feat: knowledge base for long-term memory (#1099)

backend/app/agent/factory/developer.py

@@ -25,6 +25,7 @@
 from app.service.task import Agents
 from app.utils.file_utils import get_working_directory
 from app.utils.toolkit.human_toolkit import HumanToolkit
+from app.utils.toolkit.knowledge_base_toolkit import KnowledgeBaseToolkit
 
 # TODO: Remove NoteTakingToolkit and use TerminalToolkit instead
 from app.utils.toolkit.note_taking_toolkit import NoteTakingToolkit
@@ -69,6 +70,10 @@ async def developer_agent(options: Chat):
         clone_current_env=True,
     )
     terminal_toolkit = message_integration.register_toolkits(terminal_toolkit)
+    knowledge_base_toolkit = KnowledgeBaseToolkit(
+        api_task_id=options.project_id,
+        agent_name=Agents.developer_agent,
+    )
 
     tools = [
         *HumanToolkit.get_can_use_tools(
@@ -78,6 +83,7 @@ async def developer_agent(options: Chat):
         *web_deploy_toolkit.get_tools(),
         *terminal_toolkit.get_tools(),
         *screenshot_toolkit.get_tools(),
+        *knowledge_base_toolkit.get_tools(),
     ]
     system_message = DEVELOPER_SYS_PROMPT.format(
         platform_system=platform.system(),
@@ -99,5 +105,6 @@ async def developer_agent(options: Chat):
             TerminalToolkit.toolkit_name(),
             NoteTakingToolkit.toolkit_name(),
             WebDeployToolkit.toolkit_name(),
+            KnowledgeBaseToolkit.toolkit_name(),
         ],
     )

backend/app/agent/prompt.py

@@ -374,6 +374,9 @@
 
 <mandatory_instructions>
 - You MUST use the `read_note` tool to read the ALL notes from other agents.
+- Use the `remember_this` tool to save important facts, decisions, or preferences
+  to the project's long-term knowledge base when the user or task establishes
+  something that should be remembered for future conversations.
 
 You SHOULD keep the user informed by providing message_title and message_description
     parameters when calling tools. These optional parameters are available on all tools

backend/app/agent/tools.py

@@ -29,6 +29,7 @@
 from app.utils.toolkit.google_drive_mcp_toolkit import GoogleDriveMCPToolkit
 from app.utils.toolkit.google_gmail_mcp_toolkit import GoogleGmailMCPToolkit
 from app.utils.toolkit.image_analysis_toolkit import ImageAnalysisToolkit
+from app.utils.toolkit.knowledge_base_toolkit import KnowledgeBaseToolkit
 from app.utils.toolkit.lark_toolkit import LarkToolkit
 from app.utils.toolkit.linkedin_toolkit import LinkedInToolkit
 from app.utils.toolkit.mcp_search_toolkit import McpSearchToolkit
@@ -62,6 +63,7 @@ async def get_toolkits(tools: list[str], agent_name: str, api_task_id: str):
         "google_drive_mcp_toolkit": GoogleDriveMCPToolkit,
         "google_gmail_mcp_toolkit": GoogleGmailMCPToolkit,
         "image_analysis_toolkit": ImageAnalysisToolkit,
+        "knowledge_base_toolkit": KnowledgeBaseToolkit,
         "linkedin_toolkit": LinkedInToolkit,
         "lark_toolkit": LarkToolkit,
         "mcp_search_toolkit": McpSearchToolkit,

backend/app/controller/knowledge_controller.py

@@ -0,0 +1,88 @@
+# ========= Copyright 2025-2026 @ Eigent.ai All Rights Reserved. =========
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ========= Copyright 2025-2026 @ Eigent.ai All Rights Reserved. =========
+
+from fastapi import APIRouter, HTTPException, Query
+from pydantic import BaseModel, Field
+
+from app.utils.knowledge_base import add_entry, get_entries, delete_entry
+
+router = APIRouter(prefix="/knowledge", tags=["Knowledge Base"])
+
+
+class KnowledgeAddIn(BaseModel):
+    """Request body for adding a knowledge entry."""
+
+    project_id: str = Field(..., description="Project ID (scope for this entry)")
+    content: str = Field(..., min_length=1, description="Content to store as long-term memory")
+
+
+class KnowledgeAddOut(BaseModel):
+    """Response after adding a knowledge entry."""
+
+    id: int
+    project_id: str
+    message: str = "Knowledge entry added"
+
+
+class KnowledgeEntryOut(BaseModel):
+    """A single knowledge entry."""
+
+    id: int
+    project_id: str
+    content: str
+    created_at: float
+
+
+@router.post("", name="add knowledge", response_model=KnowledgeAddOut)
+async def knowledge_add(body: KnowledgeAddIn):
+    """Add a knowledge entry for long-term memory (issue #1099)."""
+    try:
+        entry_id = add_entry(project_id=body.project_id, content=body.content)
+        return KnowledgeAddOut(id=entry_id, project_id=body.project_id)
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("", name="list knowledge")
+async def knowledge_list(
+    project_id: str = Query(..., description="Project ID"),
+    query: str | None = Query(None, description="Optional keyword filter"),
+    limit: int = Query(50, ge=1, le=200, description="Max entries to return"),
+):
+    """List knowledge entries for a project, optionally filtered by keyword."""
+    try:
+        entries = get_entries(project_id=project_id, query=query, limit=limit)
+        return {"project_id": project_id, "entries": entries}
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.delete("/{entry_id}", name="delete knowledge")
+async def knowledge_delete(
+    entry_id: int,
+    project_id: str = Query(..., description="Project ID"),
+):
+    """Delete a knowledge entry by id (scoped to project)."""
+    try:
+        deleted = delete_entry(project_id=project_id, entry_id=entry_id)
+        if not deleted:
+            raise HTTPException(
+                status_code=404,
+                detail=f"Knowledge entry {entry_id} not found for project {project_id}",
+            )
+        return {"deleted": True, "id": entry_id}
+    except HTTPException:
+        raise
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))

backend/app/router.py

@@ -13,17 +13,16 @@
 # ========= Copyright 2025-2026 @ Eigent.ai All Rights Reserved. =========
 """
 Centralized router registration for the Eigent API.
-All routers are explicitly registered here
-for better visibility and maintainability.
+All routers are explicitly registered here for better visibility and maintainability.
 """
 
 import logging
 
 from fastapi import FastAPI
-
 from app.controller import (
     chat_controller,
     health_controller,
+    knowledge_controller,
     model_controller,
     task_controller,
     tool_controller,
@@ -71,6 +70,11 @@ def register_routers(app: FastAPI, prefix: str = "") -> None:
             "tags": ["tool"],
             "description": "Tool installation and management",
         },
+        {
+            "router": knowledge_controller.router,
+            "tags": ["Knowledge Base"],
+            "description": "Knowledge base for long-term memory (issue #1099)",
+        },
     ]
 
     for config in routers_config:
@@ -79,9 +83,7 @@ def register_routers(app: FastAPI, prefix: str = "") -> None:
         )
         route_count = len(config["router"].routes)
         logger.info(
-            f"Registered {config['tags'][0]} router:"
-            f" {route_count} routes -"
-            f" {config['description']}"
+            f"Registered {config['tags'][0]} router: {route_count} routes - {config['description']}"
         )
 
     logger.info(f"Total routers registered: {len(routers_config)}")

backend/app/service/chat_service.py

@@ -48,13 +48,15 @@
     ActionImproveData,
     ActionInstallMcpData,
     ActionNewAgent,
+    ActionTimeoutData,
     Agents,
     TaskLock,
     delete_task_lock,
     set_current_task_id,
 )
 from app.utils.event_loop_utils import set_main_event_loop
 from app.utils.file_utils import get_working_directory
+from app.utils.knowledge_base import get_context_for_prompt as get_knowledge_context
 from app.utils.server.sync_step import sync_step
 from app.utils.telemetry.workforce_metrics import WorkforceMetricsCallback
 from app.utils.toolkit.human_toolkit import HumanToolkit
@@ -235,24 +237,43 @@ def check_conversation_history_length(
 
 
 def build_conversation_context(
-    task_lock: TaskLock, header: str = "=== CONVERSATION HISTORY ==="
+    task_lock: TaskLock,
+    header: str = "=== CONVERSATION HISTORY ===",
+    query: str | None = None,
 ) -> str:
     """Build conversation context from task_lock history
     with files listed only once at the end.
+    Prepends knowledge base (long-term memory) entries when available.
 
     Args:
         task_lock: TaskLock containing conversation history
         header: Header text for the context section
+        query: Optional user query to filter relevant knowledge base entries
 
     Returns:
-        Formatted context string with task history
-        and files listed once at the end
+        Formatted context string with knowledge base (if any),
+        task history and files listed once at the end
     """
     context = ""
+    try:
+        kb_context = get_knowledge_context(
+            project_id=task_lock.id,
+            query=query,
+            max_chars=4000,
+            limit_entries=20,
+        )
+        if kb_context:
+            context = kb_context
+    except Exception as e:
+        logger.warning(
+            "Failed to load knowledge base context",
+            extra={"error": str(e)},
+        )
+
     working_directories = set()  # Collect all unique working directories
 
     if task_lock.conversation_history:
-        context = f"{header}\n"
+        context += f"{header}\n"
 
         for entry in task_lock.conversation_history:
             if entry["role"] == "task_result":
@@ -531,7 +552,9 @@ async def step_solve(options: Chat, request: Request, task_lock: TaskLock):
                         "without workforce"
                     )
                     conv_ctx = build_conversation_context(
-                        task_lock, header="=== Previous Conversation ==="
+                        task_lock,
+                        header="=== Previous Conversation ===",
+                        query=question,
                     )
                     simple_answer_prompt = (
                         f"{conv_ctx}"
@@ -1222,6 +1245,7 @@ async def run_decomposition():
                             conv_ctx = build_conversation_context(
                                 task_lock,
                                 header="=== Previous Conversation ===",
+                                query=new_task_content,
                             )
                             simple_answer_prompt = (
                                 f"{conv_ctx}"
@@ -1945,7 +1969,9 @@ async def question_confirm(
     context_prompt = ""
     if task_lock:
         context_prompt = build_conversation_context(
-            task_lock, header="=== Previous Conversation ==="
+            task_lock,
+            header="=== Previous Conversation ===",
+            query=prompt,
         )
 
     full_prompt = f"""{context_prompt}User Query: {prompt}