Ada LovelaceMathematician · 1815–1852
“Does this invoice add up before I pay it?”
invoice textinvoice-validatorchecked totals
Line items, tax and totals are checked in the Engine, with every instruction counted.
How it works
Follow one question all the way down.
Isaac Newton ran the Royal Mint. His own spending is another matter. Follow his January from one question to the functions that answer it: what's his, what's shared, what was checked, what was allowed to run, and what got written down.
Start with his questionIsaac NewtonMaster of the Royal Mint, 1699–1727
- Wants to knowWhere did my money go in January?
- Brought january.csv · 10 rows
- Keeps7 category rules and 4 monthly limits
- UsesThe assistant he already has, and Kraton Companion on his Mac
01The question
Isaac asks.In the chat he already uses.
- Isaac exports January from his bank and asks his assistant where the money went.
- It is his usual assistant. Kraton has no chat of its own; it works underneath.
- His categories and limits are his. They come with the question, not from someone else's service.
Where did my money go in January? Anything over budget? january.csv · 10 rows
IsaacLet me see what can run on your Mac first.asking Kraton · nothing sent anywhere
His assistant, not Kraton's. Any supported one works.
Isaac's rules yours
Categories, first match wins
- “Baker”Food
- “Orchard”Food
- “Fishmonger”Food
- “Chandler”Candles
- “Royal Society”Dues
- “Alchemy”Research
- “South Sea”Investments
Monthly limits
- Food£30.00
- Candles£20.00
- Dues£40.00
- Research£30.00
02On this Mac
The assistant looks around.Only at what this Mac has verified.
- The assistant doesn't guess what's installed. It asks Kraton what can run here.
- Kraton lists only what it has verified on this Mac. Four functions look useful. Unverified code is never offered.
- Then it reads each contract: what goes in, what comes out, and what the function may touch. Here, nothing at all.
assistant → Kraton · list verified functions
ON THIS MACverified by Kraton · 8
invoice-validatorChecks invoice totals and tax lines
csv-importerBank export to exact pence
log-sanitizerRemoves personal data from logs
categorizerApplies your rules, in order
budget-reviewCompares spending with limits
http-fetcherFetches from allowed hostsnetwork · allowlisted
monthly-summaryTotals per category
python-analystFlags unusual numbers
1 unverified candidate · never offered to assistants
1
csv-importer0.1.0
incsv textcurrencydecimal places
outtransactions, in exact pencemay touch nothing
2
categorizer0.1.0
intransactionsyour rules
outcategorized transactionsmay touch nothing
3
budget-review0.1.0
inmonthcategorizedyour limits
outover · under · no budgetmay touch nothing
4
monthly-summary0.1.0
inmonthcategorized
outtotals by categorymay touch nothing
03The flow
It sketches a flow.Kraton checks the drawing.
- From those contracts the assistant sketches a flow. The pieces fit because they speak the same money: one shared type for a transaction.
- A wrong connection is caught on the drawing. Raw transactions can't go into the review: they have no category yet.
- Kraton checks the whole sketch before anything runs: every connection fits, every version is exact, no loops.
- january.csv
- csv-importer0.1.0
- categorizer0.1.0Isaac's rules
- budget-review0.1.0Isaac's limits2026-01monthly-summary0.1.02026-01
shared type · canonical:finance/types · transaction
- Every connection fits its type
- Exact versions, pinned by digest
- No loops
- Nothing has run yet
- transactions → budget-review · refused, no category yet
04Kept
Isaac keeps it.A flow in his file, not a feature on their server.
- The sketch arrives in Companion as a proposal. Isaac looks it over and saves it to his flows.
- Saving grants nothing. He lets his assistant run this exact flow, and only this one. He can revoke it any time.
- The assistant sees what goes in and what comes out. The inside stays in Isaac's file, on his Mac.
Proposed by your assistantchecked, not run
January budget
Save to my flows Saved to my flowsDismiss
My flowspersonal-flows.kraton
January budgetsha256:9f1c…a07e
Assistant accessthis flow
No assistant may run this flow.saving grants nothing
Isaac's assistant may run it.only sha256:9f1c…a07e · this connection
RevokeThe assistant sees
monthcsvcurrency
and gets back
reviewtotals
Stays in Isaac's file
05The run
Every step runs boxed in.Nothing plugged in that wasn't asked for.
- Before a part runs, Kraton checks it is the exact package its publisher signed. Isaac used to assay coins at the Mint. Same job.
- Inside the box nothing is plugged in: no network, no files, no clock, no secrets. Only the text Isaac handed over.
- −12.60 becomes −1260 pence. Money never turns into floating point, so nothing drifts.
- Review and summary run side by side. Every step is metered, and stopped if it overruns its compute limit.
givenjanuary.csvas text
KRATON ENGINE · THIS MAC
network files clock secrets
csv-importer 0.1.0
signed · exact bytes
8,912 fuel · 0.31 ms
categorizer 0.1.0
signed · exact bytes
6,405 fuel · 0.22 ms
budget-review 0.1.0
signed · exact bytes
5,730 fuel · 0.18 ms
monthly-summary 0.1.0
signed · exact bytes
4,981 fuel · 0.16 ms
−12.60→ −1260 pence, exactly
- receiptcsv-importer 0.1.0 · ok · 412 B in8,912 fuel
- receiptcategorizer 0.1.0 · ok · 1.1 KB in6,405 fuel
- receiptbudget-review 0.1.0 · ok · 1.3 KB in5,730 fuel
- receiptmonthly-summary 0.1.0 · ok · 1.2 KB in4,981 fuel
- flow4 steps · review and summary in parallel26,028 fuel
Example figures, not a benchmark.
06The answer
The answer.And a record of how it was reached.
- The answer comes back. Food is fine. Candles and research ran over, by a little.
- One category never had a budget at all. Some lessons are expensive.
- Activity keeps what ran: the question, the flow, exact versions and how much computing it took. On his Mac, without his data.
- Next month Isaac asks again. Same flow, same parts. Nothing to re-plan.
Food£25.85 of £30.00
£4.15 left
Candles£22.10 of £20.00
over by £2.10
Dues£40.00 of £40.00
£0.00 left
Research£34.00 of £30.00
over by £4.00
No budget set
InvestmentsSouth Sea Company shares£20,000.00
uncategorizedApothecary · no rule matched£8.35
- AskedWhere did January's money go, and what's over budget?
- FlowJanuary budget ·
sha256:9f1c…a07e - Steps4 of 4 ok · exact versions
- Metered26,028 fuel · 0.71 ms · example figures
- Kept outThe rows themselves. The record describes the run, not his money.
February: Isaac asks again. The same saved flow runs with the same parts; nobody re-plans it.
on a schedule, without asking · in development
on a schedule, without asking · in development
07How sure
How sure is the arithmetic?And what still needs proof.
- Fair question. First, the contract refuses what it can't read exactly. £1,234.50 gets an error, not a guess.
- The signature says who shipped these exact bytes. It doesn't say the arithmetic is right.
- That takes evidence for a named property. Today there are examples. The rest is an open order that anyone who needs it can fund.
The contractcsv-importer
-12.60−1260 pence£1,234.50refused: not a plain decimal12,60refused: not a plain decimalAn error you can read beats a number that looks right.
The signatureidentity
csv-importer 0.1.0
sha256:3b7e…a91c
signed by its publisher
Who shipped these exact bytes, with these permissions
Whether the arithmetic inside is right
The evidenceone property
Amounts keep exact pence. Currencies never mix silently.
- Examplesattached
- Adversarial casesopen
- Independent reviewopen
- Proof of the propertyoptional
Same anatomy. Other people, other questions.
Every flow is built the same way: an assistant reads the contracts, Kraton checks the sketch, you keep what works, and each step runs boxed in.
Marie CuriePhysicist and chemist · 1867–1934
“Can I share lab logs without anyone's personal details?”
lab.loglog-sanitizershareable log
Emails, card numbers and IP addresses are removed on her Mac, before the log goes anywhere.
Charles DarwinNaturalist · 1809–1882
“Which expedition expenses look odd?”
beagle.csvcsv-importerpython-analystoutliers
A Python analysis runs as a sandboxed component, after the same importer Isaac used.
Ask your own question. Keep the flow that answers it.
Start with Companion and the assistant you already use. Find functions in the Registry, or post a request for the one that's missing.
Illustrative people and data. Isaac Newton, Ada Lovelace, Marie Curie and Charles Darwin did not, in fact, use Kraton.