Metering & billing - Earth Care Network

Metering is the cross-cutting backbone — every AI action writes here. See the concept guide on metering & credits for the flow.

Metering (`metering` app)

Model	Purpose	Notes
`UsageEvent`	One record per AI action	Immutable. `provider`, `model`, tokens, `credits`, `cost_usd` (real cost), `byok` flag. Indexed on (org, ts).
`CreditWallet`	Per-org credit balance	1:1 Organization. Tracks `balance` + `reserved`.
`CreditTransaction`	Ledger entry	Immutable. `kind` ∈ `GRANT · TOPUP · SPEND · REFUND`.
`RateCard`	Per-feature preflight price	`credits_per_unit`, optional per-model multipliers.
`AICredential`	Self-host provider key storage	Encrypted; used by the self-host/Community edition, not hosted BYOK.

Billing (`billing` app)

Model	Purpose
`BillingPlan`	Subscription tier (price, included monthly credits, limits, Stripe price id)
`CreditPack`	One-time credit top-up (Stripe price id)
`Subscription`	Org → plan (status, Stripe subscription id, period)

Why this is trustworthy

UsageEvent.cost_usd records the real provider cost, so manage.py check_margins can prove that no feature is billed below cost and audit gross margin across both LLM and paid-data spend.

Generated from the metering and billing app models; re-syncs each iteration.