FEATURE — 08Deterministic
Ifandthen.

Teach Trout to categorize a transaction once; it does the work forever after. Multi-condition matching with proper boolean logic — not the vague "smart" guessing other apps call a rule.

Try the app
Rules fired · last 30d
4,218
Auto-categorized
99.3%
Conditions per rule
Up to 8
Operators
AND / OR / NOT
§ 01 · The builder

Build one. Watch it fire.

Change any dropdown on the left. The transactions on the right re-evaluate instantly. No "save rule", no preview mode — what you see is the rule.

Rule — draft
Ifthe payee contains
the amount is
$
thencategorize as
Compiled rule
rule {
  when: payee ~= "Amazon" and amount > 50
  then: category = "Shopping"
}
April transactions2 of 7 match
Apr 02
Amazon
headphones
$84.20Shopping
Apr 03
Amazon Prime
monthly
$14.99
Apr 05
Whole Foods
weekly
$122.10
Apr 06
Amazon
book
$18.30
Apr 10
Amazon
speakers
$142.00Shopping
Apr 14
Shell
gas
$54.80
Apr 17
Amazon
cable
$11.00
§ 02 · Specimen book

Six rules that pay rent.

Real rules from real budgets. Each one stops a recurring decision from hitting your attention ever again.

IGroceries

Groceries are groceries.

if
Whole Foods
ORTrader Joe's
ORAldi

Any of these payees, any amount, becomes groceries.

IIShopping

Big Amazon = Shopping.

if
payee contains "Amazon"
ANDamount > 50

Small Amazon buys stay uncategorized for your review.

IIISubscriptions

Subscriptions.

if
amount = 14.99
ANDmemo contains "monthly"

Netflix, Spotify, Prime — same amount every month.

IVCoffee

Not a meal.

if
payee contains "Starbucks"
ANDNOT memo contains "lunch"

Negative conditions work too. Separate coffee from meal.

VExclude

Round-trip ignore.

if
payee contains "Transfer"
ANDamount < 0.01 delta

Internal transfers should not count as spending.

VIUtilities (flag)

Utility inflation.

if
payee contains "PG&E"
ANDamount > 200

Flag utility bills that spike above last month's ceiling.

§ 03 · In flight

Every import, already sorted.

When bank sync pulls a batch in, rules run in priority order. You see only what genuinely needs a human decision.

rules.log — live● streaming
09:14Whole Foods$68.30rule-01Groceries
09:14Amazon$142.00rule-02Shopping
09:14Netflix$14.99rule-03Subscriptions
09:13Amazon$11.00— (review)needs category
09:13Starbucks$5.80rule-04Coffee
09:13Trader Joe's$44.20rule-01Groceries
09:12Transfer$200.00rule-05Exclude
09:12PG&E$218.40rule-06Utilities
7 rules evaluated · 7 of 8 matched1 transaction needs review
"

I haven't manually categorized a grocery run in four months.
— early access user, reddit

§ 04 · Mechanics

The small print, honest.

No black box. You can read, reorder, disable, or delete any rule at any time — and see exactly which rule tagged which transaction.

Priority
Rules run top-to-bottom. First match wins. Drag to reorder.
Conditions
Match on payee, memo, amount, account, date, or imported category.
Operators
equals, contains, starts-with, ends-with, regex, >, <, between.
Actions
Set category, add tag, flag for review, set memo, or exclude from budget.
Retroactive
Apply a new rule to past transactions — with a preview first.
Audit
Each auto-categorization records which rule fired, and when.