diff --git a/apps/desktop/package.json b/apps/desktop/package.json
index 8529a475251..6d74a579992 100644
--- a/apps/desktop/package.json
+++ b/apps/desktop/package.json
@@ -174,6 +174,7 @@
 		"node-addon-api": "^7.1.0",
 		"node-pty": "1.1.0",
 		"os-locale": "^6.0.2",
+		"pathe": "^2.0.3",
 		"pidtree": "^0.6.0",
 		"pidusage": "^4.0.1",
 		"posthog-js": "1.310.1",
diff --git a/apps/desktop/src/lib/trpc/routers/filesystem/index.ts b/apps/desktop/src/lib/trpc/routers/filesystem/index.ts
index 18a5a557311..00bb2597cf8 100644
--- a/apps/desktop/src/lib/trpc/routers/filesystem/index.ts
+++ b/apps/desktop/src/lib/trpc/routers/filesystem/index.ts
@@ -905,6 +905,60 @@ export const createFilesystemRouter = () => {
 				return { copied, errors };
 			}),
 
+		/**
+		 * Read a file by absolute path with size cap and binary detection.
+		 * Used for viewing files outside the current worktree.
+		 */
+		readFile: publicProcedure
+			.input(
+				z.object({
+					filePath: z.string(),
+				}),
+			)
+			.query(
+				async ({
+					input,
+				}): Promise<
+					| {
+							ok: true;
+							content: string;
+							truncated: boolean;
+							byteLength: number;
+					  }
+					| {
+							ok: false;
+							reason: "not-found" | "too-large" | "binary";
+					  }
+				> => {
+					const MAX_FILE_SIZE = 2 * 1024 * 1024;
+					try {
+						const stats = await fs.stat(input.filePath);
+						if (stats.size > MAX_FILE_SIZE) {
+							return { ok: false, reason: "too-large" };
+						}
+
+						const buffer = await fs.readFile(input.filePath);
+
+						// Binary detection (same as readWorkingFile)
+						const checkLength = Math.min(buffer.length, BINARY_CHECK_SIZE);
+						for (let i = 0; i < checkLength; i++) {
+							if (buffer[i] === 0) {
+								return { ok: false, reason: "binary" };
+							}
+						}
+
+						return {
+							ok: true,
+							content: buffer.toString("utf-8"),
+							truncated: false,
+							byteLength: buffer.length,
+						};
+					} catch {
+						return { ok: false, reason: "not-found" };
+					}
+				},
+			),
+
 		exists: publicProcedure
 			.input(z.object({ path: z.string() }))
 			.query(async ({ input }) => {
diff --git a/apps/desktop/src/renderer/screens/main/components/CommandPalette/CommandPalette.tsx b/apps/desktop/src/renderer/screens/main/components/CommandPalette/CommandPalette.tsx
index 7dad01e01a2..bfb8c6afdd2 100644
--- a/apps/desktop/src/renderer/screens/main/components/CommandPalette/CommandPalette.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/CommandPalette/CommandPalette.tsx
@@ -62,7 +62,7 @@ export function CommandPalette({
 			isLoading={isLoading}
 			results={searchResults}
 			getItemValue={(file) => `${file.path} ${query}`}
-			onSelectItem={(file) => onSelectFile(file.relativePath)}
+			onSelectItem={(file) => onSelectFile(file.path)}
 			renderItem={(file) => {
 				const { icon: Icon, color } = getFileIcon(file.name, false);
 				return (
diff --git a/apps/desktop/src/renderer/screens/main/components/KeywordSearch/useKeywordSearch.ts b/apps/desktop/src/renderer/screens/main/components/KeywordSearch/useKeywordSearch.ts
index fb96a587154..4fcbac69bcd 100644
--- a/apps/desktop/src/renderer/screens/main/components/KeywordSearch/useKeywordSearch.ts
+++ b/apps/desktop/src/renderer/screens/main/components/KeywordSearch/useKeywordSearch.ts
@@ -85,7 +85,7 @@ export function useKeywordSearch({
 	const selectMatch = useCallback(
 		(match: KeywordSearchResult) => {
 			useTabsStore.getState().addFileViewerPane(workspaceId, {
-				filePath: match.relativePath,
+				filePath: match.path,
 				line: match.line,
 				column: match.column,
 			});
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/UserMessage.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/UserMessage.tsx
index 60cf70bcb0c..0ffc951f611 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/UserMessage.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/UserMessage.tsx
@@ -1,5 +1,6 @@
 import { useCallback, useState } from "react";
 import { useTabsStore } from "renderer/stores/tabs/store";
+import { resolveToAbsolutePath } from "../../../../../../ChatPane/ChatInterface/utils/file-paths";
 import type {
 	UserMessageActionPayload,
 	UserMessageRestartRequest,
@@ -58,9 +59,17 @@ export function UserMessage({
 	);
 	const openMentionedFile = useCallback(
 		(filePath: string) => {
-			addFileViewerPane(workspaceId, { filePath, isPinned: true });
+			const absolutePath = resolveToAbsolutePath({
+				filePath,
+				workspaceRoot: workspaceCwd,
+			});
+			if (!absolutePath) return;
+			addFileViewerPane(workspaceId, {
+				filePath: absolutePath,
+				isPinned: true,
+			});
 		},
-		[addFileViewerPane, workspaceId],
+		[addFileViewerPane, workspaceCwd, workspaceId],
 	);
 	const handleCopy = useCallback(() => {
 		if (!fullText) return;
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/components/UserMessageText/UserMessageText.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/components/UserMessageText/UserMessageText.tsx
index eac5bc19b6a..df3757ab5d4 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/components/UserMessageText/UserMessageText.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatMastraPane/ChatMastraInterface/components/ChatMastraMessageList/components/UserMessage/components/UserMessageText/UserMessageText.tsx
@@ -1,4 +1,4 @@
-import { normalizeWorkspaceFilePath } from "../../../../../../../../ChatPane/ChatInterface/utils/file-paths";
+import { resolveToAbsolutePath } from "../../../../../../../../ChatPane/ChatInterface/utils/file-paths";
 import type { MastraMessage, MastraMessagePart } from "../../types";
 import { parseUserMentions } from "../../utils/parseUserMentions";
 
@@ -36,11 +36,11 @@ export function UserMessageText({
 						);
 					}
 
-					const normalizedPath = normalizeWorkspaceFilePath({
+					const absolutePath = resolveToAbsolutePath({
 						filePath: segment.relativePath,
 						workspaceRoot: workspaceCwd,
 					});
-					const canOpen = Boolean(normalizedPath);
+					const canOpen = Boolean(absolutePath);
 
 					return (
 						<button
@@ -48,8 +48,8 @@ export function UserMessageText({
 							key={`${message.id}-${partIndex}-${segmentIndex}`}
 							className="mx-0.5 inline-flex items-center gap-0.5 rounded-md bg-primary/15 px-1.5 py-0.5 font-mono text-xs text-primary transition-colors hover:bg-primary/22 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary/40 disabled:cursor-default disabled:opacity-60"
 							onClick={() => {
-								if (!normalizedPath) return;
-								onOpenMentionedFile(normalizedPath);
+								if (!absolutePath) return;
+								onOpenMentionedFile(absolutePath);
 							}}
 							disabled={!canOpen}
 							aria-label={`Open file ${segment.relativePath}`}
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MastraToolCallBlock/MastraToolCallBlock.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MastraToolCallBlock/MastraToolCallBlock.tsx
index fa224ab6065..5cc65cd4e4d 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MastraToolCallBlock/MastraToolCallBlock.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MastraToolCallBlock/MastraToolCallBlock.tsx
@@ -10,7 +10,7 @@ import { useChangesStore } from "renderer/stores/changes";
 import { useTabsStore } from "renderer/stores/tabs/store";
 import type { ChangeCategory } from "shared/changes-types";
 import { READ_ONLY_TOOLS } from "../../constants";
-import { normalizeWorkspaceFilePath } from "../../utils/file-paths";
+import { resolveToAbsolutePath } from "../../utils/file-paths";
 import type { ToolPart } from "../../utils/tool-helpers";
 import {
 	getArgs,
@@ -83,22 +83,21 @@ export function MastraToolCallBlock({
 	const toolDisplayName = toolName
 		.replace("mastra_workspace_", "")
 		.replaceAll("_", " ");
-	const normalizeFilePath = useCallback(
+	const resolveFilePath = useCallback(
 		(filePath: string) => {
-			const normalizedPath = normalizeWorkspaceFilePath({
+			return resolveToAbsolutePath({
 				filePath,
 				workspaceRoot: workspaceCwd,
 			});
-			return normalizedPath ?? null;
 		},
 		[workspaceCwd],
 	);
 	const openFileInPane = useCallback(
 		(filePath: string) => {
 			if (!workspaceId) return;
-			const normalizedPath = normalizeFilePath(filePath);
-			if (!normalizedPath) return;
-			addFileViewerPane(workspaceId, { filePath: normalizedPath });
+			const absolutePath = resolveFilePath(filePath);
+			if (!absolutePath) return;
+			addFileViewerPane(workspaceId, { filePath: absolutePath });
 			posthog.capture("chat_file_opened_from_tool", {
 				workspace_id: workspaceId,
 				session_id: sessionId ?? null,
@@ -109,7 +108,7 @@ export function MastraToolCallBlock({
 		},
 		[
 			addFileViewerPane,
-			normalizeFilePath,
+			resolveFilePath,
 			organizationId,
 			sessionId,
 			toolName,
@@ -145,21 +144,21 @@ export function MastraToolCallBlock({
 	}, [panes, tabs, workspaceId]);
 	const getDiffPaneTargetForFile = useCallback(
 		(filePath: string) => {
-			const normalizedPath = normalizeFilePath(filePath);
-			if (!normalizedPath) return null;
-			return workspaceDiffPaneByFilePath.get(normalizedPath) ?? null;
+			const absolutePath = resolveFilePath(filePath);
+			if (!absolutePath) return null;
+			return workspaceDiffPaneByFilePath.get(absolutePath) ?? null;
 		},
-		[normalizeFilePath, workspaceDiffPaneByFilePath],
+		[resolveFilePath, workspaceDiffPaneByFilePath],
 	);
 	const openFileInDiffPane = useCallback(
 		(filePath: string) => {
 			if (!workspaceId) return;
-			const normalizedPath = normalizeFilePath(filePath);
+			const absolutePath = resolveFilePath(filePath);
 			const diffPaneTarget = getDiffPaneTargetForFile(filePath);
-			if (!normalizedPath) return;
+			if (!absolutePath) return;
 
 			addFileViewerPane(workspaceId, {
-				filePath: normalizedPath,
+				filePath: absolutePath,
 				diffCategory: diffPaneTarget?.diffCategory ?? "unstaged",
 				commitHash: diffPaneTarget?.commitHash,
 				oldPath: diffPaneTarget?.oldPath,
@@ -176,7 +175,7 @@ export function MastraToolCallBlock({
 		[
 			addFileViewerPane,
 			getDiffPaneTargetForFile,
-			normalizeFilePath,
+			resolveFilePath,
 			organizationId,
 			sessionId,
 			toolName,
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MessagePartsRenderer/MessagePartsRenderer.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MessagePartsRenderer/MessagePartsRenderer.tsx
index cbe4718808d..1e2f7f89c06 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MessagePartsRenderer/MessagePartsRenderer.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/components/MessagePartsRenderer/MessagePartsRenderer.tsx
@@ -16,7 +16,7 @@ import { useTabsStore } from "renderer/stores/tabs/store";
 import { READ_ONLY_TOOLS } from "../../constants";
 import {
 	getWorkspaceToolFilePath,
-	normalizeWorkspaceFilePath,
+	resolveToAbsolutePath,
 } from "../../utils/file-paths";
 import type { ToolPart } from "../../utils/tool-helpers";
 import { getArgs, normalizeToolName } from "../../utils/tool-helpers";
@@ -63,12 +63,12 @@ export function MessagePartsRenderer({
 	const openFileInPane = useCallback(
 		(filePath: string) => {
 			if (!workspaceId) return;
-			const normalizedPath = normalizeWorkspaceFilePath({
+			const absolutePath = resolveToAbsolutePath({
 				filePath,
 				workspaceRoot: workspaceCwd,
 			});
-			if (!normalizedPath) return;
-			addFileViewerPane(workspaceId, { filePath: normalizedPath });
+			if (!absolutePath) return;
+			addFileViewerPane(workspaceId, { filePath: absolutePath });
 		},
 		[addFileViewerPane, workspaceCwd, workspaceId],
 	);
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/utils/file-paths.ts b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/utils/file-paths.ts
index dd6b7f14fae..4cf901bddde 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/utils/file-paths.ts
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/ChatPane/ChatInterface/utils/file-paths.ts
@@ -1,3 +1,5 @@
+import { isAbsolute, normalize, relative, resolve } from "pathe";
+
 export function getWorkspaceToolFilePath({
 	toolName,
 	args,
@@ -26,39 +28,74 @@ export function normalizeWorkspaceFilePath({
 	filePath: string;
 	workspaceRoot?: string;
 }): string | null {
-	let normalizedPath = filePath.trim();
+	let normalizedPath = stripFileUri(filePath.trim());
 	if (!normalizedPath) return null;
 
-	if (normalizedPath.startsWith("file://")) {
-		const rawPath = normalizedPath.slice(7);
-		try {
-			normalizedPath = decodeURIComponent(rawPath);
-		} catch {
-			normalizedPath = rawPath;
+	normalizedPath = normalize(normalizedPath);
+
+	if (workspaceRoot) {
+		const root = normalize(workspaceRoot);
+		if (normalizedPath === root) return null;
+		if (isAbsolute(normalizedPath)) {
+			const rel = relative(root, normalizedPath);
+			// relative() returns a path starting with ".." if outside the root
+			if (rel.startsWith("..")) return null;
+			normalizedPath = rel;
 		}
 	}
 
-	normalizedPath = normalizedPath.replaceAll("\\", "/");
+	if (!normalizedPath || normalizedPath === ".") return null;
+	if (isAbsolute(normalizedPath)) return null;
 
-	const normalizedRoot = workspaceRoot
-		? workspaceRoot.replaceAll("\\", "/").replace(/\/+$/, "")
-		: "";
+	return normalizedPath;
+}
 
-	if (normalizedRoot) {
-		if (normalizedPath === normalizedRoot) return null;
-		if (normalizedPath.startsWith(`${normalizedRoot}/`)) {
-			normalizedPath = normalizedPath.slice(normalizedRoot.length + 1);
-		}
+/**
+ * Resolves a file path to an absolute path given a workspace root.
+ * Handles file:// URIs, relative paths, and already-absolute paths.
+ * Returns null if the path is empty or resolves to the workspace root itself.
+ */
+export function resolveToAbsolutePath({
+	filePath,
+	workspaceRoot,
+}: {
+	filePath: string;
+	workspaceRoot?: string;
+}): string | null {
+	const normalizedPath = stripFileUri(filePath.trim());
+	if (!normalizedPath) return null;
+
+	// Remote URL — pass through
+	if (
+		normalizedPath.startsWith("https://") ||
+		normalizedPath.startsWith("http://")
+	) {
+		return normalizedPath;
 	}
 
-	while (normalizedPath.startsWith("./")) {
-		normalizedPath = normalizedPath.slice(2);
+	// Already absolute — normalize and return
+	if (isAbsolute(normalizedPath)) {
+		return normalize(normalizedPath);
 	}
 
-	if (!normalizedPath || normalizedPath === ".") return null;
-	if (normalizedPath.startsWith("/")) return null;
+	// Relative path — resolve against workspace root
+	if (!workspaceRoot) return null;
 
-	return normalizedPath;
+	const resolved = resolve(workspaceRoot, normalizedPath);
+	// Don't return the workspace root itself
+	if (resolved === normalize(workspaceRoot)) return null;
+
+	return resolved;
+}
+
+function stripFileUri(path: string): string {
+	if (!path.startsWith("file://")) return path;
+	const rawPath = path.slice(7);
+	try {
+		return decodeURIComponent(rawPath);
+	} catch {
+		return rawPath;
+	}
 }
 
 function toStringValue(value: unknown): string | null {
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/FileViewerPane.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/FileViewerPane.tsx
index d46a6061abf..608c401c7b6 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/FileViewerPane.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/FileViewerPane.tsx
@@ -1,3 +1,4 @@
+import { basename, relative } from "pathe";
 import { useCallback, useEffect, useRef, useState } from "react";
 import type { MosaicBranch } from "react-mosaic-component";
 import { useChangesStore } from "renderer/stores/changes";
@@ -244,7 +245,13 @@ export function FileViewerPane({
 		pendingModeRef.current = null;
 	};
 
-	const fileName = filePath.split("/").pop() || filePath;
+	const fileName = basename(filePath) || filePath;
+	// Derive display path: relative for in-worktree files, absolute otherwise
+	const displayPath = (() => {
+		if (!worktreePath || !filePath.startsWith(worktreePath)) return filePath;
+		const rel = relative(worktreePath, filePath);
+		return rel.startsWith("..") ? filePath : rel;
+	})();
 	const hasRenderedMode = isMarkdownFile(filePath) || isImageFile(filePath);
 	const hasDiff = !!diffCategory;
 
@@ -262,7 +269,7 @@ export function FileViewerPane({
 					<div className="flex h-full w-full">
 						<FileViewerToolbar
 							fileName={fileName}
-							filePath={filePath}
+							filePath={displayPath}
 							isDirty={isDirty}
 							viewMode={viewMode}
 							isPinned={isPinned}
@@ -284,6 +291,7 @@ export function FileViewerPane({
 				<FileViewerContent
 					viewMode={viewMode}
 					filePath={filePath}
+					displayPath={displayPath}
 					isLoadingRaw={isLoadingRaw}
 					isLoadingImage={isLoadingImage}
 					isLoadingDiff={isLoadingDiff}
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/components/FileViewerContent/FileViewerContent.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/components/FileViewerContent/FileViewerContent.tsx
index 51ab641849d..1fc01c3220c 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/components/FileViewerContent/FileViewerContent.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/components/FileViewerContent/FileViewerContent.tsx
@@ -1,3 +1,4 @@
+import { basename } from "pathe";
 import {
 	type MutableRefObject,
 	type RefObject,
@@ -61,6 +62,8 @@ interface DiffData {
 interface FileViewerContentProps {
 	viewMode: FileViewerMode;
 	filePath: string;
+	/** Worktree-relative path for display/clipboard operations */
+	displayPath: string;
 	isLoadingRaw: boolean;
 	isLoadingImage?: boolean;
 	isLoadingDiff: boolean;
@@ -104,6 +107,7 @@ interface FileViewerContentProps {
 export function FileViewerContent({
 	viewMode,
 	filePath,
+	displayPath,
 	isLoadingRaw,
 	isLoadingImage,
 	isLoadingDiff,
@@ -209,7 +213,7 @@ export function FileViewerContent({
 					contents={diffData}
 					viewMode={diffViewMode}
 					hideUnchangedRegions={hideUnchangedRegions}
-					filePath={filePath}
+					filePath={displayPath}
 					className="min-h-full"
 				/>
 			</div>
@@ -249,8 +253,8 @@ export function FileViewerContent({
 			<div className="flex h-full items-center justify-center overflow-auto bg-[#0d0d0d] p-4">
 				<img
 					src={imageData.dataUrl}
-					alt={filePath.split("/").pop() || "Image"}
-					className="max-h-full max-w-full object-contain"
+					alt={basename(filePath) || "Image"}
+					className="max-w-full max-h-full object-contain"
 					style={{ imageRendering: "auto" }}
 				/>
 			</div>
@@ -309,7 +313,7 @@ export function FileViewerContent({
 	return (
 		<FileEditorContextMenu
 			editorRef={editorRef}
-			filePath={filePath}
+			filePath={displayPath}
 			onSplitHorizontal={onSplitHorizontal}
 			onSplitVertical={onSplitVertical}
 			onSplitWithNewChat={onSplitWithNewChat}
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileContent/useFileContent.ts b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileContent/useFileContent.ts
index 183ac11c9a7..81188fccd1f 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileContent/useFileContent.ts
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileContent/useFileContent.ts
@@ -1,3 +1,4 @@
+import { isAbsolute, relative, resolve } from "pathe";
 import { useEffect, useMemo } from "react";
 import { electronTrpc } from "renderer/lib/electron-trpc";
 import type { ChangeCategory } from "shared/changes-types";
@@ -5,6 +6,7 @@ import { isImageFile } from "shared/file-types";
 
 interface UseFileContentParams {
 	worktreePath: string;
+	/** Absolute file path (or remote URL) */
 	filePath: string;
 	viewMode: "raw" | "diff" | "rendered";
 	diffCategory?: ChangeCategory;
@@ -15,6 +17,20 @@ interface UseFileContentParams {
 	originalDiffContentRef: React.MutableRefObject<string>;
 }
 
+/**
+ * Derives a worktree-relative path from an absolute path.
+ * Returns null if the path is not inside the worktree.
+ */
+function toRelativePath(filePath: string, worktreePath: string): string | null {
+	// Handle legacy persisted relative paths by resolving against worktreePath
+	const absolutePath = isAbsolute(filePath)
+		? filePath
+		: resolve(worktreePath, filePath);
+	const rel = relative(worktreePath, absolutePath);
+	if (rel.startsWith("..") || rel === "") return null;
+	return rel;
+}
+
 export function useFileContent({
 	worktreePath,
 	filePath,
@@ -30,10 +46,23 @@ export function useFileContent({
 	const isRemote =
 		filePath.startsWith("https://") || filePath.startsWith("http://");
 
+	// Derive worktree-relative path for git-aware operations (secureFs)
+	const relativePath = useMemo(
+		() => (worktreePath ? toRelativePath(filePath, worktreePath) : null),
+		[filePath, worktreePath],
+	);
+
+	// File is inside the worktree if we can derive a relative path
+	const isInsideWorktree = relativePath !== null;
+
 	const { data: branchData } = electronTrpc.changes.getBranches.useQuery(
 		{ worktreePath },
 		{
-			enabled: !isRemote && !!worktreePath && diffCategory === "against-base",
+			enabled:
+				!isRemote &&
+				isInsideWorktree &&
+				!!worktreePath &&
+				diffCategory === "against-base",
 		},
 	);
 	const effectiveBaseBranch =
@@ -41,28 +70,53 @@ export function useFileContent({
 
 	const isImage = isImageFile(filePath);
 
+	// Use filesystem.readFile for files outside the worktree (absolute paths)
+	const { data: externalFileData, isLoading: isLoadingExternal } =
+		electronTrpc.filesystem.readFile.useQuery(
+			{ filePath },
+			{
+				enabled:
+					!isRemote &&
+					!isInsideWorktree &&
+					viewMode !== "diff" &&
+					!isImage &&
+					!!filePath,
+			},
+		);
+
+	// Use changes.readWorkingFile for worktree-relative paths
 	const { data: rawFileData, isLoading: isLoadingRaw } =
 		electronTrpc.changes.readWorkingFile.useQuery(
-			{ worktreePath, filePath },
+			{ worktreePath, filePath: relativePath ?? "" },
 			{
 				enabled:
 					!isRemote &&
+					isInsideWorktree &&
 					viewMode !== "diff" &&
 					!isImage &&
-					!!filePath &&
+					!!relativePath &&
 					!!worktreePath,
 			},
 		);
 
+	// Merge external and worktree file data into a single result
+	const effectiveRawFileData = isInsideWorktree
+		? rawFileData
+		: externalFileData;
+	const effectiveIsLoadingRaw = isInsideWorktree
+		? isLoadingRaw
+		: isLoadingExternal;
+
 	const { data: imageData, isLoading: isLoadingImage } =
 		electronTrpc.changes.readWorkingFileImage.useQuery(
-			{ worktreePath, filePath },
+			{ worktreePath, filePath: relativePath ?? "" },
 			{
 				enabled:
 					!isRemote &&
+					isInsideWorktree &&
 					viewMode === "rendered" &&
 					isImage &&
-					!!filePath &&
+					!!relativePath &&
 					!!worktreePath,
 			},
 		);
@@ -71,7 +125,7 @@ export function useFileContent({
 		electronTrpc.changes.getFileContents.useQuery(
 			{
 				worktreePath,
-				filePath,
+				filePath: relativePath ?? "",
 				oldPath,
 				category: diffCategory ?? "unstaged",
 				commitHash,
@@ -81,19 +135,20 @@ export function useFileContent({
 			{
 				enabled:
 					!isRemote &&
+					isInsideWorktree &&
 					viewMode === "diff" &&
 					!!diffCategory &&
-					!!filePath &&
+					!!relativePath &&
 					!!worktreePath,
 			},
 		);
 
 	// biome-ignore lint/correctness/useExhaustiveDependencies: Only update baseline when content loads
 	useEffect(() => {
-		if (rawFileData?.ok === true && !isDirty) {
-			originalContentRef.current = rawFileData.content;
+		if (effectiveRawFileData?.ok === true && !isDirty) {
+			originalContentRef.current = effectiveRawFileData.content;
 		}
-	}, [rawFileData]);
+	}, [effectiveRawFileData]);
 
 	// biome-ignore lint/correctness/useExhaustiveDependencies: Only update baseline when diff loads
 	useEffect(() => {
@@ -112,8 +167,8 @@ export function useFileContent({
 	);
 
 	return {
-		rawFileData,
-		isLoadingRaw: isLoadingRaw || (isImage && isLoadingImage),
+		rawFileData: effectiveRawFileData,
+		isLoadingRaw: effectiveIsLoadingRaw || (isImage && isLoadingImage),
 		imageData: isRemote ? remoteImageData : imageData,
 		isLoadingImage: isRemote ? false : isLoadingImage,
 		diffData,
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileSave/useFileSave.ts b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileSave/useFileSave.ts
index b9886a164f2..e8bd078012d 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileSave/useFileSave.ts
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/TabView/FileViewerPane/hooks/useFileSave/useFileSave.ts
@@ -1,4 +1,5 @@
-import { type MutableRefObject, useCallback, useRef } from "react";
+import { isAbsolute, relative, resolve } from "pathe";
+import { type MutableRefObject, useCallback, useMemo, useRef } from "react";
 import { electronTrpc } from "renderer/lib/electron-trpc";
 import { useTabsStore } from "renderer/stores/tabs/store";
 import type { ChangeCategory } from "shared/changes-types";
@@ -6,6 +7,7 @@ import type { CodeEditorAdapter } from "../../../../../components";
 
 interface UseFileSaveParams {
 	worktreePath: string;
+	/** Absolute file path */
 	filePath: string;
 	paneId: string;
 	diffCategory?: ChangeCategory;
@@ -27,6 +29,16 @@ export function useFileSave({
 	draftContentRef,
 	setIsDirty,
 }: UseFileSaveParams) {
+	// Derive worktree-relative path for secureFs save operations.
+	// Returns null for external files (outside worktree) — save is disabled.
+	const relativeFilePath = useMemo(() => {
+		if (!worktreePath) return null;
+		const abs = isAbsolute(filePath)
+			? filePath
+			: resolve(worktreePath, filePath);
+		const rel = relative(worktreePath, abs);
+		return rel.startsWith("..") ? null : rel;
+	}, [worktreePath, filePath]);
 	const savingFromRawRef = useRef(false);
 	const utils = electronTrpc.useUtils();
 
@@ -68,14 +80,14 @@ export function useFileSave({
 	});
 
 	const handleSaveRaw = useCallback(async () => {
-		if (!editorRef.current || !filePath || !worktreePath) return;
+		if (!editorRef.current || !relativeFilePath || !worktreePath) return;
 		savingFromRawRef.current = true;
 		await saveFileMutation.mutateAsync({
 			worktreePath,
-			filePath,
+			filePath: relativeFilePath,
 			content: editorRef.current.getValue(),
 		});
-	}, [worktreePath, filePath, saveFileMutation, editorRef]);
+	}, [worktreePath, relativeFilePath, saveFileMutation, editorRef]);
 
 	return {
 		handleSaveRaw,
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/Terminal/hooks/useFileLinkClick.ts b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/Terminal/hooks/useFileLinkClick.ts
index 9ef2948743f..671d6aef6c7 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/Terminal/hooks/useFileLinkClick.ts
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/Terminal/hooks/useFileLinkClick.ts
@@ -1,4 +1,5 @@
 import { toast } from "@superset/ui/sonner";
+import { resolve } from "pathe";
 import { useCallback } from "react";
 import { electronTrpc } from "renderer/lib/electron-trpc";
 import { electronTrpcClient as trpcClient } from "renderer/lib/trpc-client";
@@ -59,7 +60,6 @@ export function useFileLinkClick({
 
 			if (behavior === "file-viewer") {
 				// If workspaceCwd is not loaded yet, fall back to external editor
-				// This prevents confusing errors when the workspace is still initializing
 				if (!workspaceCwd) {
 					console.warn(
 						"[Terminal] workspaceCwd not loaded, falling back to external editor",
@@ -68,23 +68,8 @@ export function useFileLinkClick({
 					return;
 				}
 
-				// Normalize absolute paths to worktree-relative paths for file viewer
-				// File viewer expects relative paths, but terminal links can be absolute
-				let filePath = path;
-				// Use path boundary check to avoid incorrect prefix stripping
-				// e.g., /repo vs /repo-other should not match
-				if (path === workspaceCwd) {
-					filePath = ".";
-				} else if (path.startsWith(`${workspaceCwd}/`)) {
-					filePath = path.slice(workspaceCwd.length + 1);
-				} else if (path.startsWith("/")) {
-					// Absolute path outside workspace - show warning and don't attempt to open
-					toast.warning("File is outside the workspace", {
-						description:
-							"Switch to 'External editor' in Settings to open this file",
-					});
-					return;
-				}
+				// Resolve relative paths to absolute using workspace cwd
+				const filePath = resolve(workspaceCwd, path);
 				addFileViewerPane(workspaceId, {
 					filePath,
 					line,
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/FilesView.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/FilesView.tsx
index c52a7a7e810..96f71c615ac 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/FilesView.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/FilesView.tsx
@@ -11,9 +11,12 @@ import {
 	ContextMenuItem,
 	ContextMenuTrigger,
 } from "@superset/ui/context-menu";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@superset/ui/tooltip";
+import { cn } from "@superset/ui/utils";
 import { useParams } from "@tanstack/react-router";
+import { dirname } from "pathe";
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
-import { LuFile, LuFolder } from "react-icons/lu";
+import { LuChevronRight, LuFile, LuFolder, LuHouse } from "react-icons/lu";
 import { electronTrpc } from "renderer/lib/electron-trpc";
 import { useTabsStore } from "renderer/stores/tabs/store";
 import type { DirectoryEntry } from "shared/file-tree-types";
@@ -37,11 +40,16 @@ export function FilesView() {
 	const worktreePath = workspace?.worktreePath;
 
 	const [searchTerm, setSearchTerm] = useState("");
+	// browseRoot allows navigating outside the worktree directory
+	const [browseRoot, setBrowseRoot] = useState<string | null>(null);
+	const effectiveRoot = browseRoot ?? worktreePath;
+	const isOutsideWorktree = browseRoot !== null && browseRoot !== worktreePath;
+
 	const projectId = workspace?.project?.id;
 
 	// Refs avoid stale closure in dataLoader callbacks
-	const worktreePathRef = useRef(worktreePath);
-	worktreePathRef.current = worktreePath;
+	const effectiveRootRef = useRef(effectiveRoot);
+	effectiveRootRef.current = effectiveRoot;
 
 	const trpcUtils = electronTrpc.useUtils();
 
@@ -57,7 +65,7 @@ export function FilesView() {
 					return {
 						id: "root",
 						name: "root",
-						path: worktreePathRef.current ?? "",
+						path: effectiveRootRef.current ?? "",
 						relativePath: "",
 						isDirectory: true,
 					};
@@ -72,17 +80,17 @@ export function FilesView() {
 				};
 			},
 			getChildren: async (itemId: string): Promise<string[]> => {
-				const currentPath = worktreePathRef.current;
-				if (!currentPath) return [];
+				const currentRoot = effectiveRootRef.current;
+				if (!currentRoot) return [];
 
 				const dirPath =
-					itemId === "root" ? currentPath : itemId.split(":::")[0];
+					itemId === "root" ? currentRoot : itemId.split(":::")[0];
 				if (!dirPath) return [];
 
 				try {
 					const entries = await trpcUtils.filesystem.readDirectory.fetch({
 						dirPath,
-						rootPath: currentPath,
+						rootPath: currentRoot,
 					});
 					return entries.map(
 						(e) =>
@@ -97,23 +105,39 @@ export function FilesView() {
 		features: [asyncDataLoaderFeature, selectionFeature, expandAllFeature],
 	});
 
-	const prevWorktreePathRef = useRef(worktreePath);
+	const prevEffectiveRootRef = useRef(effectiveRoot);
 	useEffect(() => {
 		if (
-			worktreePath &&
-			prevWorktreePathRef.current !== worktreePath &&
-			prevWorktreePathRef.current !== undefined
+			effectiveRoot &&
+			prevEffectiveRootRef.current !== effectiveRoot &&
+			prevEffectiveRootRef.current !== undefined
 		) {
 			tree.getItemInstance("root")?.invalidateChildrenIds();
 		}
-		prevWorktreePathRef.current = worktreePath;
-	}, [worktreePath, tree]);
+		prevEffectiveRootRef.current = effectiveRoot;
+	}, [effectiveRoot, tree]);
+
+	// Reset browseRoot when switching workspaces
+	// biome-ignore lint/correctness/useExhaustiveDependencies: Reset on worktree change only
+	useEffect(() => {
+		setBrowseRoot(null);
+	}, [worktreePath]);
+
+	const navigateToParent = useCallback(() => {
+		const current = effectiveRoot;
+		if (!current || current === "/") return;
+		setBrowseRoot(dirname(current));
+	}, [effectiveRoot]);
+
+	const navigateHome = useCallback(() => {
+		setBrowseRoot(null);
+	}, []);
 
 	const { createFile, createDirectory, rename, deleteItems, isDeleting } =
 		useFileTreeActions({
 			worktreePath,
 			onRefresh: async (parentPath: string) => {
-				const isRoot = parentPath === worktreePath;
+				const isRoot = parentPath === effectiveRoot;
 				const itemId = isRoot
 					? "root"
 					: tree
@@ -134,7 +158,7 @@ export function FilesView() {
 		isFetching: isSearchFetching,
 		hasQuery: isSearching,
 	} = useFileSearch({
-		worktreePath,
+		worktreePath: effectiveRoot,
 		searchTerm,
 	});
 
@@ -151,9 +175,7 @@ export function FilesView() {
 	const handleFileActivate = useCallback(
 		(entry: DirectoryEntry) => {
 			if (!workspaceId || !worktreePath || entry.isDirectory) return;
-			addFileViewerPane(workspaceId, {
-				filePath: entry.relativePath,
-			});
+			addFileViewerPane(workspaceId, { filePath: entry.path });
 		},
 		[workspaceId, worktreePath, addFileViewerPane],
 	);
@@ -172,7 +194,7 @@ export function FilesView() {
 
 	const handleNewFile = useCallback(
 		async (parentPath: string) => {
-			if (parentPath !== worktreePath) {
+			if (parentPath !== effectiveRoot) {
 				const item = tree
 					.getItems()
 					.find(
@@ -186,12 +208,12 @@ export function FilesView() {
 			setNewItemMode("file");
 			setNewItemParentPath(parentPath);
 		},
-		[worktreePath, tree],
+		[effectiveRoot, tree],
 	);
 
 	const handleNewFolder = useCallback(
 		async (parentPath: string) => {
-			if (parentPath !== worktreePath) {
+			if (parentPath !== effectiveRoot) {
 				const item = tree
 					.getItems()
 					.find(
@@ -205,7 +227,7 @@ export function FilesView() {
 			setNewItemMode("folder");
 			setNewItemParentPath(parentPath);
 		},
-		[worktreePath, tree],
+		[effectiveRoot, tree],
 	);
 
 	const handleNewItemSubmit = useCallback(
@@ -282,6 +304,16 @@ export function FilesView() {
 		}));
 	}, [searchResults]);
 
+	// Build breadcrumb segments for the current browse root
+	const breadcrumbSegments = useMemo(() => {
+		if (!isOutsideWorktree || !effectiveRoot) return null;
+		const parts = effectiveRoot.split("/").filter(Boolean);
+		return parts.map((name, i) => ({
+			name,
+			path: `/${parts.slice(0, i + 1).join("/")}`,
+		}));
+	}, [isOutsideWorktree, effectiveRoot]);
+
 	if (!worktreePath) {
 		return (
 			<div className="flex-1 flex items-center justify-center text-muted-foreground text-sm p-4">
@@ -295,24 +327,64 @@ export function FilesView() {
 			<FileTreeToolbar
 				searchTerm={searchTerm}
 				onSearchChange={setSearchTerm}
-				onNewFile={() => handleNewFile(worktreePath)}
-				onNewFolder={() => handleNewFolder(worktreePath)}
+				onNewFile={() => handleNewFile(effectiveRoot ?? worktreePath)}
+				onNewFolder={() => handleNewFolder(effectiveRoot ?? worktreePath)}
 				onCollapseAll={handleCollapseAll}
 				onRefresh={handleRefresh}
+				onNavigateToParent={navigateToParent}
+				onNavigateHome={isOutsideWorktree ? navigateHome : undefined}
 			/>
 
+			{breadcrumbSegments && (
+				<div className="flex items-center gap-0.5 px-2 py-1 border-b border-border text-xs text-muted-foreground overflow-x-auto shrink-0">
+					<Tooltip>
+						<TooltipTrigger asChild>
+							<button
+								type="button"
+								onClick={navigateHome}
+								className="shrink-0 p-0.5 rounded hover:bg-accent/50 hover:text-foreground transition-colors"
+							>
+								<LuHouse className="size-3" />
+							</button>
+						</TooltipTrigger>
+						<TooltipContent side="bottom">
+							Back to {worktreePath?.split("/").pop()}
+						</TooltipContent>
+					</Tooltip>
+					<LuChevronRight className="size-3 shrink-0 text-muted-foreground/50" />
+					{breadcrumbSegments.map((segment, i) => (
+						<span key={segment.path} className="flex items-center gap-0.5">
+							{i > 0 && (
+								<LuChevronRight className="size-3 shrink-0 text-muted-foreground/50" />
+							)}
+							<button
+								type="button"
+								onClick={() => setBrowseRoot(segment.path)}
+								className={cn(
+									"shrink-0 truncate max-w-[120px] hover:text-foreground transition-colors",
+									i === breadcrumbSegments.length - 1 && "text-foreground",
+								)}
+							>
+								{segment.name}
+							</button>
+						</span>
+					))}
+				</div>
+			)}
+
 			<div className="flex-1 min-h-0 overflow-hidden">
 				<ContextMenu>
 					<ContextMenuTrigger asChild className="h-full">
 						<div className="h-full overflow-auto">
-							{newItemMode && newItemParentPath === worktreePath && (
-								<NewItemInput
-									mode={newItemMode}
-									parentPath={newItemParentPath}
-									onSubmit={handleNewItemSubmit}
-									onCancel={handleNewItemCancel}
-								/>
-							)}
+							{newItemMode &&
+								newItemParentPath === (effectiveRoot ?? worktreePath) && (
+									<NewItemInput
+										mode={newItemMode}
+										parentPath={newItemParentPath}
+										onSubmit={handleNewItemSubmit}
+										onCancel={handleNewItemCancel}
+									/>
+								)}
 
 							{isSearching ? (
 								searchResultEntries.length > 0 ? (
@@ -329,7 +401,7 @@ export function FilesView() {
 												<FileSearchResultItem
 													key={entry.id}
 													entry={entry}
-													worktreePath={worktreePath}
+													worktreePath={effectiveRoot ?? worktreePath}
 													projectId={projectId}
 													onActivate={handleFileActivate}
 													onOpenInEditor={handleOpenInEditor}
@@ -373,7 +445,7 @@ export function FilesView() {
 														entry={data}
 														rowHeight={ROW_HEIGHT}
 														indent={TREE_INDENT}
-														worktreePath={worktreePath}
+														worktreePath={effectiveRoot ?? worktreePath}
 														projectId={projectId}
 														onActivate={handleFileActivate}
 														onOpenInEditor={handleOpenInEditor}
@@ -400,11 +472,15 @@ export function FilesView() {
 						</div>
 					</ContextMenuTrigger>
 					<ContextMenuContent className="w-48">
-						<ContextMenuItem onClick={() => handleNewFile(worktreePath)}>
+						<ContextMenuItem
+							onClick={() => handleNewFile(effectiveRoot ?? worktreePath)}
+						>
 							<LuFile className="mr-2 size-4" />
 							New File
 						</ContextMenuItem>
-						<ContextMenuItem onClick={() => handleNewFolder(worktreePath)}>
+						<ContextMenuItem
+							onClick={() => handleNewFolder(effectiveRoot ?? worktreePath)}
+						>
 							<LuFolder className="mr-2 size-4" />
 							New Folder
 						</ContextMenuItem>
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/components/FileTreeToolbar/FileTreeToolbar.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/components/FileTreeToolbar/FileTreeToolbar.tsx
index b048232cbd4..9a823a5177d 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/components/FileTreeToolbar/FileTreeToolbar.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/FilesView/components/FileTreeToolbar/FileTreeToolbar.tsx
@@ -3,9 +3,11 @@ import { Input } from "@superset/ui/input";
 import { Tooltip, TooltipContent, TooltipTrigger } from "@superset/ui/tooltip";
 import { useCallback, useEffect, useRef, useState } from "react";
 import {
+	LuArrowUp,
 	LuChevronsDownUp,
 	LuFilePlus,
 	LuFolderPlus,
+	LuHouse,
 	LuRefreshCw,
 	LuX,
 } from "react-icons/lu";
@@ -19,6 +21,8 @@ interface FileTreeToolbarProps {
 	onCollapseAll: () => void;
 	onRefresh: () => void;
 	isRefreshing?: boolean;
+	onNavigateToParent?: () => void;
+	onNavigateHome?: (() => void) | undefined;
 }
 
 export function FileTreeToolbar({
@@ -29,6 +33,8 @@ export function FileTreeToolbar({
 	onCollapseAll,
 	onRefresh,
 	isRefreshing = false,
+	onNavigateToParent,
+	onNavigateHome,
 }: FileTreeToolbarProps) {
 	const [localSearchTerm, setLocalSearchTerm] = useState(searchTerm);
 	const debounceTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
@@ -97,6 +103,42 @@ export function FileTreeToolbar({
 			</div>
 
 			<div className="flex items-center gap-0.5">
+				{onNavigateToParent && (
+					<Tooltip>
+						<TooltipTrigger asChild>
+							<Button
+								variant="ghost"
+								size="icon"
+								className="size-6"
+								onClick={onNavigateToParent}
+							>
+								<LuArrowUp className="size-3.5" />
+							</Button>
+						</TooltipTrigger>
+						<TooltipContent side="bottom">
+							Go to Parent Directory
+						</TooltipContent>
+					</Tooltip>
+				)}
+
+				{onNavigateHome && (
+					<Tooltip>
+						<TooltipTrigger asChild>
+							<Button
+								variant="ghost"
+								size="icon"
+								className="size-6"
+								onClick={onNavigateHome}
+							>
+								<LuHouse className="size-3.5" />
+							</Button>
+						</TooltipTrigger>
+						<TooltipContent side="bottom">
+							Back to Workspace Root
+						</TooltipContent>
+					</Tooltip>
+				)}
+
 				<Tooltip>
 					<TooltipTrigger asChild>
 						<Button
diff --git a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/index.tsx b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/index.tsx
index 4609056cd98..759b8814303 100644
--- a/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/index.tsx
+++ b/apps/desktop/src/renderer/screens/main/components/WorkspaceView/RightSidebar/index.tsx
@@ -2,6 +2,7 @@ import { Button } from "@superset/ui/button";
 import { Tooltip, TooltipContent, TooltipTrigger } from "@superset/ui/tooltip";
 import { cn } from "@superset/ui/utils";
 import { useParams } from "@tanstack/react-router";
+import { resolve } from "pathe";
 import { useCallback } from "react";
 import {
 	LuExpand,
@@ -103,22 +104,22 @@ export function RightSidebar() {
 	const { scrollToFile } = useScrollContext();
 
 	const invalidateFileContent = useCallback(
-		(filePath: string) => {
+		(relativeFilePath: string) => {
 			if (!worktreePath) return;
 
 			Promise.all([
 				trpcUtils.changes.readWorkingFile.invalidate({
 					worktreePath,
-					filePath,
+					filePath: relativeFilePath,
 				}),
 				trpcUtils.changes.getFileContents.invalidate({
 					worktreePath,
-					filePath,
+					filePath: relativeFilePath,
 				}),
 			]).catch((error) => {
 				console.error(
 					"[RightSidebar/invalidateFileContent] Failed to invalidate file content queries:",
-					{ worktreePath, filePath, error },
+					{ worktreePath, filePath: relativeFilePath, error },
 				);
 			});
 		},
@@ -128,8 +129,9 @@ export function RightSidebar() {
 	const handleFileOpenPane = useCallback(
 		(file: ChangedFile, category: ChangeCategory, commitHash?: string) => {
 			if (!workspaceId || !worktreePath) return;
+			const absolutePath = resolve(worktreePath, file.path);
 			addFileViewerPane(workspaceId, {
-				filePath: file.path,
+				filePath: absolutePath,
 				diffCategory: category,
 				fileStatus: file.status,
 				commitHash,
diff --git a/apps/desktop/src/renderer/stores/tabs/store.ts b/apps/desktop/src/renderer/stores/tabs/store.ts
index 003a92b83ed..4d7df8c64a4 100644
--- a/apps/desktop/src/renderer/stores/tabs/store.ts
+++ b/apps/desktop/src/renderer/stores/tabs/store.ts
@@ -1,3 +1,4 @@
+import { basename } from "pathe";
 import type { MosaicNode } from "react-mosaic-component";
 import { updateTree } from "react-mosaic-component";
 import { getFileOpenMode } from "renderer/hooks/useFileOpenMode";
@@ -742,8 +743,7 @@ export const useTabsStore = create<TabsStore>()(
 						}
 
 						// Different file - replace the preview pane content
-						const fileName =
-							options.filePath.split("/").pop() || options.filePath;
+						const fileName = basename(options.filePath) || options.filePath;
 
 						const viewMode = resolveFileViewerMode({
 							filePath: options.filePath,
@@ -1873,7 +1873,7 @@ export const useTabsStore = create<TabsStore>()(
 			}),
 			{
 				name: "tabs-storage",
-				version: 7,
+				version: 8,
 				storage: trpcTabsStorage,
 				migrate: (persistedState, version) => {
 					const state = persistedState as TabsState;
@@ -1920,6 +1920,19 @@ export const useTabsStore = create<TabsStore>()(
 							}
 						}
 					}
+					if (version < 8 && state.panes) {
+						// Clear file viewer panes with relative paths (pre-absolute-path era).
+						// We can't resolve them without worktreePath (server-side data).
+						for (const [id, pane] of Object.entries(state.panes)) {
+							if (
+								pane.fileViewer?.filePath &&
+								!pane.fileViewer.filePath.startsWith("/") &&
+								!pane.fileViewer.filePath.startsWith("http")
+							) {
+								delete state.panes[id];
+							}
+						}
+					}
 					return state;
 				},
 				merge: (persistedState, currentState) => {
diff --git a/apps/desktop/src/renderer/stores/tabs/utils.ts b/apps/desktop/src/renderer/stores/tabs/utils.ts
index 3417fe42ea9..1f548e20b6d 100644
--- a/apps/desktop/src/renderer/stores/tabs/utils.ts
+++ b/apps/desktop/src/renderer/stores/tabs/utils.ts
@@ -1,3 +1,4 @@
+import { basename } from "pathe";
 import type { MosaicBranch, MosaicNode } from "react-mosaic-component";
 import {
 	type ChangeCategory,
@@ -215,7 +216,7 @@ export const createFileViewerPane = (
 	};
 
 	// Use filename for display name
-	const fileName = options.filePath.split("/").pop() || options.filePath;
+	const fileName = basename(options.filePath) || options.filePath;
 
 	return {
 		id,
diff --git a/apps/desktop/src/shared/tabs-types.ts b/apps/desktop/src/shared/tabs-types.ts
index c82e6a46654..cb0255ee7cf 100644
--- a/apps/desktop/src/shared/tabs-types.ts
+++ b/apps/desktop/src/shared/tabs-types.ts
@@ -101,7 +101,7 @@ export type DiffLayout = "inline" | "side-by-side";
  * File viewer pane-specific properties
  */
 export interface FileViewerState {
-	/** Worktree-relative file path */
+	/** Absolute file path (or remote URL for images) */
 	filePath: string;
 	/** Display mode: rendered (markdown), raw (source), or diff */
 	viewMode: FileViewerMode;
diff --git a/bun.lock b/bun.lock
index 5b713c41ab3..3724478e2fd 100644
--- a/bun.lock
+++ b/bun.lock
@@ -251,6 +251,7 @@
         "node-addon-api": "^7.1.0",
         "node-pty": "1.1.0",
         "os-locale": "^6.0.2",
+        "pathe": "^2.0.3",
         "pidtree": "^0.6.0",
         "pidusage": "^4.0.1",
         "posthog-js": "1.310.1",