# Template: invoice (persistent Next.js + Mongo invoice tracker)

A real, deployable invoice tracker. Invoices live in the grid-shared MongoDB, so they
survive refresh and are shared across sessions. Same proven shape as
`app-with-data`, adapted to an `invoices` domain (number, client, amount, status, due) with a table view and per-row status changes (mark sent / paid).

**Key rules (all proven by the app-with-data end-to-end deploy):**

1. **Service code MUST live under `services/<name>/`, not the repo/template
   root.** `path:` in `cloudgrid.yaml` is the URL mount, NOT the filesystem path.
   The service named `web` → the CLI looks for `services/web/`. App files at the
   root fail with `Error: Service directory not found: …/services/web`.
2. **Read the DB connection string LAZILY (inside the getter), never at module
   top level.** The grid injects it as `DATABASE_MONGODB_URL` (plus the legacy
   `MONGODB_URL` alias) at dev-time and runtime; the app reads
   `process.env.DATABASE_MONGODB_URL || process.env.MONGODB_URL` inside `getDb`.
   A top-level read fails `next build`. Never hardcode a connection string; never
   commit a secret.
3. **Declare the datastore with `needs: { database: true }`.** The deployer
   provisions Mongo and injects the connection string. `requires:` is the
   deprecated v1 alias; don't author new yaml with it, and never set `needs:` and
   `requires:` together (the validator rejects the combination).

## File tree

```
cloudgrid.yaml                             # full-annotated reference; active: name + services.web (nextjs) + needs: { database: true }
services/web/package.json                  # next, react, react-dom, mongodb driver only
services/web/lib/db.js                     # lazy Mongo client from DATABASE_MONGODB_URL (legacy MONGODB_URL fallback)
services/web/app/layout.js                 # root layout + inline CSS
services/web/app/page.js                   # server component: reads invoices from Mongo
services/web/app/invoice-manager.js        # client table: POST / PATCH (status) / DELETE via the API
services/web/app/api/invoices/route.js              # GET (list) / POST (add) / PATCH (status) / DELETE (remove)
```

## cloudgrid.yaml

```yaml
# On disk this file is the full-annotated reference (templates/_cloudgrid.yaml.reference) with EVERY
# field present as a comment; only the fields below are uncommented, so it
# deploys to exactly these active fields.
name: my-invoices
services:
  web:
    type: nextjs
    path: /
needs:
  database: true
```

> **Capability:** this template's need is `database: true`. The deployer
> provisions Mongo and injects `DATABASE_MONGODB_URL` (plus the legacy
> `MONGODB_URL` alias). `requires:` is the deprecated v1 alias — don't mix it with
> `needs:` (the validator rejects the combination). See the capability-map for
> the full injection table.

## The invoices collection

Documents: `{ number, client, amount, status, due, createdAt }` where `status` is one of `draft` / `sent` / `paid`. The API route on `invoices` does GET (list), POST (add), PATCH (change status — e.g. mark paid), DELETE (remove); the page is a
server component that reads the collection and hands it to a client component.

## Adapt it

- Rename the `invoices` collection to your data (`estimates`, `bills`).
- Change the document fields; add amounts, currencies, line items, timestamps.
- Add more routes/collections as the app grows.
- Add `cache: true` to `needs:` only if you actually need Redis.
- Run `grid dev` to test locally, `grid plug` to deploy (async — poll to live).