VMK – Vietnamese Micro Key for Fcitx5 .Bringing the UniKey typing experience to Linux/Wayland

[thanhpy2009]

VMK – Vietnamese Micro Key for Fcitx5
Bringing the UniKey typing experience to Linux/Wayland

Hello Fcitx5 community,

My name is Võ Ngô Hoàng Thành, and I’m one of the developers of VMK (Vietnamese Micro Key) — a Vietnamese input method built specifically on top of Fcitx5.

VMK is an experimental but practical attempt to solve a long-standing usability gap for Vietnamese users on Linux, especially on Wayland and Electron-based applications.

Why “UniKey-like” behavior is critical for Vietnamese users

For Vietnamese users, UniKey is not just another input method.

On Windows, nearly 100% of Vietnamese users type using UniKey or a UniKey-compatible behavior.
This typing model has existed for more than 20 years and has become deep muscle memory for an entire user base.

The defining characteristics of this model are:

No visible preedit buffer

Characters are modified in place

Backspace behaves like a real physical key

Text is committed directly to the application

When Vietnamese users move to Linux, the biggest friction is often not missing features, but that typing no longer “feels right”.

Even technically correct behaviors such as:

underlined preedit,

delayed commits,

or different backspace semantics

are immediately noticeable and are often perceived as bugs, simply because they differ from what users have relied on for decades.

VMK’s philosophy

VMK treats UniKey-like behavior as a first-class requirement, not an optional mode.

Instead of asking users to adapt to a new typing model, VMK adapts Linux input behavior to match established Vietnamese typing habits.

Linux should feel natural to Vietnamese users — not the other way around.

To achieve this, VMK focuses on:

Backspace-based reconstruction (sending physical-like Backspace events)

Carefully tuned delay and timing logic

Zero-preedit typing whenever possible

A minimal, practical configuration model

Typing mechanisms in VMK

VMK intentionally keeps the number of modes small and purpose-driven:

VMK1 – UniKey (Windows-like)
Uses virtual Backspace + delayed commit to recreate UniKey’s non-preedit behavior.
This is the primary mode and offers the best real-world compatibility.

VMK2 – Modern Surrounding Text
Uses Fcitx5 surrounding-text APIs combined with VMK’s optimization logic for high speed and smoothness.

VMK-Pre – Standard Preedit
Uses native Fcitx5 preedit as a fully compatible fallback for all applications.

Built on great open-source work

VMK would not exist without the outstanding open-source ecosystem behind it:

Fcitx5 Framework — by Weng Xuetian (wengxt)

Bamboo Vietnamese Engine — by Lâm Quang Lương

VMK itself mainly contributes:

Virtual Backspace logic

Delay calculation and timing control

Practical adjustments for Wayland-first environments

Why Fcitx5 matters here

Fcitx5 provides a modern, clean, and extensible architecture that makes it possible to experiment with non-traditional input behaviors like VMK.

VMK does not attempt to replace or redefine Fcitx5’s design principles.
Instead, it demonstrates that Fcitx5 is flexible enough to support region-specific, culturally important typing behaviors that have become de facto standards through decades of real-world use.

Special thanks

I would like to express my deep gratitude to Weng Xuetian (wengxt).

Fcitx5 is, in my opinion, the most modern and well-designed input method framework on Linux today.
Its Wayland support, clean APIs, and long-term vision made projects like VMK possible in the first place.
Thank you for making fcitx5-bamboo. One of the best preedit vietnamese typing on linux. VMK is based on that
Thank you for your continued work on Fcitx5 and for supporting a diverse global user base.

License & project status

VMK is released under GPL-3.0.

At the moment, the source code is distributed via release archives rather than direct git cloning.
We welcome feedback, discussion, and ideas — especially around delay logic, timing, and compatibility improvements for UniKey-like behavior.
The VMK project is currently community-driven and experimental.
Source code, installers, and documentation can be found at:
https://github.com/thanhpy2009/VMK

[wengxt]

Thank you for your contribution!

let me know if you need anything from our side. (e.g. wiki update, CI support, i18n, flatpak packaging or what ever)

[hahahahacker2009]

Look at your go code you sent earlier in image. I see ``2025 CSSlayer <thanhpy...>'', it means your nickname is CSSlayer. Which is not.

You might research a bit about the spdx standard to insert your name right after CSSlayer's name and email; I don't use such long license to felt the need for spdx shortener, so I can't guide you. If you fail to comply to GPL, perhaps someone will sue you.?!

Regarding the private message you sent here, I don't think anyone would ``steal'' your code. If you see a GPL violation on your work, report it to The united nation SFC. Otherwise, don't care if people pee on your code, just focus on your work. Someone else will take the heavy lifting with licensing some day. Your project future is bright, but only if you know that anyone can re-use freely and stop thinking about licensing.

No one is stealing your code. Ever. And if they do, someone else will sue them, you are able to sue them.

[thanhpy2009]

Look at your go code you sent earlier in image. I see ``2025 CSSlayer <thanhpy...>'', it means your nickname is CSSlayer. Which is not.

You might research a bit about the spdx standard to insert your name right after CSSlayer's name and email; I don't use such long license to felt the need for spdx shortener, so I can't guide you. If you fail to comply to GPL, perhaps someone will sue you.?!

Regarding the private message you sent here, I don't think anyone would ``steal'' your code. If you see a GPL violation on your work, report it to The united nation SFC. Otherwise, don't care if people pee on your code, just focus on your work. Someone else will take the heavy lifting with licensing some day. Your project future is bright, but only if you know that anyone can re-use freely and stop thinking about licensing.

No one is stealing your code. Ever. And if they do, someone else will sue them, you are able to sue them.

no, I ask AI, It's good or not. It said it's perfect. So I don't know. I don't care that much. because I just want to do 1 project maybe disapear out of git some day

It aslo told me. this is better. Ok thankyou for your advice. I am editting it now
/*

• SPDX-FileCopyrightText: 2025 Võ Ngô Hoàng Thành thanhpy2009@gmail.com
• SPDX-License-Identifier: GPL-3.0-or-later
  */

[thanhpy2009]

Mẹ cha mấy thằng gian thần nịnh hót, người ta vừa mới làm đồ nguồn mở mà tưởng là cao siêu lắm, rồi bơm đểu người ta làm người ta nghĩ ngợi mông lung bạc cả tóc.

thôi đừng chửi bạn =))
mình xóa ảnh đó nha
mình ko xóa được cmt của bạn. tý xóa dùm nha

[hahahahacker2009]

Ông phải hiểu là đã làm mã nguồn mở thì phóng khoáng lên, chỉ nên nghĩ xem đã tuân thủ điều khoản của người ta chưa, chứ đừng nên quan tâm là ai ko tuân thủ của mình. Và phải mở khi có người tham gia... Phí hơi sức lo có người ăn trộm làm gì... rặt một lũ dở hơi không biết bơi mới đi bảo vệ tài sản chất xám v.v.

Để tuân thủ giấy phép gpl, lgpl thì ông chỉ cần giữ nguyên cái giấy phép của người ta và ko đc sửa, đặt thêm tên ông vào thì đc chứ xoá tên người ta đi thì ko đc

Thứ hai là bên tôi có ông đang dịch code crypto của go sang C, thì giữ nguyên phần notice copyright the go team trong mã C vẫn là điều nên làm :)) chả có gì thiệt thòi cả

[thanhpy2009]

Ông phải hiểu là đã làm mã nguồn mở thì phóng khoáng lên, chỉ nên nghĩ xem đã tuân thủ điều khoản của người ta chưa, chứ đừng nên quan tâm là ai ko tuân thủ của mình. Và phải mở khi có người tham gia... Phí hơi sức lo có người ăn trộm làm gì... rặt một lũ dở hơi không biết bơi mới đi bảo vệ tài sản chất xám v.v.

Để tuân thủ giấy phép gpl, lgpl thì ông chỉ cần giữ nguyên cái giấy phép của người ta và ko đc sửa, đặt thêm tên ông vào thì đc chứ xoá tên người ta đi thì ko đc

Thứ hai là bên tôi có ông đang dịch code crypto của go sang C, thì giữ nguyên phần notice copyright the go team trong mã C vẫn là điều nên làm :)) chả có gì thiệt thòi cả

ok bạn đương nhiên là hiểu. mình xài linux hơn 10 năm nói chung mình ko cần tìm hiểu chi thức cách thức của git nhiều lắm thực hiện xong ước mơ hồi trẻ thì mình biến thôi. cũng ko tha thiết lắm
nhìn mấy ban newbie linux khổ ơi là khổ đến có gõ tiếng việt ko ai chỉ cài cấu hình cho đúng, chứ đừng nói gõ ko preedit
chào há thank you

[Zebra2711]

@wengxt Sorry for the ping.

The project https://github.com/thanhpy2009/VMK is a clone of your fcitx5-bamboo repo, with all 'bamboo' references renamed to 'vmk'. I’m sure this is a case of 'vibe coding'—mixing up ibus-bamboo with AI—and somehow the AI did a good enough job to make it usable. The idea is good, but the AI-generated mess in VMK (the bamboo-patched version) is significant. If you could gracefully take a look at the VMK repo to bring some patches back to fcitx5-bamboo, there are only three files worth checking: vmk.cpp, vmk.h, and vmkconfig.h. Those contain the only meaningful changes from your original code

[thanhpy2009]

Zebra2711
In the VMK introduction, I explicitly mentioned Fcitx5 and Bamboo Engine to acknowledge their original copyrights and technical contributions:

Fcitx5 Framework (by Weng Xuetian): This is the robust 'backbone' that allows the input method to run on Linux and Wayland. VMK is built as a specialized plugin for this framework.

Bamboo Engine (by Lâm Quang Lương): This is the 'brain' behind the Vietnamese processing. VMK utilizes Bamboo's smart algorithms to ensure the most accurate tone marking.
Read "VMK would not exist without the outstanding open-source ecosystem behind it:"

For someone misunderstrand. I note the license detail forlder inside Src full for convenience compile. Just the code for convenience for compile and note in readme.md .by vietnamese Bamboo Engine is already very good, so there was no need to reinvent the wheel. VMK focuses on leveraging its rock-solid logic while giving full credit to the original author, Lâm Quang Lương. By building upon this established foundation under the GPL-3.0 license, VMK can concentrate entirely on perfecting the 'UniKey-like' experience (Virtual Backspace and Delay logic) for Linux users on Vietnamese readme.md. I fullly translatse. I don't clone anything.

VMK is a new step forward, built on the inheritance and combination of the best elements from outstanding open-source projects:

Fcitx5 Framework: The most powerful and modern input method platform on Linux/Wayland, developed by Weng Xuetian (csslayer).

Bamboo Engine: A smart Vietnamese processing engine with precise tone-marking algorithms, developed by Lâm Quang Lương (luongthanlam).

VMK Core: The core part developed by Võ Ngô Hoàng Thành & Nguyễn Văn Thoan. We focus on adding a Virtual Backspace mechanism and Delay calculation logic to bring the familiar "no preedit" typing experience of Windows users to Linux.
In fact ibus bamboo have 5 style backspace (some of them can't work on wayland) . It's horribal when you choose 1 of them too work percific software you dont know what kind. I use one style real backspace. only one can work with all software even one, strongest backspace on linux . If you can't send that backspace you can't event type english. I studied target that backspace when i began. In fact i can't read GO code. I build my own. I only use bamboo engine with wiengxt go to C code complete bind Go code
The 'backspace-send' algorithm is UniKey’s well-known algorithm. I don't need read ibus bamboo code to know that algorithm
Is ibusbamboo can type vietnamese no preedit on wine o wayland? No it can't. VNK can do that. clone ibus bamboo?Dont talk bullshit thing

[thanhpy2009]

To demonstrate the uniqueness of this project, I have a test video below. video I done for realse patch . The test is VMK1. (not using
Surrounding Text). The reason I created VMK1 is that Surrounding Text support is currently too poor. Technically, Surrounding Text fails to support more than 50% of the applications
I believe wengxt is well aware of how 'obsessed' Vietnamese users are with the UniKey experience. I just bring UniKey to linux
Typically, preedit is divided into two types: inline preedit (underlined text inside the app) and dialogue/input box preedit (a separate floating window). In most existing projects, when using apps like PyCharm, IntelliJ, or especially Proton (wine) Zalo, users are forced to type Vietnamese through a separate external input box. However, I have successfully implemented direct inline typing—no external preedit box required.
You can now type Vietnamese directly inside PyCharm, IntelliJ, and Proton (wine) Zalo just like on unikey Windows. The ability to support Vietnamese input no preedit inside software in such demanding applications demonstrates the robustness of the project. even inline preedit can't do it's huge. Even I was blown away seeing it work seamlessly with Wine.
no preedit at all, all softwares just like unikey.
Note: Vietnamese users are very hate preedit all type of preedit

This is a huge milestone. My project is getting very close to the true UniKey experience on Windows. This has been my dream since youth—and the dream of the entire Vietnamese Linux community.
The final version might only show 2,000 lines of code, but I had to write, test, and discard over 30,000 lines to reach this point. Every single line of the current core is the result of countless trials and errors. It’s not just about the quantity; it’s about the sweat and sleepless nights spent refining the logic to make it perfect. This project is my heart and soul.
What makes this project so difficult is that I am not just using standard APIs or following existing paths( for vmk1). I am tackling challenges that previous projects simply couldn't solve. I had to build my own logic from the ground up to achieve things that were once thought impossible on Linux. It's easy to clone, but it's incredibly hard to innovate when there is no roadmap to follow
I am literally in tears as I write these words. My project does not deserve the treatment it has been receiving. Some have called me a 'cloner,' and some community members even claimed someone 'stole' my code. There is too much drama, while I am simply trying to fulfill my dream.

I am not here for the drama; I am here to make the dream of a perfect Vietnamese typing experience on Linux a reality.
please Help me "I have solved the vast majority of the technical hurdles.We are now just one step away from the finish line. Soon, the long-standing excuse — 'Linux lacks UniKey, so I’m moving back to Windows' — will officially become a thing of the past
"I use AI for translation and as a coding assistant, and I’m proud of it. English is not my native language, and AI helps me translate More importantly, using AI likes helper. I am complete this project in just 2.5 months—a task that would have taken a year otherwise nothing to be ashamed of. AI alone can make something like this? No, it's imposible. AI just copy someone code. I make newone.
2.5 months to solve vietnamese linux community want for over 10 years? It's impossible. even me think about when I began this project.
Thank you.
https://www.youtube.com/watch?v=c4iBk_YHBCI

[thanhpy2009]

For short, I cut videos
IDE, VMk1hc test
https://www.youtube.com/watch?v=C9RCNVxcMkU
zalo proton
https://www.youtube.com/watch?v=dGHGZj_6hwA
You see that error in terminal right. I solve that problem can reset engine halfway thoguht. I think you can understand wiengxt. Solve this problem it's can't be someone don't undertand fcitx5.
at 3AM now I can't sleep. It's too much for today.
I never imagined that an open-source developer, working for free and out of pure passion, would have to endure such immense pressure.
" I didn't plan on asking for anything, but some community members warned me that others are trying to steal my work."
I just think "just do it The results speak for themselves". But I can't stand it anymore. I only reach out when I'm out of options
I came down now. Hope my baby (vmk) can fly someday. 36 year old man make dream when I was 20

thankyou.
the picture in the video

[thanhpy2009]

I forget you can ask anything for sure about my project I am ready for answer any question.

[hahahahacker2009]

@wengxt Sorry for the ping.
This project is currently having unhealthy maintenance. The author haven't dealt with free software before, abusing AI even in documentations and writing sent to you, but that isn't the main problem. He does not like anyone forking or contributing to his project, except his best friend.

I'm not going to disturb you with craps; you might not be interested reading anything below this line. Just ``drama'' according to thanhpy2009, the author of vmk.

======= uninteresting craps =================

An user of his project has recently discovered a serious security hole (which is the result of vibe coding), and fixed it in their fork. (it was having sockets in home directory and unsafe permissions). On facebook and github, thanhpy2009 is not friendly to these bugs report. He implied that this user who forked his repo are stealing his work, but when they try to talk with him, he denied his claims.

We are on the progress of creating a CVE so that github could remove thanhpy2009's repo. Unhealthy behavior and being rude to contributions is enough; spreading security holes is simply unacceptable.

If anyone wants to support the author: