Billing & Entitlements

The Problem

Billing is never just billing. It’s “can this user access this feature on their current plan?” — which means billing needs to talk to auth, feature flags, and rate limiting. Today, that’s all glue code.

How Flux Handles It

Flux’s billing is connected to the entitlements engine:

• Subscriptions: Create plans with feature-level granularity
• Usage metering: Track consumption across any dimension
• Entitlements: Define what each plan includes — Flux enforces it everywhere
• Stripe sync: Two-way sync with your Stripe account
• Trials and upgrades: Manage lifecycle events with hooks

What Makes It Different

// Define a plan once — Flux enforces it across auth, flags, and rate limits
let plan = flux.billing().get_plan(&user.org_id)?;

// Feature flags automatically respect plan limits
// Rate limiting automatically uses plan quotas
// No glue code required

When a customer upgrades, their feature access, rate limits, and flag evaluations all update instantly. No cache invalidation, no webhook handlers, no “eventually consistent” headaches.