Underdog AI: The Private Assistant on Your Own Computer
Underdog is an AI assistant for email, calendar, meeting notes, dictation and errands that runs on your own computer instead of in the cloud. Its own AI models do the summarizing, drafting and transcribing locally, and your mail syncs directly between your machine and Google or Microsoft. It calls itself “the most loyal AI,” is free to use, and is in an invite-only beta for Macs with Apple silicon, with Windows in beta and phones on the way.
The quick answer: Underdog is the most serious attempt yet at a private, local personal assistant, with its own small models, a detailed public security record and a free business model. It suits people who want AI help with their inbox and calendar but don’t want their mail read in a data center. It’s early, invite-only and desktop-first. A disclosure: we make Carly, an AI assistant for email, calendars and phone calls, so Underdog is a competitor. We’ve stuck to what Underdog’s own pages say.
Underdog at a glance
Checked against Underdog’s site, security page and pricing page on November 12, 2026.
| Underdog | |
|---|---|
| What it is | A personal AI for email, calendar, meeting notes, dictation and errands that runs on your computer |
| Devices | Mac with Apple silicon; Windows in beta; iPhone and iPad coming; Android and Linux later |
| AI models | Its own, run locally: Saluki 27B, Poodle 4B and Chihuahua 2B |
| Price | Free; it earns a small cut when it buys things for you |
| Access | Invite-only beta |
| Company | Automaton Research Inc., doing business as Underdog AI |
| Founder | Sigil Wen |
| Best for | People who want AI help with mail and meetings while keeping their data on their own machine |
What Underdog does
Underdog’s homepage lists six jobs:
- Email. Fast email across your accounts, with summaries, drafts and features like bulk unsubscribing from newsletters.
- Calendar. Scheduling connected to your mail and meeting notes.
- Meeting notes. Recorded and transcribed on your computer. Audio is never uploaded.
- Dictation. Speech to text, processed on your computer.
- Errands. A browser agent that books, buys and cancels things, asking first.
- Sensitive tasks. “Doctor’s appointments, prescription refills, tax paperwork. I find what you need and get the next step ready for your approval.”
The product talks about itself as a dog, which runs through everything from model names to the FAQ (“I’m very good at fetch. Woof.”). Underneath the branding, the pitch is serious: an assistant that knows your mail, calendar and meetings, without any of it leaving your computer.
How it keeps your data local
This is Underdog’s whole reason to exist, and its site is specific about how it works:
- “100% local intelligence.” Summaries, drafts and answers come from a model running on your computer, not a cloud AI service.
- Mail goes straight to your provider. “Mail syncs directly between your computer and your email provider.” Underdog says it doesn’t run email servers and never sees your password or messages.
- Encrypted on disk. Mail, calendar and saved logins are encrypted with AES-256, with the key stored in your Mac’s Keychain on that device only.
- Memory you can inspect. Saved memories stay on your computer, and you can see, edit or delete them in Settings.
- Tracking blocked. Remote images, scripts and tracking pixels in email are stripped.
- Naval mode. One switch, and “Underdog never calls home,” talking only to the servers it needs, like your mail provider.
Its security page also lists exactly what the company does receive: your account email, your membership, which days you opened the app, daily usage counts you can turn off, and crash reports only if you choose to send them. “Never your mail, notes, or audio.”
Underdog’s own AI models
Underdog trains and ships its own models instead of calling OpenAI or Anthropic:
- Saluki 27B, “the smart one,” which Underdog says scores 33.7 on the Artificial Analysis Intelligence Index against 31.9 for Claude Opus 4.6 Max.
- Poodle 4B, “the fast one,” at about 115 tokens a second by Underdog’s estimate.
- Chihuahua 2B, “the light one,” for phones.
It also ships a speech model, Bark 3.0, which it says is a 163 MB download as accurate as much larger transcription models. Those benchmark comparisons are Underdog’s own claims. The practical point is that the bigger model needs a well-equipped machine, so what you get depends on your computer’s memory.
How a free assistant makes money
Underdog’s pricing page opens with a joke plan at “$1,999 per month” before getting to the real answer: it’s “100% free.” Because the AI runs on your computer, “there is no server to pay for, no seat to count, and no cloud AI reading your mail.”
The business model is commerce. In Underdog’s words: “When you ask him to buy something, he finds the cheapest, best option… and pays with a one-time card made just for that order, and we make a tiny bit of it.” The browser agent asks before it buys, pays, sends or deletes anything, and it fills saved passwords without reading them.
That model aligns the company with saving you money on purchases, and it means Underdog only earns when its errand agent is useful. It also means the free price depends on people using Underdog to buy things.
Who has checked its security
Underdog publishes an unusually complete record on its security page, last updated October 30, 2026:
- App Defense Alliance CASA, Level 1, passed, assessed by Leviathan Security Group with all 20 requirements met. Issued September 10, 2026, renewing yearly.
- Google approval to read Gmail and Calendar, after Google’s restricted-scope review.
- Penetration tests completed by Hacktron AI (the Mac app, including the browser agent) and Zellic (the Mac app, website and Dogpark).
- An audit under way by OtterSec, and an independent teardown of the Mac app by researcher Jane Manchun Wong.
Releases are signed and notarized by Apple. For a beta-stage company, that’s more outside review than most assistants publish. Security teams can request Leviathan’s letter and find the full list in Underdog’s trust center.
Who’s behind it
Underdog is made by Automaton Research Inc. and founded by Sigil Wen, whose manifesto line is “Own your AI, don’t let it own you. I’m building Underdog for myself.” The team says it comes from Apple, Ramp, Google Brain, Meta, Baidu, Lyft, Instagram, the United Nations and the Thiel Fellowship.
According to its site, Underdog raised its first round in April 2026 from investors including Andreessen Horowitz, Khosla Ventures, Hummingbird, SV Angel, Breakneck and the Anthology Fund (run in partnership with Anthropic), with angels including Patrick Collison, Naval Ravikant, Guillermo Rauch and Noam Brown. Launch coverage dates the invite-only beta to early October 2026.
What to know before you try it
- It’s invite-only. You need an invite and a Mac with Apple silicon, or a Windows PC in the beta. Otherwise you join the waitlist.
- It lives on your computer. That’s the privacy benefit, and it also means the assistant works where your computer is. Phone apps are still coming.
- Your hardware matters. The larger local model needs more memory, so a lightweight laptop gets the smaller models.
- It’s early. Underdog ships updates quickly, which its fans praise, but expect rough edges in a beta.
How Underdog compares
Most AI assistants for email and calendars, from Superhuman to Fyxer to the agents inside ChatGPT and Claude, process your mail in the cloud. Underdog’s difference is that it doesn’t. For people who’ve avoided AI email tools because of privacy, that’s the deciding factor.
Carly works differently: it runs in the cloud, so you can text it from your phone, email it, or use it inside ChatGPT or Claude, and it can make and answer phone calls and texts too. It labels and sorts mail across all your Gmail and Outlook accounts by rules you set, and handles advanced scheduling the same way every time. If you want an assistant you can reach from anywhere, that’s the trade-off to weigh against Underdog’s on-device privacy. Our guides to the best AI email assistants and the best AI personal assistants compare the wider field.
FAQ
What is Underdog AI?
Underdog is a free personal AI assistant for email, calendar, meeting notes, dictation and errands. It runs its own AI models on your computer, so your mail and recordings stay on your machine.
Is Underdog free?
Yes. Underdog says it’s free forever because the AI runs on your computer. It earns a small cut when its errand agent buys something for you with a one-time card.
Does Underdog send my email to the cloud?
No, according to Underdog. Mail syncs directly between your computer and Google or Microsoft, and the AI processing happens on your computer. Underdog says it never sees your messages or password.
What devices does Underdog work on?
Macs with Apple silicon, with Windows in beta. iPhone and iPad apps are coming, and Android and Linux are planned.
What is Naval mode in Underdog?
A setting that stops Underdog from contacting its own servers, so it only talks to the services it needs, such as your email provider.
Who makes Underdog?
Automaton Research Inc., doing business as Underdog AI, founded by Sigil Wen.
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