Implements the ByteTinker-Bold distribution-agreement billing math and surfaces it on a
standalone admin-only route. No UI (the API figure is the deliverable). Server-side only.
Contract math (lib/billing.js, config-driven; defaults ARE the agreement):
- ASD (per device/day) = min(1.0, online_seconds / (hours*3600)) # 28800 default
- BillableScreens (per month) = round-half-up( Sum ASD / days_in_month )
- Flat tier (not marginal): 1-499 $1.50 / 500-999 $1.25 / 1000+ $1.00; cost = screens*rate.
Single global rate card for now (per-tenant is a future concern; noted in code).
Data foundation:
- New durable rollup device_usage_daily(device_id, day 'YYYY-MM-DD', online_seconds),
index on day. status_log (3d) / telemetry (24h) can't back a billing month.
- Accumulated INCREMENTALLY off the heartbeat tick from the live connection map (same
source as devices_connected) - never reconstructed from logs. Each tick credits every
connected device's today-row (min(86400, +elapsed)), chunked + transactional (non-blocking);
per-tick credit capped (accrualCapSeconds) as a stall/restart guard.
- Retention ~400d, pruned via chunked-prune (pruneUsageDaily in runMaintenance).
API: GET /api/billing/usage?month=YYYY-MM (default current), requirePlatformAdmin, mounted
SEPARATELY from /api/status (billing is revenue data + a heavier aggregate; must not touch
the hot status path). Reads the rollup only. MTD figure averages over COMPLETED days only
(today shown in `daily` but excluded until it completes); is_final + billable_screens_final
appear once the month completes.
Tests (12): ASD math; billable round-half-up; flat tier/cost boundaries; accumulator
(accrues by interval, caps at 86400/day, disconnected doesn't accrue); report MTD-excludes-
today + final-month is_final; retention prune; endpoint authz (admin 200 / non-admin 403 /
anon 401) + billing absent from /api/status. Suite 301/301. First-full-month caveat +
formula in docs/billing.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
