Add file drag-and-drop onto the terminal

Drop files onto a terminal pane and they're copied into the container and
their in-container paths typed into the prompt, so Claude Code can read
them for reference — mirroring the existing image-paste flow.

Backend: upload_host_file_to_terminal reads the dropped host file and
writes it under /tmp/triple-c-drops/<name> in the session's container,
returning that path. Rejects directories and unreadable paths.

Frontend: TerminalView subscribes to Tauri's webview onDragDropEvent
(OS file drops are intercepted at the webview level, so HTML5 ondrop
wouldn't expose paths). The window-wide event is guarded by the pane's
`active` flag plus a bounds hit-test so a drop only affects the terminal
it landed on; multiple files are uploaded and their paths inserted
space-separated (quoted when they contain spaces).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src-tauri/src/commands/terminal_commands.rs

@@ -183,6 +183,41 @@ pub async fn paste_image_to_terminal(
         .await
 }
 
+/// Copy a host file (e.g. dragged onto the terminal) into the container so
+/// Claude Code can read it, and return the in-container path. Mirrors the
+/// image-paste flow: the file is placed under /tmp/triple-c-drops/ keeping its
+/// original name. Returns an error for paths that aren't readable regular files
+/// (e.g. a dropped directory).
+#[tauri::command]
+pub async fn upload_host_file_to_terminal(
+    session_id: String,
+    host_path: String,
+    state: State<'_, AppState>,
+) -> Result<String, String> {
+    let container_id = state.exec_manager.get_container_id(&session_id).await?;
+
+    let meta = std::fs::metadata(&host_path)
+        .map_err(|e| format!("Cannot access {}: {}", host_path, e))?;
+    if meta.is_dir() {
+        return Err(format!("{} is a directory — drop individual files", host_path));
+    }
+
+    let data =
+        std::fs::read(&host_path).map_err(|e| format!("Failed to read {}: {}", host_path, e))?;
+
+    let base = std::path::Path::new(&host_path)
+        .file_name()
+        .map(|s| s.to_string_lossy().to_string())
+        .filter(|s| !s.is_empty())
+        .unwrap_or_else(|| "dropped-file".to_string());
+
+    let file_name = format!("triple-c-drops/{}", base);
+    state
+        .exec_manager
+        .write_file_to_container(&container_id, &file_name, &data)
+        .await
+}
+
 #[tauri::command]
 pub async fn start_audio_bridge(
     session_id: String,

app/src-tauri/src/lib.rs

@@ -178,6 +178,7 @@ pub fn run() {
             commands::terminal_commands::terminal_resize,
             commands::terminal_commands::close_terminal_session,
             commands::terminal_commands::paste_image_to_terminal,
+            commands::terminal_commands::upload_host_file_to_terminal,
             commands::terminal_commands::start_audio_bridge,
             commands::terminal_commands::send_audio_data,
             commands::terminal_commands::stop_audio_bridge,

app/src/components/terminal/TerminalView.tsx

@@ -7,7 +7,8 @@ import { openUrl } from "@tauri-apps/plugin-opener";
 import "@xterm/xterm/css/xterm.css";
 import { useTerminal } from "../../hooks/useTerminal";
 import { useAppState } from "../../store/appState";
-import { awsSsoRefresh } from "../../lib/tauri-commands";
+import { awsSsoRefresh, uploadHostFileToTerminal } from "../../lib/tauri-commands";
+import { getCurrentWebview } from "@tauri-apps/api/webview";
 import { UrlDetector } from "../../lib/urlDetector";
 import UrlToast from "./UrlToast";
 import { trimSelection } from "./trimSelection";
@@ -47,6 +48,67 @@ export default function TerminalView({ sessionId, active }: Props) {
   const autoFollowRef = useRef(true);
   const lastUserScrollTimeRef = useRef(0);
 
+  // Keep latest `active` readable inside long-lived listeners (drag-drop below,
+  // and the unmount-cleanup effect further down).
+  const activeRef = useRef(active);
+  activeRef.current = active;
+
+  // File drag-and-drop: dropped files are copied into the container and their
+  // in-container paths typed into the prompt so Claude Code can read them.
+  // Tauri intercepts OS file drops at the webview level, so we use
+  // onDragDropEvent (HTML5 ondrop on the element wouldn't expose file paths).
+  // The listener is window-wide, so we guard on `active` + a hit-test against
+  // this terminal's bounds to ignore drops meant for another pane.
+  useEffect(() => {
+    let unlisten: (() => void) | undefined;
+    let cancelled = false;
+
+    const insideThisTerminal = (pos: { x: number; y: number }): boolean => {
+      const rect = containerRef.current?.getBoundingClientRect();
+      if (!rect) return false;
+      const dpr = window.devicePixelRatio || 1;
+      const x = pos.x / dpr;
+      const y = pos.y / dpr;
+      return x >= rect.left && x <= rect.right && y >= rect.top && y <= rect.bottom;
+    };
+
+    const quote = (p: string) => (/\s/.test(p) ? `'${p.replace(/'/g, "'\\''")}'` : p);
+
+    (async () => {
+      const un = await getCurrentWebview().onDragDropEvent(async (event) => {
+        if (event.payload.type !== "drop") return;
+        if (!activeRef.current) return;
+        if (!insideThisTerminal(event.payload.position)) return;
+
+        const paths = event.payload.paths ?? [];
+        if (paths.length === 0) return;
+
+        setImagePasteMsg(`Adding ${paths.length} file${paths.length > 1 ? "s" : ""}…`);
+        const containerPaths: string[] = [];
+        for (const p of paths) {
+          try {
+            containerPaths.push(await uploadHostFileToTerminal(sessionId, p));
+          } catch (err) {
+            console.error("File drop upload failed for", p, err);
+          }
+        }
+        if (containerPaths.length === 0) {
+          setImagePasteMsg("File drop failed");
+          return;
+        }
+        sendInput(sessionId, containerPaths.map(quote).join(" ") + " ");
+        setImagePasteMsg(`Added ${containerPaths.length} file path${containerPaths.length > 1 ? "s" : ""}`);
+      });
+      if (cancelled) un();
+      else unlisten = un;
+    })();
+
+    return () => {
+      cancelled = true;
+      unlisten?.();
+    };
+  }, [sessionId, sendInput]);
+
   useEffect(() => {
     if (!containerRef.current) return;
 
@@ -403,8 +465,6 @@ export default function TerminalView({ sessionId, active }: Props) {
   // state so it doesn't point at a disposed terminal. (Tab switches don't
   // unmount — the deactivating terminal stays mounted but hidden — so this
   // only fires when the active session is actually closed.)
-  const activeRef = useRef(active);
-  activeRef.current = active;
   useEffect(() => {
     return () => {
       if (activeRef.current) {

app/src/lib/tauri-commands.ts

@@ -55,6 +55,8 @@ export const closeTerminalSession = (sessionId: string) =>
   invoke<void>("close_terminal_session", { sessionId });
 export const pasteImageToTerminal = (sessionId: string, imageData: number[]) =>
   invoke<string>("paste_image_to_terminal", { sessionId, imageData });
+export const uploadHostFileToTerminal = (sessionId: string, hostPath: string) =>
+  invoke<string>("upload_host_file_to_terminal", { sessionId, hostPath });
 export const startAudioBridge = (sessionId: string) =>
   invoke<void>("start_audio_bridge", { sessionId });
 export const sendAudioData = (sessionId: string, data: number[]) =>