# OpenSpec Change: enterprise-api-plugin-subscription

- **Change ID**: enterprise-api-plugin-subscription
- **Package**: `@suaveplan/api-plugin-subscription`
- **Category**: api/commerce
- **Target path**: `api/commerce/api-plugin-subscription`
- **Status**: PROPOSED
- **Date**: 2026-04-24
- **Reference spec**: `/mnt/s/web/suaveplan/enterprise/api-plugin-subscription.md`

---

## Summary

Deliver `@suaveplan/api-plugin-subscription` on the genesis branch from scratch at enterprise quality. Recurring billing plugin: plan management (monthly/annual/custom intervals), subscription lifecycle (create/upgrade/downgrade/cancel/reactivate), proration calculations, invoice generation, trial periods, dunning (failed payment retry with configurable schedule), and usage-based metering hooks. Bridges to `@suaveplan/api-plugin-payment` for charge execution. Routes under `/subscriptions`. Per-table SurrealQL. Typed events: `subscription:created`, `subscription:renewed`, `subscription:cancelled`, `subscription:payment:failed`.

---

## Available workspace deps on genesis

| Package | Role |
|---|---|
| `@suaveplan/api` (`workspace:^`) | `definePlugin` |
| `@suaveplan/api-shared` (`workspace:^`) | Helpers |
| `@suaveplan/api-plugin-auth` (`workspace:^`) | `requireAuth` |
| `@suaveplan/api-plugin-database` (`workspace:^`) | SurrealDB |
| `@suaveplan/api-plugin-payment` (`workspace:^`) | Charge execution |
| `@suaveplan/events` (`workspace:^`) | Event bus |
| `@suaveplan/retry` (`workspace:^`) | Dunning retry strategy |
| `@suaveplan/error` (`workspace:^`) | `SubscriptionError` hierarchy |
| `@suaveplan/idempotency` (`workspace:^`) | Mutation guard |
| `@suaveplan/audit-logging` (`workspace:^`) | Billing audit |
| `@suaveplan/rate-limiter` (`workspace:^`) | Rate limits |
| `hono` + `@hono/zod-openapi` + `zod` | Routes |
| `@opentelemetry/api` | OTel |

---

## Public API surface

```ts
function createSubscriptionPlugin(config?: SubscriptionPluginConfig): PluginDescriptor

// Services: PlanService, SubscriptionService, InvoiceService, DunningService, MeteringService
// Routes: /subscriptions/plans, /subscriptions, /subscriptions/:id,
//         /subscriptions/:id/cancel, /subscriptions/:id/reactivate,
//         /subscriptions/:id/usage, /subscriptions/:id/invoices
```

### Error codes

```ts
type SubscriptionErrorCode =
  | "SUBSCRIPTION_PLAN_NOT_FOUND"
  | "SUBSCRIPTION_NOT_FOUND"
  | "SUBSCRIPTION_ALREADY_CANCELLED"
  | "SUBSCRIPTION_IN_TRIAL"
  | "SUBSCRIPTION_PAYMENT_FAILED"
  | "SUBSCRIPTION_DOWNGRADE_RESTRICTED"
```

---

## File layout

```text
api/commerce/api-plugin-subscription/
  package.json  tsconfig.json  vitest.config.ts
  surql/ (plan, subscription, invoice, invoice_line, metering_record, dunning_attempt tables)
  src/
    index.ts  events.ts  types/  errors/  schemas/
    services/plan/  services/subscription/  services/invoice/
    services/dunning/  services/metering/
    routes/plans/  routes/subscriptions/
  tests/integration.test.ts
```

---

## Impact

Prerequisites: `@suaveplan/api`, `@suaveplan/api-plugin-auth`, `@suaveplan/api-plugin-database`, `@suaveplan/api-plugin-payment`, `@suaveplan/retry`.