Drafted in your voice. Never sent.
It reads the thread and your calendar, writes like you do, and opens the reply in Gmail ready to go. You press Send. Overcoat holds no permission that could send mail, so it can't, even by mistake.
Free for Mac · iPhone & Android · Claude, ChatGPT or Gemini
Private AI for your email, on your Mac.
Overcoat turns your Mac into your own AI server: its model reads your mail and calendar right there, encrypted. For the hard questions, Claude, ChatGPT or Gemini gets only the few lines that answer it, never your inbox. Or keep a chat private, and nothing leaves at all.
- Your mail stays on your Mac
- Your Mac runs its own AI
- The cloud AI sees only what a question needs
- Private mode: nothing leaves
- Claude, ChatGPT or Gemini, priced up front
- Drafts in your voice, never sends
Day to dayThis week
Anything I should know about this week?
Three things: the partner review moved to Thursday 2pm, you told Dana you'd send the pricing deck by then, and your London flight leaves Thursday 5:30pm. Leave by 3:15. Read on your Mac · ✦ Claude · 3¢
Draft a reply to Dana: the deck's coming Wednesday
Draft reply
To Dana Ruiz · Re: Partner review
Hey Dana, the deck will be in your inbox Wednesday. See you Thursday. –J
EditOpen in Gmail
- 1AI model on your Mac that reads it all
- 0emails on any server of ours
- ~3¢typical answer when a cloud AI helps
- 0emails it sends on its own, ever
How it works
Your Mac becomes your own AI server.
Your mail, calendar and chats live on your Mac, encrypted, with an AI model that runs right there. Your phone reaches it over your own private network. A frontier model is called in only when a question needs one, and only with what that question needs. Try it:
Your phone
Asks, over your private network, with a passkey
Your Mac
- Mail and calendar, encrypted
- Its own AI model reads them
- Secrets removed before anything goes out
Claude
Gets the question and the few lines that answer it
Claude answers the hard ones: the question and the few lines that answer it, never your inbox. About 3¢ an answer, billed to your own key.
A model of your own
An AI model runs on your Mac and reads your mail there, even offline. Everyday questions, sorting and summaries never leave the house.
Private mode, one tap
Mark a chat or a topic Private and only your Mac's model ever sees it. For the medical, the legal, the personal: the cloud isn't even asked.
Your pick of AI, priced up front
Claude, ChatGPT or Gemini, on your own key. The menu shows what an answer typically costs with each, and every answer shows what it cost.
What the AI sees
Frontier answers, without handing over your inbox.
Until now it was smart AI that reads everything on someone's servers, or private AI that isn't very smart. Overcoat drops the trade-off: the AI you chose gets just enough to answer, and you can read exactly what it got. Here's a real example, run through Overcoat's own code.
You ask
Did Dana get back to me about the Harbor Bank review, and what do I still owe her?
The email it found, on your Mac
Hi Jeff, Thursday 2pm works. Can you send the pricing deck before then? Call me on 415-555-0142 if anything changes. The data room login code is 482913 and our account number for the deposit is 000123456789.
Dana Ruiz
What the AI gets
Did Dana get back to me about the Harbor Bank review, and what do I still owe her?
Hi Jeff, Thursday 2pm works. Can you send the pricing deck before then? Call me on 415-555-0142 if anything changes. The data room login code is [CODE] and our account number for the deposit is [ACCOUNT NUMBER].
Dana Ruiz
Sign-in codes, passwords and card and account numbers are removed outright, whatever the wording. Links in your mail and workplaces you keep local are hidden too. Names and phone numbers go as written, so an answer about Dana can say Dana. Prefer placeholders? Turn on Hide names in Settings, or tap Hide names for a single question, and only your Mac can turn them back into names.
Encrypted on your Mac
Mail, calendar, chats, notes and files sit in one encrypted database on your Mac, with the key in your Keychain. Not on our servers, not on anyone's.
Cloud AI, on a need-to-know basis
For hard questions and the live web, the AI you chose gets the question and the few lines that answer it, never your inbox. Turn it off and Overcoat still works.
It drafts. It can't send.
Replies open in Gmail for you to send, so Overcoat holds no permission that could send mail. Reading is read-only; adding an event uses a separate, create-only permission, on your tap.
Cloud AI with Gmail connectedLocal-only AI appsOvercoat
Where your mail is readOn their serversOn your deviceOn your Mac
How smart the answers areFrontier modelA small modelFrontier model when it helps, local for the rest
What the cloud model seesWhatever it readsNothing (no cloud model)Only what the question needs, secrets removed
Can you see what was sentNoNothing isEvery request, word for word
Does things for youVaries; some send for youRarelyDrafts, events, to-dos, heads-ups; never sends
- Your phone, your network. The phone app reaches your Mac over your own private Tailscale network, with a passkey.
- A watchdog that only looks. Every 15 minutes it checks for forwarding rules, writes you didn't tap, and strays.
- Your mail is stored on your Mac, and nowhere else. In one encrypted database, along with your chats, notes and files. You create your own Google key; everything runs on hardware you own. Our only server holds your account (an email address and your plan), and it never sees your mail.
- Every request on the record. Anything sent to a cloud AI is listed in the app, exactly as it went, with where it went.
What it does
And it already knows the context.
Most AI makes you paste things in. Overcoat has your whole mailbox and calendar at hand, so its answers are about your week, your people and your plans.
A morning brief worth reading
Meetings, clashes, what's due and the few emails that need you, on your phone before coffee.
It remembers what isn't done
Promises in your sent mail, replies you're owed, decisions still open.
Calendar, by asking
“Add dinner with Sam Friday at 7.” Check the card, tap. Nobody is invited for you.
Trips, sorted
Flights and hotels from confirmation emails, with check-in and leave-by reminders.
Exact, not guessed
“Who do I email most?” Counted across all your mail, not estimated from a search.
Your pick of AI
Claude, ChatGPT or Gemini, on your own key. Switch right from the prompt box, mark a chat Private to keep it on your Mac, or turn cloud AI off: the model on your Mac still answers.
Topics that keep notes
Pin a trip, a deal or a project and it keeps a running summary: plans, bookings, decisions, key details. Every answer starts from what you've already settled.
Paste a link, drop a file
It reads the page or document you share and keeps it with the conversation, so you can ask about it next week too.
While you're busy
Ask once. It keeps working.
Tell Overcoat what to look after and it does it on its own, on your Mac, each task with its own AI budget. Nothing is ever sent for you.
Tasks, in plain words
“Every Sunday at 6pm, plan my week.” “Tell me when the school emails about a closure.” “If Dana hasn't replied by Thursday, let me know.” Check the card, set what it may spend, tap. Mac asleep at the time? It runs when it wakes, and says so.
Drafts waiting when you wake
Each morning your AI reads everything still unanswered, picks what really needs you, most important first, and drafts those replies in your voice. Read them over coffee, change a word, press Send yourself.
Research while you sleep
“Find the best toddler car seat under $400 and tell me tomorrow morning.” It searches the web in the background and comes back with a short answer and its sources.
Your phone, even with the Mac off
Today's calendar, to-dos and plans stay on your phone, sealed so only it can open them. And you can still ask your AI anything: just the question, never your mail.
A day with Overcoat
Less checking. Fewer surprises.
It speaks up when something matters and stays quiet otherwise.
- Morning brief
“Three meetings, one clash at 2:30. Dana is waiting on the pricing deck. Rent is due Friday.”
- You ask
“Did the landlord ever reply about the lease?” It finds the thread and answers in a sentence.
- A draft, not a send
“Tell Sam Thursday works.” A draft appears, checked against your calendar. One tap opens it in Gmail; you press Send.
- A heads-up
“Leave in 15 minutes for your 5:30 flight. Terminal 4, seat 22A.”
- Evening wrap
Tomorrow's plan and what's still open, on your phone or in your inbox. Nothing you've already done.
Install
Twenty minutes. No Terminal.
The app walks you through everything, and each step checks itself.
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Sign up, download, open
Get Overcoat with your email (no password, no card), download it, unzip it, drag Overcoat into Applications, and open it. It isn't notarized by Apple yet, so the first time macOS says it can't verify it: click Done, then open System Settings → Privacy & Security, scroll down to “Overcoat was blocked”, click Open Anyway, and confirm with your password or Touch ID. You only do this once.
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About you, your account, local AI
Your name and time zone; your free Overcoat account (just your email, no password, no card); then one click installs Ollama, and the AI models that run on your Mac (about 7 GB) download in the background while you connect Gmail.
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Connect Gmail and Calendar
The fiddliest part, about 10 minutes: you create a free Google Cloud project so the key is yours, not ours. The page has a button for each Google screen and says exactly what to click.
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Your phone
Your phone reaches your Mac through Tailscale, a free app that privately links your own devices (nothing is opened to the internet). Install it on the Mac and the phone and sign in to both with the same account; then scan a QR code and create a passkey. Add Overcoat to your home screen (iPhone: Safari → Share → Add to Home Screen; Android: Chrome menu → Add to Home screen) and turn on notifications, so it can tell you when an answer is ready.
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Keep it running and awake, back it up
One click keeps Overcoat running in the background. Leave the Mac plugged in with the lid open (the screen can sleep): a sleeping Mac can't answer. Your brief and reminders can still reach your phone while it sleeps. Another click sets up encrypted backups. Voice notes and a cloud AI are optional extras.
Questions
Good questions.
Does anything go to the cloud?
Only if you turn on a cloud AI (Claude, ChatGPT or Gemini, with your own key), and only what each answer looks up, with codes, passwords and account numbers removed (you can also have names hidden). When it needs something current, Claude or ChatGPT searches the web itself, with queries it writes from what it was sent. Everything Overcoat sends is listed in the app exactly as it went.
Which AI does it use?
A model that runs on your Mac reads your mail and handles everyday questions. For harder ones, and the live web, it asks the cloud AI you connect: Claude (the default), ChatGPT or Gemini, each with your own key from its maker. You can switch for a single question from the prompt box, keep any chat on your Mac only, or turn cloud AI off entirely.
Can it send email for me?
No, and it isn't able to. It writes the reply; tap Open in Gmail and it opens ready to send, and you press Send. By default Overcoat holds no Google permission that can send mail at all, so not even a bug, or something malicious on your Mac, could send through it. (You can choose to have replies saved to Gmail Drafts instead. Google's permission for that is broader, so Overcoat's software allows only the one “create a draft” request, checked on every build. Details →)
What does it cost?
Overcoat is free with a free account (just your email; no password, no card). Premium ($4.99 a month or $49 a year, 14 days free) adds the notifications, VIPs and a to-do list. If you turn on a cloud AI, you pay its maker directly for what you use, on your own key: with Claude, about 3¢ a question on average, up to about 10¢ for a long one or one that searches the web several times (ChatGPT and Gemini are similar, billed by OpenAI or Google). That's about what the same questions cost asking the AI yourself, and it all stays inside daily and monthly limits you set.
How is this different from the AI built into my email?
Cloud assistants read your mail on their servers. Overcoat keeps it on your Mac. When a cloud AI answers, it looks up only what that question needs, read-only, through your Mac, with passwords, codes and account numbers removed, and private chats never go at all. And it can't send anything, by design.
Could it mess up my Google account?
No. Reading is read-only, and it writes only what you allow, when you tap: an event on your calendar, a draft in Gmail Drafts if you turn that on, and your own morning brief in your inbox if you ask for it by email. It has no way to send, delete, move or change mail or events. Exactly what it can and can't do →
What happens when my Mac is asleep?
Your phone still shows today (calendar, to-dos, what's on your plate) from a copy sealed so only it can open it, and can ask your AI directly, without your mail or calendar. Questions about your mail wait, and are answered when the Mac is back; tasks that came due run when it wakes. Your brief and reminders can still arrive on time: with Deliver while my Mac sleeps on, your Mac hands overcoat.ai sealed copies, encrypted so only your phone can read them, to send at their times, and it can wake itself for the morning brief. A Mac that stays on (a Mac mini is ideal) is always available.
Why do I sign up to download?
So we can tell you about updates and help if setup gets stuck, and so Premium can switch on for you. Your account is an email address (no password; we email a sign-in link) and, if you choose, a first name and how you'll use it. It never sees your mail.
macOS says it can't verify Overcoat. Is that safe?
That's the standard message for apps that aren't notarized by Apple yet (it costs a yearly developer fee; it's on the list). Nothing in it tracks you: no analytics, and the only Overcoat server it talks to is your account's, for your plan and updates (never your mail). To open it: System Settings → Privacy & Security → scroll down → Open Anyway. If you'd rather not, that's a reasonable choice too.
How do I remove it?
Settings → Devices → Lock down revokes its Google access and keys; then delete the app and the ~/assistant folder.
Your inbox, your Mac, your AI.
Free, private, and yours. Twenty minutes from now your Mac could be answering your email questions.
Get Overcoat, free