Let the agent build the app.
Keep the logic inspectable.
A gallery of working apps where every pricing rule, eligibility check, and policy gate lives in a Leapter Blueprint: a side-effect-free program you can read, render, run, and trace.
Examples
10 working apps. Pick one.
Each example is a Next.js page wired to its own Leapter project. Open one, change inputs, and inspect the logic that ran.
Hello World
The simplest possible inspectable Leapter logic — type a name and watch a single decision branch live.
hello-worldOpenLeapter Blueprint Tour
Demonstrates the basic nodes of the Leapter Blueprint. Sections, assignments, decisions, and loops.
leapter-blueprint-tourOpenPizza Pricing Calculator
Calculates the price of a pizza based on size, toppings, crust, and the day of the week — with day-of-week discounts and premiums applied to the subtotal.
pizza-pricingOpenSolar Surplus Controller
Decides EV charging power from rooftop solar surplus, with a deadline override when the car must be ready in time.
pv-surplus-chargingOpenKYC Screening
Screen an individual customer and get a risk rating, decision, and explanation.
kyc-screeningOpenCredit Risk Scoring
Rate an applicant from A to E and recommend an interest rate, based on income-to-debt ratio, employment history, and payment record.
calculate-credit-risk-scoringOpenWarranty Coverage Classifier
Classifies a product's warranty coverage based on type, age, usage intensity, and premium status.
warranty-coverageOpenVehicle Tax Calculator
Computes the annual German vehicle tax (Kfz-Steuer) for passenger cars based on first registration, engine type, displacement, CO2 emissions, and emission class.
vehicle-taxOpenTower of Hanoi
Solves the classic Tower of Hanoi puzzle with a recursive Leapter blueprint and visualizes every generated move.
tower-of-hanoi-solverOpenAirline Crew Assignment Validator
Validates crew-to-flight assignments against duty time, rest, qualification, complement, base airport, and monthly hour rules.
validate-crew-scheduleOpenCreate your own
Bring a requirements doc, get a working app with a Blueprint inside. Same pattern as every card on this page.
leapter-inspectable-logic-demoHow it worksInspectable Logic
Open any example.
Inspect the logic that ran.
The panel on the right highlights the path the logic took. The blueprint is the program.
The artifact
Same file. Two views.
Both are the program.
Veritas is a text-based logic format. It validates locally, executes deterministically, and renders as an editable visual Blueprint. Sections carry the intent of a rule alongside its executable body.
Drag the handle on the showcase to compare the two representations. The diagram replays a real run with the active path lit up — the same view you can open inside every example.
hello-world / hello-world.logic.vtssection "Has username?" {
"""
If a username was provided, personalise the greeting.
Otherwise fall back to the classic "Hello, World!".
"""
choose {
if (username.length > 0) {
greeting = "Hello, " + username;
}
else {
greeting = "Hello, World!";
}
}
return greeting;
}
hello-world / hello-world
Drag the handle. Same file, two views.
Why Leapter
What happens to business logic in each approach
Build your own with the same workflow
Clone the starter, point Claude Code at a requirements doc, and it will write the Veritas, validate it, build the UI, and wire it to the runtime.