chore(tui): replace koffi with Windows VT input helper

closes #4480

packages/coding-agent/npm-shrinkwrap.json

@@ -516,9 +516,6 @@
 				"get-east-asian-width": "1.6.0",
 				"marked": "15.0.12"
 			},
-			"optionalDependencies": {
-				"koffi": "2.16.2"
-			},
 			"engines": {
 				"node": ">=22.19.0"
 			}
@@ -1369,17 +1366,6 @@
 				"safe-buffer": "^5.0.1"
 			}
 		},
-		"node_modules/koffi": {
-			"version": "2.16.2",
-			"resolved": "https://registry.npmjs.org/koffi/-/koffi-2.16.2.tgz",
-			"integrity": "sha512-owU0MRwv6xkrVqCd+33uw6BaYppkTRXbO/rVdJNI2dvZG0gzyRhYwW25eWtc5pauwK8TGh3AbkFONSezdykfSA==",
-			"license": "MIT",
-			"optional": true,
-			"hasInstallScript": true,
-			"funding": {
-				"url": "https://liberapay.com/Koromix"
-			}
-		},
 		"node_modules/long": {
 			"version": "5.3.2",
 			"resolved": "https://registry.npmjs.org/long/-/long-5.3.2.tgz",

packages/tui/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Changed
+
+- Replaced the optional `koffi` dependency for Windows VT input with a tiny vendored native helper, reducing install size while preserving Shift+Tab handling ([#4480](https://github.com/earendil-works/pi/issues/4480)).
+
 ## [0.75.4] - 2026-05-20
 
 ### Changed

packages/tui/native/win32/src/win32-console-mode.c

@@ -0,0 +1,53 @@
+#include <windows.h>
+
+#ifndef ENABLE_VIRTUAL_TERMINAL_INPUT
+#define ENABLE_VIRTUAL_TERMINAL_INPUT 0x0200
+#endif
+
+#define NAPI_AUTO_LENGTH ((unsigned long long)-1)
+
+typedef void* napi_env;
+typedef void* napi_value;
+typedef void* napi_callback_info;
+typedef napi_value (__cdecl *napi_callback)(napi_env, napi_callback_info);
+typedef int (__cdecl *napi_create_function_fn)(napi_env, const char*, unsigned long long, napi_callback, void*, napi_value*);
+typedef int (__cdecl *napi_set_named_property_fn)(napi_env, napi_value, const char*, napi_value);
+typedef int (__cdecl *napi_get_boolean_fn)(napi_env, int, napi_value*);
+
+static void* node_symbol(const char* name) {
+    HMODULE module = GetModuleHandleA(0);
+    void* proc = module ? (void*)GetProcAddress(module, name) : 0;
+    if (proc) return proc;
+
+    module = GetModuleHandleA("node.dll");
+    return module ? (void*)GetProcAddress(module, name) : 0;
+}
+
+static napi_value __cdecl enable_virtual_terminal_input(napi_env env, napi_callback_info info) {
+    (void)info;
+
+    HANDLE handle = GetStdHandle(STD_INPUT_HANDLE);
+    DWORD mode = 0;
+    int enabled = handle != INVALID_HANDLE_VALUE &&
+        GetConsoleMode(handle, &mode) &&
+        SetConsoleMode(handle, mode | ENABLE_VIRTUAL_TERMINAL_INPUT);
+
+    napi_get_boolean_fn napi_get_boolean = (napi_get_boolean_fn)node_symbol("napi_get_boolean");
+    napi_value result = 0;
+    if (napi_get_boolean) napi_get_boolean(env, enabled, &result);
+    return result;
+}
+
+__declspec(dllexport) napi_value __cdecl napi_register_module_v1(napi_env env, napi_value exports) {
+    napi_create_function_fn napi_create_function = (napi_create_function_fn)node_symbol("napi_create_function");
+    napi_set_named_property_fn napi_set_named_property = (napi_set_named_property_fn)node_symbol("napi_set_named_property");
+
+    napi_value fn = 0;
+    if (napi_create_function &&
+        napi_set_named_property &&
+        napi_create_function(env, "enableVirtualTerminalInput", NAPI_AUTO_LENGTH, enable_virtual_terminal_input, 0, &fn) == 0) {
+        napi_set_named_property(env, exports, "enableVirtualTerminalInput", fn);
+    }
+
+    return exports;
+}

packages/tui/package.json

@@ -12,6 +12,7 @@
 	},
 	"files": [
 		"dist/**/*",
+		"native/win32/prebuilds/**/*.node",
 		"README.md"
 	],
 	"keywords": [
@@ -38,9 +39,6 @@
 		"get-east-asian-width": "1.6.0",
 		"marked": "15.0.12"
 	},
-	"optionalDependencies": {
-		"koffi": "2.16.2"
-	},
 	"devDependencies": {
 		"@xterm/headless": "5.5.0",
 		"@xterm/xterm": "5.5.0",

packages/tui/src/terminal.ts

@@ -1,6 +1,7 @@
 import * as fs from "node:fs";
 import { createRequire } from "node:module";
 import * as path from "node:path";
+import { fileURLToPath } from "node:url";
 import { setKittyProtocolActive } from "./keys.ts";
 import { StdinBuffer } from "./stdin-buffer.ts";
 
@@ -210,23 +211,30 @@ export class ProcessTerminal implements Terminal {
 	private enableWindowsVTInput(): void {
 		if (process.platform !== "win32") return;
 		try {
-			// Dynamic require to avoid bundling koffi's 74MB of cross-platform
-			// native binaries into every compiled binary. Koffi is only needed
-			// on Windows for VT input support.
-			const koffi = cjsRequire("koffi");
-			const k32 = koffi.load("kernel32.dll");
-			const GetStdHandle = k32.func("void* __stdcall GetStdHandle(int)");
-			const GetConsoleMode = k32.func("bool __stdcall GetConsoleMode(void*, _Out_ uint32_t*)");
-			const SetConsoleMode = k32.func("bool __stdcall SetConsoleMode(void*, uint32_t)");
+			const arch = process.arch;
+			if (arch !== "x64" && arch !== "arm64") return;
 
-			const STD_INPUT_HANDLE = -10;
-			const ENABLE_VIRTUAL_TERMINAL_INPUT = 0x0200;
-			const handle = GetStdHandle(STD_INPUT_HANDLE);
-			const mode = new Uint32Array(1);
-			GetConsoleMode(handle, mode);
-			SetConsoleMode(handle, mode[0]! | ENABLE_VIRTUAL_TERMINAL_INPUT);
+			// Dynamic require so non-Windows and bundled/browser paths never load the
+			// native helper. In the npm package native/ is next to dist/; in compiled
+			// binary archives native/ is copied next to the executable.
+			const moduleDir = path.dirname(fileURLToPath(import.meta.url));
+			const nativePath = path.join("native", "win32", "prebuilds", `win32-${arch}`, "win32-console-mode.node");
+			const candidates = [
+				path.join(moduleDir, "..", nativePath),
+				path.join(moduleDir, nativePath),
+				path.join(path.dirname(process.execPath), nativePath),
+			];
+			for (const modulePath of candidates) {
+				try {
+					const helper = cjsRequire(modulePath) as { enableVirtualTerminalInput?: () => boolean };
+					helper.enableVirtualTerminalInput?.();
+					return;
+				} catch {
+					// Try the next possible packaging location.
+				}
+			}
 		} catch {
-			// koffi not available — Shift+Tab won't be distinguishable from Tab
+			// Native helper not available — Shift+Tab won't be distinguishable from Tab.
 		}
 	}