From f4cded781b634a6ade034979c287da0543dbb65c Mon Sep 17 00:00:00 2001
From: ciregenz <ciregenz@berkeley.edu>
Date: Mon, 27 Apr 2026 15:09:25 -0700
Subject: [PATCH] [eric] App Builder fixes: preview loads (auth-token threaded
 into iframe URL + sub-resource paths), agent keeps running when you switch
 tabs    (session+workspace persisted on the app), Settings default
 model/thinking now flow into App + Skill Builder drafts

---
 .gitattributes                                |   1 +
 backend/apps/outputs/models.py                |   9 ++
 backend/apps/outputs/outputs.py               |  59 +++++++++-
 backend/main.py                               |   5 +-
 .../src/app/pages/Skills/SkillBuilderChat.tsx |  47 +++++++-
 frontend/src/app/pages/Views/ViewEditor.tsx   | 110 +++++++++++++++++-
 frontend/src/app/pages/Views/ViewPreview.tsx  |  21 +++-
 frontend/src/shared/state/agentsSlice.ts      |  14 ++-
 frontend/src/shared/state/outputsSlice.ts     |   4 +
 9 files changed, 253 insertions(+), 17 deletions(-)
 create mode 100644 .gitattributes

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 00000000..0282f448
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+backend/mcp-bundles/** linguist-vendored
diff --git a/backend/apps/outputs/models.py b/backend/apps/outputs/models.py
index 79e1b922..e25658a6 100644
--- a/backend/apps/outputs/models.py
+++ b/backend/apps/outputs/models.py
@@ -27,6 +27,11 @@ class Output(BaseModel):
     permission: str = "ask"
     auto_run_config: Optional[AutoRunConfig] = None
     thumbnail: Optional[str] = None
+    # Linkage so reopening the App Builder reattaches to the in-progress session
+    # and reuses the same on-disk workspace folder instead of seeding a fresh one
+    # (which would orphan the running agent + lose chat history on every navigate).
+    session_id: Optional[str] = None
+    workspace_id: Optional[str] = None
     created_at: str = Field(default_factory=lambda: datetime.now().isoformat())
     updated_at: str = Field(default_factory=lambda: datetime.now().isoformat())
 
@@ -71,6 +76,8 @@ class OutputCreate(BaseModel):
     files: dict[str, str] = Field(default_factory=dict)
     auto_run_config: Optional[dict[str, Any]] = None
     thumbnail: Optional[str] = None
+    session_id: Optional[str] = None
+    workspace_id: Optional[str] = None
 
     @model_validator(mode="before")
     @classmethod
@@ -101,6 +108,8 @@ class OutputUpdate(BaseModel):
     permission: Optional[str] = None
     auto_run_config: Optional[dict[str, Any]] = None
     thumbnail: Optional[str] = None
+    session_id: Optional[str] = None
+    workspace_id: Optional[str] = None
 
     @model_validator(mode="before")
     @classmethod
diff --git a/backend/apps/outputs/outputs.py b/backend/apps/outputs/outputs.py
index eea536ad..4f82d622 100644
--- a/backend/apps/outputs/outputs.py
+++ b/backend/apps/outputs/outputs.py
@@ -1,5 +1,6 @@
 import json
 import os
+import re
 import logging
 import mimetypes
 import base64
@@ -7,6 +8,7 @@ from datetime import datetime
 from contextlib import asynccontextmanager
 from fastapi import HTTPException, Query
 from fastapi.responses import Response
+from backend.auth import get_auth_token
 from jsonschema import validate as schema_validate, ValidationError as SchemaValidationError
 from backend.config.Apps import SubApp
 from backend.apps.outputs.models import (
@@ -79,6 +81,53 @@ def _inject_data_into_html(html: str, input_json: str = "{}", result_json: str =
     return f"{injection}\n{html}"
 
 
+# URL schemes / prefixes that must NOT have ?token= appended. These are either
+# external (CDNs, mailto) or non-network references that the auth middleware
+# never sees. Anything else is treated as a same-origin relative URL pointing
+# at our /api/outputs/.../serve/ subtree, which DOES need the token.
+_ABSOLUTE_URL_PREFIXES = (
+    "http://", "https://", "//", "data:", "blob:",
+    "mailto:", "tel:", "javascript:", "about:", "#",
+)
+
+_HREF_SRC_ATTR_RE = re.compile(
+    r"""(\s(?:href|src))\s*=\s*(["'])([^"']+)\2""",
+    re.IGNORECASE,
+)
+
+
+def _inject_token_into_relative_urls(html: str, token: str) -> str:
+    """Append `?token=<t>` to every relative href/src in the served HTML.
+
+    Browsers strip the parent iframe URL's query string before resolving
+    relative `<link href="styles.css">` / `<script src="x.js">`, so without
+    this rewrite the sub-resource fetch lands at the auth middleware with no
+    credentials and gets a 401. Idempotent: skips URLs that already carry a
+    `token=` param. Skips absolute URLs (CDN, data:, etc.) — see prefix list.
+    """
+    if not token:
+        return html
+
+    def _patch(match: re.Match) -> str:
+        attr, quote, url = match.group(1), match.group(2), match.group(3)
+        lowered = url.lower().lstrip()
+        if lowered.startswith(_ABSOLUTE_URL_PREFIXES):
+            return match.group(0)
+        if "token=" in url:
+            return match.group(0)
+        # Split off any hash fragment so `?token=` lands in the query, not in
+        # the fragment: `page.html?v=1#sec` → `page.html?v=1&token=X#sec`.
+        hash_idx = url.find("#")
+        if hash_idx >= 0:
+            base, frag = url[:hash_idx], url[hash_idx:]
+        else:
+            base, frag = url, ""
+        sep = "&" if "?" in base else "?"
+        return f'{attr}={quote}{base}{sep}token={token}{frag}{quote}'
+
+    return _HREF_SRC_ATTR_RE.sub(_patch, html)
+
+
 def _decode_data_param(d: str) -> tuple[str, str]:
     """Decode the base64-encoded _d query param into (input_json, result_json)."""
     try:
@@ -170,6 +219,10 @@ async def serve_workspace_file(workspace_id: str, filepath: str, _d: str = ""):
     if filepath == "index.html":
         input_json, result_json = _decode_data_param(_d) if _d else ("{}", "null")
         content = _inject_data_into_html(content, input_json, result_json)
+        # Iframe sub-resource fetches (<link>, <script src>, <img>) drop the
+        # parent's ?token= query string, so rewrite the HTML to put the token
+        # back on every relative URL — otherwise sub-resources 401.
+        content = _inject_token_into_relative_urls(content, get_auth_token())
 
     mime, _ = mimetypes.guess_type(filepath)
     return Response(content=content, media_type=mime or "text/plain")
@@ -186,6 +239,7 @@ async def serve_output_file(output_id: str, filepath: str, _d: str = ""):
     if filepath == "index.html":
         input_json, result_json = _decode_data_param(_d) if _d else ("{}", "null")
         content = _inject_data_into_html(content, input_json, result_json)
+        content = _inject_token_into_relative_urls(content, get_auth_token())
 
     mime, _ = mimetypes.guess_type(filepath)
     return Response(content=content, media_type=mime or "text/plain")
@@ -216,7 +270,10 @@ async def read_workspace(workspace_id: str):
         except (json.JSONDecodeError, ValueError):
             pass
 
-    return {"files": files, "meta": meta}
+    # Include `path` so the frontend can rehydrate without re-calling /seed.
+    # /seed unconditionally overwrites, which would clobber any in-progress edits
+    # the agent made since the last save.
+    return {"files": files, "meta": meta, "path": os.path.abspath(folder)}
 
 
 @outputs.router.post("/workspace/seed")
diff --git a/backend/main.py b/backend/main.py
index b6623ab6..82eaada2 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -107,7 +107,10 @@ async def _auth_middleware(request: Request, call_next):
         # (CLI path — CLI sends x-api-key with our token as value).
         headers = dict(request.headers)
         x_api_key = headers.get("x-api-key") or headers.get("X-API-Key")
-        auth_ok = request_matches_token(headers)
+        # Accept `?token=<token>` query param too. Required for browser-driven
+        # GETs that can't set headers — notably the App Builder iframe loading
+        # /api/outputs/.../serve/index.html via <iframe src="...">.
+        auth_ok = request_matches_token(headers, query_params=dict(request.query_params))
         if not auth_ok and x_api_key:
             import secrets as _s
             from backend.auth import get_auth_token as _gt
diff --git a/frontend/src/app/pages/Skills/SkillBuilderChat.tsx b/frontend/src/app/pages/Skills/SkillBuilderChat.tsx
index ca064400..107f2811 100644
--- a/frontend/src/app/pages/Skills/SkillBuilderChat.tsx
+++ b/frontend/src/app/pages/Skills/SkillBuilderChat.tsx
@@ -103,10 +103,40 @@ const SkillBuilderChat: React.FC<SkillBuilderChatProps> = ({ onSkillPreview, onS
     [workspacePath],
   );
 
+  // Honor Settings → default_model + default_thinking_level. createDraftSession's
+  // hardcoded 'sonnet' / undefined-thinking would otherwise win and force every
+  // Skill Builder draft onto Sonnet + Auto thinking.
+  const defaultModel = useAppSelector((s) => s.settings.data.default_model);
+  const defaultThinkingLevel = useAppSelector((s) => s.settings.data.default_thinking_level);
+  const settingsLoaded = useAppSelector((s) => s.settings.loaded);
+  const modelsByProvider = useAppSelector((s) => s.models.byProvider);
+  const modelsLoaded = useAppSelector((s) => s.models.loaded);
+
   const initSession = useCallback(async () => {
     const wsId = `skill-ws-${Date.now().toString(36)}`;
     setStableWorkspaceId(wsId);
 
+    // Resolve provider from the model registry (mirrors ChatInput.tsx provider map).
+    const PROVIDER_MAP: Record<string, string> = {
+      anthropic: 'anthropic',
+      'openswarm pro': 'anthropic',
+      openai: 'openai',
+      google: 'gemini',
+      xai: 'openrouter',
+      meta: 'openrouter',
+      deepseek: 'openrouter',
+      mistral: 'openrouter',
+      qwen: 'openrouter',
+      cohere: 'openrouter',
+    };
+    let resolvedProvider: string | undefined;
+    for (const [prov, models] of Object.entries(modelsByProvider)) {
+      if (models.some((m: any) => m.value === defaultModel)) {
+        resolvedProvider = PROVIDER_MAP[prov.toLowerCase()] || prov.toLowerCase();
+        break;
+      }
+    }
+
     try {
       const res = await fetch(`${SKILLS_WORKSPACE_API}/workspace/seed`, {
         method: 'POST',
@@ -119,19 +149,30 @@ const SkillBuilderChat: React.FC<SkillBuilderChatProps> = ({ onSkillPreview, onS
         mode: 'skill-builder',
         setActive: false,
         targetDirectory: data.path,
+        model: defaultModel || undefined,
+        provider: resolvedProvider,
+        thinkingLevel: defaultThinkingLevel || undefined,
       }));
       setInitialDraftId(action.payload.draftId);
     } catch {
-      const action = dispatch(createDraftSession({ mode: 'skill-builder', setActive: false }));
+      const action = dispatch(createDraftSession({
+        mode: 'skill-builder',
+        setActive: false,
+        model: defaultModel || undefined,
+        provider: resolvedProvider,
+        thinkingLevel: defaultThinkingLevel || undefined,
+      }));
       setInitialDraftId(action.payload.draftId);
     }
-  }, [dispatch]);
+  }, [dispatch, defaultModel, defaultThinkingLevel, modelsByProvider]);
 
   useEffect(() => {
     if (draftCreated.current) return;
+    // Wait for settings + model registry so we don't snapshot stale 'sonnet'.
+    if (!settingsLoaded || !modelsLoaded) return;
     draftCreated.current = true;
     initSession();
-  }, [initSession]);
+  }, [initSession, settingsLoaded, modelsLoaded]);
 
   // Poll workspace for updates
   const pollRef = useRef<ReturnType<typeof setInterval> | null>(null);
diff --git a/frontend/src/app/pages/Views/ViewEditor.tsx b/frontend/src/app/pages/Views/ViewEditor.tsx
index ece0a59e..23652589 100644
--- a/frontend/src/app/pages/Views/ViewEditor.tsx
+++ b/frontend/src/app/pages/Views/ViewEditor.tsx
@@ -27,7 +27,7 @@ import ExpandMoreIcon from '@mui/icons-material/ExpandMore';
 import CheckCircleOutlineIcon from '@mui/icons-material/CheckCircleOutline';
 import ErrorOutlineIcon from '@mui/icons-material/ErrorOutline';
 import { useAppDispatch, useAppSelector } from '@/shared/hooks';
-import { createDraftSession, removeDraftSession, AgentMessage } from '@/shared/state/agentsSlice';
+import { createDraftSession, removeDraftSession, fetchSession, AgentMessage } from '@/shared/state/agentsSlice';
 import { createOutput, updateOutput, Output, executeOutput, OutputExecuteResult, autoRunOutput, autoRunAgentOutput, cleanupAutoRunAgent, AutoRunConfig, SERVE_BASE } from '@/shared/state/outputsSlice';
 import { createSessionWs } from '@/shared/ws/WebSocketManager';
 import { useClaudeTokens } from '@/shared/styles/ThemeContext';
@@ -559,14 +559,73 @@ const ViewEditor: React.FC<Props> = ({ output, onClose }) => {
 
   const [initialDraftId, setInitialDraftId] = useState<string | null>(null);
   const [workspacePath, setWorkspacePath] = useState<string | null>(null);
-  const [stableWorkspaceId] = useState(() => `ws-${Date.now().toString(36)}`);
+  // Reuse the workspace_id stored on the Output if present so we don't seed a
+  // fresh folder every time the editor remounts (which would orphan the agent's
+  // in-progress edits and lose chat continuity). Only mint a new id for first-
+  // time outputs that don't yet have one persisted.
+  const [stableWorkspaceId] = useState(() => output?.workspace_id || `ws-${Date.now().toString(36)}`);
   const draftCreated = useRef(false);
 
+  // Honor the user's Settings → default_model + default_thinking_level.
+  // Without this, createDraftSession's hardcoded 'sonnet' / undefined-thinking
+  // fallbacks win and App Builder always opens on Sonnet + Auto thinking
+  // regardless of what the user picked in Settings.
+  const defaultModel = useAppSelector((s) => s.settings.data.default_model);
+  const defaultThinkingLevel = useAppSelector((s) => s.settings.data.default_thinking_level);
+  const settingsLoaded = useAppSelector((s) => s.settings.loaded);
+  const modelsByProvider = useAppSelector((s) => s.models.byProvider);
+  const modelsLoaded = useAppSelector((s) => s.models.loaded);
+
   useEffect(() => {
     if (draftCreated.current) return;
+    // Wait for settings + model registry before seeding the draft, otherwise
+    // we'd snapshot the Redux initial 'sonnet' default and ignore the user's pick.
+    if (!settingsLoaded || !modelsLoaded) return;
     draftCreated.current = true;
 
+    // Resolve provider from the model registry. Group names mirror the
+    // provider map in ChatInput.tsx (Anthropic / OpenSwarm Pro → 'anthropic',
+    // Google → 'gemini', xAI/Meta/etc → 'openrouter').
+    const PROVIDER_MAP: Record<string, string> = {
+      anthropic: 'anthropic',
+      'openswarm pro': 'anthropic',
+      openai: 'openai',
+      google: 'gemini',
+      xai: 'openrouter',
+      meta: 'openrouter',
+      deepseek: 'openrouter',
+      mistral: 'openrouter',
+      qwen: 'openrouter',
+      cohere: 'openrouter',
+    };
+    let resolvedProvider: string | undefined;
+    for (const [prov, models] of Object.entries(modelsByProvider)) {
+      if (models.some((m: any) => m.value === defaultModel)) {
+        resolvedProvider = PROVIDER_MAP[prov.toLowerCase()] || prov.toLowerCase();
+        break;
+      }
+    }
+
     (async () => {
+      // Reattach branch: this Output already has a session + workspace from a
+      // prior visit. Skip seeding (would clobber any in-progress edits the
+      // agent made) and skip createDraftSession (would orphan the live session).
+      // Just resolve the workspace path and tell AgentChat which session to bind to.
+      if (output?.session_id && output?.workspace_id) {
+        try {
+          const res = await fetch(`${WORKSPACE_API}/${output.workspace_id}`);
+          if (res.ok) {
+            const data = await res.json();
+            if (data.path) setWorkspacePath(data.path);
+          }
+        } catch { /* path is best-effort; chat still works without it */ }
+        // Pull the latest session state from the backend so the chat catches up
+        // on anything the agent did while the user was on another tab.
+        dispatch(fetchSession(output.session_id));
+        setInitialDraftId(output.session_id);
+        return;
+      }
+
       const seedBody: Record<string, any> = { workspace_id: stableWorkspaceId };
       if (output) {
         const seedFiles: Record<string, string> = { ...output.files };
@@ -588,14 +647,23 @@ const ViewEditor: React.FC<Props> = ({ output, onClose }) => {
           mode: 'view-builder',
           setActive: false,
           targetDirectory: data.path,
+          model: defaultModel || undefined,
+          provider: resolvedProvider,
+          thinkingLevel: defaultThinkingLevel || undefined,
         }));
         setInitialDraftId(action.payload.draftId);
       } catch {
-        const action = dispatch(createDraftSession({ mode: 'view-builder', setActive: false }));
+        const action = dispatch(createDraftSession({
+          mode: 'view-builder',
+          setActive: false,
+          model: defaultModel || undefined,
+          provider: resolvedProvider,
+          thinkingLevel: defaultThinkingLevel || undefined,
+        }));
         setInitialDraftId(action.payload.draftId);
       }
     })();
-  }, [dispatch, output, stableWorkspaceId]);
+  }, [dispatch, output, stableWorkspaceId, settingsLoaded, modelsLoaded, defaultModel, defaultThinkingLevel, modelsByProvider]);
 
   const effectiveSessionId = useAppSelector((state) => {
     if (!initialDraftId) return null;
@@ -671,14 +739,46 @@ const ViewEditor: React.FC<Props> = ({ output, onClose }) => {
     prevAgentActive.current = isAgentActive;
   }, [isAgentActive, workspaceId, pollWorkspace]);
 
+  // Hold the latest session status in a ref so the unmount cleanup can read it
+  // at teardown time (the cleanup closure would otherwise capture a stale value
+  // from when the effect first ran).
+  const sessionStatusRef = useRef<string | null>(null);
+  sessionStatusRef.current = agentStatus;
+  const isLaunchedRef = useRef(false);
+  isLaunchedRef.current = isLaunched;
+
   useEffect(() => {
     return () => {
-      if (initialDraftId) {
+      // Only garbage-collect drafts the user abandoned without launching. Once
+      // a session is launched, the agent runs on the backend independent of
+      // the frontend — leave the Redux entry alive so navigating away doesn't
+      // wipe in-progress work or chat history.
+      if (initialDraftId && sessionStatusRef.current === 'draft' && !isLaunchedRef.current) {
         dispatch(removeDraftSession(initialDraftId));
       }
     };
   }, [initialDraftId, dispatch]);
 
+  // Persist session_id + workspace_id onto the saved Output the moment the
+  // session goes from draft to launched. Without this, reopening the App later
+  // would have no way to find its in-progress session and would seed a fresh one.
+  // Use `createdId` (state) not `createdIdRef.current` so the effect re-fires
+  // after autosave creates the Output for a brand-new app. `output` prop is a
+  // parent snapshot that doesn't refresh, so we dedup via a ref.
+  const persistedLinkageRef = useRef<string | null>(null);
+  useEffect(() => {
+    const eid = output?.id ?? createdId;
+    if (!eid || !effectiveSessionId || !isLaunched) return;
+    const fingerprint = `${eid}:${effectiveSessionId}:${stableWorkspaceId}`;
+    if (persistedLinkageRef.current === fingerprint) return;
+    persistedLinkageRef.current = fingerprint;
+    dispatch(updateOutput({
+      id: eid,
+      session_id: effectiveSessionId,
+      workspace_id: stableWorkspaceId,
+    }));
+  }, [effectiveSessionId, isLaunched, output?.id, createdId, stableWorkspaceId, dispatch]);
+
   const schemaText = files['schema.json'] ?? '{"type":"object","properties":{},"required":[]}';
 
   const parsedSchema = useMemo(() => {
diff --git a/frontend/src/app/pages/Views/ViewPreview.tsx b/frontend/src/app/pages/Views/ViewPreview.tsx
index 74e0008b..62aa935e 100644
--- a/frontend/src/app/pages/Views/ViewPreview.tsx
+++ b/frontend/src/app/pages/Views/ViewPreview.tsx
@@ -2,6 +2,7 @@ import React, { useRef, useEffect, useMemo, forwardRef, useImperativeHandle, use
 import Box from '@mui/material/Box';
 import { useElementSelection } from '@/app/components/ElementSelectionContext';
 import { useIframeElementSelector } from './useIframeElementSelector';
+import { getAuthToken, ensureAuthToken } from '@/shared/config';
 
 export interface ViewPreviewHandle {
   reload: () => void;
@@ -54,6 +55,19 @@ const ViewPreview = forwardRef<ViewPreviewHandle, Props>(({
   const iframeRef = useRef<HTMLIFrameElement>(null);
   const ctx = useElementSelection();
   const [reloadKey, setReloadKey] = useState(0);
+  // Track auth token in state so the iframe URL is rebuilt the moment the
+  // token IPC roundtrip resolves. Without this, the first render runs while
+  // _authTokenCache is still '' and the iframe loads a tokenless URL → 401
+  // → the JSON error renders inside the preview pane.
+  const [authToken, setAuthToken] = useState(() => getAuthToken());
+  useEffect(() => {
+    if (authToken) return;
+    let cancelled = false;
+    ensureAuthToken().then((tok) => {
+      if (!cancelled && tok) setAuthToken(tok);
+    });
+    return () => { cancelled = true; };
+  }, [authToken]);
 
   useEffect(() => {
     if (ctx && iframeRef.current) {
@@ -65,10 +79,13 @@ const ViewPreview = forwardRef<ViewPreviewHandle, Props>(({
 
   const iframeSrc = useMemo(() => {
     if (!serveUrl) return undefined;
+    // Don't ship a tokenless URL — the backend auth middleware would 401 and
+    // the iframe would render the JSON error. Wait for the token to load.
+    if (!authToken) return undefined;
     const dataParam = encodeDataParam(inputData, backendResult);
     const sep = serveUrl.includes('?') ? '&' : '?';
-    return `${serveUrl}${sep}_d=${encodeURIComponent(dataParam)}&_v=${reloadKey}`;
-  }, [serveUrl, inputData, backendResult, reloadKey]);
+    return `${serveUrl}${sep}_d=${encodeURIComponent(dataParam)}&_v=${reloadKey}&token=${encodeURIComponent(authToken)}`;
+  }, [serveUrl, inputData, backendResult, reloadKey, authToken]);
 
   const srcdoc = useMemo(() => {
     if (serveUrl || !frontendCode) return undefined;
diff --git a/frontend/src/shared/state/agentsSlice.ts b/frontend/src/shared/state/agentsSlice.ts
index 36035eed..a5d01f50 100644
--- a/frontend/src/shared/state/agentsSlice.ts
+++ b/frontend/src/shared/state/agentsSlice.ts
@@ -436,14 +436,14 @@ const agentsSlice = createSlice({
   initialState,
   reducers: {
     createDraftSession: {
-      reducer(state, action: PayloadAction<{ draftId: string; mode: string; setActive: boolean; targetDirectory?: string }>) {
-        const { draftId, mode, setActive, targetDirectory } = action.payload;
+      reducer(state, action: PayloadAction<{ draftId: string; mode: string; setActive: boolean; targetDirectory?: string; model?: string; provider?: string; thinkingLevel?: 'off' | 'low' | 'medium' | 'high' | 'auto' }>) {
+        const { draftId, mode, setActive, targetDirectory, model, provider, thinkingLevel } = action.payload;
         state.sessions[draftId] = {
           id: draftId,
           name: 'New chat',
           status: 'draft',
-          provider: 'anthropic',
-          model: 'sonnet',
+          provider: provider || 'anthropic',
+          model: model || 'sonnet',
           mode,
           worktree_path: null,
           branch_name: null,
@@ -461,6 +461,7 @@ const agentsSlice = createSlice({
           streamingMessage: null,
           target_directory: targetDirectory || null,
           tool_group_meta: {},
+          thinking_level: thinkingLevel,
         };
         if (setActive) {
           state.activeSessionId = draftId;
@@ -469,13 +470,16 @@ const agentsSlice = createSlice({
           }
         }
       },
-      prepare(opts?: { mode?: string; setActive?: boolean; targetDirectory?: string }) {
+      prepare(opts?: { mode?: string; setActive?: boolean; targetDirectory?: string; model?: string; provider?: string; thinkingLevel?: 'off' | 'low' | 'medium' | 'high' | 'auto' }) {
         return {
           payload: {
             draftId: `draft-${Date.now().toString(36)}`,
             mode: opts?.mode || 'agent',
             setActive: opts?.setActive !== false,
             targetDirectory: opts?.targetDirectory,
+            model: opts?.model,
+            provider: opts?.provider,
+            thinkingLevel: opts?.thinkingLevel,
           },
         };
       },
diff --git a/frontend/src/shared/state/outputsSlice.ts b/frontend/src/shared/state/outputsSlice.ts
index 1ab4bf80..d17a07ab 100644
--- a/frontend/src/shared/state/outputsSlice.ts
+++ b/frontend/src/shared/state/outputsSlice.ts
@@ -25,6 +25,10 @@ export interface Output {
   permission: string;
   auto_run_config?: AutoRunConfig | null;
   thumbnail?: string | null;
+  // Linkage so reopening App Builder reattaches to the in-progress session
+  // and reuses the on-disk workspace folder instead of seeding a fresh one.
+  session_id?: string | null;
+  workspace_id?: string | null;
   created_at: string;
   updated_at: string;
 }