Skip to content
Your second brain, on your machine.

Drop anything in.

Drop in a link, PDF, video, or newsletter. BlackHole writes a clean, linked note, files it in your own knowledge base on your machine, and answers your questions from the notes it wrote.

blackhole · localhost:7777
arxiv.org/abs/1706.03762Ingest →
2026-06-15 · arxiv.org

Attention Is All You Need

Introduces the Transformer: an architecture built entirely on self-attention, dropping recurrence for parallelism and long-range context.

#transformers#attention#nlp
links[[Self-Attention]][[Encoder–Decoder]]
Filed in Resources/AIlinked to 4 notes

You're great at saving things.
Terrible at coming back to them.

Five browser windows, a hundred open tabs, a Drive full of PDFs, a read-later app you stopped opening. The information's all there. It's just not organized, connected, or findable. And tools that promise to fix it hand you a blank vault and ask you to become a part-time librarian first. Most people quit before the payoff.

BlackHole does the librarian part for you.

  • Drop in a link and get a clean, filed note
  • Everything connects to what you already saved
  • Ask a question, get an answer with citations
47 open tabs
Read-later (213)
Drive / PDFs
Bookmarks/
Screenshots/
“I'll read this later”
Slack saved items
Downloads/
How it works

Three steps. Then BlackHole runs itself.

PDF
01

Drop it in.

A URL, PDF, image, audio, video, or a tweet thread. Drag it, paste it, or capture the current tab in one click.

note.md
02

BlackHole does the work.

BlackHole reads or transcribes what you dropped in, writes a clean note with a title, summary, tags, and source, then links it to your related notes and files it where it belongs.

03

BlackHole keeps itself organized.

In the background, BlackHole keeps the graph current: new links, merged duplicates, tidy tags. Your knowledge base gets better as it grows, not messier.

Then ask BlackHole anything: “what did I save about the Roman Empire?”, “connect these two ideas,” “draft an outline from everything I saved on sourdough.”

Your data stays yours

Runs completely offline. And shows you it did.

Flip one switch and BlackHole runs with zero cloud. Every outbound AI request is blocked, and the Activity page keeps a live counter you can watch sit at zero.

Cloud AI with your own API key, for the best results. What you ask about goes to your chosen model provider (for example, OpenRouter).

See it for yourself

Pick a local mode and BlackHole stops every outbound AI request. The Activity page logs what it does, so you can see exactly what happened and watch the cloud-call count sit at zero.

blackhole · ActivityCloud · your key
3AI cloud calls

each one logged with host and purpose

Ingested deposition-transcript.pdflocal
url extract → r.jina.aicloud
Redacted 2 secrets before sendguard
Wrote note · 6 tags → openrouter.aicloud
Answered “what did the expert say about scope?” → openrouter.aicloud

secrets stripped before every send · PII opt-in

Runs on your machine

A local model that files your notes right.

Tag, link, and file every note with an AI that runs entirely on your own hardware. We benchmarked seven small local models on an everyday laptop to pick one that's genuinely good at the job, then made it switchable per note.

Files notes to the right folder, in our tests~2 GB of RAM$0 · fully offlineSwitchable per note

Want maximum quality? Bring your own cloud key. Want maximum privacy? The local model is right there. Your data, your call.

Powered by Ollama: local models you run yourself, free and open-source.

Offline mode's one exception is an anonymous license check (your key and a machine id). Never your notes.

Text, articles, audio, and documents work fully offline.

On-device image captioningComing soon

Chat answers come with citations to the notes they used, and it's built to say “I couldn't find that” rather than guess.

Want it fully offline on day one?

Get BlackHole
~/BlackHoleVault
~/BlackHoleVault/
└─ 00 Inbox/BlackHole/
└─ Projects/
└─ Areas/
└─ Resources/
└─ AI/attention-is-all-you-need.md
└─ Archive/
└─ Home.md

Filing follows PARA. Every note is sorted by how actionable it is, most active first:

Projects
active work with a goal or deadline
Areas
ongoing responsibilities you maintain
Resources
topics and references for later
Archive
anything finished or inactive
Your files

It all lives in a folder you can open without us.

BlackHole writes standard Markdown into a folder you control, sorted with PARA so you can always find things. Nothing's trapped in a proprietary format.

  • Works with any Obsidian vault
  • Readable in any text editor, forever
  • Delete BlackHole and your notes stay put

Filing follows the PARA method — Tiago Forte's system from Building a Second Brain. Read about PARA (opens in new tab)

What you save comes back to you.

The return trip, built in: a fast triage inbox, a morning digest, and search that works by meaning.

Inbox3 left
deposition-transcript.pdfProjects/Case
Pocket export · 213 links
“read this later”
KKeepSSkipCClear

Triage inbox

A fast, keyboard-driven keep / skip / clear queue, so your inbox hits zero instead of becoming a junk drawer. “Keep” accepts the suggested folder in one tap.

Today's digest
On this day your sourdough deep-dive, 1 year ago
5 things you saved about the Roman Empire
Saved, never read 12 waiting

Digests & resurfacing

BlackHole brings things back on its own: “on this day”, buried gems, the read-laters you never opened. No flashcards, no homework.

that guide about starter hydration
Sourdough hydration, explained
#bakingwebthis year

Search by meaning

Find what you saved by what it’s about, not the exact words. Filter by tag, type, and date, then jump to the chat to ask about it.

When you ask, BlackHole reads the whole note, not scraps.

Most “chat with your notes” tools paste in tiny fragments and hope. BlackHole works out the right scope (a topic, a folder, a cluster) and hands the AI the full notes, the way you'd brief a sharp assistant. Ask BlackHole to draft an outline of everything you saved about something, and it compiles a brief and files it back.

Under the hood: a token-budget router. Full notes when they fit, search as the fallback, graph-aware for “how do these connect” questions.

Most tools: chopped snippets
…the starter……75% hydration……fold at 30min……1,500 chars…
best-effort, ungrounded
BlackHole: whole notes in context
Sourdough, the deep dive
Hydration ratios, explained
Wild yeast starters
filed back: brief, Sourdough.md

Convinced?

Get BlackHole

A famous AI researcher builds his notes this way. By hand.

In April 2026, Andrej Karpathy popularized building a personal “LLM knowledge base”: let an AI compile your sources into a linked Markdown wiki you can load straight into context. It works, if you're willing to wire it up by hand. BlackHole is the same idea, without the setup.

The manual way

Curate the sources, write the wiki, keep every page linked and current. Yourself.

BlackHole

Drop things in. The wiki writes, links, and maintains itself.

Karpathy's LLM wiki, but without being Karpathy.

Read the original post (opens in new tab)
Beyond capture

It keeps working after you save.

The vault is the foundation. A maintenance layer runs on top of it, and most of it is already in the build.

01

A librarian that works nights

Live

A nightly job already rebuilds your knowledge graph, and a morning digest resurfaces what you'd forgotten. Next up: proposed merges and tag cleanups you approve with a click, each landing as a diff you can undo.

Last night's runran locally · 02:14
  • +Rebuilt your knowledge graph
  • +Linked 12 new captures into the graph
  • +Resurfaced 3 notes in today’s digest
  • !Flagged 2 stale notes for review
Every proposed change lands as a reviewable diff. Nothing happens you can't undo.
02

Use it from any AI

Live

From Claude or any MCP-capable AI: say “save this to my second brain” or “what did I save about X” and it routes through BlackHole into your local vault. Capture, search, and grounded answers ship as MCP tools.

Claude · connected to BlackHoleMCP
“save this to my second brain”
capture · BlackHole
filed, tagged, linked · 00 Inbox/BlackHole
Works from Claude today. Any MCP-capable AI can connect.
03

A map of everything you know

Live

BlackHole finds the people, concepts, and things your notes are about and how they connect, then uses that map to link notes and answer questions. This one is live — explore it.

mapping your vault…
A live map of your vault
How it compares

The part others skip is the whole product.

What BlackHole does — that the others don't

  • Auto tags, links & filingYes
  • Brings things back to youYes
  • Maintains itself (dedupe, re-linking, tag cleanup)Yes
  • Your data stays localYes
  • Runs fully offline (no-cloud AI)Yes
  • Use from any AIComing soon
  • Own it: one-timeYes

Obsidian needs manual plugins; read-later apps keep your notes on their servers; Smart Connections only suggests similar notes.

Read-later apps = Recall, Readwise and similar, which hold your notes on their servers. Smart Connections is the Obsidian similarity plugin. Obsidian runs fully offline with manual plugin setup. ~ = partial.

What it does today

Everything BlackHole already does.

The whole feature set that ships today — before anything on the roadmap below.

Capture

  • Drop a URL, PDF, image, audio, video, or text
  • One-click capture from your browser
  • Bulk import — Pocket, Readwise, Instapaper, bookmarks

Organize

  • Clean Markdown notes with frontmatter + reuse-first tags
  • Filed straight into your Obsidian vault
  • Auto wiki-linking to related notes
  • Dedup on re-drop · triage of low-confidence notes

Retrieve

  • Ask your vault — streamed answers with [[citations]]
  • Hybrid search (meaning + keyword)
  • Knowledge graph + maps of content
  • Daily digest + stale-note resurfacing

Privacy & control

  • Cloud (BYOK), Local-only, or Offline modes
  • Egress guard + activity view
  • Your files stay plain Markdown you own

Integrations

  • MCP — talk to your vault from Claude Desktop or Code
  • Self-updating, signed & notarized macOS app
Roadmap

Where BlackHole goes next.

Beta · v0.2v0.3 coming soon

It's all free during the beta. The first 100 Founders help decide what we build first.

Now

Building it
  • Sharper answersv0.2

    Smarter chunking for more precise retrieval and citations from your vault.

Next

Planned
  • Research my vaultv0.4Founders vote

    Ask one big question, get a synthesized answer across your whole vault.

  • Guided setupv0.3

    A five-minute first run with a demo vault, so you see the magic before committing your own notes.

  • Trustworthy citationsv0.3

    Every answer labeled by how well its source backs it — extracted, inferred, or unsupported.

  • Keys in the Keychainv0.3

    Your API keys stored in the macOS Keychain, not a plain config file.

  • True offlinev0.4

    Fully offline, zero network — a verified license with no cloud check at all.

Later

We're exploring
  • More ways inFounders vote

    Forward an email or share from your iPhone straight into your vault.

  • Faster transcriptionFounders vote

    Native Apple-Silicon speed for local audio and video.

  • Smarter local searchFounders vote

    Reranking and stronger local embeddings for better offline results.

  • Vault upkeepFounders vote

    Keeps your vault clean as it grows — duplicate detection and a health scan.

Version tags are targets, not promises. Everything here is free during the beta; “Later” items are things we're exploring, and Founders help set the order.

Pricing

One price, no meter running.

Free

$0

For trying the whole thing

  • The full product — no features held back
  • 50 saves to try — total, not monthly
  • Unlimited questions
  • Bring your own AI key, or run fully local
Founders EditionFirst 100 licenses

Pro

$129$79once
Founders price — first 100 lock it in for life

For everyday use

  • Unlimited saves
  • Every version, free for life — v1, v2, v3…
  • 2 devices
  • Bring your own AI key, or run fully local
  • Search and auto-linking run on your machine, free
  • 30-day money-back guarantee

Managed

Later
Coming after launch

For hands-off AI, no keys

  • We host the AI — no keys to manage
  • Priced separately when it lands
  • Everything in Pro, always current

Available after launch

Founders Edition

First 100 licenses

BlackHole is built by one person. The first 100 people who back it at launch aren't just early customers — they're the reason it exists past week one. So Founders get more than a discount.

  • Every version, free for lifev1, v2, v3, forever — Founders never pay for an upgrade.
  • A numbered Founder badge (#001–#100)plus your name in the credits.
  • A direct line to the founderpriority support, answered by the person who built it.
  • A vote on the roadmapyou help decide what ships next.
  • Early accessnew builds before anyone else.
  • Founding price, locked$79 now · Standard is $129.
I'm not a company with a marketing budget — I'm a developer who got tired of watching my own vault rot, and built the fix. If you're one of the first 100, you're funding the roadmap, and I want you to feel that. Thank you.

What does “bring your own key” actually cost?

Or run fully local — $0, forever.

You pay your AI provider directly for what you use — no markup from us. On a cheap model it's pocket change, and in fully-local mode there's no bill at all.

under 2¢Save a PDF or articlea few model calls to tag, file, and link it
under 3¢Save a 10-min videoit reads the video's own captions, so transcription's free
~$2–3A typical montharound 50 saves and 100 questions$0 fully local

Typical costs on cheap OpenRouter models (Gemini Flash, GPT-4.1-mini); your provider bills you directly. Asking questions is the main cost — saving is nearly free, and embeddings always run locally. Even a “search my whole vault” question runs about a dime. Fully-local mode costs nothing.

30-day money-back guarantee. Pay once, keep every 1.x update, own it outright.

Pro billing runs through Polar, which handles tax and license keys.

FAQ

Answers for the skeptical.

Mac, Windows, or Linux?

macOS first. Windows and Linux are on the roadmap.

Is my data private?

Yes, and you can prove it. Pick Cloud, Local-only, or Offline at setup. In a local mode a network guard blocks every outbound AI call, and the Activity page shows a live count that stays at zero. Either way your notes are plain Markdown on your machine.

What's the difference between Cloud, Local-only, and Offline?

Cloud (the default) uses cloud AI with your own key, for the best quality. Local-only runs the AI on your machine with Ollama, with no cloud calls. Offline goes further: zero outbound except an anonymous license check, never your notes.

Do I need Obsidian?

No. BlackHole works on its own with a plain Markdown folder. If you love Obsidian, one click sets it up over the same folder.

Do I need an API key?

For Pro and Free, you bring your own (OpenRouter takes a minute and costs a few dollars a month for most people). Search and auto-linking run on your machine, free. Managed includes everything; no keys.

I don't want to deal with API keys.

That's what the Managed tier is for: we host the AI, you never touch a key. It lands after launch — join the waitlist and we'll tell you when it's live. Or run Local-only with Ollama and skip keys entirely.

What do I get on the free tier?

The whole product — nothing held back — on your first 50 saves. That's a lifetime allowance, not a monthly reset: a trial that never expires. Questions are unlimited even on Free. When BlackHole earns a place in your week, Pro lifts the save cap for one payment.

How do updates work?

Every 1.x update is delivered automatically — free, and no account required. A built-in updater keeps the app current, so “pay once, updates included” is literally true rather than a promise.

What happens at version 2?

Founders Edition (the first 100) includes every future version free for life — v1, v2, v3, for as long as the product exists. Standard includes all 1.x updates; a major release like v2 is a paid upgrade. Both are personal-use licenses, good on up to 2 devices.

What happens if you shut down?

You lose nothing. Your notes are plain Markdown files in your own folder, search runs locally, and a one-time license doesn't phone home to stay valid. The app keeps working; the files were always yours.

Does it lock me in?

No. It's just Markdown files. Export, switch tools, or open them in any editor anytime.

What can I drop in?

Links and web pages, PDFs, images, audio, video, YouTube, and tweet threads (auto-unrolled). More import sources (Pocket, Readwise, bookmarks) are on the way.

Is this RAG?

Not the usual kind. Instead of pasting chopped fragments into the prompt, it loads the full relevant notes into context, and only falls back to search-style retrieval when a topic outgrows the token budget.

Won't you end up with a giant, unsearchable Markdown repo?

The Markdown is just storage. Findability comes from an index next to your files (embeddings + keywords in one SQLite file), so search works the same at a hundred notes or fifty thousand.

Read more →
Does it scan the whole corpus on every query?

No. Each note is indexed when it's saved, so a query is a lookup against a bounded set of the most relevant notes — never a scan of the vault.

Read more →
What if it files or categorizes something wrong?

Filing is confidence-gated. If the model isn't sure where a note belongs, it parks it in your inbox instead of guessing, so the worst case is “waiting for you to look,” not “buried somewhere wrong.” It also doesn't matter much, because links are computed from a note's content, not its folder. A misfiled note still connects to the right things, and moving it later doesn't break anything.

Why sqlite-vec instead of a dedicated vector DB like LanceDB or pgvector?

Everything already lives in one SQLite file, and sqlite-vec keeps the vectors there too: one store, no extra process, installs clean, runs offline. The tradeoff (exact search, not approximate) is ideal for a personal vault and wrong for millions of documents — we're the former.

Read more →
How does it chunk my documents?

Mostly it doesn't. Whole notes are loaded into context when they fit the token budget; chunking is a query-time fallback for oversized notes, never something that happens at intake.

Read more →
How are related notes actually linked?

Four signals get fused: exact title and alias matches, semantic similarity from embeddings, shared entities in a knowledge graph, and shared tags. Strong matches become inline [[wikilinks]]; softer ones go in a Related list. None of the four looks at the folder, so connections survive any reorganizing you do later.

Read more →

Start saving things you'll actually use again.

One-time license · Your data stays yours · No lock-in (it's just Markdown)