Add model selection and local RAG

README.md

@@ -1,6 +1,6 @@
 # llm_web
 
-Local LLM chat web page powered by Ollama and `qwen2.5:7b`.
+Local LLM chat web page powered by Ollama.
 
 ## Run
 
@@ -23,3 +23,26 @@ http://<notebook-ip>:8787
 ```
 
 Chat history is stored locally in `data/chats.json`. The `data/*.json` files are ignored by Git.
+
+## Models
+
+The web UI can switch between installed Ollama models:
+
+- `qwen2.5:7b`: default, best speed/quality balance on this notebook
+- `llama3.1:8b`: available for comparison
+- `qwen2.5:14b`: test-only; can be slow or memory hungry on 16 GB RAM
+- `qwen2.5:3b`: fallback model
+
+Recent quick benchmark:
+
+```text
+qwen2.5:7b   18.0s
+llama3.1:8b  32.4s
+qwen2.5:14b  82.7s
+```
+
+## RAG
+
+RAG is enabled by default. The server indexes local `.md`, `.txt`, `.py`, `.js`, `.html`, `.css`, and `.ps1` files, excluding `.git`, `.venv`, `__pycache__`, and `data`.
+
+Use the `Reindex files` button after adding or editing reference files.

app.js

@@ -5,11 +5,16 @@ const sendButton = document.querySelector("#sendButton");
 const newChatButton = document.querySelector("#newChat");
 const historyEl = document.querySelector("#history");
 const chatTitleEl = document.querySelector("#chatTitle");
+const modelSelect = document.querySelector("#modelSelect");
+const ragToggle = document.querySelector("#ragToggle");
+const ragStatus = document.querySelector("#ragStatus");
+const reindexButton = document.querySelector("#reindexButton");
+const metaLine = document.querySelector("#metaLine");
 
 let activeChatId = null;
 let messages = [];
 
-function addMessage(role, content) {
+function addMessage(role, content, meta = "") {
   const article = document.createElement("article");
   article.className = `message ${role}`;
 
@@ -21,6 +26,13 @@ function addMessage(role, content) {
   bubble.className = "bubble";
   bubble.textContent = content;
 
+  if (meta) {
+    const metaEl = document.createElement("div");
+    metaEl.className = "message-meta";
+    metaEl.textContent = meta;
+    bubble.append(document.createElement("br"), metaEl);
+  }
+
   article.append(avatar, bubble);
   messagesEl.append(article);
   messagesEl.scrollTop = messagesEl.scrollHeight;
@@ -31,7 +43,7 @@ function renderMessages() {
   messagesEl.innerHTML = "";
 
   if (!messages.length) {
-    addMessage("assistant", "안녕하세요. 이 노트북에서 실행되는 로컬 LLM입니다.");
+    addMessage("assistant", "Local LLM is ready. Ask in Korean or English.");
     return;
   }
 
@@ -42,6 +54,32 @@ function setTitle(title) {
   chatTitleEl.textContent = title || "Local LLM";
 }
 
+function selectedModel() {
+  return modelSelect.value || "qwen2.5:7b";
+}
+
+async function loadModels() {
+  const response = await fetch("/api/models");
+  const data = await response.json();
+  modelSelect.innerHTML = "";
+
+  data.models.forEach((model) => {
+    const option = document.createElement("option");
+    option.value = model;
+    option.textContent = model;
+    if (model === data.defaultModel) {
+      option.selected = true;
+    }
+    modelSelect.append(option);
+  });
+}
+
+async function loadRagStatus() {
+  const response = await fetch("/api/rag/status");
+  const data = await response.json();
+  ragStatus.textContent = `RAG: ${data.files} files, ${data.chunks} chunks`;
+}
+
 async function loadHistory() {
   const response = await fetch("/api/chats");
   const data = await response.json();
@@ -62,6 +100,8 @@ async function loadChat(chatId) {
   const data = await response.json();
   activeChatId = data.chat.id;
   messages = data.chat.messages || [];
+  modelSelect.value = data.chat.model || selectedModel();
+  ragToggle.checked = data.chat.useRag !== false;
   setTitle(data.chat.title);
   renderMessages();
   await loadHistory();
@@ -91,6 +131,18 @@ promptInput.addEventListener("keydown", (event) => {
 
 newChatButton.addEventListener("click", resetChat);
 
+reindexButton.addEventListener("click", async () => {
+  reindexButton.disabled = true;
+  ragStatus.textContent = "RAG: indexing";
+  try {
+    const response = await fetch("/api/rag/reindex", { method: "POST" });
+    const data = await response.json();
+    ragStatus.textContent = `RAG: ${data.files} files, ${data.chunks} chunks`;
+  } finally {
+    reindexButton.disabled = false;
+  }
+});
+
 form.addEventListener("submit", async (event) => {
   event.preventDefault();
 
@@ -105,32 +157,49 @@ form.addEventListener("submit", async (event) => {
   messages.push({ role: "user", content });
 
   sendButton.disabled = true;
-  const pending = addMessage("assistant", "생각 중...");
+  const pending = addMessage("assistant", "Thinking...");
 
   try {
     const response = await fetch("/api/chat", {
       method: "POST",
       headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ chatId: activeChatId, messages }),
+      body: JSON.stringify({
+        chatId: activeChatId,
+        messages,
+        model: selectedModel(),
+        useRag: ragToggle.checked,
+      }),
     });
 
     const data = await response.json();
     if (!response.ok) {
-      throw new Error(data.error || "응답 생성 실패");
+      throw new Error(data.error || "Response failed");
     }
 
+    const sourceText = data.sources?.length
+      ? `sources: ${data.sources.map((item) => item.source).join(", ")}`
+      : "no sources";
     pending.textContent = data.reply;
+
+    const meta = document.createElement("div");
+    meta.className = "message-meta";
+    meta.textContent = `${data.model} / ${(data.elapsedMs / 1000).toFixed(1)}s / ${sourceText}`;
+    pending.append(document.createElement("br"), meta);
+
     activeChatId = data.chatId;
     messages = data.chat.messages || [...messages, { role: "assistant", content: data.reply }];
     setTitle(data.chat.title);
+    metaLine.textContent = `${data.model} with RAG ${ragToggle.checked ? "on" : "off"}`;
     await loadHistory();
   } catch (error) {
-    pending.textContent = `오류: ${error.message}`;
+    pending.textContent = `Error: ${error.message}`;
   } finally {
     sendButton.disabled = false;
     promptInput.focus();
   }
 });
 
+loadModels();
+loadRagStatus();
 renderMessages();
 loadHistory();

benchmark_models.py

@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+import time
+
+import ollama
+
+
+MODELS = ["qwen2.5:7b", "llama3.1:8b", "qwen2.5:14b"]
+PROMPT = (
+    "Answer in Korean in exactly three bullets. Compare your usefulness for "
+    "local coding assistance, Korean Q&A, and careful reasoning."
+)
+
+
+def main() -> None:
+    for model in MODELS:
+        started = time.perf_counter()
+        try:
+            response = ollama.chat(
+                model=model,
+                messages=[
+                    {"role": "system", "content": "Be concise and practical."},
+                    {"role": "user", "content": PROMPT},
+                ],
+            )
+            elapsed = time.perf_counter() - started
+            text = response["message"]["content"].strip().replace("\n", " ")
+            print(f"{model}\t{elapsed:.1f}s\t{text[:180]}")
+        except Exception as exc:
+            elapsed = time.perf_counter() - started
+            print(f"{model}\t{elapsed:.1f}s\tERROR: {exc}")
+
+
+if __name__ == "__main__":
+    main()

index.html

@@ -8,24 +8,31 @@
   </head>
   <body>
     <aside class="sidebar">
-      <button class="new-chat" id="newChat" type="button">+ 새 대화</button>
+      <button class="new-chat" id="newChat" type="button">+ New chat</button>
+      <label class="control-label" for="modelSelect">Model</label>
+      <select id="modelSelect" class="select"></select>
+      <label class="toggle">
+        <input id="ragToggle" type="checkbox" checked />
+        <span>Use RAG</span>
+      </label>
+      <button class="secondary" id="reindexButton" type="button">Reindex files</button>
+      <div class="rag-status" id="ragStatus">RAG: loading</div>
       <div class="history" id="history"></div>
-      <div class="model">qwen2.5:7b</div>
     </aside>
 
     <main class="chat-shell">
       <header class="topbar">
         <div>
           <strong id="chatTitle">Local LLM</strong>
-          <span>Ollama on this notebook</span>
+          <span id="metaLine">Ollama on this notebook</span>
         </div>
       </header>
 
       <section class="messages" id="messages" aria-live="polite"></section>
 
       <form class="composer" id="chatForm">
-        <textarea id="prompt" rows="1" placeholder="메시지를 입력하세요" autofocus></textarea>
+        <textarea id="prompt" rows="1" placeholder="Type a message" autofocus></textarea>
-        <button id="sendButton" type="submit">전송</button>
+        <button id="sendButton" type="submit">Send</button>
       </form>
     </main>
 

server.py

@@ -1,11 +1,16 @@
 from __future__ import annotations
 
 import json
+import math
+import re
 import socket
+import time
 import uuid
+from collections import Counter
 from datetime import datetime, timezone
 from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
 from pathlib import Path
+from urllib.parse import urlparse
 
 import ollama
 
@@ -13,9 +18,15 @@ import ollama
 ROOT = Path(__file__).parent
 DATA_DIR = ROOT / "data"
 CHATS_FILE = DATA_DIR / "chats.json"
-MODEL = "qwen2.5:7b"
+DEFAULT_MODEL = "qwen2.5:7b"
+AVAILABLE_MODELS = ["qwen2.5:7b", "llama3.1:8b", "qwen2.5:14b", "qwen2.5:3b"]
 HOST = "0.0.0.0"
 PORT = 8787
+RAG_EXTENSIONS = {".md", ".txt", ".py", ".js", ".html", ".css", ".ps1"}
+RAG_EXCLUDED_DIRS = {".git", ".venv", "__pycache__", "data"}
+
+rag_chunks: list[dict] = []
+rag_indexed_at = ""
 
 
 def now_iso() -> str:
@@ -41,8 +52,114 @@ def chat_title(messages: list[dict]) -> str:
     for message in messages:
         if message.get("role") == "user" and message.get("content"):
             title = " ".join(str(message["content"]).split())
-            return title[:40] or "새 대화"
+            return title[:40] or "New chat"
-    return "새 대화"
+    return "New chat"
+
+
+def installed_models() -> list[str]:
+    try:
+        response = ollama.list()
+    except Exception:
+        return AVAILABLE_MODELS
+
+    names: list[str] = []
+    for model in response.get("models", []):
+        if isinstance(model, dict):
+            name = model.get("name") or model.get("model")
+        else:
+            name = getattr(model, "name", None) or getattr(model, "model", None)
+        if name:
+            names.append(name)
+
+    ordered = [name for name in AVAILABLE_MODELS if name in names]
+    ordered.extend(name for name in names if name not in ordered)
+    return ordered or AVAILABLE_MODELS
+
+
+def tokenize(text: str) -> list[str]:
+    return [token for token in re.findall(r"\w+", text.lower(), flags=re.UNICODE) if len(token) > 1]
+
+
+def iter_rag_files() -> list[Path]:
+    files: list[Path] = []
+    for path in ROOT.rglob("*"):
+        if any(part in RAG_EXCLUDED_DIRS for part in path.relative_to(ROOT).parts):
+            continue
+        if path.is_file() and path.suffix.lower() in RAG_EXTENSIONS:
+            files.append(path)
+    return sorted(files)
+
+
+def chunk_text(path: Path, text: str, size: int = 1800, overlap: int = 250) -> list[dict]:
+    chunks: list[dict] = []
+    start = 0
+    rel = path.relative_to(ROOT).as_posix()
+    while start < len(text):
+        end = min(start + size, len(text))
+        chunk = text[start:end].strip()
+        if chunk:
+            chunks.append({"source": rel, "text": chunk, "tokens": Counter(tokenize(chunk))})
+        if end == len(text):
+            break
+        start = max(0, end - overlap)
+    return chunks
+
+
+def build_rag_index() -> dict:
+    global rag_chunks, rag_indexed_at
+
+    chunks: list[dict] = []
+    for path in iter_rag_files():
+        try:
+            text = path.read_text(encoding="utf-8", errors="replace")
+        except OSError:
+            continue
+        chunks.extend(chunk_text(path, text))
+
+    rag_chunks = chunks
+    rag_indexed_at = now_iso()
+    return rag_status()
+
+
+def rag_status() -> dict:
+    return {
+        "chunks": len(rag_chunks),
+        "indexedAt": rag_indexed_at,
+        "files": len({chunk["source"] for chunk in rag_chunks}),
+    }
+
+
+def search_rag(query: str, limit: int = 5) -> list[dict]:
+    if not rag_chunks:
+        build_rag_index()
+
+    query_tokens = Counter(tokenize(query))
+    if not query_tokens:
+        return []
+
+    scored: list[tuple[float, dict]] = []
+    total = max(1, len(rag_chunks))
+    doc_freq = Counter()
+    for chunk in rag_chunks:
+        for token in chunk["tokens"]:
+            doc_freq[token] += 1
+
+    for chunk in rag_chunks:
+        score = 0.0
+        chunk_tokens = chunk["tokens"]
+        for token, query_count in query_tokens.items():
+            if token not in chunk_tokens:
+                continue
+            idf = math.log((total + 1) / (doc_freq[token] + 1)) + 1
+            score += min(query_count, chunk_tokens[token]) * idf
+        if score:
+            scored.append((score, chunk))
+
+    scored.sort(key=lambda item: item[0], reverse=True)
+    return [
+        {"source": chunk["source"], "text": chunk["text"], "score": round(score, 3)}
+        for score, chunk in scored[:limit]
+    ]
 
 
 class Handler(SimpleHTTPRequestHandler):
@@ -50,21 +167,35 @@ class Handler(SimpleHTTPRequestHandler):
         super().__init__(*args, directory=str(ROOT), **kwargs)
 
     def do_GET(self) -> None:
-        if self.path == "/api/chats":
+        path = urlparse(self.path).path
+
+        if path == "/api/models":
+            self._send_json(200, {"defaultModel": DEFAULT_MODEL, "models": installed_models()})
+            return
+
+        if path == "/api/rag/status":
+            if not rag_chunks:
+                build_rag_index()
+            self._send_json(200, rag_status())
+            return
+
+        if path == "/api/chats":
             store = read_store()
             chats = [
                 {
                     "id": chat["id"],
-                    "title": chat.get("title", "새 대화"),
+                    "title": chat.get("title", "New chat"),
                     "updatedAt": chat.get("updatedAt", ""),
+                    "model": chat.get("model", DEFAULT_MODEL),
+                    "useRag": chat.get("useRag", True),
                 }
                 for chat in store.get("chats", [])
             ]
             self._send_json(200, {"chats": chats})
             return
 
-        if self.path.startswith("/api/chats/"):
+        if path.startswith("/api/chats/"):
-            chat_id = self.path.rsplit("/", 1)[-1]
+            chat_id = path.rsplit("/", 1)[-1]
             store = read_store()
             chat = next((item for item in store.get("chats", []) if item["id"] == chat_id), None)
             if not chat:
@@ -77,7 +208,12 @@ class Handler(SimpleHTTPRequestHandler):
         super().do_GET()
 
     def do_POST(self) -> None:
-        if self.path != "/api/chat":
+        path = urlparse(self.path).path
+        if path == "/api/rag/reindex":
+            self._send_json(200, build_rag_index())
+            return
+
+        if path != "/api/chat":
             self.send_error(404)
             return
 
@@ -85,38 +221,59 @@ class Handler(SimpleHTTPRequestHandler):
         data = json.loads(self.rfile.read(length) or b"{}")
         chat_id = data.get("chatId")
         messages = data.get("messages", [])
+        model = data.get("model") or DEFAULT_MODEL
+        use_rag = bool(data.get("useRag", True))
 
         try:
+            sources = search_rag(messages[-1]["content"]) if use_rag and messages else []
+            system_prompt = (
+                "You are a concise local assistant. Reply in Korean unless the user asks otherwise. "
+                "If reference context is provided, use it and mention source filenames when useful. "
+                "If the context is not enough, say so clearly."
+            )
+            if sources:
+                context = "\n\n".join(
+                    f"[{index + 1}] {item['source']}\n{item['text']}" for index, item in enumerate(sources)
+                )
+                system_prompt += f"\n\nReference context:\n{context}"
+
+            started = time.perf_counter()
             response = ollama.chat(
-                model=MODEL,
+                model=model,
                 messages=[
-                    {
+                    {"role": "system", "content": system_prompt},
-                        "role": "system",
-                        "content": "You are a concise local assistant. Reply in Korean unless the user asks otherwise.",
-                    },
                     *messages,
                 ],
             )
+            elapsed_ms = round((time.perf_counter() - started) * 1000)
             reply = response["message"]["content"]
             saved_messages = [*messages, {"role": "assistant", "content": reply}]
-            chat = self._save_chat(chat_id, saved_messages)
+            chat = self._save_chat(chat_id, saved_messages, model, use_rag)
-            payload = {"chatId": chat["id"], "reply": reply, "chat": chat}
+            payload = {
+                "chatId": chat["id"],
+                "reply": reply,
+                "chat": chat,
+                "model": model,
+                "elapsedMs": elapsed_ms,
+                "sources": [{"source": item["source"], "score": item["score"]} for item in sources],
+            }
             self._send_json(200, payload)
         except Exception as exc:
             self._send_json(500, {"error": str(exc)})
 
     def do_DELETE(self) -> None:
-        if not self.path.startswith("/api/chats/"):
+        path = urlparse(self.path).path
+        if not path.startswith("/api/chats/"):
             self.send_error(404)
             return
 
-        chat_id = self.path.rsplit("/", 1)[-1]
+        chat_id = path.rsplit("/", 1)[-1]
         store = read_store()
         store["chats"] = [item for item in store.get("chats", []) if item["id"] != chat_id]
         write_store(store)
         self._send_json(200, {"ok": True})
 
-    def _save_chat(self, chat_id: str | None, messages: list[dict]) -> dict:
+    def _save_chat(self, chat_id: str | None, messages: list[dict], model: str, use_rag: bool) -> dict:
         store = read_store()
         chats = store.setdefault("chats", [])
         chat = next((item for item in chats if item["id"] == chat_id), None)
@@ -132,12 +289,14 @@ class Handler(SimpleHTTPRequestHandler):
 
         chat["title"] = chat_title(messages)
         chat["messages"] = messages
+        chat["model"] = model
+        chat["useRag"] = use_rag
         chat["updatedAt"] = now_iso()
         chats.sort(key=lambda item: item.get("updatedAt", ""), reverse=True)
         write_store(store)
         return chat
 
-    def _send_json(self, status: int, payload: dict[str, str]) -> None:
+    def _send_json(self, status: int, payload: dict) -> None:
         body = json.dumps(payload, ensure_ascii=False).encode("utf-8")
         self.send_response(status)
         self.send_header("content-type", "application/json; charset=utf-8")
@@ -147,6 +306,7 @@ class Handler(SimpleHTTPRequestHandler):
 
 
 def main() -> None:
+    build_rag_index()
     server = ThreadingHTTPServer((HOST, PORT), Handler)
     local_ip = socket.gethostbyname(socket.gethostname())
     print(f"LLM web is running locally at http://127.0.0.1:{PORT}")

styles.css

@@ -34,7 +34,9 @@ body {
 }
 
 .new-chat,
-.history-item {
+.history-item,
+.secondary,
+.select {
   width: 100%;
   min-height: 42px;
   border: 1px solid #3a3a3a;
@@ -47,8 +49,43 @@ body {
   cursor: pointer;
 }
 
+.select {
+  appearance: none;
+  background: var(--sidebar-soft);
+}
+
+.secondary {
+  text-align: center;
+  background: var(--sidebar-soft);
+}
+
+.secondary:disabled {
+  cursor: wait;
+  opacity: 0.6;
+}
+
+.control-label,
+.toggle,
+.rag-status,
+.message-meta {
+  color: #b8b8b8;
+  font-size: 12px;
+}
+
+.toggle {
+  min-height: 32px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.rag-status {
+  padding: 0 4px 8px;
+}
+
 .history {
   flex: 1;
+  overflow: auto;
 }
 
 .history-item.active {
@@ -125,6 +162,12 @@ body {
   overflow-wrap: anywhere;
 }
 
+.message-meta {
+  display: inline-block;
+  margin-top: 8px;
+  color: var(--muted);
+}
+
 .composer {
   position: fixed;
   left: 260px;