Fix inspector CWD handling

frontend/packages/inspector/src/App.tsx

@@ -773,7 +773,7 @@ export default function App() {
     setSessionError(null);
   };
 
-  const createNewSession = async (nextAgentId: string, config: { agentMode: string; model: string }) => {
+  const createNewSession = async (nextAgentId: string, config: { agentMode: string; model: string; cwd: string }) => {
     console.log("[createNewSession] Creating session for agent:", nextAgentId, "config:", config);
     setSessionError(null);
     creatingSessionRef.current = true;
@@ -784,7 +784,7 @@ export default function App() {
       const createSessionPromise = getClient().createSession({
         agent: nextAgentId,
         sessionInit: {
-          cwd: "/",
+          cwd: config.cwd,
           mcpServers: [],
         },
       });

frontend/packages/inspector/src/components/SessionCreateMenu.tsx

@@ -8,9 +8,16 @@ type AgentModelInfo = { id: string; name?: string };
 export type SessionConfig = {
   agentMode: string;
   model: string;
+  cwd: string;
 };
 
 const CUSTOM_MODEL_VALUE = "__custom__";
+const DEFAULT_CWD = "/";
+const LAST_CWD_KEY = "sandbox-agent-inspector-last-cwd";
+
+type InspectorRuntimeConfig = {
+  defaultCwd?: string;
+};
 
 const agentLabels: Record<string, string> = {
   claude: "Claude Code",
@@ -29,6 +36,56 @@ const agentLogos: Record<string, string> = {
   pi: `${import.meta.env.BASE_URL}logos/pi.svg`,
 };
 
+function normalizeCwd(value: string | null | undefined) {
+  if (!value) {
+    return null;
+  }
+
+  const trimmed = value.trim();
+  return trimmed ? trimmed : null;
+}
+
+function getQueryDefaultCwd() {
+  if (typeof window === "undefined") {
+    return null;
+  }
+
+  const params = new URLSearchParams(window.location.search);
+  return normalizeCwd(params.get("cwd")) ?? normalizeCwd(params.get("defaultCwd"));
+}
+
+function getRuntimeDefaultCwd() {
+  if (typeof window === "undefined") {
+    return null;
+  }
+
+  const runtimeWindow = window as typeof window & {
+    __SANDBOX_AGENT_INSPECTOR_CONFIG__?: InspectorRuntimeConfig;
+  };
+  return normalizeCwd(runtimeWindow.__SANDBOX_AGENT_INSPECTOR_CONFIG__?.defaultCwd);
+}
+
+function getStoredCwd() {
+  if (typeof window === "undefined") {
+    return null;
+  }
+
+  try {
+    return normalizeCwd(window.localStorage.getItem(LAST_CWD_KEY));
+  } catch {}
+
+  return null;
+}
+
+function getInitialCwd() {
+  return (
+    getQueryDefaultCwd() ??
+    getRuntimeDefaultCwd() ??
+    getStoredCwd() ??
+    DEFAULT_CWD
+  );
+}
+
 const SessionCreateMenu = ({
   agents,
   agentsLoading,
@@ -58,6 +115,7 @@ const SessionCreateMenu = ({
   const [selectedModel, setSelectedModel] = useState("");
   const [customModel, setCustomModel] = useState("");
   const [isCustomModel, setIsCustomModel] = useState(false);
+  const [cwd, setCwd] = useState(getInitialCwd);
   const [creating, setCreating] = useState(false);
 
   // Reset state when menu closes
@@ -69,6 +127,7 @@ const SessionCreateMenu = ({
       setSelectedModel("");
       setCustomModel("");
       setIsCustomModel(false);
+      setCwd(getInitialCwd());
       setCreating(false);
     }
   }, [open]);
@@ -138,12 +197,17 @@ const SessionCreateMenu = ({
   };
 
   const resolvedModel = isCustomModel ? customModel : selectedModel;
+  const resolvedCwd = cwd.trim() || getInitialCwd();
 
   const handleCreate = async () => {
     if (!selectedAgent) return;
     setCreating(true);
     try {
-      await onCreateSession(selectedAgent, { agentMode, model: resolvedModel });
+      try {
+        window.localStorage.setItem(LAST_CWD_KEY, resolvedCwd);
+      } catch {}
+
+      await onCreateSession(selectedAgent, { agentMode, model: resolvedModel, cwd: resolvedCwd });
       onClose();
     } catch (error) {
       console.error("[SessionCreateMenu] Failed to create session:", error);
@@ -286,6 +350,19 @@ const SessionCreateMenu = ({
             </select>
           </div>
         )}
+        <div className="setup-field">
+          <span className="setup-label">Working directory</span>
+          <input
+            className="setup-input mono"
+            type="text"
+            value={cwd}
+            onChange={(e) => setCwd(e.target.value)}
+            placeholder={DEFAULT_CWD}
+            spellCheck={false}
+            autoCapitalize="off"
+            autoCorrect="off"
+          />
+        </div>
       </div>
 
       <div className="session-create-actions">

server/packages/sandbox-agent/src/cli.rs

@@ -93,6 +93,9 @@ pub struct ServerArgs {
     #[arg(long, short = 'p', default_value_t = DEFAULT_PORT)]
     port: u16,
 
+    #[arg(long = "inspector-default-cwd")]
+    inspector_default_cwd: Option<String>,
+
     #[arg(long = "cors-allow-origin", short = 'O')]
     cors_allow_origin: Vec<String>,
 
@@ -421,6 +424,8 @@ fn run_server(cli: &CliConfig, server: &ServerArgs) -> Result<(), CliError> {
 
     let agent_manager = AgentManager::new(default_install_dir())
         .map_err(|err| CliError::Server(err.to_string()))?;
+    ui::configure_default_cwd(server.inspector_default_cwd.clone());
+
     let state = Arc::new(AppState::with_branding(auth, agent_manager, branding));
     let (mut router, state) = build_router_with_state(state);
 

server/packages/sandbox-agent/src/ui.rs

@@ -1,4 +1,5 @@
 use std::path::Path;
+use std::sync::OnceLock;
 
 use axum::body::Body;
 use axum::extract::Path as AxumPath;
@@ -9,10 +10,18 @@ use axum::Router;
 
 include!(concat!(env!("OUT_DIR"), "/inspector_assets.rs"));
 
+static INSPECTOR_DEFAULT_CWD: OnceLock<String> = OnceLock::new();
+
 pub fn is_enabled() -> bool {
     INSPECTOR_ENABLED
 }
 
+pub fn configure_default_cwd(value: Option<String>) {
+    if let Some(value) = normalize_cwd(value) {
+        let _ = INSPECTOR_DEFAULT_CWD.set(value);
+    }
+}
+
 pub fn router() -> Router {
     if !INSPECTOR_ENABLED {
         return Router::new()
@@ -72,6 +81,10 @@ fn serve_path(path: &str) -> Response {
 }
 
 fn file_response(file: &include_dir::File) -> Response {
+    if file.path().file_name().and_then(|name| name.to_str()) == Some("index.html") {
+        return index_response(file);
+    }
+
     let mut response = Response::new(Body::from(file.contents().to_vec()));
     *response.status_mut() = StatusCode::OK;
     let content_type = content_type_for(file.path());
@@ -80,6 +93,58 @@ fn file_response(file: &include_dir::File) -> Response {
     response
 }
 
+fn index_response(file: &include_dir::File) -> Response {
+    let html = String::from_utf8_lossy(file.contents());
+    let config_json = serde_json::json!({
+        "defaultCwd": resolve_default_cwd(),
+    })
+    .to_string();
+    let config_script = format!(
+        r#"<script>window.__SANDBOX_AGENT_INSPECTOR_CONFIG__={};</script>"#,
+        config_json
+    );
+
+    let body = if let Some(position) = html.find("</head>") {
+        let mut injected = String::with_capacity(html.len() + config_script.len());
+        injected.push_str(&html[..position]);
+        injected.push_str(&config_script);
+        injected.push_str(&html[position..]);
+        injected
+    } else {
+        let mut injected = html.into_owned();
+        injected.push_str(&config_script);
+        injected
+    };
+
+    let mut response = Response::new(Body::from(body));
+    *response.status_mut() = StatusCode::OK;
+    response.headers_mut().insert(
+        header::CONTENT_TYPE,
+        HeaderValue::from_static("text/html; charset=utf-8"),
+    );
+    response
+}
+
+fn resolve_default_cwd() -> String {
+    INSPECTOR_DEFAULT_CWD
+        .get()
+        .cloned()
+        .or_else(|| normalize_cwd(std::env::var("SANDBOX_AGENT_INSPECTOR_DEFAULT_CWD").ok()))
+        .or_else(|| normalize_cwd(std::env::var("HOME").ok()))
+        .unwrap_or_else(|| "/".to_string())
+}
+
+fn normalize_cwd(value: Option<String>) -> Option<String> {
+    value.and_then(|value| {
+        let trimmed = value.trim();
+        if trimmed.is_empty() {
+            None
+        } else {
+            Some(trimmed.to_string())
+        }
+    })
+}
+
 fn content_type_for(path: &Path) -> &'static str {
     match path.extension().and_then(|ext| ext.to_str()) {
         Some("html") => "text/html; charset=utf-8",