Add optional remembered assistant settings

example.env

@@ -2,4 +2,8 @@
 
 # GitHub repo hosting study materials (owner/repo format)
 # Defaults to KunalGupta25/plexi-materials if not set
-# MATERIALS_REPO=KunalGupta25/plexi-materials
+# MATERIALS_REPO=KunalGupta25/plexi-materials
+
+# Secret used to encrypt browser-saved Plexi assistant settings
+# Required for "remember settings on this device"
+# PLEXI_COOKIE_PASSWORD=replace-with-a-long-random-secret

pages/Plexi-Assistant.py

@@ -10,8 +10,19 @@ Flow per user message:
   3. Build focused prompt with retrieved chunks -> call user's LLM
 """
 
+import json
+import os
+
 import requests
 import streamlit as st
+
+try:
+    from streamlit_cookies_manager_ext import EncryptedCookieManager
+
+    COOKIES_MANAGER_AVAILABLE = True
+except ImportError:
+    EncryptedCookieManager = None
+    COOKIES_MANAGER_AVAILABLE = False
 from utils import (
     fetch_rag_index,
     get_manifest,
@@ -104,6 +115,17 @@ PROVIDER_NAMES = list(PROVIDERS.keys())
 PLEXI_GPT_URL = "https://chatgpt.com/g/g-69caa671910481919ce71d19952e34e5-plexi"
 PLEXI_MCP_GUIDE_URL = "https://lazyhuman.notion.site/Setting-Up-Plexi-MCP-for-Claude-and-ChatGPT-336e3502f0918090b69fdbed148e8e55"
 PLEXI_MCP_ENDPOINT = "https://plexi-mcp.vercel.app/api/mcp"
+SAVED_CONFIG_COOKIE = "assistant_config"
+COOKIE_PASSWORD = os.getenv("PLEXI_COOKIE_PASSWORD") or os.getenv("COOKIES_PASSWORD")
+
+cookies = None
+if COOKIE_PASSWORD and COOKIES_MANAGER_AVAILABLE:
+    cookies = EncryptedCookieManager(
+        prefix="plexi/assistant/",
+        password=COOKIE_PASSWORD,
+    )
+    if not cookies.ready():
+        st.stop()
 
 
 def _matches_scope(node, semester: str, subject: str) -> bool:
@@ -118,6 +140,77 @@ def queue_prompt(prompt: str):
     st.rerun()
 
 
+def _saved_config_available():
+    return cookies is not None
+
+
+def _load_saved_config():
+    """Load saved assistant settings from the browser cookie."""
+    if not _saved_config_available():
+        return None
+
+    raw_config = cookies.get(SAVED_CONFIG_COOKIE)
+    if not raw_config:
+        return None
+
+    try:
+        return json.loads(raw_config)
+    except (TypeError, json.JSONDecodeError):
+        del cookies[SAVED_CONFIG_COOKIE]
+        cookies.save()
+        return None
+
+
+def _save_config(config):
+    """Persist assistant settings in the browser cookie."""
+    if not _saved_config_available():
+        return
+
+    cookies[SAVED_CONFIG_COOKIE] = json.dumps(config)
+    cookies.save()
+
+
+def _clear_saved_config():
+    """Remove the saved browser-side assistant settings."""
+    if not _saved_config_available():
+        return
+
+    if SAVED_CONFIG_COOKIE in cookies:
+        del cookies[SAVED_CONFIG_COOKIE]
+        cookies.save()
+
+
+def _current_config(selected_semester=None, selected_subject=None, api_key=None):
+    """Build the current assistant configuration payload."""
+    return {
+        "cfg_provider": st.session_state.get("cfg_provider"),
+        "cfg_base_url": st.session_state.get("cfg_base_url"),
+        "cfg_model": st.session_state.get("cfg_model"),
+        "api_key": api_key if api_key is not None else st.session_state.get("api_key"),
+        "asst_semester": selected_semester
+        if selected_semester is not None
+        else st.session_state.get("asst_semester"),
+        "asst_subject": selected_subject
+        if selected_subject is not None
+        else st.session_state.get("asst_subject"),
+    }
+
+
+def _hydrate_saved_config():
+    """Hydrate session state from a remembered browser config once per load."""
+    if st.session_state.get("_saved_config_hydrated"):
+        return
+
+    saved_config = _load_saved_config()
+    if saved_config:
+        for key, value in saved_config.items():
+            if value and key not in st.session_state:
+                st.session_state[key] = value
+        st.session_state["remember_device"] = True
+
+    st.session_state["_saved_config_hydrated"] = True
+
+
 def render_external_access():
     """Render low-emphasis outbound access actions."""
     st.markdown(
@@ -263,9 +356,33 @@ def render_onboarding(manifest):
             api_key = st.text_input(
                 "API Key",
                 type="password",
+                value=st.session_state.get("api_key", ""),
                 placeholder="Paste your API key here",
             )
 
+        remember_default = bool(
+            st.session_state.get("remember_device") or _load_saved_config()
+        )
+        remember_device = st.checkbox(
+            "Remember these settings on this device",
+            value=remember_default,
+            disabled=not _saved_config_available(),
+            help=(
+                "Saves your provider settings and API key in this browser only."
+                if _saved_config_available()
+                else (
+                    "Install the optional cookie dependency and set "
+                    "PLEXI_COOKIE_PASSWORD to enable saved browser settings."
+                )
+            ),
+        )
+        if not _saved_config_available():
+            st.caption(
+                "Saved browser settings are disabled until "
+                "`streamlit-cookies-manager-ext` is installed and "
+                "`PLEXI_COOKIE_PASSWORD` is set."
+            )
+
         semester_names = sorted(manifest.keys())
         default_semester = st.session_state.get("asst_semester")
         semester_index = (
@@ -311,8 +428,24 @@ def render_onboarding(manifest):
             st.session_state.cfg_model = model_name
             st.session_state.asst_semester = selected_semester
             st.session_state.asst_subject = selected_subject
+            st.session_state.remember_device = remember_device
             if api_key:
                 st.session_state.api_key = api_key
+            elif "api_key" in st.session_state:
+                del st.session_state.api_key
+            if remember_device:
+                _save_config(
+                    {
+                        "cfg_provider": provider_name,
+                        "cfg_base_url": base_url,
+                        "cfg_model": model_name,
+                        "api_key": api_key,
+                        "asst_semester": selected_semester,
+                        "asst_subject": selected_subject,
+                    }
+                )
+            else:
+                _clear_saved_config()
             st.session_state.pop("messages", None)
             st.rerun()
 
@@ -346,6 +479,7 @@ def render_onboarding(manifest):
         )
 
 
+_hydrate_saved_config()
 render_sidebar_intro()
 
 try:
@@ -467,24 +601,70 @@ with st.sidebar:
                 key="sb_api_key",
             )
 
+        remember_sidebar = st.checkbox(
+            "Remember these settings on this device",
+            value=bool(st.session_state.get("remember_device")),
+            disabled=not _saved_config_available(),
+            key="sb_remember_device",
+            help=(
+                "Keeps the selected provider, key, and scope in this browser."
+                if _saved_config_available()
+                else (
+                    "Install the optional cookie dependency and set "
+                    "PLEXI_COOKIE_PASSWORD to enable saved browser settings."
+                )
+            ),
+        )
+
         changed = (
             new_provider != provider_name
             or new_base_url != base_url
             or new_model != model_name
             or new_key != api_key
+            or remember_sidebar != bool(st.session_state.get("remember_device"))
         )
         if changed and new_model:
             if st.button("Apply Changes", use_container_width=True, type="primary"):
                 st.session_state.cfg_provider = new_provider
                 st.session_state.cfg_base_url = new_base_url
                 st.session_state.cfg_model = new_model
+                st.session_state.remember_device = remember_sidebar
                 if new_key:
                     st.session_state.api_key = new_key
                 elif "api_key" in st.session_state:
                     del st.session_state.api_key
+                if remember_sidebar:
+                    _save_config(
+                        {
+                            "cfg_provider": new_provider,
+                            "cfg_base_url": new_base_url,
+                            "cfg_model": new_model,
+                            "api_key": new_key,
+                            "asst_semester": selected_semester,
+                            "asst_subject": selected_subject,
+                        }
+                    )
+                else:
+                    _clear_saved_config()
                 st.session_state.pop("messages", None)
                 st.rerun()
 
+    if _load_saved_config():
+        if st.button("Forget Saved Settings", use_container_width=True):
+            _clear_saved_config()
+            st.session_state.remember_device = False
+            for key in (
+                "cfg_provider",
+                "cfg_base_url",
+                "cfg_model",
+                "api_key",
+                "asst_semester",
+                "asst_subject",
+            ):
+                st.session_state.pop(key, None)
+            st.session_state.pop("messages", None)
+            st.rerun()
+
     if st.button("New Chat", use_container_width=True):
         st.session_state.pop("messages", None)
         st.rerun()
@@ -503,6 +683,15 @@ render_page_header(
 
 render_external_access()
 
+if st.session_state.get("remember_device") and _saved_config_available():
+    desired_config = _current_config(
+        selected_semester=selected_semester,
+        selected_subject=selected_subject,
+        api_key=api_key,
+    )
+    if desired_config != _load_saved_config():
+        _save_config(desired_config)
+
 render_stat_cards(
     [
         {
@@ -636,6 +825,8 @@ if prompt:
                     st.stop()
                 if "AUTH_ERROR" in err_text:
                     st.error(err_text.split(": ", 1)[1])
+                    _clear_saved_config()
+                    st.session_state.remember_device = False
                     if "api_key" in st.session_state:
                         del st.session_state.api_key
                     st.session_state.messages.pop()

requirements.txt

@@ -5,4 +5,5 @@ PyPDF2
 streamlit-pdf-viewer
 llama-index-core
 llama-index-embeddings-huggingface
-sentence-transformers
+sentence-transformers
+streamlit-cookies-manager-ext