Full reference: [`docs/source/Eng/doc/new_features/v66_features_doc.rst`](docs/source/Eng/doc/new_features/v66_features_doc.rst).

diff --git a/README/README_zh-CN.md b/README/README_zh-CN.md
@@ -12,6 +12,7 @@
 
 ## 目录
 
+- [本次更新 (2026-06-21) — 文本 Diff、应用与三方合并](#本次更新-2026-06-21--文本-diff应用与三方合并)
 - [本次更新 (2026-06-21) — 日历周期规则(RRULE)](#本次更新-2026-06-21--日历周期规则rrule)
 - [本次更新 (2026-06-21) — 统计与 A/B 显著性](#本次更新-2026-06-21--统计与-ab-显著性)
 - [本次更新 (2026-06-21) — 全文搜索(BM25)](#本次更新-2026-06-21--全文搜索bm25)
@@ -118,6 +119,12 @@
 
 ---
 
+## 本次更新 (2026-06-21) — 文本 Diff、应用与三方合并
+
+应用并合并文本 diff。完整参考:[`docs/source/Zh/doc/new_features/v67_features_doc.rst`](../docs/source/Zh/doc/new_features/v67_features_doc.rst)。
+
+- **`unified_diff` / `apply_unified` / `three_way_merge`**(`AC_unified_diff`、`AC_apply_unified`、`AC_three_way_merge`):`difflib` 会*生成* unified diff,但标准库无法*应用*,也没有三方合并。本功能补上缺少的应用器(走访 `@@` 块、验证 context、不符即抛出)与以行为单位的三方合并(不重叠编辑干净合并;重叠则产生 `<<<<<<<` 冲突标记)。与 `json_patch`(结构化 JSON)互补;纯标准库 `difflib`。
+
 ## 本次更新 (2026-06-21) — 日历周期规则(RRULE)
 
 排程「每月第 2 个星期二」。完整参考:[`docs/source/Zh/doc/new_features/v66_features_doc.rst`](../docs/source/Zh/doc/new_features/v66_features_doc.rst)。

diff --git a/README/README_zh-TW.md b/README/README_zh-TW.md
@@ -12,6 +12,7 @@
 
 ## 目錄
 
+- [本次更新 (2026-06-21) — 文字 Diff、套用與三方合併](#本次更新-2026-06-21--文字-diff套用與三方合併)
 - [本次更新 (2026-06-21) — 行事曆週期規則(RRULE)](#本次更新-2026-06-21--行事曆週期規則rrule)
 - [本次更新 (2026-06-21) — 統計與 A/B 顯著性](#本次更新-2026-06-21--統計與-ab-顯著性)
 - [本次更新 (2026-06-21) — 全文搜尋(BM25)](#本次更新-2026-06-21--全文搜尋bm25)
@@ -118,6 +119,12 @@
 
 ---
 
+## 本次更新 (2026-06-21) — 文字 Diff、套用與三方合併
+
+套用並合併文字 diff。完整參考:[`docs/source/Zh/doc/new_features/v67_features_doc.rst`](../docs/source/Zh/doc/new_features/v67_features_doc.rst)。
+
+- **`unified_diff` / `apply_unified` / `three_way_merge`**(`AC_unified_diff`、`AC_apply_unified`、`AC_three_way_merge`):`difflib` 會*產生* unified diff,但標準函式庫無法*套用*,也沒有三方合併。本功能補上缺少的套用器(走訪 `@@` 區塊、驗證 context、不符即拋出)與以行為單位的三方合併(不重疊編輯乾淨合併;重疊則產生 `<<<<<<<` 衝突標記)。與 `json_patch`(結構化 JSON)互補;純標準函式庫 `difflib`。
+
 ## 本次更新 (2026-06-21) — 行事曆週期規則(RRULE)
 
 排程「每月第 2 個星期二」。完整參考:[`docs/source/Zh/doc/new_features/v66_features_doc.rst`](../docs/source/Zh/doc/new_features/v66_features_doc.rst)。

diff --git a/docs/source/Eng/doc/new_features/v67_features_doc.rst b/docs/source/Eng/doc/new_features/v67_features_doc.rst
@@ -0,0 +1,42 @@
+Text Diff, Patch & Three-Way Merge
+==================================
+
+``difflib`` *generates* a unified diff but the standard library cannot *apply*
+one, and there was no three-way merge anywhere — so updating a ``.received``
+artifact, replaying a recorded text edit, or merging two edits of a base file
+had no headless primitive. This adds the missing pieces. It complements
+``utils/json_patch`` (structured JSON); this is line-based text.
+
+Pure standard library (``difflib`` + ``re``); imports no ``PySide6``.
+
+Headless API
+------------
+
+.. code-block:: python
+
+    from je_auto_control import unified_diff, apply_unified, three_way_merge
+
+    diff = unified_diff(original, edited)
+    restored = apply_unified(original, diff)        # == edited
+
+    merge = three_way_merge(base, ours, theirs)
+    if merge.clean:
+        save(merge.text)
+    else:
+        print(merge.conflicts, "conflict(s)")       # text has <<<<<<< markers
+
+``unified_diff`` wraps ``difflib``; ``apply_unified`` is the missing applier —
+it walks each ``@@`` hunk, verifies the context/removed lines match, and raises
+``PatchApplyError`` on mismatch. ``three_way_merge`` merges line-based:
+non-overlapping edits from each side combine cleanly; if both sides edit the
+same region (and differ), it emits a conflict block with
+``<<<<<<< / ======= / >>>>>>>`` markers and reports ``clean=False``. Trivial
+cases (one side unchanged, or identical edits) resolve automatically.
+
+Executor commands
+-----------------
+
+``AC_unified_diff`` (``{diff}``), ``AC_apply_unified`` (``{result}``) and
+``AC_three_way_merge`` (``{text, clean, conflicts}``). Each is also exposed as
+an MCP tool (``ac_unified_diff`` / ``ac_apply_unified`` / ``ac_three_way_merge``)
+and as a Script Builder command under **Data**.
diff --git a/docs/source/Eng/eng_index.rst b/docs/source/Eng/eng_index.rst
@@ -89,6 +89,7 @@ Comprehensive guides for all AutoControl features.
    doc/new_features/v64_features_doc
    doc/new_features/v65_features_doc
    doc/new_features/v66_features_doc
+   doc/new_features/v67_features_doc
    doc/ocr_backends/ocr_backends_doc
    doc/observability/observability_doc
    doc/operations_layer/operations_layer_doc

diff --git a/docs/source/Zh/doc/new_features/v67_features_doc.rst b/docs/source/Zh/doc/new_features/v67_features_doc.rst
@@ -0,0 +1,37 @@
+文字 Diff、套用與三方合併
+========================
+
+``difflib`` 會*產生* unified diff,但標準函式庫無法*套用*它,而且各處都沒有三方合併 —— 因此更新
+``.received`` 產物、重播錄製的文字編輯,或合併對同一基底檔案的兩份編輯,都缺少無頭原語。本功能補上
+缺少的部分,與 ``utils/json_patch``(結構化 JSON)互補;這裡處理以行為單位的文字。
+
+純標準函式庫(``difflib`` + ``re``);不匯入 ``PySide6``。
+
+無頭 API
+--------
+
+.. code-block:: python
+
+    from je_auto_control import unified_diff, apply_unified, three_way_merge
+
+    diff = unified_diff(original, edited)
+    restored = apply_unified(original, diff)        # == edited
+
+    merge = three_way_merge(base, ours, theirs)
+    if merge.clean:
+        save(merge.text)
+    else:
+        print(merge.conflicts, "個衝突")             # text 含 <<<<<<< 標記
+
+``unified_diff`` 包裝 ``difflib``;``apply_unified`` 是缺少的套用器 —— 它逐一走訪每個 ``@@``
+區塊,驗證 context/移除行是否相符,不符時拋出 ``PatchApplyError``。``three_way_merge`` 以行為單位
+合併:兩側不重疊的編輯會乾淨合併;若兩側編輯同一區域(且不同),則產生帶有
+``<<<<<<< / ======= / >>>>>>>`` 標記的衝突區塊並回報 ``clean=False``。瑣碎情況(一側未變動,或兩側
+相同編輯)會自動解決。
+
+執行器命令
+----------
+
+``AC_unified_diff``(``{diff}``)、``AC_apply_unified``(``{result}``)與
+``AC_three_way_merge``(``{text, clean, conflicts}``)。每個亦以 MCP 工具(``ac_unified_diff`` /
+``ac_apply_unified`` / ``ac_three_way_merge``)以及 Script Builder 中 **Data** 分類下的命令提供。
diff --git a/docs/source/Zh/zh_index.rst b/docs/source/Zh/zh_index.rst
@@ -89,6 +89,7 @@ AutoControl 所有功能的完整使用指南。
    doc/new_features/v64_features_doc
    doc/new_features/v65_features_doc
    doc/new_features/v66_features_doc
+   doc/new_features/v67_features_doc
    doc/ocr_backends/ocr_backends_doc
    doc/observability/observability_doc
    doc/operations_layer/operations_layer_doc

diff --git a/je_auto_control/__init__.py b/je_auto_control/__init__.py
@@ -342,6 +342,10 @@
 from je_auto_control.utils.recurrence import (
     Recurrence, next_occurrence, occurrences, parse_rrule,
 )
+# Unified-diff generate/apply + three-way text merge
+from je_auto_control.utils.text_diff import (
+    MergeResult, PatchApplyError, apply_unified, three_way_merge, unified_diff,
+)
 # Background popup/interrupt watchdog (unattended automation)
 from je_auto_control.utils.watchdog import (
     PopupWatchdog, WatchdogRule, default_popup_watchdog,
@@ -828,6 +832,8 @@ def start_autocontrol_gui(*args, **kwargs):
     "chi_square_2x2", "cohens_d", "describe", "normal_cdf", "percentile",
     "two_proportion_z_test", "welch_t_test",
     "Recurrence", "next_occurrence", "occurrences", "parse_rrule",
+    "MergeResult", "PatchApplyError", "apply_unified", "three_way_merge",
+    "unified_diff",
     # MCP server
     "AuditLogger", "HttpMCPServer", "MCPContent", "MCPPrompt",
     "MCPPromptArgument", "MCPResource", "MCPServer", "MCPTool",

diff --git a/je_auto_control/gui/script_builder/command_schema.py b/je_auto_control/gui/script_builder/command_schema.py
@@ -1155,6 +1155,31 @@ def _add_misc_specs(specs: List[CommandSpec]) -> None:
         ),
         description="Validate JSON against a JSON Schema; returns {ok, errors}.",
     ))
+    specs.append(CommandSpec(
+        "AC_unified_diff", "Data", "Text: Unified Diff",
+        fields=(
+            FieldSpec("a", FieldType.STRING, placeholder="original text"),
+            FieldSpec("b", FieldType.STRING, placeholder="changed text"),
+        ),
+        description="Unified diff transforming a into b; returns {diff}.",
+    ))
+    specs.append(CommandSpec(
+        "AC_apply_unified", "Data", "Text: Apply Diff",
+        fields=(
+            FieldSpec("text", FieldType.STRING, placeholder="original text"),
+            FieldSpec("diff", FieldType.STRING, placeholder="@@ -1 +1 @@ ..."),
+        ),
+        description="Apply a unified diff to text; returns {result}.",
+    ))
+    specs.append(CommandSpec(
+        "AC_three_way_merge", "Data", "Text: Three-Way Merge",
+        fields=(
+            FieldSpec("base", FieldType.STRING, placeholder="base text"),
+            FieldSpec("ours", FieldType.STRING, placeholder="our text"),
+            FieldSpec("theirs", FieldType.STRING, placeholder="their text"),
+        ),
+        description="Merge ours/theirs against base; returns {text, clean, conflicts}.",
+    ))
     specs.append(CommandSpec(
         "AC_rrule_occurrences", "Flow", "Recurrence: Expand (RRULE)",
         fields=(

diff --git a/je_auto_control/utils/executor/action_executor.py b/je_auto_control/utils/executor/action_executor.py
@@ -2928,6 +2928,26 @@ def _rate_limit(name: str, rate: float = 1.0, capacity: float = 1.0,
             "wait": round(bucket.time_until_available(float(n)), 4)}
 
 
+def _unified_diff(a: str, b: str) -> Dict[str, Any]:
+    """Adapter: unified diff transforming text a into b."""
+    from je_auto_control.utils.text_diff import unified_diff
+    return {"diff": unified_diff(a, b)}
+
+
+def _apply_unified(text: str, diff: str) -> Dict[str, Any]:
+    """Adapter: apply a unified diff to text."""
+    from je_auto_control.utils.text_diff import apply_unified
+    return {"result": apply_unified(text, diff)}
+
+
+def _three_way_merge(base: str, ours: str, theirs: str) -> Dict[str, Any]:
+    """Adapter: three-way merge ours/theirs against base."""
+    from je_auto_control.utils.text_diff import three_way_merge
+    outcome = three_way_merge(base, ours, theirs)
+    return {"text": outcome.text, "clean": outcome.clean,
+            "conflicts": outcome.conflicts}
+
+
 def _rrule_occurrences(rule: str, dtstart: str,
                        count: int = 10) -> Dict[str, Any]:
     """Adapter: expand an RRULE from an ISO dtstart into ISO datetimes."""
@@ -3834,6 +3854,9 @@ def __init__(self):
             "AC_ab_significance": _ab_significance,
             "AC_rrule_occurrences": _rrule_occurrences,
             "AC_rrule_next": _rrule_next,
+            "AC_unified_diff": _unified_diff,
+            "AC_apply_unified": _apply_unified,
+            "AC_three_way_merge": _three_way_merge,
             "AC_resolve_pointer": _resolve_pointer,
             "AC_apply_json_patch": _apply_json_patch,
             "AC_make_json_patch": _make_json_patch,

diff --git a/je_auto_control/utils/mcp_server/tools/_factories.py b/je_auto_control/utils/mcp_server/tools/_factories.py
@@ -3343,6 +3343,40 @@ def rate_limit_tools() -> List[MCPTool]:
     ]
 
 
+def text_diff_tools() -> List[MCPTool]:
+    return [
+        MCPTool(
+            name="ac_unified_diff",
+            description="Unified diff transforming text 'a' into 'b'. "
+                        "Returns {diff}.",
+            input_schema=schema(
+                {"a": {"type": "string"}, "b": {"type": "string"}}, ["a", "b"]),
+            handler=h.unified_diff,
+            annotations=READ_ONLY,
+        ),
+        MCPTool(
+            name="ac_apply_unified",
+            description="Apply a unified 'diff' to 'text' (raises on context "
+                        "mismatch). Returns {result}.",
+            input_schema=schema(
+                {"text": {"type": "string"}, "diff": {"type": "string"}},
+                ["text", "diff"]),
+            handler=h.apply_unified,
+            annotations=READ_ONLY,
+        ),
+        MCPTool(
+            name="ac_three_way_merge",
+            description="Three-way merge 'ours' and 'theirs' against 'base' "
+                        "(line-based). Returns {text, clean, conflicts}.",
+            input_schema=schema(
+                {"base": {"type": "string"}, "ours": {"type": "string"},
+                 "theirs": {"type": "string"}}, ["base", "ours", "theirs"]),
+            handler=h.three_way_merge,
+            annotations=READ_ONLY,
+        ),
+    ]
+
+
 def recurrence_tools() -> List[MCPTool]:
     return [
         MCPTool(
@@ -4656,7 +4690,7 @@ def media_assert_tools() -> List[MCPTool]:
     process_mining_tools, asset_tools, events_tools, notify_channel_tools,
     jsonpath_tools, json_schema_tools, vuln_scan_tools, vex_tools,
     license_policy_tools, jwt_tools, rate_limit_tools, json_patch_tools,
-    search_index_tools, stats_tools, recurrence_tools,
+    search_index_tools, stats_tools, recurrence_tools, text_diff_tools,
     saga_tools, decision_table_tools, locator_repair_tools,
     pii_text_tools, sarif_tools,
     screen_record_tools,

diff --git a/je_auto_control/utils/mcp_server/tools/_handlers.py b/je_auto_control/utils/mcp_server/tools/_handlers.py
@@ -1664,6 +1664,23 @@ def rrule_next(rule, dtstart, now=None):
     return {"next": moment.isoformat() if moment else None}
 
 
+def unified_diff(a, b):
+    from je_auto_control.utils.text_diff import unified_diff as _diff
+    return {"diff": _diff(a, b)}
+
+
+def apply_unified(text, diff):
+    from je_auto_control.utils.text_diff import apply_unified as _apply
+    return {"result": _apply(text, diff)}
+
+
+def three_way_merge(base, ours, theirs):
+    from je_auto_control.utils.text_diff import three_way_merge as _merge
+    outcome = _merge(base, ours, theirs)
+    return {"text": outcome.text, "clean": outcome.clean,
+            "conflicts": outcome.conflicts}
+
+
 def run_saga(steps):
     from je_auto_control.utils.saga import run_saga as _run
     result = _run(steps)

diff --git a/je_auto_control/utils/text_diff/__init__.py b/je_auto_control/utils/text_diff/__init__.py
@@ -0,0 +1,9 @@
+"""Unified-diff generation, application and three-way text merge."""
+from je_auto_control.utils.text_diff.text_diff import (
+    MergeResult, PatchApplyError, apply_unified, three_way_merge, unified_diff,
+)
+
+__all__ = [
+    "MergeResult", "PatchApplyError", "apply_unified", "three_way_merge",
+    "unified_diff",
+]