refactor(session): clarify reference boundaries

nanobot/agent/tools/sessions.py

@@ -33,19 +33,19 @@ def session_extra(metadata: Mapping[str, Any] | None) -> dict[str, Any]:
 
 def _session_scope() -> SessionAccessScope | None:
     ctx = current_request_context()
-    if ctx is None:
+    if ctx is None or not ctx.session_key:
         return None
-    session_key = ctx.session_key
+    prefix = ctx.metadata.get(INBOUND_META_SESSION_READ_SCOPE)
     if (
-        ctx.channel != "websocket"
-        or session_key is None
-        or not session_key.startswith("websocket:")
-        or ctx.metadata.get(INBOUND_META_SESSION_READ_SCOPE) is not True
+        not isinstance(prefix, str)
+        or not prefix.endswith(":")
+        or not ctx.session_key.startswith(prefix)
     ):
         return None
     workspace = current_workspace_scope()
     return SessionAccessScope(
-        current_session_key=session_key,
+        current_session_key=ctx.session_key,
+        session_key_prefix=prefix,
         project_path=workspace.project_path if workspace is not None else ctx.workspace,
         restrict_to_workspace=workspace.restrict_to_workspace if workspace is not None else False,
     )
@@ -131,20 +131,30 @@ class SearchSessionsTool(_SessionTool):
             return ToolResult.error("Error: session search is not available to this client")
         matches = await asyncio.to_thread(self._access.search, scope, query, _SEARCH_LIMIT)
         needle = query.casefold()
-        for match in matches:
-            match["session_ref"] = _session_ref(match["session_key"])
-            match["excerpts"] = [
+        result = {
+            "notice": _UNTRUSTED_NOTICE,
+            "query": query,
+            "results": [
                 {
-                    "message_index": message["message_index"],
-                    "role": message["role"],
-                    "content": _excerpt(message["content"], needle, _SEARCH_EXCERPT_CHARS),
+                    "session_key": match["session_key"],
+                    "session_ref": _session_ref(match["session_key"]),
+                    "title": match["title"],
+                    "updated_at": match["updated_at"],
+                    "excerpts": [
+                        {
+                            "message_index": message["message_index"],
+                            "role": message["role"],
+                            "content": _excerpt(
+                                message["content"], needle, _SEARCH_EXCERPT_CHARS
+                            ),
+                        }
+                        for message in match["messages"]
+                    ],
                 }
-                for message in match.pop("messages")
-            ]
-        return json.dumps(
-            {"notice": _UNTRUSTED_NOTICE, "query": query, "results": matches},
-            ensure_ascii=False,
-        )
+                for match in matches
+            ],
+        }
+        return json.dumps(result, ensure_ascii=False)
 
 
 @tool_parameters(
@@ -205,13 +215,16 @@ class ReadSessionTool(_SessionTool):
         if match is None:
             return ToolResult.error(f"Error: session not found: {session_key}")
         needle = query_text.casefold()
-        match.update({
+        result = {
             "notice": _UNTRUSTED_NOTICE,
+            "session_key": match["session_key"],
             "session_ref": _session_ref(session_key),
+            "title": match["title"],
+            "updated_at": match["updated_at"],
             "query": query_text or None,
             "messages": [
                 {**message, "content": _excerpt(message["content"], needle, _READ_MESSAGE_CHARS)}
                 for message in match["messages"]
             ],
-        })
-        return json.dumps(match, ensure_ascii=False)
+        }
+        return json.dumps(result, ensure_ascii=False)

nanobot/bus/events.py

@@ -15,7 +15,7 @@ OUTBOUND_META_AGENT_UI = "_agent_ui"
 # Internal-only inbound metadata used by in-process channels to ask the agent
 # loop to update runtime state without going through a user session.
 INBOUND_META_RUNTIME_CONTROL = "_runtime_control"
-# Trusted WebUI grant for read-only persisted-session tools.
+# Trusted namespace grant for read-only persisted-session tools.
 INBOUND_META_SESSION_READ_SCOPE = "_session_read_scope"
 RUNTIME_CONTROL_ACK = "_ack"
 RUNTIME_CONTROL_MCP_RELOAD = "mcp_reload"

nanobot/channels/websocket/runtime.py

@@ -814,7 +814,7 @@ class WebSocketChannel(BaseChannel):
                 metadata.update(self._transcripts.client_turn_metadata(envelope.get("turn_id")))
             trusted_webui = metadata.get("webui") is True and connection in self._webui_connections
             if trusted_webui:
-                metadata[INBOUND_META_SESSION_READ_SCOPE] = True
+                metadata[INBOUND_META_SESSION_READ_SCOPE] = f"{self.name}:"
             cli_apps = normalize_cli_app_mentions(envelope.get("cli_apps"))
             if cli_apps:
                 metadata["cli_apps"] = cli_apps
@@ -831,6 +831,7 @@ class WebSocketChannel(BaseChannel):
                     envelope.get("session_mentions"),
                     SessionAccessScope(
                         current_session_key=f"{self.name}:{cid}",
+                        session_key_prefix=f"{self.name}:",
                         project_path=scope.project_path,
                         restrict_to_workspace=scope.restrict_to_workspace,
                     ),

nanobot/channels/websocket/tests/test_websocket_envelope_media.py

@@ -219,7 +219,7 @@ async def test_webui_message_forwards_verified_session_mentions(tmp_path) -> Non
 
     channel._handle_message.assert_awaited_once()
     metadata = channel._handle_message.call_args.kwargs["metadata"]
-    assert metadata[INBOUND_META_SESSION_READ_SCOPE] is True
+    assert metadata[INBOUND_META_SESSION_READ_SCOPE] == "websocket:"
     assert metadata["session_mentions"] == [{
         "name": "pricing",
         "session_key": "websocket:pricing",

nanobot/webui/session_access.py

@@ -7,7 +7,7 @@ from collections.abc import Mapping
 from dataclasses import dataclass
 from functools import cache
 from pathlib import Path
-from typing import Any, cast
+from typing import Any, TypedDict, cast
 
 from nanobot.runtime_context import (
     RuntimeContextBlock,
@@ -24,24 +24,39 @@ from nanobot.webui.transcript import (
 )
 
 _VISIBLE_ROLES = {"user", "assistant"}
-_WEBUI_SESSION_PREFIX = "websocket:"
 
 
-SessionMention = dict[str, str]
-SessionMessage = dict[str, Any]
-SessionMatch = dict[str, Any]
+class SessionMention(TypedDict):
+    name: str
+    session_key: str
+    title: str
+
+
+class SessionMessage(TypedDict):
+    message_index: int
+    role: str
+    timestamp: str | int | None
+    content: str
+
+
+class SessionMatch(TypedDict):
+    session_key: str
+    title: str
+    updated_at: str | None
+    messages: list[SessionMessage]
 
 
 @dataclass(frozen=True)
 class SessionAccessScope:
     current_session_key: str
+    session_key_prefix: str
     project_path: Path | None = None
     restrict_to_workspace: bool = False
 
     def allows(self, session_key: object) -> bool:
         return (
             isinstance(session_key, str)
-            and session_key.startswith(_WEBUI_SESSION_PREFIX)
+            and session_key.startswith(self.session_key_prefix)
             and session_key != self.current_session_key
         )
 
@@ -245,7 +260,7 @@ class WebuiSessionAccess:
         seen_keys: set[str] = set()
         seen_names: set[str] = set()
         for raw_mention in normalize_session_mentions_metadata(raw):
-            mention = raw_mention
+            mention = cast(SessionMention, raw_mention)
             key = mention["session_key"]
             folded_name = mention["name"].lower()
             payload = self._metadata(key, scope)

tests/agent/tools/test_sessions.py

@@ -46,7 +46,7 @@ def _webui_request(
         channel="websocket",
         chat_id=session_key.removeprefix("websocket:"),
         session_key=session_key,
-        metadata={INBOUND_META_SESSION_READ_SCOPE: True},
+        metadata={INBOUND_META_SESSION_READ_SCOPE: "websocket:"},
     ))
 
 
@@ -284,3 +284,24 @@ async def test_session_tools_reject_unscoped_and_out_of_scope_sessions(tmp_path)
     assert spoofed.is_error
     assert [row["session_key"] for row in search["results"]] == ["websocket:visible"]
     assert read.is_error
+
+
+@pytest.mark.asyncio
+async def test_session_tools_use_the_scope_granted_by_the_channel(tmp_path):
+    manager = SessionManager(tmp_path)
+    _save_session(
+        manager,
+        "custom:history",
+        title="History",
+        messages=[{"role": "user", "content": "custom needle"}],
+    )
+
+    with request_context(RequestContext(
+        channel="custom",
+        chat_id="current",
+        session_key="custom:current",
+        metadata={INBOUND_META_SESSION_READ_SCOPE: "custom:"},
+    )):
+        result = _decode(await SearchSessionsTool(manager).execute(query="needle"))
+
+    assert [row["session_key"] for row in result["results"]] == ["custom:history"]

tests/webui/test_session_mentions.py

@@ -51,7 +51,7 @@ def test_normalize_session_mentions_keeps_only_authorized_distinct_targets(
             {"name": "STRASSE", "session_key": "websocket:upper"},
             {"name": "private", "session_key": "telegram:private"},
         ],
-        SessionAccessScope("websocket:current"),
+        SessionAccessScope("websocket:current", "websocket:"),
     )
 
     assert mentions == [
@@ -99,6 +99,7 @@ def test_restricted_scope_rejects_sessions_from_other_projects(tmp_path) -> None
     access = WebuiSessionAccess(manager)
     scope = SessionAccessScope(
         "websocket:current",
+        "websocket:",
         project_path=project_a,
         restrict_to_workspace=True,
     )

webui/src/components/thread/ThreadComposer.tsx

@@ -1325,14 +1325,23 @@ export function ThreadComposer({
         logoUrl: preset.logo_url ?? null,
         initials: mcpPresetInitials(preset),
       }));
-    return [
-      ...sessionCandidates.slice(0, 4),
-      ...cliCandidates.slice(0, 2),
-      ...mcpCandidates.slice(0, 2),
-      ...sessionCandidates.slice(4),
-      ...cliCandidates.slice(2),
-      ...mcpCandidates.slice(2),
-    ].slice(0, 8);
+    const groups = [
+      { candidates: cliCandidates, reserved: 2 },
+      { candidates: mcpCandidates, reserved: 2 },
+      { candidates: sessionCandidates, reserved: 4 },
+    ];
+    let remaining = 8;
+    const counts = groups.map(({ candidates, reserved }) => {
+      const count = Math.min(candidates.length, reserved);
+      remaining -= count;
+      return count;
+    });
+    for (const index of [2, 0, 1]) {
+      const extra = Math.min(remaining, groups[index].candidates.length - counts[index]);
+      counts[index] += extra;
+      remaining -= extra;
+    }
+    return groups.flatMap(({ candidates }, index) => candidates.slice(0, counts[index]));
   }, [activeSessionMentions, availableSessionMentions, cliAppMention, cliApps, mcpPresets]);
 
   const showCliAppMenu = filteredMentionCandidates.length > 0;
@@ -2660,7 +2669,7 @@ function CliAppMentionPalette({
     layout.maxHeight - SLASH_PALETTE_CHROME_PX,
   );
   const listRef = useSelectedOptionScroll(selectedIndex);
-  const groupedCandidates = (["session", "cli", "mcp"] as const)
+  const groupedCandidates = (["cli", "mcp", "session"] as const)
     .map((kind) => ({
       kind,
       label: kind === "session"

webui/src/tests/thread-composer.test.tsx

@@ -1596,6 +1596,7 @@ describe("ThreadComposer", () => {
         onSend={vi.fn()}
         placeholder="Type your message..."
         cliApps={CLI_APPS}
+        mcpPresets={MCP_PRESETS}
         sessions={[
           ...["a", "b"].map((chatId) => session(chatId, "Plan")),
           session("blender-chat", "Blender", "3D notes"),
@@ -1606,6 +1607,10 @@ describe("ThreadComposer", () => {
     const input = screen.getByLabelText("Message input");
     fireEvent.change(input, { target: { value: "@", selectionStart: 1 } });
 
+    const palette = screen.getByRole("listbox", { name: "Mentions" });
+    expect(within(palette).getAllByRole("group").map((group) => (
+      group.getAttribute("aria-label")
+    ))).toEqual(["CLI apps", "MCP services", "Nanobot conversations"]);
     const options = screen.getAllByRole("option", { name: /Plan @Plan/i });
     expect(options.map((option) => option.textContent)).toEqual([
       expect.stringContaining("@Plan"),