Tools

Calculators and field guides for people building a selling system.

Use these tools when Stripe fees, checkout pricing, payment options, invoices, tax settings, or post-purchase automation affect the offer you are about to publish.

The Numi Stripe payment methods settings page showing card, wallet, bank transfer, and buy now pay later options.

Builder paths

A tool should tell you what to change next.

Calculators, audits, and generators should connect directly to the Plandalf surface that makes the answer operational: prices, payment options, hosted checkout, invoices, deadline campaigns, API docs, SDK checkout, webhooks, integrations, and comparisons.

The Numi pricing table showing configured offer prices.
The Numi hosted checkout product surface.

Compare processor checkout with an offer layer

Use this path when a calculator raises the bigger question: whether Stripe Checkout alone is enough, or whether the offer, invoice, product, price, and automation context should stay together.

The Numi promo overview product surface.

Turn discount math into a promotion

Use this path when the tool is deciding a coupon, deadline, launch window, email countdown GIF, save offer, or price change that must match the checkout.

The Numi API documentation surface with SDK and endpoint navigation.

Route the answer into the business stack

Use this path when the calculator output belongs in an API-first app, SDK checkout flow, webhook fanout, tax-compliant SaaS stack, CRM, or analytics workflow.

The product surfaces behind the tools.

A good calculator should tell you where to act next: edit prices, adjust payment options, test checkout, check invoices, or route webhooks after purchase.

The Numi Stripe payment methods settings page showing card, wallet, bank transfer, and buy now pay later options.

Processor choices change the math

A Stripe calculator matters more when it points back to payment options, prices, checkout tests, and invoices.

The Numi pricing table showing configured offer prices.

Fee math becomes a price record

Use the result before editing prices, coupons, subscriptions, packages, and hosted checkout pages.

The Numi offer invoices page showing invoice status, customer, amount, and line item information.

Invoices preserve the decision

After checkout, invoices keep the product, price, customer, tax, and payment state readable for operations.

The Numi coupon expiration settings panel.

Discounts need expiry state

Coupon math should point into deadline campaigns, Timers, checkout prices, and save-offer sequences.

The Numi offer editor automation tab showing sequence controls.

The result should trigger work

Once the price, tax, and payment path are set, purchase automations carry the checkout event into CRM, email, webhooks, and fulfilment.

The Numi API documentation surface with endpoint navigation.

Tools should end in implementation

API docs, SDK checkout, and webhooks make a calculator useful to agents and developers building the next step.

Recipes that make the tools operational.

Stack

Pricing Packaging Lab

Model the catalog and pricing system before sending plan changes into lifecycle messaging.

Feature and docs references to keep open.

Feature

Prices

Set one-time, package, subscription, tiered, and custom prices.

Feature

Invoices

Keep records, line items, payment state, and customer context after purchase.

Feature

Coupons

Discount the offer without losing the pricing record.

Build the checkout after the math.

Use Plandalf Offers for the buying surface, Timers for deadlines, and Automations for the work after checkout.

Feature detail