v0.5 · macOS 12+ · Apple Silicon

Two tools,
one hotkey.

Hold Right ⌘ for fast on-device dictation. Double-tap, then hold, to send the transcript through Claude with screen context for a polished, tone-matched reply.

Download for macOS · 144 MB
↳ Apple Silicon · macOS 12+ ↳ free during beta
Mail — Re: dates for the Lisbon trip
recording
NICK · 11:42
Hey — would the 14th–17th still work for you, or do we need to push it back? Totally fine either way, just need to lock the flights tonight.
polish mode · double-tap, hold Right ⌘
"uh tell nick yeah fourteenth works actually I can wait a day or two if he needs more time"
pasted · ~1.5s
The 14th–17th works on my end. If Nick needs another day or two, I'm flexible — happy to wait. Lock whichever's easier.
tone matched · casual · context: thread above
↩ Send
How it works

One hotkey, two modes.

Quick mode · Hold Right ⌘

Transcribe and paste.

Whisper runs on-device, fixes punctuation, drops the result in the active field. No API call.

↳ sub-second ↳ works offline
Polish mode · Double-tap Right ⌘

Claude polishes the reply.

Murmur sends the transcript — plus a screenshot, if you've enabled it — to Anthropic, then pastes a tone-matched message into the focused field.

↳ ~1.5s end-to-end ↳ screen context opt-in
Privacy, in plain language

Your voice never leaves the device.

Audio
On-device, always. Whisper runs via MLX. No streaming, no upload, nothing stored on a server.
Screen context
Opt-in, polish-mode only. One screenshot per request — sent to api.anthropic.com with your transcript, discarded on receipt.
Replies
Generated by Anthropic, returned to your Mac, never logged by us. Anthropic's terms apply to their side.
API keys
Local config file (~/.config/voice-reply/config.json), readable only by your user. No server to send them to.
Customise

Tune Murmur to the way you actually talk.

Accuracy

Three model tiers.

Switch any time. Models cache locally; delete from the picker.

Fast · 140 MB
Balanced · 470 MB
Best · 1.5 GB
Vocabulary

Snippets and shortcuts.

Teach Murmur your proper nouns. Add phrase = value lines to expand text on the fly.

say "calendar link"
→ https://cal.com/james
Prompt

Tune how Claude writes.

Edit length, tone, formality. Saved instantly. No restart.

"keep replies under 3 sentences"
"never say 'I hope this finds you well'"
Compare

Where Murmur fits.

Murmur Apple Dictation Wispr Flow ChatGPT voice
Local transcription ✓ ✓ ✓ ✗
Pastes into the active field ✓ ✗ ✓ ✗
Screen-aware AI polish ✓ (opt-in) — — ✗
Single hotkey, two modes ✓ — — —
Works offline ✓ (quick mode) ✓ ✓ ✗
Free during beta ✓ (free) (paid) (paid)
Setup

Drag, grant, done.

  1. Install Drag Murmur to /Applications. First launch opens the wizard.
  2. Input Monitoring So the hotkey works globally. System Settings → Privacy & Security.
  3. Accessibility So Murmur can paste into the focused field. Same Settings pane.
  4. Microphone Asked once on first record. Approve and you're set.
  5. Screen context (optional) Lets polish mode use a screenshot. Adds an Anthropic API key prompt. Skip and quick mode still works.
↳ everything's revocable in System Settings at any time
↳ full step-by-step setup guide