diff --git a/server/app_legacy.py b/server/app_legacy.py
index ba23f6d8..678fac6a 100644
--- a/server/app_legacy.py
+++ b/server/app_legacy.py
@@ -34,6 +34,7 @@ from server.status import status_bp
 from server.tasks import tasks_bp
 from server.api_v1 import api_v1_bp
 from server.multi_agent import multi_agent_bp
+from server.conversation_bootstrap import conversation_bootstrap_bp
 from server.socket_handlers import socketio
 from server.security import attach_security_hooks
 from werkzeug.utils import secure_filename
@@ -298,6 +299,7 @@ app.register_blueprint(status_bp)
 app.register_blueprint(tasks_bp)
 app.register_blueprint(api_v1_bp)
 app.register_blueprint(multi_agent_bp)
+app.register_blueprint(conversation_bootstrap_bp)
 
 # 安全钩子（CSRF 校验 + 响应头）
 attach_security_hooks(app)
diff --git a/server/conversation_bootstrap.py b/server/conversation_bootstrap.py
new file mode 100644
index 00000000..331bbf04
--- /dev/null
+++ b/server/conversation_bootstrap.py
@@ -0,0 +1,237 @@
+"""对话进入聚合接口（方案 B：统一加载协议）。
+
+GET /api/conversations/<id>/bootstrap 一次性返回进入对话所需的全部数据：
+元数据、文件态消息、运行状态聚合与任务重放决策（needs_rebuild/replay_from）。
+
+只读语义：不写对话文件、不调用 terminal.load_conversation、不切换工作区级 terminal
+的当前上下文，天然规避 safe_nav 双轨问题与旧内存回写面。为聚合后台运行状态，
+会按需获取/创建对话级 terminal（与既有 running-status 端点行为一致，属内存态操作）。
+设计文档：docs/conversation_load_unification_plan.md
+"""
+from __future__ import annotations
+
+from typing import Any, Dict, List, Optional
+
+from flask import Blueprint, jsonify, request, session
+
+from server.auth_helpers import api_login_required, get_current_username
+from server.context import get_user_resources
+from server.tasks import task_manager
+from server.tasks.helpers import _task_public_payload
+from server.utils_common import debug_log
+
+conversation_bootstrap_bp = Blueprint("conversation_bootstrap", __name__)
+
+_ACTIVE_TASK_STATUSES = {"pending", "running", "cancel_requested"}
+
+# 与前端 compression.ts needsRebuild 判据中的事件类型集合对齐
+_ASSISTANT_RESPONSE_EVENTS = {
+    "ai_message_start", "thinking_start", "thinking_chunk", "thinking_end",
+    "text_start", "text_chunk", "text_end",
+    "tool_preparing", "tool_start", "tool_update", "tool_complete",
+}
+_ASSISTANT_CONTENT_EVENTS = {
+    "thinking_chunk", "text_chunk",
+    "tool_preparing", "tool_start", "tool_update", "tool_complete",
+}
+
+
+def _normalize_conv_id(conversation_id: str) -> str:
+    conv = (conversation_id or "").strip()
+    if not conv:
+        return conv
+    return conv if conv.startswith("conv_") else f"conv_{conv}"
+
+
+def _find_active_main_task(username: str, normalized_id: str):
+    """取该对话最新的活动主任务（对齐 running-status 语义，rec 侧做前缀归一）。"""
+    main_rec = None
+    for rec in task_manager.list_tasks(username):
+        rec_cid = _normalize_conv_id(getattr(rec, "conversation_id", "") or "")
+        if rec_cid != normalized_id or rec.status not in _ACTIVE_TASK_STATUSES:
+            continue
+        if main_rec is None or rec.created_at > main_rec.created_at:
+            main_rec = rec
+    return main_rec
+
+
+def _analyze_task_events(events: List[Dict[str, Any]]) -> Dict[str, bool]:
+    """分析任务事件流的流式状态（移植自前端 compression.ts needsRebuild 判据）。"""
+    in_thinking = False
+    in_text = False
+    has_text_chunk_event = False
+    has_assistant_response_event = False
+    has_assistant_content_event = False
+    for event in events:
+        event_type = str((event or {}).get("type") or "")
+        if event_type in _ASSISTANT_RESPONSE_EVENTS:
+            has_assistant_response_event = True
+        if event_type in _ASSISTANT_CONTENT_EVENTS:
+            has_assistant_content_event = True
+        if event_type == "thinking_start":
+            in_thinking = True
+        elif event_type == "thinking_end":
+            in_thinking = False
+        if event_type == "text_start":
+            in_text = True
+        elif event_type == "text_end":
+            in_text = False
+        if event_type == "text_chunk":
+            has_text_chunk_event = True
+    return {
+        "in_thinking": in_thinking,
+        "in_text": in_text,
+        "has_text_chunk_event": has_text_chunk_event,
+        "has_assistant_response_event": has_assistant_response_event,
+        "has_assistant_content_event": has_assistant_content_event,
+        "force_rebuild_for_streaming_text": in_text or has_text_chunk_event or in_thinking,
+    }
+
+
+def _is_empty_assistant_message(message: Optional[Dict[str, Any]]) -> bool:
+    """文件态的「空 assistant」：无正文、无思考内容、无工具调用。
+
+    对应前端判据「末条 assistant 无 actions」——actions 是渲染层结构，
+    文件态用内容字段等价判断。
+    """
+    if not isinstance(message, dict):
+        return True
+    if str(message.get("content") or "").strip():
+        return False
+    if str(message.get("reasoning_content") or "").strip():
+        return False
+    if message.get("tool_calls"):
+        return False
+    return True
+
+
+def _decide_task_replay(messages: List[Dict[str, Any]], events: List[Dict[str, Any]]) -> Dict[str, Any]:
+    """移植前端 needsRebuild 判据：任一成立即 needs_rebuild=True。
+
+    1. 文件态末条不是 assistant（任务产生的 assistant 内容未落盘）；
+    2. 文件态末条是空 assistant；
+    3. 事件流处于流式中段（inText / hasTextChunkEvent / inThinking）；
+    4. 文件态末条 assistant 带 tool_calls（工具结果消息尚未落盘，视为进行中）。
+    """
+    last_message = messages[-1] if messages else None
+    is_assistant = isinstance(last_message, dict) and last_message.get("role") == "assistant"
+    event_state = _analyze_task_events(events)
+    empty_assistant = _is_empty_assistant_message(last_message) if is_assistant else False
+    has_pending_tool_calls = bool(
+        is_assistant and isinstance(last_message, dict) and last_message.get("tool_calls")
+    )
+
+    needs_rebuild = (
+        not is_assistant
+        or empty_assistant
+        or event_state["force_rebuild_for_streaming_text"]
+        or has_pending_tool_calls
+    )
+
+    event_count = len(events)
+    return {
+        "event_count": event_count,
+        "needs_rebuild": needs_rebuild,
+        "replay_from": 0 if needs_rebuild else event_count,
+        "decision_inputs": {
+            "is_assistant_last": is_assistant,
+            "empty_assistant_last": empty_assistant,
+            "has_pending_tool_calls": has_pending_tool_calls,
+            **event_state,
+        },
+    }
+
+
+@conversation_bootstrap_bp.route("/api/conversations/<conversation_id>/bootstrap", methods=["GET"])
+@api_login_required
+def bootstrap_conversation(conversation_id: str):
+    """进入对话聚合接口：meta + messages + running + task_replay（纯只读）。"""
+    username = get_current_username()
+    normalized_id = _normalize_conv_id(conversation_id)
+    if not normalized_id:
+        return jsonify({"success": False, "error": "缺少 conversation_id"}), 400
+
+    workspace_id = (request.args.get("workspace_id") or "").strip() or None
+
+    # 工作区级资源：只取 context_manager 读文件，绝不调用 load_conversation
+    try:
+        ws_terminal, _workspace = get_user_resources(username, workspace_id=workspace_id)
+    except RuntimeError as exc:
+        return jsonify({"success": False, "error": str(exc)}), 503
+
+    ctx_manager = getattr(ws_terminal, "context_manager", None)
+    if ctx_manager is None:
+        return jsonify({"success": False, "error": "终端上下文不可用"}), 503
+
+    cm = ctx_manager._get_conversation_manager_for_id(normalized_id)
+    conversation_data = cm.load_conversation(normalized_id) if cm else None
+    if not conversation_data:
+        return jsonify({"success": False, "error": f"对话 {normalized_id} 不存在"}), 404
+
+    raw_meta = conversation_data.get("metadata", {}) or {}
+    messages = conversation_data.get("messages", []) or []
+    run_mode = raw_meta.get("run_mode") or ("thinking" if raw_meta.get("thinking_mode") else "fast")
+
+    # 运行状态聚合（对齐 tasks/api.py running-status：主 task + 三类后台）
+    main_rec = _find_active_main_task(username, normalized_id)
+    effective_workspace_id = (
+        workspace_id
+        or (getattr(main_rec, "workspace_id", None) if main_rec else None)
+        or (session.get("workspace_id") or None)
+    )
+    bg_status = {
+        "has_running_sub_agents": False,
+        "has_running_background_commands": False,
+        "has_running_multi_agent": False,
+    }
+    try:
+        conv_terminal, _ = get_user_resources(
+            username, workspace_id=effective_workspace_id, conversation_id=normalized_id
+        )
+    except Exception as exc:
+        debug_log(f"[Bootstrap] 获取对话级终端失败: {exc}")
+        conv_terminal = None
+    if conv_terminal is not None:
+        bg_status = task_manager.get_conversation_running_status(conv_terminal, normalized_id)
+
+    is_main_running = main_rec is not None
+    running = {
+        "is_main_running": is_main_running,
+        "main_task_id": getattr(main_rec, "task_id", None) if main_rec else None,
+        "main_task_type": getattr(main_rec, "task_type", "chat") if main_rec else None,
+        **bg_status,
+        "is_truly_active": is_main_running or any(bg_status.values()),
+    }
+
+    data: Dict[str, Any] = {
+        "conversation_id": normalized_id,
+        "meta": {
+            "title": conversation_data.get("title", "未知对话"),
+            "run_mode": run_mode,
+            "thinking_mode": bool(raw_meta.get("thinking_mode", run_mode != "fast")),
+            "model_key": raw_meta.get("model_key"),
+            "multi_agent_mode": bool(raw_meta.get("multi_agent_mode", False)),
+            "permission_mode": raw_meta.get("permission_mode") or "",
+            "execution_mode": raw_meta.get("execution_mode") or "",
+            "network_permission": raw_meta.get("network_permission") or "",
+            "messages_count": len(messages),
+        },
+        "messages": messages,
+        "running": running,
+    }
+
+    if is_main_running:
+        events = list(getattr(main_rec, "events", []) or [])
+        replay = _decide_task_replay(messages, events)
+        replay["task_id"] = main_rec.task_id
+        # 任务摘要与全量事件：前端恢复时免去 GET /api/tasks 与 GET /api/tasks/{id} 两次请求
+        replay["task"] = _task_public_payload(main_rec)
+        replay["events"] = events
+        data["task_replay"] = replay
+        debug_log(
+            f"[Bootstrap] conv={normalized_id} task={main_rec.task_id} "
+            f"events={replay['event_count']} needs_rebuild={replay['needs_rebuild']} "
+            f"inputs={replay['decision_inputs']}"
+        )
+
+    return jsonify({"success": True, "data": data})