YiYan

Natural English, picked up as you go

Keep working in Pi, Claude Code, Codex or OpenCode, type directly into YiYan, or refine the field in front of you from a shortcut or the menu bar. YiYan reuses an available signed-in assistant on your Mac to return natural English and focused notes, with your history available on iPhone through iCloud.

  • Your request is sent as usual
  • Refine the field you are in
  • No extra model or API to set up

Pi · Claude Code · Codex · OpenCode

Type as usual — or directly

Write as usual in a supported tool, or type straight into YiYan. Your original request goes out first; direct entries are clearly marked as Me.

Shortcut · Services · Menu bar

Refine the field in front of you

Select text to replace it in place. With no selection, YiYan keeps the original and appends the refined version, without taking you out of the app you are using.

Reuses an available assistant

No setup to repeat

YiYan finds the most recently successful or currently available signed-in assistant on your Mac. Its menu-bar mark quietly shows when refinement is underway.

What you really said is the practice

Learn from the comparison

Your original wording, the natural English and at most three notes sit side by side: what changed, why it reads better, and how to reuse it next time.

Learn from what you actually wrote

Same meaning, smoother wording

Understanding it is easy. Saying it your way is the hard part.

What you just wrote

Delete the decoration elements, make the key points prominent, use the original components, and do not play by yourself.

A more natural way to say it

Remove the decorative elements, keep the focus on the content, and use the original components as-is instead of adding your own spin.

Why it reads that way

“keep the focus on…” lands better in design feedback than a literal “highlight the key points”; “as-is” says use it exactly as shipped, and “add your own spin” is how a native speaker names improvising.

Reuse it next time

keep the focus on …use … as-isadd your own spin

iPhone public beta

Synced over iCloud

Build it up on Mac, review it on iPhone.

Entries and favourites you finish on Mac sync to iPhone automatically over iCloud. Away from the computer you can still browse by date, listen to the natural English, and review anything you saved.

Try it on TestFlight

Before your first run, turn on iCloud sync in Settings in YiYan for Mac, and make sure Mac and iPhone are signed in to the same Apple Account. The iPhone version is still a public beta and keeps improving.

One YiYan entry: the original wording, the natural English, and the key notes

Boundaries, stated plainly

Only what learning needs

Only new messages you send while it is running.

YiYan does not install itself into Pi, Claude Code, Codex or OpenCode, and never changes their settings.

What becomes an entry?

Messages of yours that say something whole and are genuinely worth learning from. Your own language becomes natural English, English gets polished, and a mix of the two is rewritten as complete English.

What gets skipped?

Messages that are only code, paths, URLs or images; short confirmations like “ok” or “go on”; and short repository commands like “commit and push”.

What is never stored?

AI replies, tool output, system messages, session IDs and session file paths never make it into a YiYan entry.

Where does it live?

On this Mac first. Only after you turn on iCloud sync do finished entries and favourites go to your own iCloud and reach your iPhone. Anything that looks like a secret is redacted with high confidence before it enters a learning task or an entry.

Do I need another model?

No. The natural English and the notes come from the Pi, Claude Code, Codex or OpenCode you were just using; YiYan ships no model and no API credentials of its own.

How does it relate to the rest?

YiYan is a standalone Mac app from lazyapps. Privacy policy