diff --git a/packages/coding-agent/src/cli/config-selector.ts b/packages/coding-agent/src/cli/config-selector.ts
index b21e1231..cba05d86 100644
--- a/packages/coding-agent/src/cli/config-selector.ts
+++ b/packages/coding-agent/src/cli/config-selector.ts
@@ -22,7 +22,7 @@ export async function selectConfig(options: ConfigSelectorOptions): Promise<void
 	initTheme(options.settingsManager.getTheme(), true);
 
 	return new Promise((resolve) => {
-		const ui = new TUI(new ProcessTerminal());
+		const ui = new TUI(new ProcessTerminal(), undefined, options.agentDir);
 		let resolved = false;
 
 		const selector = new ConfigSelectorComponent(
diff --git a/packages/coding-agent/src/cli/startup-ui.ts b/packages/coding-agent/src/cli/startup-ui.ts
index 73c0271c..12669e79 100644
--- a/packages/coding-agent/src/cli/startup-ui.ts
+++ b/packages/coding-agent/src/cli/startup-ui.ts
@@ -79,7 +79,7 @@ export async function createStartupTui(settingsManager: SettingsManager): Promis
 	const terminalTheme = detectTerminalBackgroundFromEnv().theme;
 	initTheme(resolveThemeSetting(settingsManager.getThemeSetting(), terminalTheme) ?? terminalTheme);
 	setKeybindings(KeybindingsManager.create());
-	const ui = new TUI(new ProcessTerminal(), settingsManager.getShowHardwareCursor());
+	const ui = new TUI(new ProcessTerminal(), settingsManager.getShowHardwareCursor(), getAgentDir());
 	ui.setClearOnShrink(settingsManager.getClearOnShrink());
 	return ui;
 }
diff --git a/packages/coding-agent/src/modes/interactive/interactive-mode.ts b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
index 7a31aa84..6a20b677 100644
--- a/packages/coding-agent/src/modes/interactive/interactive-mode.ts
+++ b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
@@ -450,7 +450,7 @@ export class InteractiveMode {
 			await this.rebindCurrentSession({ renderBeforeBind: true });
 		});
 		this.version = VERSION;
-		this.ui = new TUI(new ProcessTerminal(), this.settingsManager.getShowHardwareCursor());
+		this.ui = new TUI(new ProcessTerminal(), this.settingsManager.getShowHardwareCursor(), getAgentDir());
 		this.ui.setClearOnShrink(this.settingsManager.getClearOnShrink());
 		this.headerContainer = new Container();
 		this.loadedResourcesContainer = new Container();
diff --git a/packages/tui/src/tui.ts b/packages/tui/src/tui.ts
index b7ebaea9..954256a1 100644
--- a/packages/tui/src/tui.ts
+++ b/packages/tui/src/tui.ts
@@ -319,15 +319,17 @@ export class TUI extends Container {
 	private pendingOsc11BackgroundQueries: PendingOsc11BackgroundQuery[] = [];
 	private terminalColorSchemeListeners = new Set<(scheme: TerminalColorScheme) => void>();
 	private terminalColorSchemeNotificationsEnabled = false;
+	private readonly logDirectory: string;
 
 	// Overlay stack for modal components rendered on top of base content
 	private focusOrderCounter = 0;
 	private overlayStack: OverlayStackEntry[] = [];
 	private overlayFocusRestore: OverlayFocusRestoreState = { status: "inactive" };
 
-	constructor(terminal: Terminal, showHardwareCursor?: boolean) {
+	constructor(terminal: Terminal, showHardwareCursor?: boolean, logDirectory?: string) {
 		super();
 		this.terminal = terminal;
+		this.logDirectory = logDirectory ?? process.env.PI_CODING_AGENT_DIR ?? path.join(os.homedir(), ".pi", "agent");
 		if (showHardwareCursor !== undefined) {
 			this.showHardwareCursor = showHardwareCursor;
 		}
@@ -1329,8 +1331,9 @@ export class TUI extends Container {
 		const debugRedraw = process.env.PI_DEBUG_REDRAW === "1";
 		const logRedraw = (reason: string): void => {
 			if (!debugRedraw) return;
-			const logPath = path.join(os.homedir(), ".pi", "agent", "pi-debug.log");
+			const logPath = path.join(this.logDirectory, "pi-debug.log");
 			const msg = `[${new Date().toISOString()}] fullRender: ${reason} (prev=${this.previousLines.length}, new=${newLines.length}, height=${height})\n`;
+			fs.mkdirSync(path.dirname(logPath), { recursive: true });
 			fs.appendFileSync(logPath, msg);
 		};
 
@@ -1521,7 +1524,7 @@ export class TUI extends Container {
 			buffer += "\x1b[2K"; // Clear current line
 			if (!isImage && visibleWidth(line) > width) {
 				// Log all lines to crash file for debugging
-				const crashLogPath = path.join(os.homedir(), ".pi", "agent", "pi-crash.log");
+				const crashLogPath = path.join(this.logDirectory, "pi-crash.log");
 				const crashData = [
 					`Crash at ${new Date().toISOString()}`,
 					`Terminal width: ${width}`,
diff --git a/packages/tui/test/tui-render.test.ts b/packages/tui/test/tui-render.test.ts
index ab038ac7..484639ba 100644
--- a/packages/tui/test/tui-render.test.ts
+++ b/packages/tui/test/tui-render.test.ts
@@ -1,4 +1,7 @@
 import assert from "node:assert";
+import { mkdtempSync, readFileSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
 import { describe, it } from "node:test";
 import type { Terminal as XtermTerminalType } from "@xterm/headless";
 import { Image } from "../src/components/image.ts";
@@ -71,6 +74,28 @@ function getCellItalic(terminal: VirtualTerminal, row: number, col: number): num
 	return cell.isItalic();
 }
 
+describe("TUI debug logging", () => {
+	it("writes redraw logs to the provided directory", async () => {
+		const logDir = mkdtempSync(join(tmpdir(), "pi-tui-log-"));
+		try {
+			await withEnv({ PI_DEBUG_REDRAW: "1" }, async () => {
+				const terminal = new VirtualTerminal(40, 10);
+				const tui = new TUI(terminal, undefined, logDir);
+				const component = new TestComponent();
+				tui.addChild(component);
+				component.lines = ["test"];
+				tui.start();
+				await terminal.waitForRender();
+
+				assert.match(readFileSync(join(logDir, "pi-debug.log"), "utf-8"), /fullRender: first render/);
+				tui.stop();
+			});
+		} finally {
+			rmSync(logDir, { recursive: true, force: true });
+		}
+	});
+});
+
 describe("TUI Kitty image cleanup", () => {
 	it("clears reserved Kitty image rows before drawing appended image placements", async () => {
 		setCapabilities({ images: "kitty", trueColor: true, hyperlinks: true });