How Lyra uses the cloud
The short version
Lyra is 100% private. Everything it does runs on your Mac with a private on-device model, and works offline. Nothing you write ever leaves your Mac — unless you choose to subscribe to Lyra Cloud, which is off unless you subscribe and switch it on, and even then sends only what is listed on this page.
This page is the full account: which features run where, what Lyra Cloud adds, how to switch it off, and what our server sees. It is the canonical description — where another page on this site summarises any of it, this page is the detail.
What runs where
| Feature | Lyra (on your Mac) | With Lyra Cloud |
|---|---|---|
| Fix-as-you-type | Yes | Still on your Mac — the cloud is too slow for it |
| Sentence polish at the end of a sentence | Yes, English | Cloud model, and every language |
| “Rewrite for clarity” on longer messages | Yes, English | Cloud model, and every language |
| ⌘⌘ Professional and Friendly tones | Yes | Cloud model |
| Voice profile classification | Never | Only if you switch voice profiles on |
| While the model downloads on first launch | Suggestions start once it's ready; nothing is sent meanwhile | Cloud model straight away |
Without Lyra Cloud, Lyra works in English. Text in another language gets no suggestion rather than a risky one: a small on-device model can translate it by accident, so Lyra leaves it alone.
The on-device model
Macs with 12GB of memory or more, including 16GB Macs, use Google's Gemma 3n. Macs with 8GB use the smaller Qwen3. If a Mac keeps running short of memory with Gemma loaded, Lyra switches it to Qwen for a week by itself, then tries Gemma again. The model is released when you are not writing, so its memory goes back to your Mac.
Voice profiles (how Lyra learns how you write to each person)
Voice profiles need Lyra Cloud, and are off by default — none of what follows happens unless you subscribe and turn them on in Settings.
Lyra keeps a record of messages you actually sent — your words, as you wrote them — in a local database on your Mac. Messages Lyra rewrote are excluded from this learning, so the profile reflects your voice, not Lyra's suggestions.
To turn that history into a usable profile ("casual with Dave on WhatsApp, professional with Jamie on Outlook"), Lyra periodically sends a small sample of your sent messages for one recipient to our server, which asks the AI model to classify the writing style. The result — a register label and a short list of words you use — is stored back on your Mac. The sampled messages are processed for that classification and are not stored on our servers or used to train anything.
This happens at most once per week per contact, only for contacts you've written to at least 30 times, and only while voice profiles are enabled.
Your controls: turn voice profiles off entirely in Settings; turn them off for one person in "How Lyra sees your writing"; or switch Lyra Cloud off, which disables this along with every other cloud feature. You can view, correct, and delete every profile Lyra has derived.
Lyra and Lyra Cloud
Lyra — $69.99 $34.99 once
Every feature above that runs on your Mac, yours for good. New users get a 7-day free trial first, no card needed. Nothing you write is ever sent anywhere.
Lyra Cloud — $9.99/month or $99.99/year
An optional subscription. It adds a larger cloud model for sentence polish, “Rewrite for clarity” and ⌘⌘ tones, and every language, and it includes the app while you are subscribed. Every request is authenticated as you, and your plan is checked on our server.
Setting up
Lyra downloads its private on-device model the first time you launch it. Suggestions start as soon as the download finishes; nothing you write is sent anywhere in the meantime. The menu bar shows the download while it happens. If you subscribe to Lyra Cloud, you get cloud suggestions straight away.
Switching the cloud off
Lyra Cloud is a single switch in Settings, and it is off unless you subscribe. Subscribers can switch it off at any time and keep using Lyra entirely on their Mac; switch it back on whenever you like.
Working offline
Your writing needs no connection at all once the model has downloaded — everything works with the Wi-Fi off. If you subscribe to Lyra Cloud, its extras simply pause while you are offline.
What our server sees — and does not store
Cloud requests go to a small server we run, which holds the model API key so the app never has to. Concretely:
What leaves your Mac
| Feature | What is sent | When | What comes back | Stored on our servers |
|---|---|---|---|---|
| Everyday corrections | Nothing — runs entirely on your Mac | Never | — | Nothing |
| Cloud rewrite (Lyra Cloud) | The text being rewritten, plus a short stated style rule. No historical messages. | Only while you subscribe and Lyra Cloud is switched on | The rewritten text | Not stored, never used for training |
| Voice profile classification | Sample of your sent messages to one contact | Weekly at most, per contact with 30+ messages, only if enabled | Register label + keep-words, cached on your Mac | Not stored |
| Usage telemetry | Feature-event names and daily counts, app version, macOS version, your Mac's RAM size, local model tier, and whether Apple's on-device model is available on your Mac. Never your text. | As you use the app | — | Yes, linked to your account — unless you switch it off in Settings → Privacy |
Cloud rewrites and voice profiles run under the same server terms set out here. Usage telemetry is the one thing in that table we do keep; it is described in full in the Privacy Policy, and it has its own off switch in Settings → Privacy.
- It sees the text of the specific sentence being upgraded, for the duration of that one request, and your account identity. If you have voice profiles switched on, it also sees the sample of sent messages for the contact being classified. In every case, for the duration of that one request.
- It does not store your text. Nothing you write is retained, logged as content, or used for training — ours or anyone else's.
- There is no shared password in the app. Every request is signed with your own login, so there is no shared secret to leak and every call is tied to a real account.
- Your plan is checked server-side. The server independently confirms whether you subscribe to Lyra Cloud; the app cannot claim it.
- Usage is capped per account. A generous daily limit, well above any real person's use, means a bug or an abuser cannot run up an open-ended bill.
The model provider for the cloud path is Google (Gemini), reached through our server. See Privacy for the full list of subprocessors and what account data we hold.
Questions
If anything here is unclear, or you want a detail we have not covered, email founder@heylyra.co.uk.