Live mode: open a saved project, switch between open projects

open_project opens a .qet and makes it current, as File > Open does but
with no file dialog and no error windows: a missing, unreadable or
foreign file is refused in the answer. A project already open is only
made current. switch_project makes another open project current, by its
index or its file. status now lists every open project (index, title,
file, folios, unsaved changes, current), so the assistant sees what it
can switch to. MCP: qet_live_open_project, qet_live_switch_project; both
paths go through the workspace policy.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

misc/qet-mcp/qet_mcp.py

@@ -4101,6 +4101,29 @@ def tool_live_new_project(title: str = "", folios: int = 1, path: str = "") -> d
     return _live_call(request)
 
 
+def tool_live_open_project(path: str) -> dict:
+    if not isinstance(path, str) or not path.strip():
+        raise ValueError("'path' must be the project's file, e.g. /home/me/projects/pump.qet")
+    p = Path(path).expanduser()
+    if not p.is_absolute():
+        raise ValueError("'path' must be absolute, e.g. /home/me/projects/pump.qet")
+    return _live_call({"cmd": "open_project", "path": str(p)})
+
+
+def tool_live_switch_project(index: int | None = None, path: str = "") -> dict:
+    if (index is None) == (not path):
+        raise ValueError("give exactly one of 'index' (from qet_live_status's "
+                         "\"projects\") or 'path'")
+    if index is not None:
+        if not isinstance(index, int) or isinstance(index, bool) or index < 0:
+            raise ValueError("'index' must be a whole number counted from 0")
+        return _live_call({"cmd": "switch_project", "index": index})
+    p = Path(path).expanduser()
+    if not p.is_absolute():
+        raise ValueError("'path' must be absolute")
+    return _live_call({"cmd": "switch_project", "path": str(p)})
+
+
 def tool_live_undo_last() -> dict:
     _require_script_consent()
     return _live_call({"cmd": "undo_last"})
@@ -5107,7 +5130,9 @@ TOOLS = [
         "name": "qet_live_status",
         "description": "LIVE MODE. Ask the QElectroTech the user has open what is on "
                        "screen: the project, the folio shown (index and title), the "
-                       "selected elements, the last undo step and the stored scripts. "
+                       "selected elements, the last undo step, the stored scripts, and "
+                       "\"projects\": every project open in the window (index, title, "
+                       "file, folios, unsaved changes, which is current). "
                        "Works only if the user switched live mode on in QElectroTech "
                        "and accepted its warning at this start; the error says which "
                        "step is missing. Changes nothing.",
@@ -5205,6 +5230,33 @@ TOOLS = [
         "handler": lambda a: tool_live_new_project(a.get("title", ""), a.get("folios", 1),
                                                    a.get("path", "")),
     },
+    {
+        "name": "qet_live_open_project",
+        "description": "LIVE MODE. Open a saved project (.qet, absolute path) in the "
+                       "QElectroTech the user has open and make it current, as File > "
+                       "Open does but with no dialog; errors come back as text. A "
+                       "project already open is only made current. Every following "
+                       "qet_live_* call works on it.",
+        "inputSchema": {
+            "type": "object",
+            "properties": {"path": {"type": "string", "description": "absolute .qet path"}},
+            "required": ["path"],
+        },
+        "handler": lambda a: tool_live_open_project(a["path"]),
+    },
+    {
+        "name": "qet_live_switch_project",
+        "description": "LIVE MODE. Make another project that is already open the "
+                       "current one, by its index in qet_live_status's \"projects\" or "
+                       "by its file path. Every following qet_live_* call works on it. "
+                       "Changes no project.",
+        "inputSchema": {
+            "type": "object",
+            "properties": {"index": {"type": "integer", "minimum": 0},
+                           "path": {"type": "string"}},
+        },
+        "handler": lambda a: tool_live_switch_project(a.get("index"), a.get("path", "")),
+    },
     {
         "name": "qet_live_undo_last",
         "description": "LIVE MODE. Undo the newest step in the open project, only if "
@@ -5342,6 +5394,8 @@ _DATA_PATHS = {
     # QElectroTech writes this file, but where is the client's choice:
     # held to the same workspace as every other file a tool writes.
     "qet_live_new_project": {"write": ("path",)},
+    "qet_live_open_project": {"read": ("path",)},
+    "qet_live_switch_project": {"read": ("path",)},
     "qet_element_build":  {"write": ("output",)},
     # The scripts folder is chosen by scripts_dir(), never by the client,
     # so only the project a script is tried on is a data path here.

misc/qet-mcp/test_qet_mcp.py

@@ -184,7 +184,8 @@ class ToolRegistry(unittest.TestCase):
         "qet_live_run_stored", "qet_live_command", "qet_live_show_folio",
         "qet_live_undo_last", "qet_live_screenshot", "qet_about",
         "qet_recording_list", "qet_recording_read", "qet_recording_check",
-        "qet_recording_remove", "qet_layout_check", "qet_live_new_project"})
+        "qet_recording_remove", "qet_layout_check", "qet_live_new_project",
+        "qet_live_open_project", "qet_live_switch_project"})
 
 
 class EditValidation(unittest.TestCase):
@@ -3562,6 +3563,25 @@ class LiveClient(unittest.TestCase):
             m.tool_live_new_project(path="pump.qet")
         self.assertEqual(len(self.seen), 2)
 
+    def test_open_and_switch_send_only_what_was_given(self):
+        self.session()
+        m.tool_live_open_project("/tmp/x/pump.qet")
+        m.tool_live_switch_project(1)
+        m.tool_live_switch_project(path="/tmp/x/pump.qet")
+        self.assertEqual([{k: v for k, v in r.items() if k not in ("token", "id")}
+                          for r in self.seen],
+                         [{"cmd": "open_project", "path": "/tmp/x/pump.qet"},
+                          {"cmd": "switch_project", "index": 1},
+                          {"cmd": "switch_project", "path": "/tmp/x/pump.qet"}])
+        for bad in ({}, {"index": 0, "path": "/a.qet"}, {"index": -1},
+                    {"index": True}, {"path": "rel.qet"}):
+            with self.assertRaises(ValueError):
+                m.tool_live_switch_project(**bad)
+        for bad in ("", "rel.qet"):
+            with self.assertRaises(ValueError):
+                m.tool_live_open_project(bad)
+        self.assertEqual(len(self.seen), 3)
+
     def test_new_project_needs_script_consent(self):
         self.session()
         with mock.patch.dict(os.environ, {"QET_ENABLE_SCRIPTING": ""}):