Claude Code Plugin

BillingPlane

4,000 lines of Stripe billing intelligence that catches revenue-losing bugs before they ship. Zero runtime dependencies.

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claude --plugin-dir ./billingplane
4,093
Lines of billing intelligence
18
Files
56
Test specifications
15
Guardrail rules
12
Stripe events handled
0
Runtime dependencies
What it is

BillingPlane is build-time intelligence, not runtime middleware. It teaches your AI coding assistant how to build billing correctly, then gets out of the way. The generated code is yours. No SDK dependency. No vendor lock-in. No ongoing fees.

≠ Billing middleware
Autumn, Lago, Schematic sit in your production path. You call their API every request. Switching costs are enormous.
= Billing knowledge layer
BillingPlane encodes production patterns into your IDE. Claude generates correct code from the start. You own everything.
Commands

Four commands. Full billing coverage.

/billingplane:audit

Scan your codebase for 25+ billing violation patterns across 8 categories. Hardcoded keys, missing webhooks, non-atomic entitlements, lifecycle gaps.

CRITICAL, HIGH, MEDIUM severity ranking with exact file locations and fixes.

Coverage

What BillingPlane knows

Webhooks12 events, 6-layer middleware, idempotency, signature verification
LifecycleCancel (3 variants), reactivate, past_due, default fallback, trials, upgrades
Feature GatingBoolean / metered / credit systems, atomic check+track, entity-level, overage, preview
Usage Billing6 billing types, invoice.created handler, final invoice, balance reset
EntitlementsLazy reset, rollover with expiry, Decimal.js precision, default deny
ConcurrencySubscription locks, cache invalidation, Redis Lua, SELECT FOR UPDATE
Guardrails

The 15 non-negotiable rules

Get started

Three ways to install

From GitHub
/plugin marketplace add kamesh231/billingplane-marketplace
/plugin install billingplane@kamesh231
Local
git clone https://github.com/kamesh231/billingplane.git
claude --plugin-dir ./billingplane
Team setup (.claude/settings.json)
{
  "plugins": {
    "marketplaces": ["kamesh231/billingplane-marketplace"],
    "autoInstall": ["billingplane@kamesh231"]
  }
}
Origin

Built by reverse-engineering a production billing platform — 23MB codebase, 300+ test files, 12 webhook event handlers, 6 billing types, 3 feature types, entity-level gating, credit system fallback cascades, rollover expiry chains, and atomic entitlement deduction patterns. Every guardrail in BillingPlane exists because a real production system needed it.