Nim's Windows API and COM Library



Winim contains Windows API, struct, and constant definitions for Nim. The definitions are translated from MinGW's Windows headers.

The module also include some Windows string type utilities and Windows COM support. See winstr.nim and com.nim for details.

If you are looking for Windows GUI framework, try wNim.


With git on windows:

nimble install winim

Without git:

1. Download and unzip this moudle (by click "Clone or download" button).
2. Start a console, change current dir to the folder which include "winim.nimble" file.
   (for example: C:\winim-master\winim-master>)
3. Run "nimble install"


import winim # import all modules, except COM support.


import winim/lean # for core SDK only, this speed up compiling time.


import winim/mean # for core SDK + Shell + OLE API.


import winim/com # winim/mean + Windows COM support.

API modules can import one by one if needed, for example:

import winim/utils
import winim/winstr
import winim/inc/windef
import winim/inc/winbase
import winim/inc/winuser


import winim/[utils, winstr]
import winim/inc/[windef, winbase, winuser]

WinHTTP and WinINet module are incompatible with each other. So they are not imported by default. Add one of them if needed:

import winim/inc/winhttp


import winim/inc/wininet

MSHTML module is too big. So it is not imported by default. Add this module only if needed:

import winim/inc/mshtml


nim c source.nim
  add -d:winansi or -d:useWinAnsi for Ansi version (Unicode by default)
  add -d:noDiscardableApi if not like discardable windows API
  add -d:noRes to disable the visual styles (not to link winim32.res or winim64.res).
  add -d:lean same as import winim/lean
  add -d:mean or -d:win32_lean_and_mean same as import winim/mean
  add -d:notrace disable COM objects trace. See com.nim for details.


An hello world program:

import winim/lean
MessageBox(0, "Hello, world !", "Nim is Powerful", 0)

Write codes work under both unicode and ansi mode:

import winim/lean
# T macro generate unicode string or ansi string depend on conditional symbol: useWinAnsi.
MessageBox(0, T"Hello, world !", T"Nim is Powerful 中文測試", 0)

Example to use the IShellLink interface:

import os, winim/mean

  pIL: ptr IShellLink
  pPF: ptr IPersistFile


  if CoCreateInstance(&CLSID_ShellLink, nil, CLSCTX_LOCAL_SERVER, &IID_IShellLink, cast[ptr PVOID](&pIL)).FAILED: raise
  defer: pIL.Release()

  if pIL.QueryInterface(&IID_IPersistFile, cast[ptr PVOID](&pPF)).FAILED: raise
  defer: pPF.Release()

  if pIL.SetPath(getAppFilename()).FAILED or pPF.Save("link.lnk", true).FAILED: raise

  echo "something wrong !!"

Use COM objects like a script langauge:

import winim/com

  var dict = CreateObject("Scripting.Dictionary")
  dict.add("a", "the")
  dict.add("b", "quick")
  dict.add("c", "fox")
  dict.item("c") = "dog" # this line needs comScript macro

  for key in dict:
    echo key, " => ", dict.item(key)


Winimx is a standalone tool to generate the minfied Winim module. It also can be used to generate the necessary definitions at compile time. For more information, see the document.

Cross Compile

Windows programs using Winim module should be compiled successfully by gcc, tcc, vcc on Windows, and MinGW toolchain on Linux. The target file can be PE (32 bits) or PE+ (64 bits).

The suggested Nim compiler is amd64 version. You can download both mingw32 and mingw64 from the Nim's website and put them into nim\dist\mingw32 and nim\dist\mingw64. Modify the nim.cfg:

@if windows:
  @if i386:
    gcc.path = r"$nim\dist\mingw32\bin"
    gcc.path = r"$nim\dist\mingw64\bin"

Now, you can add --cpu:i386 for 32 bits target, and --cpu:amd64 for 64 bits target. To use tcc (Tiny C Compiler), here are some more information.

To cross compile from Linux or macOS. Here is the instruction.



Read license.txt for more details.

Copyright (c) 2016-2020 Kai-Hung Chen, Ward. All rights reserved.

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