Launching today

Skim

Launching today

Free, open-source AI email client for Windows

100 followers

Free, open-source AI email client for Windows

100 followers

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Skim is a free, open-source (MIT) email client for Windows. ✂️ Minimal on purpose: no calendar, no rules engine, no bloat. Fewer buttons, less cognitive load. ⚡ Native Rust core (Tauri 2): ~5 MB installer, sub-second cold start, instant full-text search. 🔒 Local-first, offline-ready, zero telemetry. ✦ AI on your terms: bring your own Anthropic or OpenRouter key and Skim drafts replies in your voice and answers questions across your whole mailbox.

Free

Launch tags:Windows•Email•Open Source

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Skim

Maker

📌

I built Skim because I wanted a Windows email client that doesn't suck that hard and couldn't find one. Now I wanna share it with you. Skim is open source and MIT-licensed, free forever. No subscription, no telemetry. Join as a contributor plz! 🙏 https://github.com/nikserg/skim Skim is small: a native Rust core (Tauri 2, no Electron), a ~5 MB installer, offline-first IMAP sync into local SQLite, instant full-text search, and a keyboard-first UI with a Ctrl+K palette. ✦ The AI part works on your terms: paste your own Anthropic or OpenRouter key to enable AI features: ✍️ it drafts replies in your voice (and can learn from your sent emails) 📥 summarizes your unread mail 🔍 answers questions across your whole mailbox, with cited sources Pretty basic, huh? Right. That's all I need, and I believe there are people who need the same. Requests go straight from your machine to the provider: no middleman, no markup, no subscription. Let me share a bit of the philosophy I try to follow while building Skim: ✂️ Minimalism. It's an email client and that's it. No integrations -> no bloat. Cognitive load matters! 🎯 Contextual actions. Skim tries to be the kind of software that thinks FOR you to save your cognitive resources. Buttons show up only when needed, the app always does the most obvious thing, and the defaults should be the best ones. ⚡ Resource efficiency. Skim is built to run in the background 24/7, so it stays as humble as possible and eats as few resources as it can. That's why the installer is under 5 MB 😄 So, with all that said: please, have fun with Skim! I'd love your feedback, especially from folks tired of heavy clients. What would make you switch? What's missing? How could I trick you into contributing? 🤘

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1d ago

Unabyss

@nikita_zarubin I've migrated from Windows this year, but upvoted for branding only - great job, I like the anti-boring approach ;)

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3h ago

@nikita_zarubin Congrats on the launch! LOVE the website - you clearly put a lot of thought and personality into it.

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28m ago

Skim

Maker

@anna_ludwinowski that's true, I did! So glad you liked it! 🫶

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26m ago

Curious how you handle Gmail OAuth secrets in a public repo though! Great launch, refreshing branding, and love every MIT license.

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6h ago

Skim

Maker

@aidan_codefox Hey, I'm flattered you love the branding! It's something I'm secretly proud of. At first I went the usual route - you know, purple, polished, sterile shit - but then I thought, "Hey, it's free and open source, right? Fuck it, let's have fun," and ended up with this wonderful zine landing you're looking at.

Okay, flex time's over - to your question.

tl;dr: there are no secrets in the repo. The magic is called PKCE.

Brace for the AI-slop explanation, if you're curious:

Gmail uses the installed-app flow (loopback + PKCE), where the "client secret" isn't actually a secret. Google's own docs say the client secret for installed apps "is obviously not treated as a secret" — a distributed desktop app can't keep one confidential, so security comes from PKCE (S256) and the 127.0.0.1 loopback redirect, not from a secret. There's no server in the middle; the token exchange goes straight from your machine to Google.
The client ID/secret aren't committed — they're baked in at build time from env vars (SKIM_GOOGLE_CLIENT_ID / _SECRET), injected in CI from GitHub Actions secrets. So official installers carry them, but nothing sensitive sits in the source tree. Build from source and you just plug in your own Google Cloud project.
Microsoft/Outlook is a true public client — PKCE only, no secret at all.
Per-user tokens never touch disk in plaintext. Refresh tokens, app passwords, and the AI API key live in the Windows Credential Manager — never in the SQLite DB or any config file.
So "public repo" and "OAuth" coexist fine here: the only thing that would be dangerous to leak (per-user refresh tokens) never leaves your OS keychain, and the app-level identifiers are the kind Google/Microsoft explicitly design to ship inside native binaries. 🔒

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6h ago

Do you have plans for Mac or Linux, or is Windows the main focus? The ~5MB installer and sub-second startup would be a pretty strong selling point for anyone tired of bloated Electron apps, so I'm wondering if expanding makes sense or if you want to keep it tight and focused.

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1h ago

Skim

Maker

@talhakhalidmtk I'd rather focus on Windows, but not because it's against product philosophy, but because I use only Windows 😄 If you want to add a builder for another OS - feel free to contribute!

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1h ago

I will take a look because anything has the be better than MS Outlook these days! Does it handle multiple email accounts?

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7h ago

Skim

Maker

@siridley Hey, my thoughts exactly 😄

No multi-account support rn. I thought it wasn't needed, but just yesterday I found myself in a situation where I actually did!

Soooo I'll probably add multi-account support in the next release or so. There are usually 2-3 releases a day btw 😄

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6h ago

Skim

Maker

@siridley Just added multi-account feature in new 1.0.4 release! 🎉

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10m ago

Hey Nikita, congrats!
Any plans to release a Mac version?

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2h ago

Skim

Maker

@luis_parker thanks! I don't use Mac, but there's no obstacles to have such version. It would require new building pipeline and some settings. I invite you to contribute 😄

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2h ago

The Rust-backed cold start is genuinely instant, feels closer to opening a text editor than an email app. Glad the AI part is opt-in with your own key instead of some bundled subscription, keeps things lean.

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3h ago

Skim

Maker

@nilferkofag6jt True! 🤘

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2h ago

Forum Threads

p/skim-5

•

1d ago

What's missing?

I built Skim for myself. And it works better that any other email client for me.

But you're not me, right?

View all

Okay, flex time's over - to your question.

tl;dr: there are no secrets in the repo. The magic is called PKCE.

Brace for the AI-slop explanation, if you're curious:

Gmail uses the installed-app flow (loopback + PKCE), where the "client secret" isn't actually a secret. Google's own docs say the client secret for installed apps "is obviously not treated as a secret" — a distributed desktop app can't keep one confidential, so security comes from PKCE (S256) and the 127.0.0.1 loopback redirect, not from a secret. There's no server in the middle; the token exchange goes straight from your machine to Google.
The client ID/secret aren't committed — they're baked in at build time from env vars (SKIM_GOOGLE_CLIENT_ID / _SECRET), injected in CI from GitHub Actions secrets. So official installers carry them, but nothing sensitive sits in the source tree. Build from source and you just plug in your own Google Cloud project.
Microsoft/Outlook is a true public client — PKCE only, no secret at all.
Per-user tokens never touch disk in plaintext. Refresh tokens, app passwords, and the AI API key live in the Windows Credential Manager — never in the SQLite DB or any config file.
So "public repo" and "OAuth" coexist fine here: the only thing that would be dangerous to leak (per-user refresh tokens) never leaves your OS keychain, and the app-level identifiers are the kind Google/Microsoft explicitly design to ship inside native binaries. 🔒