Simplify task graph to single-source blockedBy (PR #127)

Remove unused blocks field and add_blocks parameter. The LLM never
used add_blocks in practice, making it dead code that taught a
misleading bidirectional pattern. Replace with remove_blocked_by
for dependency rewiring. Single-source-of-truth with blockedBy only.

agents/s07_task_system.py

@@ -4,12 +4,12 @@
 s07_task_system.py - Tasks
 
 Tasks persist as JSON files in .tasks/ so they survive context compression.
-Each task has a dependency graph (blockedBy/blocks).
+Each task has a dependency graph (blockedBy).
 
     .tasks/
       task_1.json  {"id":1, "subject":"...", "status":"completed", ...}
       task_2.json  {"id":2, "blockedBy":[1], "status":"pending", ...}
-      task_3.json  {"id":3, "blockedBy":[2], "blocks":[], ...}
+      task_3.json  {"id":3, "blockedBy":[2], ...}
 
     Dependency resolution:
     +----------+     +----------+     +----------+
@@ -67,7 +67,7 @@ class TaskManager:
     def create(self, subject: str, description: str = "") -> str:
         task = {
             "id": self._next_id, "subject": subject, "description": description,
-            "status": "pending", "blockedBy": [], "blocks": [], "owner": "",
+            "status": "pending", "blockedBy": [], "owner": "",
         }
         self._save(task)
         self._next_id += 1
@@ -77,37 +77,18 @@ class TaskManager:
         return json.dumps(self._load(task_id), indent=2, ensure_ascii=False)
 
     def update(self, task_id: int, status: str = None,
-               add_blocked_by: list = None, add_blocks: list = None) -> str:
+               add_blocked_by: list = None, remove_blocked_by: list = None) -> str:
         task = self._load(task_id)
         if status:
             if status not in ("pending", "in_progress", "completed"):
                 raise ValueError(f"Invalid status: {status}")
             task["status"] = status
-            # When a task is completed, remove it from all other tasks' blockedBy
             if status == "completed":
                 self._clear_dependency(task_id)
         if add_blocked_by:
             task["blockedBy"] = list(set(task["blockedBy"] + add_blocked_by))
-            # Bidirectional: also update the blocker tasks' blocks lists
+        if remove_blocked_by:
-            for blocker_id in add_blocked_by:
+            task["blockedBy"] = [x for x in task["blockedBy"] if x not in remove_blocked_by]
-                try:
-                    blocker = self._load(blocker_id)
-                    if task_id not in blocker["blocks"]:
-                        blocker["blocks"].append(task_id)
-                        self._save(blocker)
-                except ValueError:
-                    pass
-        if add_blocks:
-            task["blocks"] = list(set(task["blocks"] + add_blocks))
-            # Bidirectional: also update the blocked tasks' blockedBy lists
-            for blocked_id in add_blocks:
-                try:
-                    blocked = self._load(blocked_id)
-                    if task_id not in blocked["blockedBy"]:
-                        blocked["blockedBy"].append(task_id)
-                        self._save(blocked)
-                except ValueError:
-                    pass
         self._save(task)
         return json.dumps(task, indent=2, ensure_ascii=False)
 
@@ -195,7 +176,7 @@ TOOL_HANDLERS = {
     "write_file":  lambda **kw: run_write(kw["path"], kw["content"]),
     "edit_file":   lambda **kw: run_edit(kw["path"], kw["old_text"], kw["new_text"]),
     "task_create": lambda **kw: TASKS.create(kw["subject"], kw.get("description", "")),
-    "task_update": lambda **kw: TASKS.update(kw["task_id"], kw.get("status"), kw.get("addBlockedBy"), kw.get("addBlocks")),
+    "task_update": lambda **kw: TASKS.update(kw["task_id"], kw.get("status"), kw.get("addBlockedBy"), kw.get("removeBlockedBy")),
     "task_list":   lambda **kw: TASKS.list_all(),
     "task_get":    lambda **kw: TASKS.get(kw["task_id"]),
 }
@@ -212,7 +193,7 @@ TOOLS = [
     {"name": "task_create", "description": "Create a new task.",
      "input_schema": {"type": "object", "properties": {"subject": {"type": "string"}, "description": {"type": "string"}}, "required": ["subject"]}},
     {"name": "task_update", "description": "Update a task's status or dependencies.",
-     "input_schema": {"type": "object", "properties": {"task_id": {"type": "integer"}, "status": {"type": "string", "enum": ["pending", "in_progress", "completed"]}, "addBlockedBy": {"type": "array", "items": {"type": "integer"}}, "addBlocks": {"type": "array", "items": {"type": "integer"}}}, "required": ["task_id"]}},
+     "input_schema": {"type": "object", "properties": {"task_id": {"type": "integer"}, "status": {"type": "string", "enum": ["pending", "in_progress", "completed"]}, "addBlockedBy": {"type": "array", "items": {"type": "integer"}}, "removeBlockedBy": {"type": "array", "items": {"type": "integer"}}}, "required": ["task_id"]}},
     {"name": "task_list", "description": "List all tasks with status summary.",
      "input_schema": {"type": "object", "properties": {}}},
     {"name": "task_get", "description": "Get full details of a task by ID.",

agents/s_full.py

@@ -277,7 +277,7 @@ class TaskManager:
 
     def create(self, subject: str, description: str = "") -> str:
         task = {"id": self._next_id(), "subject": subject, "description": description,
-                "status": "pending", "owner": None, "blockedBy": [], "blocks": []}
+                "status": "pending", "owner": None, "blockedBy": []}
         self._save(task)
         return json.dumps(task, indent=2)
 
@@ -285,7 +285,7 @@ class TaskManager:
         return json.dumps(self._load(tid), indent=2)
 
     def update(self, tid: int, status: str = None,
-               add_blocked_by: list = None, add_blocks: list = None) -> str:
+               add_blocked_by: list = None, remove_blocked_by: list = None) -> str:
         task = self._load(tid)
         if status:
             task["status"] = status
@@ -300,8 +300,8 @@ class TaskManager:
                 return f"Task {tid} deleted"
         if add_blocked_by:
             task["blockedBy"] = list(set(task["blockedBy"] + add_blocked_by))
-        if add_blocks:
+        if remove_blocked_by:
-            task["blocks"] = list(set(task["blocks"] + add_blocks))
+            task["blockedBy"] = [x for x in task["blockedBy"] if x not in remove_blocked_by]
         self._save(task)
         return json.dumps(task, indent=2)
 
@@ -587,7 +587,7 @@ TOOL_HANDLERS = {
     "check_background": lambda **kw: BG.check(kw.get("task_id")),
     "task_create":      lambda **kw: TASK_MGR.create(kw["subject"], kw.get("description", "")),
     "task_get":         lambda **kw: TASK_MGR.get(kw["task_id"]),
-    "task_update":      lambda **kw: TASK_MGR.update(kw["task_id"], kw.get("status"), kw.get("add_blocked_by"), kw.get("add_blocks")),
+    "task_update":      lambda **kw: TASK_MGR.update(kw["task_id"], kw.get("status"), kw.get("add_blocked_by"), kw.get("remove_blocked_by")),
     "task_list":        lambda **kw: TASK_MGR.list_all(),
     "spawn_teammate":   lambda **kw: TEAM.spawn(kw["name"], kw["role"], kw["prompt"]),
     "list_teammates":   lambda **kw: TEAM.list_all(),
@@ -626,7 +626,7 @@ TOOLS = [
     {"name": "task_get", "description": "Get task details by ID.",
      "input_schema": {"type": "object", "properties": {"task_id": {"type": "integer"}}, "required": ["task_id"]}},
     {"name": "task_update", "description": "Update task status or dependencies.",
-     "input_schema": {"type": "object", "properties": {"task_id": {"type": "integer"}, "status": {"type": "string", "enum": ["pending", "in_progress", "completed", "deleted"]}, "add_blocked_by": {"type": "array", "items": {"type": "integer"}}, "add_blocks": {"type": "array", "items": {"type": "integer"}}}, "required": ["task_id"]}},
+     "input_schema": {"type": "object", "properties": {"task_id": {"type": "integer"}, "status": {"type": "string", "enum": ["pending", "in_progress", "completed", "deleted"]}, "add_blocked_by": {"type": "array", "items": {"type": "integer"}}, "remove_blocked_by": {"type": "array", "items": {"type": "integer"}}}, "required": ["task_id"]}},
     {"name": "task_list", "description": "List all tasks.",
      "input_schema": {"type": "object", "properties": {}}},
     {"name": "spawn_teammate", "description": "Spawn a persistent autonomous teammate.",

docs/en/s07-task-system.md

@@ -14,7 +14,7 @@ Without explicit relationships, the agent can't tell what's ready, what's blocke
 
 ## Solution
 
-Promote the checklist into a **task graph** persisted to disk. Each task is a JSON file with status, dependencies (`blockedBy`), and dependents (`blocks`). The graph answers three questions at any moment:
+Promote the checklist into a **task graph** persisted to disk. Each task is a JSON file with status, dependencies (`blockedBy`). The graph answers three questions at any moment:
 
 - **What's ready?** -- tasks with `pending` status and empty `blockedBy`.
 - **What's blocked?** -- tasks waiting on unfinished dependencies.
@@ -60,7 +60,7 @@ class TaskManager:
     def create(self, subject, description=""):
         task = {"id": self._next_id, "subject": subject,
                 "status": "pending", "blockedBy": [],
-                "blocks": [], "owner": ""}
+                "owner": ""}
         self._save(task)
         self._next_id += 1
         return json.dumps(task, indent=2)
@@ -81,12 +81,16 @@ def _clear_dependency(self, completed_id):
 
 ```python
 def update(self, task_id, status=None,
-           add_blocked_by=None, add_blocks=None):
+           add_blocked_by=None, remove_blocked_by=None):
     task = self._load(task_id)
     if status:
         task["status"] = status
         if status == "completed":
             self._clear_dependency(task_id)
+    if add_blocked_by:
+        task["blockedBy"] = list(set(task["blockedBy"] + add_blocked_by))
+    if remove_blocked_by:
+        task["blockedBy"] = [x for x in task["blockedBy"] if x not in remove_blocked_by]
     self._save(task)
 ```
 
@@ -110,7 +114,7 @@ From s07 onward, the task graph is the default for multi-step work. s03's Todo r
 |---|---|---|
 | Tools | 5 | 8 (`task_create/update/list/get`) |
 | Planning model | Flat checklist (in-memory) | Task graph with dependencies (on disk) |
-| Relationships | None | `blockedBy` + `blocks` edges |
+| Relationships | None | `blockedBy` edges |
 | Status tracking | Done or not | `pending` -> `in_progress` -> `completed` |
 | Persistence | Lost on compression | Survives compression and restarts |
 

docs/ja/s07-task-system.md

@@ -14,7 +14,7 @@ s03のTodoManagerはメモリ上のフラットなチェックリストに過ぎ
 
 ## 解決策
 
-フラットなチェックリストをディスクに永続化する**タスクグラフ**に昇格させる。各タスクは1つのJSONファイルで、ステータス・前方依存(`blockedBy`)・後方依存(`blocks`)を持つ。タスクグラフは常に3つの問いに答える:
+フラットなチェックリストをディスクに永続化する**タスクグラフ**に昇格させる。各タスクは1つのJSONファイルで、ステータス・前方依存(`blockedBy`)を持つ。タスクグラフは常に3つの問いに答える:
 
 - **何が実行可能か?** -- `pending`ステータスで`blockedBy`が空のタスク。
 - **何がブロックされているか?** -- 未完了の依存を待つタスク。
@@ -60,7 +60,7 @@ class TaskManager:
     def create(self, subject, description=""):
         task = {"id": self._next_id, "subject": subject,
                 "status": "pending", "blockedBy": [],
-                "blocks": [], "owner": ""}
+                "owner": ""}
         self._save(task)
         self._next_id += 1
         return json.dumps(task, indent=2)
@@ -81,12 +81,16 @@ def _clear_dependency(self, completed_id):
 
 ```python
 def update(self, task_id, status=None,
-           add_blocked_by=None, add_blocks=None):
+           add_blocked_by=None, remove_blocked_by=None):
     task = self._load(task_id)
     if status:
         task["status"] = status
         if status == "completed":
             self._clear_dependency(task_id)
+    if add_blocked_by:
+        task["blockedBy"] = list(set(task["blockedBy"] + add_blocked_by))
+    if remove_blocked_by:
+        task["blockedBy"] = [x for x in task["blockedBy"] if x not in remove_blocked_by]
     self._save(task)
 ```
 
@@ -110,7 +114,7 @@ s07以降、タスクグラフがマルチステップ作業のデフォルト
 |---|---|---|
 | Tools | 5 | 8 (`task_create/update/list/get`) |
 | 計画モデル | フラットチェックリスト (メモリ) | 依存関係付きタスクグラフ (ディスク) |
-| 関係 | なし | `blockedBy` + `blocks` エッジ |
+| 関係 | なし | `blockedBy` エッジ |
 | ステータス追跡 | 完了か未完了 | `pending` -> `in_progress` -> `completed` |
 | 永続性 | 圧縮で消失 | 圧縮・再起動後も存続 |
 

docs/zh/s07-task-system.md

@@ -14,7 +14,7 @@ s03 的 TodoManager 只是内存中的扁平清单: 没有顺序、没有依赖
 
 ## 解决方案
 
-把扁平清单升级为持久化到磁盘的**任务图**。每个任务是一个 JSON 文件, 有状态、前置依赖 (`blockedBy`) 和后置依赖 (`blocks`)。任务图随时回答三个问题:
+把扁平清单升级为持久化到磁盘的**任务图**。每个任务是一个 JSON 文件, 有状态、前置依赖 (`blockedBy`)。任务图随时回答三个问题:
 
 - **什么可以做?** -- 状态为 `pending` 且 `blockedBy` 为空的任务。
 - **什么被卡住?** -- 等待前置任务完成的任务。
@@ -60,7 +60,7 @@ class TaskManager:
     def create(self, subject, description=""):
         task = {"id": self._next_id, "subject": subject,
                 "status": "pending", "blockedBy": [],
-                "blocks": [], "owner": ""}
+                "owner": ""}
         self._save(task)
         self._next_id += 1
         return json.dumps(task, indent=2)
@@ -81,12 +81,16 @@ def _clear_dependency(self, completed_id):
 
 ```python
 def update(self, task_id, status=None,
-           add_blocked_by=None, add_blocks=None):
+           add_blocked_by=None, remove_blocked_by=None):
     task = self._load(task_id)
     if status:
         task["status"] = status
         if status == "completed":
             self._clear_dependency(task_id)
+    if add_blocked_by:
+        task["blockedBy"] = list(set(task["blockedBy"] + add_blocked_by))
+    if remove_blocked_by:
+        task["blockedBy"] = [x for x in task["blockedBy"] if x not in remove_blocked_by]
     self._save(task)
 ```
 
@@ -110,7 +114,7 @@ TOOL_HANDLERS = {
 |---|---|---|
 | Tools | 5 | 8 (`task_create/update/list/get`) |
 | 规划模型 | 扁平清单 (仅内存) | 带依赖关系的任务图 (磁盘) |
-| 关系 | 无 | `blockedBy` + `blocks` 边 |
+| 关系 | 无 | `blockedBy` 边 |
 | 状态追踪 | 做完没做完 | `pending` -> `in_progress` -> `completed` |
 | 持久化 | 压缩后丢失 | 压缩和重启后存活 |