E-commerce & Payments Skill
Ecommerce Stack Decision Framework
E-commerce stack decision framework
$15
Billing Automation
Build automated billing systems for recurring payments, invoicing, subscription lifecycle, and…
A complete blueprint for building automated recurring-billing systems: subscription lifecycle, invoice generation, dunning recovery, proration, tax, and usage-based billing. It ships working Python patterns for the subscription state machine (trial, active, past_due, canceled, paused) and the billing-cycle engine that charges, generates invoices, and triggers recovery on failure. The goal is a billing pipeline that runs itself and stops leaking revenue.
$15 one-time
Add to a kit → Prices include 20% VAT. · Forged on real agency work · one-time, no lock-in
- Type Skill
- Category E-commerce & Payments
- Delivery Email · instant
- License One-time
Inside the run · no black box
See the actual work before you buy it.
Recurring billing is a state machine with money attached. Here is how a subscription moves from invoice generation through tax, idempotent charging, dunning and proration without ever double-billing a customer.
- Models the subscription lifecycle as a state machine (trial, active, past_due, paused, canceled) so an invalid state transition can never fire a charge.
- On each billing date it generates the invoice: the plan line item, usage-based charges if the plan is metered, then tax by jurisdiction (US sales tax, EU VAT, AU GST) before the invoice is finalized.
- Charges the saved payment method with an idempotency key built from customer, billing period and plan, so a network retry or duplicate webhook can never double-bill.
- On a failed charge it starts the dunning ladder: automatic retry first, then emails at day 3, 7 and 14, service restriction before cancellation, each step weighing recovery against churn.
- Prorates mid-cycle plan changes by day: unused old-plan time is credited against the new-plan charge, and seat additions are billed only for the remaining days.
- Logs every billing event to an audit trail and keeps the customer's service alive through a grace period while the payment issue is being resolved.
One power source. 6 lines out.
billing-automation · core
core active · 6 lines
- ✓ implementing saas subscr…
Implementing SaaS subscription billing with monthly, annual, or custom cycles
- ✓ recovering failed payments
Recovering failed payments with a staged dunning ladder and retry schedule
- ✓ calculating fair proration
Calculating fair proration for mid-cycle plan upgrades, downgrades, and seat changes
- ✓ generating and delivering
Generating and delivering invoices as HTML or PDF with line items and tax
- ✓ handling sales tax, vat
Handling sales tax, VAT, and GST by customer jurisdiction
- ✓ billing usage-based char…
Billing usage-based charges with tiered, per-unit, or volume pricing
Yours to keep.
Drag time forward. Watch what stays.
Forever
That's what owning means.
The rented stack
ai writing tool: subscription
expired · access lostanalytics suite: subscription
expired · access lostdesign platform: subscription
expired · access lost(nothing left)
Your forge
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Recovered revenue from failed payments via a dunning escalation ladder that balances pressure and retention
license: perpetual -
Lower involuntary churn by replacing hard lock-outs with grace periods on card expiry and gateway outages
license: perpetual -
No duplicate charges, because idempotent invoicing makes retries and webhook duplicates safe
license: perpetual -
Accurate books with deferred-then-recognized revenue handling for annual and monthly plans
license: perpetual
subscriptions expire · deeds don't
Everything in the box.
Pick a piece up. Watch it work.
Subscription lifecycle state machine with trial, activation, past-due, and cancellation logic
6 parts · one working system · ships instantly by email
This wasn't forged for everyone.
- Not for you if you'd rather rent a tool than own one.
- Not for you if you want someone else to run your stack.
- Not for you if you're happy guessing.
Backend engineers and SaaS builders implementing or automating subscription billing who need fair proration, resilient payment recovery, and correct tax handling.
then this was forged for you.Works with
Universal by design: these run in any AI. Delivered in the open Agent Skills + MCP format (native in Claude); ChatGPT, Gemini, Cursor and Copilot adapt the same files their own way.
- Claude Native format
- ChatGPT Adapts via open standards
- Gemini Adapts via open standards
- Cursor Adapts via open standards
- Copilot Adapts via open standards
Catch what's on your mind.
the air is clear. nothing between you and the forge.
catch a spark: the forge will answer
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Does this replace Stripe, or sit on top of a payment processor?
It's the billing logic above the processor: the subscription state machine, invoicing, dunning, and proration. You still need a processor underneath to actually charge cards; this models the system that decides what to charge and when.
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Proration is where billing quietly breaks. Does this really get upgrades and seat changes right?
It ships proration patterns built specifically for mid-cycle upgrades, downgrades, and seat changes. The fairness logic is encoded, but you have to wire it to your real plan definitions, it can't guess your pricing rules.
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Will it handle tax compliance across regions for me?
It treats tax as part of the billing model, but it isn't a jurisdiction-by-jurisdiction tax engine. For real multi-region compliance you pair it with a dedicated tax service; this gives you the hook, not the ruling.
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How is it delivered?
By email right after purchase: ready to run, downloaded instantly, no setup wait.
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One-time or subscription?
A one-time purchase; no subscription or hidden fees. VAT (20%) is included.
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Can I get a refund?
As a digital product, it can’t be refunded once downloaded. That’s why we show exactly what’s inside and who it’s for, right here.