A second brain that marks its own homework.

Notes are plain markdown in a folder — the same folder Obsidian opens. Some of those notes make a claim about the future. Those settle themselves.

python 3.10+ · zero dependencies · MIT

_{the program does not touch it — what that means}

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The thirty seconds

git clone https://github.com/DefiLeoo/YOINK && cd YOINK
pip install -e .

yoink demo          # writes a vault that already has a life
yoink               # open it

  /\_/\
 ( o.o)
  > ^ <
  a vault with a life  ·  ~/yoink-vault

  35 notes · 14 alive · 21 never opened again
  5 claims settled on the spot · 2 still open
  said 75%, right 40% — +35 pts

  every number above was computed from those files, not written here.

---

What it is

Two things that usually live apart, in one folder.

An Obsidian vault. Markdown files with frontmatter and [[wikilinks]]. Open the same folder in Obsidian and everything works — the links resolve, the tags show up, the graph draws. Nothing is in a database. Nothing is in a format you need this tool to read.

A terminal. Four panes, keyboard only, launched with one word. Capture, search, follow links, read, settle — without leaving the shell you were already in.

And one thing that lives in neither.

---

The idea

Every note app can tell you how many notes you have.

None of them can tell you whether a single one of them was right.

yoink adds four lines to a note's frontmatter, and those four lines turn a thought into a bet with a date on it:

---
title: Robinhood Chain testnet clears 10M transactions
claim: tx count is at or above 10000000
settles: 2026-10-01
reads: chain:robinhood-testnet/txcount
test: gte 10000000
confidence: 0.7
---

When the date arrives, yoink settle reads the source, applies the test, and writes the answer back into the note itself:

outcome: false
reading: 8412998
settled: 2026-10-01T09:14:22
read_from: robinhood-testnet @ block 9412998

Your vault now holds not only what you thought, but what happened — attached to the thought, in the same file, in plain text, forever.

That is the whole trick. Everything else in this repository exists to make it work and to stop you from cheating at it.

---

The pulse

Because the notes carry outcomes, the vault can be scored. yoink score prints two things nobody's note app wants to print.

the vault
──────────────────────────────────────────────────────────────
  notes      35
  words      851
  links      16
  alive      14  (40%)
  dead       21  nothing links to them and you never went back  ·  yoink dead

the record
──────────────────────────────────────────────────────────────
  settled    5   graded 5
  said       75%      average confidence, folded to the side you took
  right      40%      how often that side was the right one
  gap        +35 pts   overconfident
  brier      0.388    0 perfect · 0.25 a coin · 1 certain and wrong

Dead notes. A note is alive if something links to it, it links to something, you came back to it after the day you saved it, or it carries a bet that has not closed. Otherwise it is dead. In most vaults this is a third of everything, and it is invisible, which is why people believe their vault is working.

The gap. said − right. You said 75%; you were right 40% of the time. That is 35 points of overconfidence, computed from your own notes. It cannot be improved by writing more notes — only by being right, or by saying a smaller number and meaning it.

The grading is the Brier score, (p − outcome)², used for weather forecasts since 1950 and chosen for one property: your best expected score comes from saying what you actually believe. Claiming 99% to look decisive costs you badly when it goes the other way, which is the point.

Every figure above comes out of yoink demo on a fixed seed. python scripts/figures.py --check fails if this page and the code disagree.

_{The same vault as a graph — notes and tags as nodes. The gold cloud is #inbox: twenty-one things saved once, linked to nothing, never reopened. Sixty per cent of the vault.}

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The terminal

_{Not a mock-up: a pseudo terminal, opened by scripts/screens.py, with yoink running inside it.}

The header carries the pulse at all times — on the demo vault it reads:

Y O I N K  ( o.o)  ·  35 notes  ·  14 alive  ·  21 never opened again  ·  5 claims settled  ·  +35 pts overconfident

One rule for the colour: gold marks what needs you — a claim that is due, a link that dangles, the share of your vault that is dead. Everything healthy is green and quiet. If every pane glowed, none of them would mean anything.

1  VAULT    the list, filtered        j / k      move
2  NOTE     the note, wrapped         enter      open
3  LINKS    ← in, → out               /          search
4  PULSE    alive, dead, the gap      a d c u o  all, dead, claims, due, orphans
                                      t g s r    tags, graph, settle, rescan

r rescans from disk, so editing a note in Obsidian in another window and pressing r shows the change. There is no index to go stale, because there is no index.

---

The command line

The terminal is for when you sit down on purpose. The rest of the time there is one verb, and it takes whatever you have:

yoink "the thing I just thought"      # an argument
pbpaste | yoink                       # a pipe
yoink --file notes.txt                # a file
yoink --url https://…                 # a link, fetched and stripped to text

Nothing opens. No prompt appears. No folder must be chosen. Capture has to be faster than the thought, or you stop doing it, and a second brain you do not feed is worse than none because you believed you had one.

yoink	the four panes
yoink add	capture text, a file, or a page
yoink claim <note>	turn a note into a bet with a date on it
yoink settle	read the sources, answer everything due
yoink score	the vault, and how right you have been
yoink dead	notes nothing points at that you never reopened
yoink graph [note]	the shape of the vault, or one neighbourhood
yoink search <q> --why	no index, so it is never stale
yoink tags [tag]	every tag, or every note under one
yoink show <note>	print a note, and record that you read it
yoink ledger	what happened, and whether it has been edited
yoink doctor	vault health, ledger integrity, claim sanity
yoink demo	write a vault that already has a life

--vault, then $YOINK_VAULT, then ~/yoink-vault. A machine with one vault never types a path.

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Where an answer can come from

A claim is only worth making if somebody who was not there can check it. Four kinds of source, and every one of them names where the number came from:

file:data/readings.json#chain.block     a JSON file, by key path
csv:bars.csv#close@2026-10-01           a column, on a date
chain:robinhood-testnet/blocknumber     a public chain, over JSON-RPC
manual:https://…                        you read it, and the URL is recorded

manual: is not a loophole. It stores the address and the number you typed, so the settlement can be argued with later. What it will not let you do is settle without writing down where you got it.

The chain

chain: reads a public EVM chain over JSON-RPC, and exists for one reason: a block height is a number nobody in this repository controls.

_{Every call on the wire, and the answer written back into the note.}

network	chain id
robinhood — Robinhood Chain	4663
robinhood-testnet	46630
ethereum	1

Two things are true of src/yoink/chain.py and both are enforced by tests:

• Before any settlement it calls eth_chainId and refuses if the endpoint reports a different chain than the one the claim named. A mainnet answer cannot quietly settle a testnet bet.
• It has four methods and all four read. There is no eth_sendRawTransaction, no key handling, no signing, no wallet. yoink cannot spend anything, because the capability is absent from the source — and a test parses the file to prove the words are not there.

Delete that file and everything else still works. The demo vault settles entirely from files inside itself, so the test suite never opens a socket.

Not affiliated with, endorsed by, or connected to Robinhood Markets, Inc. Robinhood Chain is read here the way any public chain is read: over its public RPC, without permission and without an account.

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What it refuses

This is the part that makes the score mean anything. Each of these is a claim that could never be graded, and yoink turns it away with the reason:

$ yoink claim idea --claim "it will moon" --settles 2027-01-01 …
✗ refused: "moon" cannot be settled by reading a number. Say what number, and which way

$ yoink claim idea --claim "block height is at or above 5" --settles 2020-01-01 …
✗ refused: 2020-01-01 is not in the future. You cannot bet on yesterday's race

$ yoink claim idea --reads nowhere …
✗ refused: 'nowhere' is not a source. Use file:, csv:, chain: or manual:<url>

$ yoink claim idea --test "goes up" …
✗ refused: 'goes up' is not a test. Use one of: gte 10, lte 3.5, gt 0, eq 1, between 2 4

And two rules that hold after the fact:

• A settled claim cannot be settled again. No settling, looking, and settling differently.
• A claim cannot be attached to a date that has passed. No backdating a forecast you already know the answer to.

---

On disk

~/yoink-vault/
├── 2026-09-11-robinhood-chain-testnet.md
├── claims-need-a-date-and-a-number.md
├── data/
│   └── readings.json          ← what some claims settle against
└── .yoink/
    └── ledger.jsonl           ← the only thing here that is not a note

That is the whole storage layer. No database, no index file, no lock file. Everything yoink knows — the graph, the search, the pulse — is recomputed from the files on every run. Ten thousand notes scan in well under a second, and in exchange there is no second copy of the truth to drift away from your notes.

Edit a note in Obsidian, in vim, in TextEdit, or with cat >> from a script. yoink sees it next time it looks. Delete yoink and nothing is lost, because there was never anything but your files.

The ledger

.yoink/ledger.jsonl is append-only, one JSON object per line, each hashed over the one before it:

hash_n = sha256( seq | at | kind | body | hash_{n-1} )

It holds what was captured, what you opened, what became a claim, and how each claim settled. None of it is a note. Delete the whole .yoink/ directory and you lose the history; you do not lose a single note. That asymmetry is deliberate — the notes are yours and portable, the bookkeeping is yoink's and disposable.

It is hashed because the pulse makes a claim about you, and a scoreboard you can quietly edit is not a scoreboard. Change one confidence after a bad outcome and yoink doctor names the line.

What it is not: proof of when anything happened. Whoever holds the file can rewrite it end to end, and a test in this repository demonstrates exactly that. It makes a single edit obvious, which is the thing that actually happens.

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Why there are no dependencies

The vault, the graph, the search, the four-pane terminal, the frontmatter parser, the JSON-RPC reader — all standard library. pip install yoink pulls in nothing else, and nothing else can break it.

That is not minimalism for its own sake. A tool that holds ten years of your thinking should not be able to stop working because a package three levels down changed its API.

python -m unittest discover -s tests -t .      # 201 tests, no network, under a second
python scripts/figures.py --check              # the README agrees with the code

scripts/screens.py opens a pseudo terminal, runs yoink inside it, presses keys, and photographs what comes back. The still in The terminal is one of those: not a mock-up, and if a pane is misaligned there it is misaligned in the app.

The three animations are the other kind of picture — visualisations, drawn to explain. They use the same demo vault and the same numbers, but they are not recordings of the program, and the graph view one of them shows is a way of looking at the vault rather than a pane you can press a key to reach. The banner is artwork too. Those four are the drawn things on this page; everything else is either a capture or a number the code produced.

(Each animation also ships as an mp4 next to its gif — assets/panes.mp4, assets/graph.mp4, assets/chain.mp4 — for when the gif's palette is not kind enough to the text.)

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The program does not touch it. yoink holds no key, has no wallet, and cannot sign a transaction — src/yoink/chain.py has four JSON-RPC methods and all four read, which a test enforces by parsing the file. Nothing here checks a balance before letting you write a note. Nothing here works differently if you hold the token or if you never do. The vault is markdown in a folder either way.

The address is above so it sits in one place, spelled in full and checksummed, rather than in a reply somewhere that can be edited. Copy it from here, check it against the chain yourself before sending anything anywhere, and trust the block explorer over any page — this one included.

That habit is the entire subject of the rest of this README.

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Honest limits

• The ledger is tamper-evident, not tamper-proof. See above. It catches the edit people actually make.
• The demo numbers are from a demo. They are reproducible, and they are not a record of anyone's forecasting. Yours starts empty.
• chain: needs the endpoint to be up. When it is not, the claim stays open rather than settling on a guess — yoink doctor --chain says which endpoints answered.
• The frontmatter parser handles the subset Obsidian writes: strings, numbers, booleans, dates, flat lists. It is not a YAML implementation, because that would be a dependency.
• Nothing here predicts anything. yoink has no model and no opinion. It records what you said, reads what happened, and does the subtraction.

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Docs

docs/VAULT.md	the file format, and why it is Obsidian's
docs/CLAIMS.md	sources, tests, refusals, settlement
docs/SCORING.md	alive/dead, Brier, what the gap means
docs/TERMINAL.md	the panes and every key

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MIT · built for the fun of it

_{Everything you yoinked is a note. Some notes make a claim about the future. Those settle themselves.}