feat(webui): persist agent activity events

nanobot/agent/loop.py

@@ -33,7 +33,6 @@ from nanobot.config.schema import AgentDefaults, ModelPresetConfig
 from nanobot.providers.base import LLMProvider
 from nanobot.providers.factory import ProviderSnapshot
 from nanobot.session.goal_state import (
-    goal_state_ws_blob,
     runner_wall_llm_timeout_s,
 )
 from nanobot.session.manager import Session, SessionManager
@@ -44,8 +43,11 @@ from nanobot.utils.helpers import truncate_text as truncate_text_fn
 from nanobot.utils.image_generation_intent import image_generation_prompt
 from nanobot.utils.runtime import EMPTY_FINAL_RESPONSE_MESSAGE
 from nanobot.utils.session_attachments import merge_turn_media_into_last_assistant
-from nanobot.utils.webui_titles import mark_webui_session, maybe_generate_webui_title_after_turn
+from nanobot.utils.webui_turn_helpers import (
-from nanobot.utils.webui_turn_helpers import publish_turn_run_status
+    WebuiTurnCoordinator,
+    build_bus_progress_callback,
+    mark_webui_session,
+)
 
 if TYPE_CHECKING:
     from nanobot.config.schema import (
@@ -237,6 +239,11 @@ class AgentLoop:
 
         self.context = ContextBuilder(workspace, timezone=timezone, disabled_skills=disabled_skills)
         self.sessions = session_manager or SessionManager(workspace)
+        self._webui_turns = WebuiTurnCoordinator(
+            bus=self.bus,
+            sessions=self.sessions,
+            schedule_background=lambda coro: self._schedule_background(coro),
+        )
         self.tools = ToolRegistry()
         # One file-read/write tracker per logical session. The tool registry is
         # shared by this loop, so tools resolve the active state via contextvars.
@@ -524,34 +531,7 @@ class AgentLoop:
         self, msg: InboundMessage
     ) -> Callable[..., Awaitable[None]]:
         """Build a progress callback that publishes to the message bus."""
-
+        return build_bus_progress_callback(self.bus, msg)
-        async def _bus_progress(
-            content: str,
-            *,
-            tool_hint: bool = False,
-            tool_events: list[dict[str, Any]] | None = None,
-            reasoning: bool = False,
-            reasoning_end: bool = False,
-        ) -> None:
-            meta = dict(msg.metadata or {})
-            meta["_progress"] = True
-            meta["_tool_hint"] = tool_hint
-            if reasoning:
-                meta["_reasoning_delta"] = True
-            if reasoning_end:
-                meta["_reasoning_end"] = True
-            if tool_events:
-                meta["_tool_events"] = tool_events
-            await self.bus.publish_outbound(
-                OutboundMessage(
-                    channel=msg.channel,
-                    chat_id=msg.chat_id,
-                    content=content,
-                    metadata=meta,
-                )
-            )
-
-        return _bus_progress
 
     async def _build_retry_wait_callback(
         self, msg: InboundMessage
@@ -938,38 +918,12 @@ class AgentLoop:
                             content="", metadata=msg.metadata or {},
                         ))
                     if msg.channel == "websocket":
-                        # Signal that the turn is fully complete (all tools executed,
-                        # final text streamed).  This lets WS clients know when to
-                        # definitively stop the loading indicator.
                         turn_lat = self._pending_turn_latency_ms.pop(session_key, None)
-                        turn_metadata: dict[str, Any] = {**msg.metadata, "_turn_end": True}
+                        await self._webui_turns.handle_turn_end(
-                        if turn_lat is not None:
+                            msg,
-                            turn_metadata["latency_ms"] = int(turn_lat)
+                            session_key=session_key,
-                        sess_turn = self.sessions.get_or_create(session_key)
+                            latency_ms=turn_lat,
-                        turn_metadata["goal_state"] = goal_state_ws_blob(sess_turn.metadata)
+                        )
-                        await self.bus.publish_outbound(OutboundMessage(
-                            channel=msg.channel, chat_id=msg.chat_id,
-                            content="", metadata=turn_metadata,
-                        ))
-                        if msg.metadata.get("webui") is True:
-                            async def _generate_title_and_notify() -> None:
-                                generated = await maybe_generate_webui_title_after_turn(
-                                    channel=msg.channel,
-                                    metadata=msg.metadata,
-                                    sessions=self.sessions,
-                                    session_key=session_key,
-                                    provider=self.provider,
-                                    model=self.model,
-                                )
-                                if generated:
-                                    await self.bus.publish_outbound(OutboundMessage(
-                                        channel=msg.channel,
-                                        chat_id=msg.chat_id,
-                                        content="",
-                                        metadata={**msg.metadata, "_session_updated": True},
-                                    ))
-
-                            self._schedule_background(_generate_title_and_notify())
                 except asyncio.CancelledError:
                     logger.info("Task cancelled for session {}", session_key)
                     # Preserve partial context from the interrupted turn so
@@ -1021,8 +975,9 @@ class AgentLoop:
                         "Re-published {} leftover message(s) to bus for session {}",
                         leftover, session_key,
                     )
-            await publish_turn_run_status(self.bus, msg, "idle")
+            await self._webui_turns.publish_run_status(msg, "idle")
             self._pending_turn_latency_ms.pop(session_key, None)
+            self._webui_turns.discard(session_key)
 
     async def close_mcp(self) -> None:
         """Drain pending background archives, then close MCP connections."""
@@ -1338,6 +1293,12 @@ class AgentLoop:
             "include_timestamps": True,
         }
         ctx.history = ctx.session.get_history(**_hist_kwargs)
+        self._webui_turns.capture_title_context(
+            ctx.session_key,
+            ctx.msg,
+            self.provider,
+            self.model,
+        )
 
         ctx.initial_messages = self._build_initial_messages(
             ctx.msg, ctx.session, ctx.history, ctx.pending_summary
@@ -1354,7 +1315,7 @@ class AgentLoop:
         return "ok"
 
     async def _state_run(self, ctx: TurnContext) -> str:
-        await publish_turn_run_status(self.bus, ctx.msg, "running")
+        await self._webui_turns.publish_run_status(ctx.msg, "running")
         result = await self._run_agent_loop(
             ctx.initial_messages,
             on_progress=ctx.on_progress,

nanobot/agent/runner.py

@@ -15,6 +15,12 @@ from loguru import logger
 from nanobot.agent.hook import AgentHook, AgentHookContext
 from nanobot.agent.tools.registry import ToolRegistry
 from nanobot.providers.base import LLMProvider, LLMResponse, ToolCallRequest
+from nanobot.utils.file_edit_events import (
+    build_file_edit_end_event,
+    build_file_edit_error_event,
+    build_file_edit_start_event,
+    prepare_file_edit_tracker,
+)
 from nanobot.utils.helpers import (
     IncrementalThinkExtractor,
     build_assistant_message,
@@ -26,6 +32,7 @@ from nanobot.utils.helpers import (
     strip_think,
     truncate_text,
 )
+from nanobot.utils.progress_events import invoke_file_edit_progress
 from nanobot.utils.prompt_templates import render_template
 from nanobot.utils.runtime import (
     EMPTY_FINAL_RESPONSE_MESSAGE,
@@ -813,6 +820,21 @@ class AgentRunner:
             return prep_error + hint, event, (
                 RuntimeError(prep_error) if spec.fail_on_tool_error else None
             )
+        file_edit_tracker = prepare_file_edit_tracker(
+            call_id=tool_call.id,
+            tool_name=tool_call.name,
+            tool=tool,
+            workspace=spec.workspace,
+            params=params if isinstance(params, dict) else None,
+        )
+        if file_edit_tracker is not None and spec.progress_callback is not None:
+            await invoke_file_edit_progress(
+                spec.progress_callback,
+                [build_file_edit_start_event(
+                    file_edit_tracker,
+                    params if isinstance(params, dict) else None,
+                )],
+            )
         try:
             if tool is not None:
                 result = await tool.execute(**params)
@@ -821,6 +843,11 @@ class AgentRunner:
         except asyncio.CancelledError:
             raise
         except BaseException as exc:
+            if file_edit_tracker is not None and spec.progress_callback is not None:
+                await invoke_file_edit_progress(
+                    spec.progress_callback,
+                    [build_file_edit_error_event(file_edit_tracker, str(exc))],
+                )
             event = {
                 "name": tool_call.name,
                 "status": "error",
@@ -842,6 +869,11 @@ class AgentRunner:
             return payload, event, None
 
         if isinstance(result, str) and result.startswith("Error"):
+            if file_edit_tracker is not None and spec.progress_callback is not None:
+                await invoke_file_edit_progress(
+                    spec.progress_callback,
+                    [build_file_edit_error_event(file_edit_tracker, result)],
+                )
             event = {
                 "name": tool_call.name,
                 "status": "error",
@@ -860,6 +892,12 @@ class AgentRunner:
                 return result + hint, event, RuntimeError(result)
             return result + hint, event, None
 
+        if file_edit_tracker is not None and spec.progress_callback is not None:
+            await invoke_file_edit_progress(
+                spec.progress_callback,
+                [build_file_edit_end_event(file_edit_tracker)],
+            )
+
         detail = "" if result is None else str(result)
         detail = detail.replace("\n", " ").strip()
         if not detail:

nanobot/channels/websocket.py

@@ -1606,6 +1606,7 @@ class WebSocketChannel(BaseChannel):
         if not conns:
             if (
                 msg.metadata.get("_progress")
+                or msg.metadata.get("_file_edit_events")
                 or msg.metadata.get("_turn_end")
                 or msg.metadata.get("_session_updated")
                 or msg.metadata.get("_goal_status")
@@ -1638,7 +1639,22 @@ class WebSocketChannel(BaseChannel):
             await self.send_turn_end(msg.chat_id, latency_ms=lat_i, goal_state=gs_blob)
             return
         if msg.metadata.get("_session_updated"):
-            await self.send_session_updated(msg.chat_id)
+            scope = msg.metadata.get("_session_update_scope")
+            await self.send_session_updated(
+                msg.chat_id,
+                scope=scope if isinstance(scope, str) else None,
+            )
+            return
+        if msg.metadata.get("_file_edit_events"):
+            payload: dict[str, Any] = {
+                "event": "file_edit",
+                "chat_id": msg.chat_id,
+                "edits": msg.metadata["_file_edit_events"],
+            }
+            self._try_append_webui_transcript(msg.chat_id, payload)
+            raw = json.dumps(payload, ensure_ascii=False)
+            for connection in conns:
+                await self._safe_send_to(connection, raw, label=" ")
             return
         text = msg.content
         payload: dict[str, Any] = {
@@ -1805,12 +1821,14 @@ class WebSocketChannel(BaseChannel):
         for connection in conns:
             await self._safe_send_to(connection, raw, label=" goal_status ")
 
-    async def send_session_updated(self, chat_id: str) -> None:
+    async def send_session_updated(self, chat_id: str, *, scope: str | None = None) -> None:
         """Notify clients that session metadata changed outside the main turn."""
         conns = list(self._subs.get(chat_id, ()))
         if not conns:
             return
         body: dict[str, Any] = {"event": "session_updated", "chat_id": chat_id}
+        if scope:
+            body["scope"] = scope
         raw = json.dumps(body, ensure_ascii=False)
         for connection in conns:
             await self._safe_send_to(connection, raw, label=" session_updated ")

nanobot/utils/file_edit_events.py

@@ -0,0 +1,311 @@
+"""File-edit activity helpers for WebUI progress events."""
+
+from __future__ import annotations
+
+import difflib
+import json
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+
+TRACKED_FILE_EDIT_TOOLS = frozenset({"write_file", "edit_file", "notebook_edit"})
+_MAX_SNAPSHOT_BYTES = 2 * 1024 * 1024
+
+
+@dataclass(slots=True)
+class FileSnapshot:
+    path: Path
+    exists: bool
+    text: str | None
+    unreadable: bool = False
+    binary: bool = False
+    oversized: bool = False
+
+    @property
+    def countable(self) -> bool:
+        return (
+            self.text is not None
+            and not self.binary
+            and not self.oversized
+            and not self.unreadable
+        )
+
+
+@dataclass(slots=True)
+class FileEditTracker:
+    call_id: str
+    tool: str
+    path: Path
+    display_path: str
+    before: FileSnapshot
+
+
+def is_file_edit_tool(tool_name: str | None) -> bool:
+    return bool(tool_name) and tool_name in TRACKED_FILE_EDIT_TOOLS
+
+
+def resolve_file_edit_path(
+    tool: Any,
+    workspace: Path | None,
+    params: dict[str, Any] | None,
+) -> Path | None:
+    """Resolve the target file path after tool argument preparation."""
+    if not isinstance(params, dict):
+        return None
+    raw_path = params.get("path")
+    if not isinstance(raw_path, str) or not raw_path.strip():
+        return None
+    resolver = getattr(tool, "_resolve", None)
+    if callable(resolver):
+        try:
+            resolved = resolver(raw_path)
+            if isinstance(resolved, Path):
+                return resolved
+            if resolved:
+                return Path(resolved)
+        except Exception:
+            return None
+    if workspace is None:
+        return Path(raw_path).expanduser().resolve()
+    return (workspace / raw_path).expanduser().resolve()
+
+
+def display_file_edit_path(path: Path, workspace: Path | None) -> str:
+    if workspace is not None:
+        try:
+            return path.resolve().relative_to(workspace.resolve()).as_posix()
+        except Exception:
+            pass
+    return path.as_posix()
+
+
+def read_file_snapshot(path: Path, *, max_bytes: int = _MAX_SNAPSHOT_BYTES) -> FileSnapshot:
+    try:
+        if not path.exists() or not path.is_file():
+            return FileSnapshot(path=path, exists=False, text="")
+        size = path.stat().st_size
+        if size > max_bytes:
+            return FileSnapshot(path=path, exists=True, text=None, oversized=True)
+        raw = path.read_bytes()
+    except OSError:
+        return FileSnapshot(path=path, exists=path.exists(), text=None, unreadable=True)
+    if b"\x00" in raw:
+        return FileSnapshot(path=path, exists=True, text=None, binary=True)
+    try:
+        text = raw.decode("utf-8")
+    except UnicodeDecodeError:
+        return FileSnapshot(path=path, exists=True, text=None, binary=True)
+    return FileSnapshot(path=path, exists=True, text=text.replace("\r\n", "\n"))
+
+
+def line_diff_stats(before: str | None, after: str | None) -> tuple[int, int]:
+    """Return ``(added, deleted)`` for a UTF-8 text line-level diff."""
+    if before is None or after is None:
+        return 0, 0
+    before_lines = before.replace("\r\n", "\n").splitlines()
+    after_lines = after.replace("\r\n", "\n").splitlines()
+    added = 0
+    deleted = 0
+    matcher = difflib.SequenceMatcher(a=before_lines, b=after_lines, autojunk=False)
+    for tag, i1, i2, j1, j2 in matcher.get_opcodes():
+        if tag == "equal":
+            continue
+        if tag in ("replace", "delete"):
+            deleted += i2 - i1
+        if tag in ("replace", "insert"):
+            added += j2 - j1
+    return added, deleted
+
+
+def prepare_file_edit_tracker(
+    *,
+    call_id: str,
+    tool_name: str,
+    tool: Any,
+    workspace: Path | None,
+    params: dict[str, Any] | None,
+) -> FileEditTracker | None:
+    if not is_file_edit_tool(tool_name):
+        return None
+    path = resolve_file_edit_path(tool, workspace, params)
+    if path is None:
+        return None
+    before = read_file_snapshot(path)
+    return FileEditTracker(
+        call_id=str(call_id or ""),
+        tool=tool_name,
+        path=path,
+        display_path=display_file_edit_path(path, workspace),
+        before=before,
+    )
+
+
+def build_file_edit_start_event(
+    tracker: FileEditTracker,
+    params: dict[str, Any] | None,
+) -> dict[str, Any]:
+    predicted_after = _predict_after_text(tracker.tool, params or {}, tracker.before)
+    if tracker.before.countable and predicted_after is not None:
+        added, deleted = line_diff_stats(tracker.before.text, predicted_after)
+    else:
+        added, deleted = 0, 0
+    return _event_payload(
+        tracker,
+        phase="start",
+        status="editing",
+        added=added,
+        deleted=deleted,
+        approximate=True,
+    )
+
+
+def build_file_edit_end_event(tracker: FileEditTracker) -> dict[str, Any]:
+    after = read_file_snapshot(tracker.path)
+    if tracker.before.countable and after.countable:
+        added, deleted = line_diff_stats(tracker.before.text, after.text)
+    else:
+        added, deleted = 0, 0
+    return _event_payload(
+        tracker,
+        phase="end",
+        status="done",
+        added=added,
+        deleted=deleted,
+        approximate=False,
+        binary=after.binary or after.oversized or after.unreadable,
+    )
+
+
+def build_file_edit_error_event(tracker: FileEditTracker, error: str | None = None) -> dict[str, Any]:
+    payload = _event_payload(
+        tracker,
+        phase="error",
+        status="error",
+        added=0,
+        deleted=0,
+        approximate=False,
+    )
+    if error:
+        payload["error"] = error.strip()[:240]
+    return payload
+
+
+def _event_payload(
+    tracker: FileEditTracker,
+    *,
+    phase: str,
+    status: str,
+    added: int,
+    deleted: int,
+    approximate: bool,
+    binary: bool = False,
+) -> dict[str, Any]:
+    payload: dict[str, Any] = {
+        "version": 1,
+        "call_id": tracker.call_id,
+        "tool": tracker.tool,
+        "path": tracker.display_path,
+        "phase": phase,
+        "added": max(0, int(added)),
+        "deleted": max(0, int(deleted)),
+        "approximate": bool(approximate),
+        "status": status,
+    }
+    if binary:
+        payload["binary"] = True
+    return payload
+
+
+def _predict_after_text(
+    tool_name: str,
+    params: dict[str, Any],
+    before: FileSnapshot,
+) -> str | None:
+    if not before.countable:
+        return None
+    before_text = before.text or ""
+    if tool_name == "write_file":
+        content = params.get("content")
+        return content if isinstance(content, str) else ""
+    if tool_name == "edit_file":
+        old_text = params.get("old_text")
+        new_text = params.get("new_text")
+        if not isinstance(old_text, str) or not isinstance(new_text, str):
+            return None
+        replace_all = bool(params.get("replace_all"))
+        if old_text == "":
+            return new_text if not before.exists else before_text
+        if old_text in before_text:
+            if replace_all:
+                return before_text.replace(old_text, new_text)
+            return before_text.replace(old_text, new_text, 1)
+        return None
+    if tool_name == "notebook_edit":
+        return _predict_notebook_after_text(params, before_text)
+    return None
+
+
+def _predict_notebook_after_text(params: dict[str, Any], before_text: str) -> str | None:
+    try:
+        nb = json.loads(before_text) if before_text.strip() else _empty_notebook()
+    except Exception:
+        return None
+    cells = nb.get("cells")
+    if not isinstance(cells, list):
+        return None
+    try:
+        cell_index = int(params.get("cell_index", 0))
+    except (TypeError, ValueError):
+        return None
+    new_source = params.get("new_source")
+    source = new_source if isinstance(new_source, str) else ""
+    cell_type = params.get("cell_type") if params.get("cell_type") in ("code", "markdown") else "code"
+    mode = params.get("edit_mode") if params.get("edit_mode") in ("replace", "insert", "delete") else "replace"
+    if mode == "delete":
+        if 0 <= cell_index < len(cells):
+            cells.pop(cell_index)
+        else:
+            return None
+    elif mode == "insert":
+        insert_at = min(max(cell_index + 1, 0), len(cells))
+        cells.insert(insert_at, _new_notebook_cell(source, str(cell_type)))
+    else:
+        if not (0 <= cell_index < len(cells)):
+            return None
+        cell = cells[cell_index]
+        if not isinstance(cell, dict):
+            return None
+        cell["source"] = source
+        cell["cell_type"] = cell_type
+        if cell_type == "code":
+            cell.setdefault("outputs", [])
+            cell.setdefault("execution_count", None)
+        else:
+            cell.pop("outputs", None)
+            cell.pop("execution_count", None)
+    nb["cells"] = cells
+    try:
+        return json.dumps(nb, indent=1, ensure_ascii=False)
+    except Exception:
+        return None
+
+
+def _empty_notebook() -> dict[str, Any]:
+    return {
+        "nbformat": 4,
+        "nbformat_minor": 5,
+        "metadata": {
+            "kernelspec": {"display_name": "Python 3", "language": "python", "name": "python3"},
+            "language_info": {"name": "python"},
+        },
+        "cells": [],
+    }
+
+
+def _new_notebook_cell(source: str, cell_type: str) -> dict[str, Any]:
+    cell: dict[str, Any] = {"cell_type": cell_type, "source": source, "metadata": {}}
+    if cell_type == "code":
+        cell["outputs"] = []
+        cell["execution_count"] = None
+    return cell

nanobot/utils/progress_events.py

@@ -10,13 +10,21 @@ from nanobot.agent.hook import AgentHookContext
 
 
 def on_progress_accepts_tool_events(cb: Callable[..., Any]) -> bool:
+    return _on_progress_accepts(cb, "tool_events")
+
+
+def on_progress_accepts_file_edit_events(cb: Callable[..., Any]) -> bool:
+    return _on_progress_accepts(cb, "file_edit_events")
+
+
+def _on_progress_accepts(cb: Callable[..., Any], name: str) -> bool:
     try:
         sig = inspect.signature(cb)
     except (TypeError, ValueError):
         return False
     if any(p.kind == inspect.Parameter.VAR_KEYWORD for p in sig.parameters.values()):
         return True
-    return "tool_events" in sig.parameters
+    return name in sig.parameters
 
 
 async def invoke_on_progress(
@@ -32,6 +40,15 @@ async def invoke_on_progress(
     await on_progress(content, tool_hint=tool_hint)
 
 
+async def invoke_file_edit_progress(
+    on_progress: Callable[..., Awaitable[None]],
+    file_edit_events: list[dict[str, Any]],
+) -> None:
+    if not file_edit_events or not on_progress_accepts_file_edit_events(on_progress):
+        return
+    await on_progress("", file_edit_events=file_edit_events)
+
+
 def build_tool_event_start_payload(tool_call: Any) -> dict[str, Any]:
     return {
         "version": 1,

nanobot/utils/webui_titles.py

@@ -1,138 +0,0 @@
-"""Helpers for WebUI chat title generation."""
-
-from __future__ import annotations
-
-import re
-from typing import Any
-
-from loguru import logger
-
-from nanobot.providers.base import LLMProvider
-from nanobot.session.manager import Session, SessionManager
-from nanobot.utils.helpers import truncate_text
-
-WEBUI_SESSION_METADATA_KEY = "webui"
-WEBUI_TITLE_METADATA_KEY = "title"
-WEBUI_TITLE_USER_EDITED_METADATA_KEY = "title_user_edited"
-TITLE_MAX_CHARS = 60
-
-
-def mark_webui_session(session: Session, metadata: dict[str, Any]) -> bool:
-    """Persist a WebUI marker only when the inbound websocket frame opted in."""
-    if metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
-        return False
-    session.metadata[WEBUI_SESSION_METADATA_KEY] = True
-    return True
-
-
-def clean_generated_title(raw: str | None) -> str:
-    text = (raw or "").strip()
-    if not text:
-        return ""
-    text = re.sub(r"^\s*(title|标题)\s*[:：]\s*", "", text, flags=re.IGNORECASE)
-    text = text.strip().strip("\"'`“”‘’")
-    text = re.sub(r"\s+", " ", text).strip()
-    text = text.rstrip("。.!！?？,，;；:")
-    if len(text) > TITLE_MAX_CHARS:
-        text = text[: TITLE_MAX_CHARS - 1].rstrip() + "…"
-    return text
-
-
-def _title_inputs(session: Session) -> tuple[str, str]:
-    user_text = ""
-    assistant_text = ""
-    for message in session.messages:
-        role = message.get("role")
-        content = message.get("content")
-        if not isinstance(content, str) or not content.strip():
-            continue
-        if role == "user" and not user_text:
-            user_text = content.strip()
-        elif role == "assistant" and not assistant_text:
-            assistant_text = content.strip()
-        if user_text and assistant_text:
-            break
-    return user_text, assistant_text
-
-
-async def maybe_generate_webui_title(
-    *,
-    sessions: SessionManager,
-    session_key: str,
-    provider: LLMProvider,
-    model: str,
-) -> bool:
-    """Generate and persist a short title for WebUI-owned sessions only."""
-    session = sessions.get_or_create(session_key)
-    if session.metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
-        return False
-    if session.metadata.get(WEBUI_TITLE_USER_EDITED_METADATA_KEY) is True:
-        return False
-    current_title = session.metadata.get(WEBUI_TITLE_METADATA_KEY)
-    if isinstance(current_title, str) and current_title.strip():
-        return False
-
-    user_text, assistant_text = _title_inputs(session)
-    if not user_text:
-        return False
-
-    prompt = (
-        "Generate a concise title for this chat.\n"
-        "Rules:\n"
-        "- Use the same language as the user when practical.\n"
-        "- 3 to 8 words.\n"
-        "- No quotes.\n"
-        "- No punctuation at the end.\n"
-        "- Return only the title.\n\n"
-        f"User: {truncate_text(user_text, 1_000)}"
-    )
-    if assistant_text:
-        prompt += f"\nAssistant: {truncate_text(assistant_text, 1_000)}"
-
-    try:
-        response = await provider.chat_with_retry(
-            [
-                {
-                    "role": "system",
-                    "content": (
-                        "You write short, neutral chat titles. "
-                        "Return only the title text."
-                    ),
-                },
-                {"role": "user", "content": prompt},
-            ],
-            tools=None,
-            model=model,
-            max_tokens=32,
-            temperature=0.2,
-            retry_mode="standard",
-        )
-    except Exception:
-        logger.debug("Failed to generate webui session title for {}", session_key, exc_info=True)
-        return False
-
-    title = clean_generated_title(response.content)
-    if not title or title.lower().startswith("error"):
-        return False
-    session.metadata[WEBUI_TITLE_METADATA_KEY] = title
-    sessions.save(session)
-    return True
-
-
-async def maybe_generate_webui_title_after_turn(
-    *,
-    channel: str,
-    metadata: dict[str, Any],
-    sessions: SessionManager,
-    session_key: str,
-    provider: LLMProvider,
-    model: str,
-) -> bool:
-    if channel != "websocket" or metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
-        return False
-    return await maybe_generate_webui_title(
-        sessions=sessions,
-        session_key=session_key,
-        provider=provider,
-        model=model,
-    )

nanobot/utils/webui_transcript.py

@@ -125,11 +125,25 @@ def replay_transcript_to_ui_messages(
     buffer_message_id: str | None = None
     buffer_parts: list[str] = []
     suppress_until_turn_end = False
+    active_activity_segment_id: str | None = None
+    active_file_edit_segment_id: str | None = None
+    activity_segment_counter = 0
     _ts_base = int(time.time() * 1000)
 
     def _new_id(prefix: str, idx: int) -> str:
         return f"{prefix}-{idx}-{uuid.uuid4().hex[:8]}"
 
+    def _new_activity_segment(*, activate: bool = True) -> str:
+        nonlocal active_activity_segment_id, activity_segment_counter
+        activity_segment_counter += 1
+        segment_id = f"activity-{activity_segment_counter}"
+        if activate:
+            active_activity_segment_id = segment_id
+        return segment_id
+
+    def _ensure_activity_segment() -> str:
+        return active_activity_segment_id or _new_activity_segment()
+
     def attach_reasoning_chunk(prev: list[dict[str, Any]], chunk: str, idx: int) -> None:
         for i in range(len(prev) - 1, -1, -1):
             candidate = prev[i]
@@ -151,12 +165,19 @@ def replay_transcript_to_ui_messages(
                     **candidate,
                     "reasoning": (str(candidate.get("reasoning") or "")) + chunk,
                     "reasoningStreaming": True,
+                    "activitySegmentId": candidate.get("activitySegmentId") or _ensure_activity_segment(),
                 }
                 return
             if not has_answer and candidate.get("isStreaming"):
-                prev[i] = {**candidate, "reasoning": chunk, "reasoningStreaming": True}
+                prev[i] = {
+                    **candidate,
+                    "reasoning": chunk,
+                    "reasoningStreaming": True,
+                    "activitySegmentId": candidate.get("activitySegmentId") or _ensure_activity_segment(),
+                }
                 return
             break
+        segment = _ensure_activity_segment()
         prev.append(
             {
                 "id": _new_id("as", idx),
@@ -165,6 +186,7 @@ def replay_transcript_to_ui_messages(
                 "isStreaming": True,
                 "reasoning": chunk,
                 "reasoningStreaming": True,
+                "activitySegmentId": segment,
                 "createdAt": _ts_base + idx,
             },
         )
@@ -221,6 +243,7 @@ def replay_transcript_to_ui_messages(
                 return
 
     def absorb_complete(extra: dict[str, Any], idx: int) -> None:
+        nonlocal active_activity_segment_id
         last = messages[-1] if messages else None
         if last and is_reasoning_only_placeholder(last):
             messages[-1] = {
@@ -238,10 +261,76 @@ def replay_transcript_to_ui_messages(
                     **extra,
                 },
             )
+        active_activity_segment_id = None
+
+    def _file_edit_key(edit: dict[str, Any]) -> str:
+        return "|".join(
+            str(edit.get(k) or "")
+            for k in ("call_id", "tool", "path")
+        )
+
+    def upsert_file_edits(edits: list[dict[str, Any]], idx: int) -> None:
+        nonlocal active_file_edit_segment_id
+        if not edits:
+            return
+        last = messages[-1] if messages else None
+        if (
+            active_file_edit_segment_id
+            and last
+            and last.get("kind") == "trace"
+            and last.get("fileEdits")
+        ):
+            segment = active_file_edit_segment_id
+        else:
+            segment = _new_activity_segment(activate=False)
+            active_file_edit_segment_id = segment
+        if not (
+            last
+            and last.get("kind") == "trace"
+            and not last.get("isStreaming")
+            and last.get("fileEdits")
+            and last.get("activitySegmentId") == segment
+        ):
+            messages.append(
+                {
+                    "id": _new_id("tr", idx),
+                    "role": "tool",
+                    "kind": "trace",
+                    "content": "",
+                    "traces": [],
+                    "fileEdits": [],
+                    "activitySegmentId": segment,
+                    "createdAt": _ts_base + idx,
+                },
+            )
+            last = messages[-1]
+        existing = list(last.get("fileEdits") or [])
+        index_by_key = {
+            _file_edit_key(edit): pos
+            for pos, edit in enumerate(existing)
+            if isinstance(edit, dict)
+        }
+        for edit in edits:
+            if not isinstance(edit, dict):
+                continue
+            key = _file_edit_key(edit)
+            if key in index_by_key:
+                pos = index_by_key[key]
+                existing[pos] = {**existing[pos], **edit}
+            else:
+                index_by_key[key] = len(existing)
+                existing.append(dict(edit))
+        messages[-1] = {
+            **last,
+            "fileEdits": existing,
+            "activitySegmentId": last.get("activitySegmentId") or segment,
+        }
 
     for idx, rec in enumerate(lines):
         ev = rec.get("event")
         if ev == "user":
+            active_activity_segment_id = None
+            active_file_edit_segment_id = None
             text = rec.get("text")
             text_s = text if isinstance(text, str) else ""
             media_paths = rec.get("media_paths")
@@ -264,6 +353,12 @@ def replay_transcript_to_ui_messages(
             messages.append(row)
             continue
 
+        if ev == "file_edit":
+            raw_edits = rec.get("edits")
+            if isinstance(raw_edits, list):
+                upsert_file_edits([e for e in raw_edits if isinstance(e, dict)], idx)
+            continue
+
         if ev == "delta":
             if suppress_until_turn_end:
                 continue
@@ -338,14 +433,21 @@ def replay_transcript_to_ui_messages(
                 trace_lines = structured if structured else ([text] if isinstance(text, str) and text else [])
                 if not trace_lines:
                     continue
+                segment = _ensure_activity_segment()
                 last = messages[-1] if messages else None
-                if last and last.get("kind") == "trace" and not last.get("isStreaming"):
+                if (
+                    last
+                    and last.get("kind") == "trace"
+                    and not last.get("isStreaming")
+                    and (last.get("activitySegmentId") in (None, segment))
+                ):
                     prev_traces = list(last.get("traces") or [last.get("content")])
                     merged_traces = prev_traces + trace_lines
                     messages[-1] = {
                         **last,
                         "traces": merged_traces,
                         "content": trace_lines[-1],
+                        "activitySegmentId": last.get("activitySegmentId") or segment,
                     }
                 else:
                     messages.append(
@@ -355,6 +457,7 @@ def replay_transcript_to_ui_messages(
                             "kind": "trace",
                             "content": trace_lines[-1],
                             "traces": trace_lines,
+                            "activitySegmentId": segment,
                             "createdAt": _ts_base + idx,
                         },
                     )
@@ -389,6 +492,8 @@ def replay_transcript_to_ui_messages(
 
         if ev == "turn_end":
             suppress_until_turn_end = False
+            active_activity_segment_id = None
+            active_file_edit_segment_id = None
             for i, m in enumerate(messages):
                 if m.get("isStreaming"):
                     messages[i] = {**m, "isStreaming": False}

nanobot/utils/webui_turn_helpers.py

@@ -6,15 +6,161 @@ AgentLoop uses these without importing a concrete channel plugin; only
 
 from __future__ import annotations
 
+import re
 import time
+from collections.abc import Awaitable, Callable
+from dataclasses import dataclass, field
 from typing import Any
 
+from loguru import logger
+
 from nanobot.bus.events import InboundMessage, OutboundMessage
 from nanobot.bus.queue import MessageBus
+from nanobot.providers.base import LLMProvider
+from nanobot.session.goal_state import goal_state_ws_blob
+from nanobot.session.manager import Session, SessionManager
+from nanobot.utils.helpers import truncate_text
+
+WEBUI_SESSION_METADATA_KEY = "webui"
+WEBUI_TITLE_METADATA_KEY = "title"
+WEBUI_TITLE_USER_EDITED_METADATA_KEY = "title_user_edited"
+TITLE_MAX_CHARS = 60
+TITLE_GENERATION_MAX_TOKENS = 96
+TITLE_GENERATION_REASONING_EFFORT = "none"
 
 # Wall-clock turn start per ``chat_id`` (websocket only). Survives browser refresh while the
 # gateway process stays up; cleared on idle/stop and implicitly dropped on restart.
 _WEBSOCKET_TURN_WALL_STARTED_AT: dict[str, float] = {}
+TitleContext = tuple[LLMProvider, str]
+
+
+def mark_webui_session(session: Session, metadata: dict[str, Any]) -> bool:
+    """Persist a WebUI marker only when the inbound websocket frame opted in."""
+    if metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
+        return False
+    session.metadata[WEBUI_SESSION_METADATA_KEY] = True
+    return True
+
+
+def clean_generated_title(raw: str | None) -> str:
+    text = (raw or "").strip()
+    if not text:
+        return ""
+    text = re.sub(r"^\s*(title|标题)\s*[:：]\s*", "", text, flags=re.IGNORECASE)
+    text = text.strip().strip("\"'`“”‘’")
+    text = re.sub(r"\s+", " ", text).strip()
+    text = text.rstrip("。.!！?？,，;；:")
+    if len(text) > TITLE_MAX_CHARS:
+        text = text[: TITLE_MAX_CHARS - 1].rstrip() + "…"
+    return text
+
+
+def _title_inputs(session: Session) -> tuple[str, str]:
+    user_text = ""
+    assistant_text = ""
+    for message in session.messages:
+        if message.get("_command") is True:
+            continue
+        role = message.get("role")
+        content = message.get("content")
+        if not isinstance(content, str) or not content.strip():
+            continue
+        if role == "user" and not user_text:
+            user_text = content.strip()
+        elif role == "assistant" and not assistant_text:
+            assistant_text = content.strip()
+        if user_text and assistant_text:
+            break
+    return user_text, assistant_text
+
+
+async def maybe_generate_webui_title(
+    *,
+    sessions: SessionManager,
+    session_key: str,
+    provider: LLMProvider,
+    model: str,
+) -> bool:
+    """Generate and persist a short title for WebUI-owned sessions only."""
+    session = sessions.get_or_create(session_key)
+    if session.metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
+        return False
+    if session.metadata.get(WEBUI_TITLE_USER_EDITED_METADATA_KEY) is True:
+        return False
+    current_title = session.metadata.get(WEBUI_TITLE_METADATA_KEY)
+    if isinstance(current_title, str) and current_title.strip():
+        return False
+
+    user_text, assistant_text = _title_inputs(session)
+    if not user_text:
+        return False
+
+    prompt = (
+        "Generate a concise title for this chat.\n"
+        "Rules:\n"
+        "- Use the same language as the user when practical.\n"
+        "- 3 to 8 words.\n"
+        "- No quotes.\n"
+        "- No punctuation at the end.\n"
+        "- Return only the title.\n\n"
+        f"User: {truncate_text(user_text, 1_000)}"
+    )
+    if assistant_text:
+        prompt += f"\nAssistant: {truncate_text(assistant_text, 1_000)}"
+
+    try:
+        response = await provider.chat_with_retry(
+            [
+                {
+                    "role": "system",
+                    "content": (
+                        "You write short, neutral chat titles. "
+                        "Return only the title text."
+                    ),
+                },
+                {"role": "user", "content": prompt},
+            ],
+            tools=None,
+            model=model,
+            max_tokens=TITLE_GENERATION_MAX_TOKENS,
+            temperature=0.2,
+            reasoning_effort=TITLE_GENERATION_REASONING_EFFORT,
+            retry_mode="standard",
+        )
+    except Exception:
+        logger.debug("Failed to generate webui session title for {}", session_key, exc_info=True)
+        return False
+
+    title = clean_generated_title(response.content)
+    if not title or title.lower().startswith("error"):
+        logger.debug(
+            "WebUI title generation returned no usable title for {} (finish_reason={})",
+            session_key,
+            response.finish_reason,
+        )
+        return False
+    session.metadata[WEBUI_TITLE_METADATA_KEY] = title
+    sessions.save(session)
+    return True
+
+
+async def maybe_generate_webui_title_after_turn(
+    *,
+    channel: str,
+    metadata: dict[str, Any],
+    sessions: SessionManager,
+    session_key: str,
+    provider: LLMProvider,
+    model: str,
+) -> bool:
+    if channel != "websocket" or metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
+        return False
+    return await maybe_generate_webui_title(
+        sessions=sessions,
+        session_key=session_key,
+        provider=provider,
+        model=model,
+    )
 
 
 def websocket_turn_wall_started_at(chat_id: str) -> float | None:
@@ -46,3 +192,125 @@ async def publish_turn_run_status(bus: MessageBus, msg: InboundMessage, status:
             metadata=meta,
         ),
     )
+
+
+def build_bus_progress_callback(
+    bus: MessageBus,
+    msg: InboundMessage,
+) -> Callable[..., Awaitable[None]]:
+    """Return the bus progress callback for agent runtime events."""
+
+    async def _bus_progress(
+        content: str,
+        *,
+        tool_hint: bool = False,
+        tool_events: list[dict[str, Any]] | None = None,
+        file_edit_events: list[dict[str, Any]] | None = None,
+        reasoning: bool = False,
+        reasoning_end: bool = False,
+    ) -> None:
+        if file_edit_events and msg.channel != "websocket":
+            return
+        meta = dict(msg.metadata or {})
+        meta["_progress"] = True
+        meta["_tool_hint"] = tool_hint
+        if reasoning:
+            meta["_reasoning_delta"] = True
+        if reasoning_end:
+            meta["_reasoning_end"] = True
+        if tool_events:
+            meta["_tool_events"] = tool_events
+        if file_edit_events:
+            meta["_file_edit_events"] = file_edit_events
+        await bus.publish_outbound(
+            OutboundMessage(
+                channel=msg.channel,
+                chat_id=msg.chat_id,
+                content=content,
+                metadata=meta,
+            )
+        )
+
+    return _bus_progress
+
+
+@dataclass
+class WebuiTurnCoordinator:
+    """Own the WebUI/WebSocket wire details that hang off AgentLoop turns."""
+
+    bus: MessageBus
+    sessions: SessionManager
+    schedule_background: Callable[[Awaitable[None]], None]
+    _title_contexts: dict[str, TitleContext] = field(default_factory=dict)
+
+    def capture_title_context(
+        self,
+        session_key: str,
+        msg: InboundMessage,
+        provider: LLMProvider,
+        model: str,
+    ) -> None:
+        if msg.channel == "websocket" and msg.metadata.get("webui") is True:
+            self._title_contexts[session_key] = (provider, model)
+
+    def discard(self, session_key: str) -> None:
+        self._title_contexts.pop(session_key, None)
+
+    async def publish_run_status(self, msg: InboundMessage, status: str) -> None:
+        await publish_turn_run_status(self.bus, msg, status)
+
+    async def handle_turn_end(
+        self,
+        msg: InboundMessage,
+        *,
+        session_key: str,
+        latency_ms: int | None,
+    ) -> None:
+        if msg.channel != "websocket":
+            return
+
+        turn_metadata: dict[str, Any] = {**msg.metadata, "_turn_end": True}
+        if latency_ms is not None:
+            turn_metadata["latency_ms"] = int(latency_ms)
+        session = self.sessions.get_or_create(session_key)
+        turn_metadata["goal_state"] = goal_state_ws_blob(session.metadata)
+        await self.bus.publish_outbound(OutboundMessage(
+            channel=msg.channel,
+            chat_id=msg.chat_id,
+            content="",
+            metadata=turn_metadata,
+        ))
+        self._schedule_title_update(msg, session_key=session_key)
+
+    def _schedule_title_update(self, msg: InboundMessage, *, session_key: str) -> None:
+        title_context = self._title_contexts.pop(session_key, None)
+        if msg.metadata.get("webui") is not True or title_context is None:
+            return
+
+        title_provider, title_model = title_context
+
+        async def _generate_title_and_notify(
+            provider: LLMProvider = title_provider,
+            model: str = title_model,
+        ) -> None:
+            generated = await maybe_generate_webui_title_after_turn(
+                channel=msg.channel,
+                metadata=msg.metadata,
+                sessions=self.sessions,
+                session_key=session_key,
+                provider=provider,
+                model=model,
+            )
+            if generated:
+                await self.bus.publish_outbound(OutboundMessage(
+                    channel=msg.channel,
+                    chat_id=msg.chat_id,
+                    content="",
+                    metadata={
+                        **msg.metadata,
+                        "_session_updated": True,
+                        "_session_update_scope": "metadata",
+                    },
+                ))
+
+        self.schedule_background(_generate_title_and_notify())

tests/agent/test_loop_progress.py

@@ -82,6 +82,96 @@ class TestToolEventProgress:
             ),
         ]
 
+    @pytest.mark.asyncio
+    async def test_write_file_emits_file_edit_progress(self, tmp_path: Path) -> None:
+        loop = _make_loop(tmp_path)
+        target = tmp_path / "foo.txt"
+        target.write_text("old\n", encoding="utf-8")
+        tool_call = ToolCallRequest(
+            id="call-write",
+            name="write_file",
+            arguments={"path": "foo.txt", "content": "new\nextra\n"},
+        )
+        calls = iter([
+            LLMResponse(content="", tool_calls=[tool_call]),
+            LLMResponse(content="Done", tool_calls=[]),
+        ])
+        loop.provider.chat_with_retry = AsyncMock(side_effect=lambda *a, **kw: next(calls))
+        loop.tools.get_definitions = MagicMock(return_value=[])
+        loop.tools.prepare_call = MagicMock(
+            return_value=(None, {"path": "foo.txt", "content": "new\nextra\n"}, None),
+        )
+
+        async def execute(name: str, params: dict) -> str:
+            target.write_text(params["content"], encoding="utf-8")
+            return "ok"
+
+        loop.tools.execute = AsyncMock(side_effect=execute)
+        file_events: list[dict] = []
+
+        async def on_progress(
+            content: str,
+            *,
+            tool_hint: bool = False,
+            tool_events: list[dict] | None = None,
+            file_edit_events: list[dict] | None = None,
+        ) -> None:
+            if file_edit_events:
+                file_events.extend(file_edit_events)
+
+        final_content, _, _, _, _ = await loop._run_agent_loop([], on_progress=on_progress)
+
+        assert final_content == "Done"
+        assert [event["phase"] for event in file_events] == ["start", "end"]
+        assert file_events[0] == {
+            "version": 1,
+            "call_id": "call-write",
+            "tool": "write_file",
+            "path": "foo.txt",
+            "phase": "start",
+            "added": 2,
+            "deleted": 1,
+            "approximate": True,
+            "status": "editing",
+        }
+        assert file_events[1]["status"] == "done"
+        assert file_events[1]["approximate"] is False
+        assert (file_events[1]["added"], file_events[1]["deleted"]) == (2, 1)
+
+    @pytest.mark.asyncio
+    async def test_exec_does_not_emit_file_edit_progress(self, tmp_path: Path) -> None:
+        loop = _make_loop(tmp_path)
+        tool_call = ToolCallRequest(
+            id="call-exec",
+            name="exec",
+            arguments={"command": "printf hi > foo.txt"},
+        )
+        calls = iter([
+            LLMResponse(content="", tool_calls=[tool_call]),
+            LLMResponse(content="Done", tool_calls=[]),
+        ])
+        loop.provider.chat_with_retry = AsyncMock(side_effect=lambda *a, **kw: next(calls))
+        loop.tools.get_definitions = MagicMock(return_value=[])
+        loop.tools.prepare_call = MagicMock(
+            return_value=(None, {"command": "printf hi > foo.txt"}, None),
+        )
+        loop.tools.execute = AsyncMock(return_value="ok")
+        file_events: list[dict] = []
+
+        async def on_progress(
+            content: str,
+            *,
+            tool_hint: bool = False,
+            tool_events: list[dict] | None = None,
+            file_edit_events: list[dict] | None = None,
+        ) -> None:
+            if file_edit_events:
+                file_events.extend(file_edit_events)
+
+        await loop._run_agent_loop([], on_progress=on_progress)
+
+        assert file_events == []
+
     @pytest.mark.asyncio
     async def test_bus_progress_forwards_tool_events_to_outbound_metadata(self, tmp_path: Path) -> None:
         """When run() handles a bus message, _tool_events lands in OutboundMessage metadata."""
@@ -130,6 +220,42 @@ class TestToolEventProgress:
         assert finish["phase"] == "end"
         assert finish["result"] == "file.txt"
 
+    @pytest.mark.asyncio
+    async def test_bus_progress_forwards_file_edit_events_for_websocket_only(self, tmp_path: Path) -> None:
+        bus = MessageBus()
+        provider = MagicMock()
+        provider.get_default_model.return_value = "test-model"
+        loop = AgentLoop(bus=bus, provider=provider, workspace=tmp_path, model="test-model")
+        edit_events = [{
+            "call_id": "call-write",
+            "tool": "write_file",
+            "path": "foo.txt",
+            "phase": "start",
+            "added": 1,
+            "deleted": 0,
+            "approximate": True,
+            "status": "editing",
+        }]
+
+        websocket_progress = await loop._build_bus_progress_callback(InboundMessage(
+            channel="websocket",
+            sender_id="u1",
+            chat_id="chat1",
+            content="edit",
+        ))
+        await websocket_progress("", file_edit_events=edit_events)
+        outbound = await bus.consume_outbound()
+        assert outbound.metadata["_file_edit_events"] == edit_events
+
+        telegram_progress = await loop._build_bus_progress_callback(InboundMessage(
+            channel="telegram",
+            sender_id="u1",
+            chat_id="chat2",
+            content="edit",
+        ))
+        await telegram_progress("", file_edit_events=edit_events)
+        assert bus.outbound_size == 0
+
     @pytest.mark.asyncio
     async def test_non_streaming_channel_does_not_publish_codex_progress_deltas(
         self,
@@ -353,8 +479,93 @@ class TestToolEventProgress:
         assert session_updated is not None
 
         assert (session_updated.metadata or {}).get("_session_updated") is True
+        assert (session_updated.metadata or {}).get("_session_update_scope") == "metadata"
         assert provider.chat_with_retry.await_count == 2
 
+    @pytest.mark.asyncio
+    async def test_webui_title_generation_uses_turn_model_snapshot(
+        self,
+        tmp_path: Path,
+        monkeypatch: pytest.MonkeyPatch,
+    ) -> None:
+        bus = MessageBus()
+        provider = MagicMock()
+        provider.get_default_model.return_value = "test-model"
+        provider.chat_with_retry = AsyncMock(return_value=LLMResponse(content="Done", tool_calls=[]))
+        loop = AgentLoop(bus=bus, provider=provider, workspace=tmp_path, model="test-model")
+        loop.tools.get_definitions = MagicMock(return_value=[])
+        loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
+
+        captured: dict[str, object] = {}
+
+        async def fake_title_after_turn(**kwargs: object) -> bool:
+            captured.update(kwargs)
+            return False
+
+        monkeypatch.setattr(
+            "nanobot.utils.webui_turn_helpers.maybe_generate_webui_title_after_turn",
+            fake_title_after_turn,
+        )
+        scheduled_title: list[object] = []
+
+        def schedule_background(coro: object) -> None:
+            name = getattr(coro, "__qualname__", "")
+            if "_generate_title_and_notify" in name:
+                scheduled_title.append(coro)
+            elif hasattr(coro, "close"):
+                coro.close()
+
+        loop._schedule_background = schedule_background  # type: ignore[method-assign]
+
+        await loop._dispatch(InboundMessage(
+            channel="websocket",
+            sender_id="u1",
+            chat_id="chat1",
+            content="say hello",
+            metadata={"webui": True},
+        ))
+
+        assert len(scheduled_title) == 1
+        loop.provider = MagicMock()
+        loop.model = "switched-after-turn"
+
+        await scheduled_title[0]  # type: ignore[misc]
+
+        assert captured["provider"] is provider
+        assert captured["model"] == "test-model"
+
+    @pytest.mark.asyncio
+    async def test_webui_command_turn_does_not_schedule_title_generation(
+        self,
+        tmp_path: Path,
+        monkeypatch: pytest.MonkeyPatch,
+    ) -> None:
+        bus = MessageBus()
+        provider = MagicMock()
+        provider.get_default_model.return_value = "test-model"
+        provider.chat_with_retry = AsyncMock(return_value=LLMResponse(content="Done", tool_calls=[]))
+        loop = AgentLoop(bus=bus, provider=provider, workspace=tmp_path, model="test-model")
+
+        async def fake_title_after_turn(**_kwargs: object) -> bool:
+            raise AssertionError("command-only turns should not generate titles")
+
+        monkeypatch.setattr(
+            "nanobot.utils.webui_turn_helpers.maybe_generate_webui_title_after_turn",
+            fake_title_after_turn,
+        )
+        scheduled: list[object] = []
+        loop._schedule_background = scheduled.append  # type: ignore[method-assign]
+
+        await loop._dispatch(InboundMessage(
+            channel="websocket",
+            sender_id="u1",
+            chat_id="chat1",
+            content="/model",
+            metadata={"webui": True},
+        ))
+
+        assert scheduled == []
+
     @pytest.mark.asyncio
     async def test_non_websocket_dispatch_does_not_publish_turn_end_marker(self, tmp_path: Path) -> None:
         bus = MessageBus()

tests/agent/test_loop_save_turn.py

@@ -11,7 +11,9 @@ from nanobot.bus.queue import MessageBus
 from nanobot.providers.base import LLMResponse
 from nanobot.session.goal_state import GOAL_STATE_KEY
 from nanobot.session.manager import Session
-from nanobot.utils.webui_titles import (
+from nanobot.utils.webui_turn_helpers import (
+    TITLE_GENERATION_MAX_TOKENS,
+    TITLE_GENERATION_REASONING_EFFORT,
     WEBUI_SESSION_METADATA_KEY,
     WEBUI_TITLE_METADATA_KEY,
     maybe_generate_webui_title,
@@ -55,6 +57,11 @@ async def test_generate_webui_title_only_for_marked_webui_sessions(tmp_path: Pat
     assert generated is True
     assert session.metadata[WEBUI_TITLE_METADATA_KEY] == "优化 WebUI 侧边栏"
     loop.provider.chat_with_retry.assert_awaited_once()
+    assert loop.provider.chat_with_retry.await_args.kwargs["max_tokens"] == TITLE_GENERATION_MAX_TOKENS
+    assert (
+        loop.provider.chat_with_retry.await_args.kwargs["reasoning_effort"]
+        == TITLE_GENERATION_REASONING_EFFORT
+    )
 
 
 @pytest.mark.asyncio
@@ -79,6 +86,31 @@ async def test_generate_webui_title_skips_plain_websocket_sessions(tmp_path: Pat
     loop.provider.chat_with_retry.assert_not_awaited()
 
 
+@pytest.mark.asyncio
+async def test_generate_webui_title_ignores_command_only_sessions(tmp_path: Path) -> None:
+    loop = _make_full_loop(tmp_path)
+    session = loop.sessions.get_or_create("websocket:command-title")
+    session.metadata[WEBUI_SESSION_METADATA_KEY] = True
+    session.add_message("user", "/model deep", _command=True)
+    session.add_message(
+        "assistant",
+        "Switched model preset to `deep`.\n- Model: `deepseek-v4-pro`",
+        _command=True,
+    )
+    loop.sessions.save(session)
+
+    generated = await maybe_generate_webui_title(
+        sessions=loop.sessions,
+        session_key="websocket:command-title",
+        provider=loop.provider,
+        model=loop.model,
+    )
+
+    assert generated is False
+    assert WEBUI_TITLE_METADATA_KEY not in session.metadata
+    loop.provider.chat_with_retry.assert_not_awaited()
+
+
 def test_save_turn_skips_multimodal_user_when_only_runtime_context() -> None:
     loop = _mk_loop()
     session = Session(key="test:runtime-only")

tests/channels/test_websocket_channel.py

@@ -370,6 +370,55 @@ async def test_send_progress_includes_structured_tool_events() -> None:
     ]
 
 
+@pytest.mark.asyncio
+async def test_send_file_edit_progress_uses_file_edit_event() -> None:
+    bus = MagicMock()
+    channel = WebSocketChannel({"enabled": True, "allowFrom": ["*"]}, bus)
+    mock_ws = AsyncMock()
+    channel._attach(mock_ws, "chat-1")
+
+    await channel.send(OutboundMessage(
+        channel="websocket",
+        chat_id="chat-1",
+        content="",
+        metadata={
+            "_progress": True,
+            "_file_edit_events": [
+                {
+                    "version": 1,
+                    "phase": "start",
+                    "call_id": "call-1",
+                    "tool": "write_file",
+                    "path": "src/app.py",
+                    "added": 12,
+                    "deleted": 2,
+                    "approximate": True,
+                    "status": "editing",
+                }
+            ],
+        },
+    ))
+
+    payload = json.loads(mock_ws.send.await_args.args[0])
+    assert payload == {
+        "event": "file_edit",
+        "chat_id": "chat-1",
+        "edits": [
+            {
+                "version": 1,
+                "phase": "start",
+                "call_id": "call-1",
+                "tool": "write_file",
+                "path": "src/app.py",
+                "added": 12,
+                "deleted": 2,
+                "approximate": True,
+                "status": "editing",
+            }
+        ],
+    }
+
+
 @pytest.mark.asyncio
 async def test_send_progress_includes_agent_ui_blob() -> None:
     bus = MagicMock()
@@ -758,6 +807,25 @@ async def test_send_session_updated_emits_session_updated_event() -> None:
     assert body == {"event": "session_updated", "chat_id": "chat-1"}
 
 
+@pytest.mark.asyncio
+async def test_send_session_updated_includes_scope_when_present() -> None:
+    bus = MagicMock()
+    channel = WebSocketChannel({"enabled": True, "allowFrom": ["*"]}, bus)
+    mock_ws = AsyncMock()
+    channel._attach(mock_ws, "chat-1")
+
+    await channel.send(OutboundMessage(
+        channel="websocket",
+        chat_id="chat-1",
+        content="",
+        metadata={"_session_updated": True, "_session_update_scope": "metadata"},
+    ))
+
+    mock_ws.send.assert_awaited_once()
+    body = json.loads(mock_ws.send.await_args.args[0])
+    assert body == {"event": "session_updated", "chat_id": "chat-1", "scope": "metadata"}
+
+
 @pytest.mark.asyncio
 async def test_send_non_connection_closed_exception_is_raised() -> None:
     bus = MagicMock()

tests/utils/test_file_edit_events.py

@@ -0,0 +1,83 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from nanobot.utils.file_edit_events import (
+    build_file_edit_end_event,
+    build_file_edit_start_event,
+    line_diff_stats,
+    prepare_file_edit_tracker,
+    read_file_snapshot,
+)
+
+
+def test_line_diff_stats_counts_replacements_insertions_and_deletions() -> None:
+    added, deleted = line_diff_stats("a\nb\nc\n", "a\nB\nc\nd\n")
+    assert (added, deleted) == (2, 1)
+
+
+def test_line_diff_stats_normalizes_crlf() -> None:
+    assert line_diff_stats("a\r\nb\r\n", "a\nb\nc\n") == (1, 0)
+
+
+def test_write_file_start_predicts_and_end_calibrates_exact_diff(tmp_path: Path) -> None:
+    target = tmp_path / "notes.txt"
+    target.write_text("old\nkeep\n", encoding="utf-8")
+    params = {"path": "notes.txt", "content": "new\nkeep\nextra\n"}
+    tracker = prepare_file_edit_tracker(
+        call_id="call-write",
+        tool_name="write_file",
+        tool=None,
+        workspace=tmp_path,
+        params=params,
+    )
+
+    assert tracker is not None
+    start = build_file_edit_start_event(tracker, params)
+    assert start == {
+        "version": 1,
+        "call_id": "call-write",
+        "tool": "write_file",
+        "path": "notes.txt",
+        "phase": "start",
+        "added": 2,
+        "deleted": 1,
+        "approximate": True,
+        "status": "editing",
+    }
+
+    target.write_text("new\nkeep\nextra\n", encoding="utf-8")
+    end = build_file_edit_end_event(tracker)
+    assert end["phase"] == "end"
+    assert end["status"] == "done"
+    assert end["approximate"] is False
+    assert (end["added"], end["deleted"]) == (2, 1)
+
+
+def test_binary_file_is_reported_but_not_counted(tmp_path: Path) -> None:
+    target = tmp_path / "data.bin"
+    target.write_bytes(b"\x00\x01before")
+    tracker = prepare_file_edit_tracker(
+        call_id="call-bin",
+        tool_name="edit_file",
+        tool=None,
+        workspace=tmp_path,
+        params={"path": "data.bin", "old_text": "before", "new_text": "after"},
+    )
+
+    assert tracker is not None
+    assert not read_file_snapshot(target).countable
+    target.write_bytes(b"\x00\x01after")
+    event = build_file_edit_end_event(tracker)
+    assert event["binary"] is True
+    assert (event["added"], event["deleted"]) == (0, 0)
+
+
+def test_untracked_tools_do_not_prepare_file_edit_tracker(tmp_path: Path) -> None:
+    assert prepare_file_edit_tracker(
+        call_id="call-exec",
+        tool_name="exec",
+        tool=None,
+        workspace=tmp_path,
+        params={"path": "created-by-shell.txt"},
+    ) is None

tests/utils/test_webui_transcript.py

@@ -42,6 +42,62 @@ def test_replay_delta_and_turn_end(tmp_path, monkeypatch) -> None:
     assert msgs[1]["latencyMs"] == 42
 
 
+def test_replay_file_edit_event_creates_file_activity(tmp_path, monkeypatch) -> None:
+    monkeypatch.setattr("nanobot.config.paths.get_data_dir", lambda: tmp_path)
+    key = "websocket:t-file"
+    for ev in (
+        {"event": "user", "chat_id": "t-file", "text": "edit"},
+        {
+            "event": "message",
+            "chat_id": "t-file",
+            "text": 'write_file({"path":"foo.txt"})',
+            "kind": "tool_hint",
+        },
+        {
+            "event": "file_edit",
+            "chat_id": "t-file",
+            "edits": [
+                {
+                    "version": 1,
+                    "call_id": "call-write",
+                    "tool": "write_file",
+                    "path": "foo.txt",
+                    "phase": "end",
+                    "added": 2,
+                    "deleted": 1,
+                    "approximate": False,
+                    "status": "done",
+                },
+            ],
+        },
+    ):
+        append_transcript_object(key, ev)
+
+    msgs = replay_transcript_to_ui_messages(read_transcript_lines(key))
+
+    assert len(msgs) == 3
+    assert msgs[1]["kind"] == "trace"
+    assert msgs[1]["traces"] == ['write_file({"path":"foo.txt"})']
+    assert "fileEdits" not in msgs[1]
+    assert msgs[2]["kind"] == "trace"
+    assert msgs[2]["traces"] == []
+    assert msgs[2]["fileEdits"] == [
+        {
+            "version": 1,
+            "call_id": "call-write",
+            "tool": "write_file",
+            "path": "foo.txt",
+            "phase": "end",
+            "added": 2,
+            "deleted": 1,
+            "approximate": False,
+            "status": "done",
+        },
+    ]
+    assert msgs[2]["activitySegmentId"]
+    assert msgs[2]["activitySegmentId"] != msgs[1]["activitySegmentId"]
+
+
 def test_build_response_schema(monkeypatch, tmp_path) -> None:
     from nanobot.utils.webui_transcript import build_webui_thread_response