On the Mac, LocalInbox can use Claude or OpenAI with your own API key. It's off until you add one. You choose which features use it and which accounts it may read, and requests go straight from your Mac to the provider, because LocalInbox has no server in between. Without a key, the AI stays on your Mac. The iPhone and iPad use Apple's on-device model only.
Needs your own API key from Anthropic or OpenAI, which that provider bills you for. Mac only. It works on macOS 15 or later, on Intel Macs and on Macs without Apple Intelligence.
When you ask
On once you add a key, and sent only when you press the button. Opening a conversation sends nothing, so arrowing through your mail uploads none of it. Each row in Settings › Intelligence says what it reads and writes, and each has its own switch:
- Summarize. Reads this conversation, up to 9,000 characters without quotes and signatures. Writes a summary, key points and suggested replies.
- Draft with AI. Reads your description and, for a reply, that conversation. Writes a draft you check before sending.
- Rewrite. Reads your draft or the selection. Writes a new version of it.
- Ask your mailbox. Reads your question and up to 6 matching emails, 900 characters each with attachment text. Writes an answer with numbered sources.
- Write Rule. Reads your description and the names of your folders and categories. Writes a rule you check first.
On its own
Off until you turn each one on, and each asks first. Only mail dated after you agreed goes, never what's already here. Until you turn one on, the model on your Mac or the rules keep doing that job, as they do without a key:
- Summaries and suggested replies. Reads each new message, whether or not you open it.
- Meetings, tasks, travel and parcels. Reads each new message, for Today.
- Waiting On. Reads mail you send, to tell whether it waits on an answer.
- Morning brief. Reads the mail since yesterday that needs you most.
What never goes
- Suspected phishing and spam.
- Mail in Junk or Trash, and mail you've just moved or deleted.
- Sign-in codes and magic links.
- A conversation with any of those in it.
- Any account you untick under Accounts it may read, including what you write from it.
Where it goes, and who can see your key
Straight from your Mac to api.anthropic.com or api.openai.com. LocalInbox has no server in between, so we never see your key or what you send. Your key stays in the Keychain on this Mac and doesn't follow you through iCloud.
The provider's terms decide what it keeps and for how long. Requests to OpenAI ask it not to store them. Settings › Privacy counts what went each week, and keeps only the counts.
You can always tell who wrote it
When a cloud model writes something, the summary, the reply box, the composer and Ask say so by name. Check what it writes before you send it: details it doesn't know show as [placeholders]. A suspected phishing message never names a provider, because none gets it.
Set it up
- Get an API key from Anthropic or OpenAI.
- In LocalInbox, open Settings › Intelligence and click Add Key… beside Use your own Claude or OpenAI key.
- Read what will go, and paste the key.
- Turn off anything you'd rather keep on your Mac, and untick any account it shouldn't read.
Questions
Does my Claude or ChatGPT subscription work?
No. LocalInbox needs an API key, which you create on the provider's developer site and which is billed separately from a Claude or ChatGPT subscription.
What does it cost?
LocalInbox adds nothing. The provider charges your account for what you use, at its prices. On its own costs the most, because it runs on each new message, so it stops at a daily limit you set, 200 requests by default. Past that, the model on your Mac or the rules take over until the next day.
Which models can I use?
Any on the list Anthropic or OpenAI shows for your key, chosen in Settings. When you ask and On its own each have their own choice, and On its own starts on a cheaper model.
What if the key stops working or the provider is down?
The button says what happened. Nothing moves to another service. What runs on its own pauses and tries again once the provider is back, and what it couldn't finish waits rather than being lost.
Does it run while LocalInbox is locked?
No. What runs on its own pauses while App Lock is on.
Is my email used to train AI?
LocalInbox doesn't train anything and has no server. What a provider does with API requests is set by its terms for your account, so check them before you add a key.
Can I use another provider, or my own address?
No, only Anthropic and OpenAI, at their own addresses. Every connection the app can make is published, and an address you could change couldn't be. For a model you run yourself, use a model server on your Mac.
How do I stop?
Remove the key in Settings › Intelligence. Nothing more goes to the provider, what you allowed is forgotten, the key is deleted from your Keychain, and everything goes back to your Mac.
Does it work on iPhone or iPad?
No. The iPhone and iPad use Apple's on-device model only, and your key stays on the Mac.