MouthPiece.

Speak it,
ship it.

Hold a key, say the messy version — ramble, back up, change your mind. MouthPiece hands back clean, publish-ready text in the tone you pick.

Free · open source · runs on your machine

download for Mac
00:00

Try it — click and talk

01Why MouthPiece

Your computer.
Your keys.
Your words.

Runs on your machine

Local-first, no lock-in

Runs on your machine

Clone it, run it, own it. Your audio and history stay on your device.

Free & open source
Your own API keys
Works with zero keys
History stored locally
See the code
Accounts without
the account.

No email. No password. No "verify your identity."

No signup. Ever.

Your account is a key

No signup. Ever.

Sync is a long random key, not an email and password. Turn it on, open the share link on another device, done.

One tap to enable
Share link pairs devices
History follows you
Turn it off anytime
Open the app
Ramble in,
email out.

Filler words, false starts, and grammar slips disappear.

Six tones

Same voice, right register

Six tones

The cleanup pass rewrites your ramble for where it's going.

Auto
Email
Message
Formal
Notes
Comment
Try a tone

02Run it yourself

Two minutes to a
working copy.

Everything works out of the box — add keys only for the parts you want. No key? You still get recording, live transcription, and rule-based cleanup.

  • ANTHROPIC_API_KEY — Claude cleanup
  • GROQ_API_KEY — Whisper transcription
  • SUPABASE_* — cross-device sync
  • nothing — still works
git clone https://github.com/matthewjmortimer11/mouthpiece
cd mouthpiece && npm install
cp .env.local.example .env.local   # optional: add keys
npm run dev

03Mac app

Or live in any text field.

Hold ⌥ Space in anyapp — speech is transcribed on your device, cleaned up, and pasted right where you're typing.

Apple Silicon · 4 MB · unsigned
MouthPiece 0.1 · privacyspeak it, ship it