ChiaKey— Yahoo! KeyKey, evolving for modern macOS
The familiar Bopomofo (Zhuyin) composing experience and candidate window, now with Apple Silicon support.
History
What is ChiaKey?
ChiaKey is a macOS input method for Traditional Chinese that uses Bopomofo (also known as Zhuyin), the phonetic script commonly used in Taiwan. Built from Yahoo! KeyKey’s open-source code, it carries its familiar experience forward while continually repairing, improving, and building a new lexicon and language model.
2008
Yahoo! KeyKey launches
A free, cross-platform intelligent input method.
2013
Project closes; source code opens
Released under a BSD-style license on GitHub (YahooArchive/KeyKey). The final installer has been continuously adapted by the community ever since.
2026
Apple announces the end of x86 support
The final-generation installer will no longer install on macOS 26 and later.
ChiaKey
Repairs the app and keeps building its word-selection lexicon for Apple Silicon and modern macOS.
After ending the project, Yahoo! released its code as open source. ChiaKey starts from that codebase: replacing obsolete APIs, repairing missing pieces, and continually improving the app, its performance, and its lexicon so the familiar input experience can keep evolving on modern macOS.
Keep the familiar feel
The first goal is to carry forward Yahoo! KeyKey’s composition and candidate window, while a new lexicon makes that familiar feel better suited to Taiwanese usage today.
Modernize carefully
Improve security and algorithms with modern APIs and compile for Apple Silicon.
A conservative pace
ChiaKey is not trying to compete on features with modern input methods. Its focus is stability.
Precision
0rules that refer to earlier words
From 470 million characters of real Taiwanese text, we found 32 million neighboring word pairs and distilled nearly 400,000 pairings that can help choose the right character.
Note: many cases still do not reveal intent. For example, 我們在做, 我們再做, and 我們在座 can all be correct, so they cannot be resolved automatically.
Features
The familiar way, made easier
Careful refinements preserve the familiar feel while improving security and performance.
Adaptive candidates
The input method looks at the sentence and your selection history when ordering candidates. Characters you choose often rise to the top next time.
Add phrases
Hold Shift and press ← to expand the selection one character at a time, then press Enter to add it to your user dictionary. Ctrl+3 adds the three characters before the cursor directly (Ctrl+1–9 sets the length).
Symbol table
Control+Command+. opens the symbol table. When the composition area is empty, Ctrl+0 also shows punctuation candidates.
Traditional-to-Simplified Chinese
Control+Command+G toggles the output filter: type Bopomofo as usual and commit Simplified Chinese. Command+Shift+Space toggles full-width Latin characters.
Tab segmentation
Move the cursor to where you want a break while composing and press Tab to force segmentation—the sentence is then recomposed around that boundary.
The old friends are still here
The default is smart Bopomofo composition, while the traditional Bopomofo, Cangjie, and Simple modules from the OpenVanilla era remain available. You can also import your own .cin tables to add table-based methods such as Cantonese or Hakka.
Lexicon
Layered lexicons that understand you
A lexicon is more than one list. ChiaKey combines multiple sources to preserve a familiar feel while continuously choosing vocabulary suited to everyday Taiwanese usage; after installation on your Mac, it adds two layers that are yours.
Everyday word data
Context-aware corrections
Recently trending words
Taiwan usage adjustments
User dictionary + learning cache
· your machine
Everyday word data
Combines everyday characters, words, and readings so you can type daily Chinese smoothly.
Context-aware corrections
When words sound alike, it refers to the surrounding context to help choose the candidate that best fits the sentence.
Recently trending words
Automatically collects trending topics and names from the web, then updates the lexicon.
Taiwan usage adjustments
Adjusts common Taiwanese writing and candidate order, while reducing words being split or combined incorrectly.
User dictionary + learning cache
The words you add and your selection habits stay on this Mac; custom words can be imported or exported.
The lexicon was the hardest part of this project.
470 million characters for more accurate selection
Yahoo! KeyKey used surrounding words to help choose characters, but that data was never released with its code. ChiaKey draws on about 470 million characters of real Taiwanese text—government news, Legislative Yuan transcripts, PTT, Plurk, and Traditional Chinese Wikipedia—to find word pairings that help distinguish homophones in context.
Trending words, freshly stocked
Language evolves over time. ChiaKey tries to keep up by regularly watching for trending words and loading them automatically with every lexicon update. It carries forward more than the code: the lexicon keeps moving forward too.
Update lexicons without reinstalling
The built-in word data is independently updated after ChiaKey-Lexicon builds ChiaKey-Lexicon. The input method automatically checks the newest version before enabling it. Your custom phrases and selection history stay on your Mac.
DOWNLOAD
Install
Download and install the .pkg, then add ChiaKey in System Settings → Keyboard → Input Sources. Apple Silicon is supported.
ChiaKey is not an official Yahoo product. Its source is released under a BSD-style license; the Yahoo! name and contributor names may not endorse derivative products without written permission.
Is this for you?
01
You want an accurate Bopomofo input method tuned to everyday Taiwanese usage
02
You miss the composing feel and candidate window of Yahoo! KeyKey
03
You want an app that stays conservative and stable while the lexicon keeps improving
FAQ
Frequently asked questions
ChiaKey starts from the code Yahoo! open-sourced after KeyKey was discontinued. It carries the familiar input experience forward while extensively repairing and improving it, building a new lexicon and language model, and maintaining compatibility wherever possible. It is not an official Yahoo product; the source is released under a BSD-style license.
The last official installer is Intel-only and needs Rosetta on Apple Silicon. Apple has announced that macOS 26 and later will no longer support Intel architecture. ChiaKey runs natively on Apple Silicon and modern macOS.
Yes. The current minimum deployment target is macOS 10.13 High Sierra, which almost every Intel Mac from 2009 onward can upgrade to.
Yes—free and open source. Download the .pkg to install; the source code is on GitHub.
ChiaKey is fully compatible with Yahoo! KeyKey dictionaries, including data accumulated through smart learning. Go to Preferences → Phrase Management → Import Yahoo Input Method Data. Note: because of KeyKey’s architecture, Yahoo! KeyKey must be running to use this import.
Yes. Older .cin table input methods can be imported. ChiaKey keeps OpenVanilla’s table engine: in Preferences → Custom Input Methods, click + or drag a .cin table file onto the list. It will then appear in the input menu. Tables for Cantonese, Hakka, Taiwanese, Array, Dayi and more are available from projects such as cin-tables.
Thank you! You can support the project through Ko-fi.com (outside Taiwan) or ECPay sponsorship (Taiwan credit cards, Apple Pay, ATM, or convenience-store payment codes only).
Please use the GitHub report page to report a missing word or candidate issue.