feat(kanban): per-task model override on create

hermes_cli/kanban.py

@@ -76,6 +76,7 @@ def _task_to_dict(t: kb.Task) -> dict[str, Any]:
         "completed_at": t.completed_at,
         "result": t.result,
         "skills": list(t.skills) if t.skills else [],
+        "model_override": t.model_override,
         "max_retries": t.max_retries,
         "session_id": t.session_id,
         "workflow_template_id": t.workflow_template_id,
@@ -345,6 +346,16 @@ def build_parser(parent_subparsers: argparse._SubParsersAction) -> argparse.Argu
                                "(repeatable). The kanban lifecycle is already "
                                "injected automatically. Example: "
                                "--skill translation --skill github-code-review")
+    p_create.add_argument("--model", default=None, dest="model_override",
+                          metavar="MODEL",
+                          help="Per-task model override. When set, the "
+                               "dispatcher runs this task's worker with "
+                               "-m <MODEL>, overriding the assignee profile's "
+                               "configured model for this run only "
+                               "(e.g. --model claude-sonnet-5-0 to run a "
+                               "simple card on a cheaper model while the "
+                               "lane defaults to opus). Omit to use the "
+                               "profile's model.default.")
     p_create.add_argument("--max-retries", type=int, default=None,
                           metavar="N",
                           help="Per-task override for the consecutive-failure "
@@ -1363,6 +1374,7 @@ def _cmd_create(args: argparse.Namespace) -> int:
             goal_mode=bool(getattr(args, "goal_mode", False)),
             goal_max_turns=getattr(args, "goal_max_turns", None),
             initial_status=getattr(args, "initial_status", "running"),
+            model_override=getattr(args, "model_override", None),
         )
         task = kb.get_task(conn, task_id)
     if getattr(args, "json", False):

hermes_cli/kanban_db.py

@@ -2782,6 +2782,7 @@ def create_task(
     session_id: Optional[str] = None,
     board: Optional[str] = None,
     project_id: Optional[str] = None,
+    model_override: Optional[str] = None,
 ) -> str:
     """Create a new task and optionally link it under parent tasks.
 
@@ -3149,8 +3150,9 @@ def create_task(
                         created_by, created_at, workspace_kind, workspace_path,
                         branch_name, project_id, tenant, idempotency_key,
                         max_runtime_seconds,
-                        skills, max_retries, goal_mode, goal_max_turns, session_id
-                    ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+                        skills, max_retries, goal_mode, goal_max_turns, session_id,
+                        model_override
+                    ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
                     """,
                     (
                         task_id,
@@ -3173,6 +3175,7 @@ def create_task(
                         1 if goal_mode else 0,
                         int(goal_max_turns) if goal_max_turns is not None else None,
                         session_id,
+                        (model_override.strip() or None) if model_override else None,
                     ),
                 )
                 for pid in parents:

tests/hermes_cli/test_kanban_cli.py

@@ -250,6 +250,32 @@ def test_kanban_list_json_includes_session_id(kanban_home):
     )
 
 
+def test_kanban_json_includes_model_override(kanban_home):
+    """The per-task model override must be visible on every JSON surface
+    (`create`/`show`/`list --json`), not just plain-text `show`, so a
+    scripted consumer that sets `--model` can read back the value it wrote.
+    Omitting `--model` leaves the field null."""
+    created = json.loads(
+        kc.run_slash("create 'with model' --assignee alice --model m-x --json")
+    )
+    assert created["model_override"] == "m-x"
+    tid = created["id"]
+
+    shown = json.loads(kc.run_slash(f"show {tid} --json"))
+    assert shown["task"]["model_override"] == "m-x"
+
+    listed = json.loads(kc.run_slash("list --json"))
+    assert any(
+        row.get("id") == tid and row.get("model_override") == "m-x"
+        for row in listed
+    )
+
+    omitted = json.loads(
+        kc.run_slash("create 'no model' --assignee alice --json")
+    )
+    assert omitted["model_override"] is None
+
+
 def test_run_slash_usage_error_returns_message(kanban_home):
     # Missing required argument for create
     out = kc.run_slash("create")

tests/hermes_cli/test_kanban_db.py

@@ -244,6 +244,30 @@ def test_create_task_no_parents_is_ready(kanban_home):
     assert t.workspace_kind == "scratch"
 
 
+def test_create_task_persists_model_override(kanban_home):
+    """A per-task model override round-trips through create_task -> row.
+
+    The dispatcher spawns the worker with ``-m <model_override>`` when set,
+    so an override must survive the INSERT. Omitting it (or passing blank)
+    must leave the column NULL so the worker falls back to the profile model.
+    """
+    with kb.connect() as conn:
+        tid = kb.create_task(
+            conn, title="cheap card", assignee="alice",
+            model_override="claude-sonnet-5-0",
+        )
+        default_tid = kb.create_task(conn, title="normal card", assignee="alice")
+        blank_tid = kb.create_task(
+            conn, title="blank override", assignee="alice", model_override="  ",
+        )
+        overridden = kb.get_task(conn, tid)
+        defaulted = kb.get_task(conn, default_tid)
+        blanked = kb.get_task(conn, blank_tid)
+    assert overridden.model_override == "claude-sonnet-5-0"
+    assert defaulted.model_override is None
+    assert blanked.model_override is None
+
+
 def test_create_task_with_parent_is_todo_until_parent_done(kanban_home):
     with kb.connect() as conn:
         p = kb.create_task(conn, title="parent")

tools/kanban_tools.py

@@ -985,6 +985,7 @@ def _handle_create(args: dict, **kw) -> str:
                 created_by=os.environ.get("HERMES_PROFILE") or "worker",
                 session_id=session_id,
                 board=board,
+                model_override=args.get("model") or None,
             )
             new_task = kb.get_task(conn, new_tid)
             subscribed = _maybe_auto_subscribe(conn, new_tid)
@@ -1596,6 +1597,17 @@ def _board_schema_prop() -> dict[str, str]:
                     "true. Defaults to the goal-engine default (20)."
                 ),
             },
+            "model": {
+                "type": "string",
+                "description": (
+                    "Per-task model override. When set, the dispatcher runs "
+                    "this task's worker with this model, overriding the "
+                    "assignee profile's configured model for this run only "
+                    "(e.g. 'claude-sonnet-5-0' to run a simple card on a "
+                    "cheaper model while the lane defaults to a stronger "
+                    "one). Omit to use the profile's default model."
+                ),
+            },
             "board": _board_schema_prop(),
         },
         "required": ["title", "assignee"],