When a task requires factual information (API specifications, context window sizes, library versions, pricing, rate limits, etc.), **look it up** using web search. Do not rely on educated guesses or assumptions from training data. If you're unsure whether something is a guess, look it up anyway.
- If `apps/dashboard/src/lib/utils/translations/en.json` changes, update the other dashboard locale files before staging or committing.
- To translate dashboard locale changes, run `cd apps/dashboard && pnpm translate`.
- After running translation, review the generated locale changes and make sure placeholders wrapped in `{}` were preserved exactly. Fix any translated variable names before continuing.
- Format changed files with the repo's changed-file formatter before staging. Prefer `pnpm format:changed` from the repository root. Use broader format commands only if the changed-file formatter is not sufficient for the task.
- If you changed files under `packages/ui/src/**`, make sure the required `ui:` Tailwind prefix rules still pass. Run `pnpm --filter @cio/ui prefix` if needed before the final formatting pass.
- Stage files only after translation and formatting are complete. Prefer explicit staging such as `git add path/to/file` or `git add <changed-files>` over broad staging commands.
- Before creating a commit, manually run the current `lefthook` checks that would run on `pre-commit`:
-`pnpm format:check`
-`pnpm --filter @cio/ui prefix:check:staged` if staged changes include `packages/ui/src/**/*.{svelte,ts,tsx,js,jsx}`
- Commit messages must follow the Conventional Commits 1.0.0 spec: https://www.conventionalcommits.org/en/v1.0.0/
- Never include agent-provider attribution in commits or commit trailers. Do not add `Co-authored-by` lines for Cursor, Claude, Codex, or any other tool.
- **Variables must read clearly at the call site.** Avoid opaque single-letter or ultra-short names (`d`, `x`, `tmp`) unless they match a universal convention (e.g. `i` in a trivial index loop). Prefer names that state intent (`deadlineDate`, `parsedUrl`, `nextSection`).
- **After an early `return` (or other guard exit), leave a blank line** before the next statement so the “happy path” block is visually separated from guards.
- **Never put an `await` or a complex/multi-call expression inside an object literal** (construction or update). Assign each value to a well-named local first, then reference it in the object. This keeps the call site readable and debuggable.
Put all direct database access in pure query functions under `packages/db/src/queries/{domain}/`. Routes and services never call Drizzle/`db` (or equivalent) directly—they import and compose these helpers.
```typescript
// packages/db/src/queries/auth/profile.ts
export async function updateProfile(userId: string, data: Partial<TProfile>) {
// …db update returning the row or null if missing
}
```
### Step 3: Service
Services orchestrate one or more query functions (often inside a transaction), apply business rules, and raise `AppError` when something is invalid or missing. **Do not put SQL or other direct DB access in services**—only call query-layer functions and handle in-memory shaping or validation there.
Routes must return a single type (or a response shape whose `data` is a single type). If multiple shapes are needed, use separate endpoints or a keyed structure (e.g. `data` indexed by a key) so clients get one type per endpoint or key. Do not return a union of shapes from one route based on query parameters.
```typescript
// apps/api/src/routes/account/account.ts
export const accountRouter = new Hono().put(
'/user',
authMiddleware,
zValidator('json', ZUpdateProfile),
async (c) => {
try {
const user = c.get('user')!;
const data = c.req.valid('json');
const result = await updateUser(user.id, data);
return c.json({ success: true, data: result });
} catch (error) {
return handleError(c, error, 'Failed to update profile');
**Route mounts in `app.ts` must use a single root segment.** Do not mount nested paths like `.route('/internal/compliance', ...)` directly in `app.ts`. If a domain has sub-routers, compose them inside the domain's `routes/{domain}/index.ts` and expose a single aggregate router that `app.ts` mounts at `/${domain}`.
```typescript
// apps/api/src/routes/internal/index.ts
import { Hono } from '@api/utils/hono';
import { internalAnalyticsRouter } from './analytics';
import { internalComplianceRouter } from './compliance';
export const internalRouter = new Hono()
.route('/compliance', internalComplianceRouter)
.route('/analytics', internalAnalyticsRouter);
// apps/api/src/app.ts
import { internalRouter } from '@api/routes/internal';
export const app = new Hono().route('/internal', internalRouter);
```
**Route mounts in `app.ts` must use a single root segment.** Do not mount nested paths like `.route('/internal/compliance', ...)` directly in `app.ts`. If a domain has sub-routers, compose them inside the domain's `routes/{domain}/index.ts` and expose a single aggregate router that `app.ts` mounts at `/${domain}`.
```typescript
// apps/api/src/routes/internal/index.ts
import { Hono } from '@api/utils/hono';
import { internalAnalyticsRouter } from './analytics';
import { internalComplianceRouter } from './compliance';
export const internalRouter = new Hono()
.route('/compliance', internalComplianceRouter)
.route('/analytics', internalAnalyticsRouter);
// apps/api/src/app.ts
import { internalRouter } from '@api/routes/internal';
export const app = new Hono().route('/internal', internalRouter);
if ('field' in result) this.errors[result.field] = result.error;
}
});
}
}
```
## Frontend Conventions
### Request Types and Where Types Live
Define all request and response-related types in the feature’s `utils/types.ts` file. **Do not define types or interfaces in `.svelte.ts` files** (e.g. `api/*.svelte.ts` or `store/*.svelte.ts`). Infer types from the API: request type from the RPC call, then success/data from the response type.
For response shapes that need a small normalization (e.g. API returns `JSONValue`, app needs `Record<string, number>`), derive a normalized type in `types.ts` from the success `data` type (e.g. `Omit<Data, 'roleMapping'> & { roleMapping: Record<string, number> }`).
**Do not export custom types from `apps/api/src/rpc-types.ts`.** Only re-export Hono client types (e.g. `InferRequestType`, `InferResponseType`) and the typed client (`Client`, `hcWithType`). All feature-specific types belong in the dashboard's feature `utils/types.ts`, inferred from the API.
### API Class Pattern
API classes handle all logic; components should be thin.
### Translations (UI copy)
- No hardcoded user-facing text in components.
- Strings live in `apps/dashboard/src/lib/utils/translations/en.json`.
- Use `$t('key.path')` in markup and `t('key.path')` in script.
Example:
```svelte
<script lang="ts">
import { t } from '$lib/utils/functions/translations';
- Use translation keys directly (e.g. `snackbar.success('snackbar.profile.updated')`).
- Only use `t(...)` when combining keys or building dynamic strings.
Outside Svelte components:
- Use `t.get('key.path')` inside plain functions or utilities.
### Utility Functions Pattern
- Extract reusable transformations to `apps/dashboard/src/lib/features/{domain}/utils/{feature}-utils.ts`.
- Keep functions pure and accept all required data as parameters.
### Svelte store binding
You can bind form controls directly to a writable store’s properties. Svelte compiles `bind:value={$store.someProp}` so that reads come from the store and writes go back through the store (via `set`/`update`). Prefer this over duplicating state in the component and syncing with `$effect` (which can cause infinite loops or redundant updates).
Use `@cio/ui/custom/*-field` wrappers for standard app forms. When building larger settings/editor screens that need legends, descriptions, separators, grouped rows, or mixed controls such as `Switch`, `Checkbox`, `RadioGroup`, image pickers, and action buttons, compose the form with `@cio/ui/base/field` primitives and the matching base inputs instead.
In Svelte 5, the built-in `Set` and `Map` classes are **not** reactive. Use `SvelteSet` and `SvelteMap` from `svelte/reactivity` instead. They are already reactive on their own — do **not** wrap them in `$state()`.
```svelte
<script lang="ts">
import { SvelteSet } from 'svelte/reactivity';
let selectedIds = new SvelteSet<string>();
// Mutations are reactive — no clone-and-reassign needed
### Avoiding Svelte 5 rerender and `$effect` loops
`$effect` re-runs when any reactive value it **reads** changes. Writing state inside an effect can retrigger it and cause infinite loops, redundant work, or flicker. Prefer explicit event handlers and bindings over effect-driven syncing.
**Do not reset UI state in an effect tied to a steady condition** (e.g. “whenever `open` is false”). While the condition stays true, the effect keeps running and rewriting state:
```svelte
// ❌ don't — resets on every run while closed; can loop with bound children
$effect(() => {
if (open) return;
step = STEPS.STEP_1;
fields = { fullname: '', email: '' };
errors = { fullname: '', email: '' };
});
```
**Reset on transitions** — when a dialog closes, a route changes, or the user submits — not on every render where a flag is false:
```svelte
// ✅ do — reset only when the dialog actually closes
**Prefer `bind:` over `$effect` for keeping two sources in sync.** If a control can bind directly to a store or `$state` field, use that instead of reading one value in an effect and writing another (see **Svelte store binding** above).
**When resetting bound form state, mutate properties in place** instead of replacing the whole object. Reassigning `fields = { ... }` breaks `bind:value={fields.fullname}` and can trigger extra updates downstream:
```svelte
// ❌ don't
fields = { fullname: '', email: '' };
// ✅ do
fields.fullname = '';
fields.email = '';
```
**Other common pitfalls:**
- **Effect writes what it reads** — e.g. `$effect(() => { count = count + 1 })` loops forever.
- **Effect mirrors props into local state** — use `$bindable`, `bind:`, or derive a value; only copy props when you need a draft the user can cancel.
- **Effect fetches or navigates on every dependency tick** — gate with a guard, run on submit/route enter, or track “already loaded” so work runs once per intent.
When cleanup or reset must follow a specific lifecycle moment, use the matching hook: `onOpenChange` for dialogs, submit/success handlers for forms, `onMount` / load functions for one-time setup.
- **All Tailwind utility classes in `packages/ui/src/**` must use the `ui:` prefix** (see `packages/ui/README.md`). Pre-commit and CI run `pnpm --filter @cio/ui prefix:check` on touched UI files; fix with `pnpm --filter @cio/ui prefix`.
- Document component usage and props in `packages/ui/README.md`.
- Add example usages and variants in Storybook stories under `packages/storybook/src`.
- See `packages/ui/README.md` and `packages/storybook/README.md` for full guidance.
- For dashboard forms, prefer `@cio/ui/custom/*-field` wrappers (for example `InputField`, `TextareaField`, `CheckboxField`) so label/error/spacing behavior stays consistent.
- Use base primitives (`@cio/ui/base/input`, `@cio/ui/base/textarea`, `@cio/ui/base/checkbox`, `@cio/ui/base/label`) only when creating/updating reusable UI components or when no custom field wrapper exists.
- In app-level form UIs, do not introduce native form controls (`<input>`, `<textarea>`, `<label>`) when equivalent `packages/ui` components exist.
- **Theme color classes:** Classes that use colors from `packages/ui/src/index.css` (e.g. `text-muted-foreground`, `text-primary`) must be prefixed with `ui:` in dashboard code so they resolve against the UI theme (e.g. `ui:text-muted-foreground`, `ui:text-primary`). Only color-related utilities need the prefix; layout/sizing classes like `rounded`, `border`, `p-4` stay unprefixed (Tailwind defaults).
Every transactional email in `packages/email/src/emails` is one of two kinds — decide deliberately, because it changes the branding, the schema, and the `from` address.
- **System emails** — ClassroomIO (the platform) addressing a user/account owner/admin about their *ClassroomIO account*: auth (verify/reset password), billing, **plan limits & usage**, license, workspace. These are **ClassroomIO-branded**:
- No `branding` field in the schema.
- Render with `getDefaultTemplate(content)` (no branding arg) — falls back to the ClassroomIO logo + default button color.
- Send from the default `EMAIL_FROM`; do **not** override `from` with the org name.
- **Org-branded emails** — an *organization* addressing its own members (students/tutors): course invites, welcome/completion, newsfeed, cohort, session reminders. These carry the org's identity:
- Add a `branding: ZEmailBranding` field.
- Render with `getDefaultTemplate(content, fields.branding)`.
- Callers build branding via `buildEmailBranding({ name, avatarUrl, theme })` and send with `from: buildEmailFromName('<Org> (via ClassroomIO.com)')`.
Rule of thumb: if the recipient is being addressed **as a ClassroomIO customer** (account/billing/limits), it's a system email → ClassroomIO branding. If they're addressed **as a member of a specific org**, it's org-branded.
The full setup/run flow lives in `README.md` and `DEV_SETUP_NOTES.md`. The notes below cover only the non-obvious, cloud-VM-specific caveats. The update script already runs `pnpm install` on startup.
### Node version (important)
The sandbox injects `/exec-daemon/node` (Node 22) at the front of `PATH`, so a bare `node`/`pnpm` runs under Node 22 even though the repo requires Node `^20.19.3` (`.nvmrc`). Node 20.19.3 is installed via nvm and set as the nvm default. Before running any `pnpm`/dev command, prepend the repo Node to `PATH`:
`pnpm install` itself succeeds under either version (there is no `engine-strict`), but run the dev servers and DB scripts on Node 20.
### Services & how to run them
Docker is installed and provides Postgres 16 + Redis 7 (the app does not run them natively). After a fresh VM boot the Docker daemon is usually not running — start it (it needs the snapshot's `/etc/docker/daemon.json`, which already sets `fuse-overlayfs` + disables the containerd snapshotter, plus `iptables-legacy`):
```bash
sudo dockerd > /tmp/dockerd.log 2>&1 &
sudo chmod 666 /var/run/docker.sock # or prefix docker commands with sudo
docker compose -f docker/docker-compose.yaml up -d postgres redis
```
The per-app `.env` files (`apps/api/.env`, `apps/dashboard/.env`, `apps/jobs/.env`, `packages/db/.env`) are gitignored but persist in the VM snapshot with a matching `PRIVATE_SERVER_KEY`. If any are missing, recreate them per `README.md` (generate secrets with `openssl rand -hex 32`; the two `PRIVATE_SERVER_KEY` values must match).
The Postgres docker volume persists in the snapshot already seeded with demo data (login `admin@test.com` / `123456`). Re-seed only if needed: `pnpm --filter @cio/db db:setup:seed`.
Run the app (two long-lived processes; use tmux):
- `pnpm api:dev` → API on `http://localhost:3002` + 5 BullMQ workers.
- `pnpm dashboard:dev` → dashboard on `http://localhost:5173` + the `@cio/ui` Tailwind CSS watcher.
Do not use `pnpm dev` (it trips turbo's concurrency cap). Build shared package `dist/` once with `pnpm build` if you see `Failed to resolve entry for package "@cio/*"`.
### Known caveats
- **Vite SSR circular dependency (layerchart):** authenticated/chart pages occasionally render "Something unexpected occurred" on a cold load. Reload the page (or restart `dashboard:dev`) and it renders — it is intermittent, not a setup failure.
- **MinIO is optional and not started by default.** Without it, image/media thumbnails show "Failed to load"; that is expected. Start it with `docker compose -f docker-compose.yaml --profile minio up -d minio minio-init` and add the `OBJECT_STORAGE_*` vars from `README.md` to `apps/api/.env`.
- **Pre-existing lint/test issues (not environment problems):** `pnpm --filter @cio/api lint` fails (missing ESLint v9 `eslint.config.*`); `pnpm --filter @cio/dashboard lint` runs but reports pre-existing errors; api `vitest run` passes 61 tests but 5 files fail to load `@cio/core/services/*/*` subpaths (Vite nested-wildcard exports quirk; Node resolves them fine); `pnpm --filter @cio/dashboard test` (jest) fails to parse `jest.config.ts`. The pre-commit gate `pnpm format:check` passes.
- The optional `@cio/storybook` build fails on an unresolved `@lucide/svelte/icons/bot` import; it does not affect api/dashboard.
### Deployment mode: self-hosted vs cloud (affects which features you can test)
A single flag, `PUBLIC_IS_SELFHOSTED`, switches the whole product between **self-hosted** and **cloud** behavior. It is read in two places: the dashboard via `$env/static/public` (e.g. `apps/dashboard/src/lib/features/app/layout-setup.ts`) and the API/db layer via `@cio/core/config/env` (e.g. `apps/api/src/services/license.ts`, `apps/api/src/middlewares/license.ts`, `apps/api/src/services/onboarding.ts`). `FEATURE_AUDIT.md` §5 is the source-of-truth feature-by-feature map.
**This VM's local env is configured for CLOUD mode** (`PUBLIC_IS_SELFHOSTED=false` in both `apps/dashboard/.env` and `apps/api/.env`) so multi-tenant and all license-gated features are testable. The README contributor default is self-hosted; to switch this VM back, set `PUBLIC_IS_SELFHOSTED=true` in both files (or remove it from `apps/api/.env`) and restart both dev servers.
- **Self-hosted (`PUBLIC_IS_SELFHOSTED=true`)** — the README contributor default:
- Single organization, single domain: creating a 2nd org is blocked (`onboarding.ts`), the "add org" UI is hidden, and the org is auto-assigned a `selfhosted` `ENTERPRISE` plan.
- Enterprise features `sso`, `token-auth`, `no-tracking` are gated behind `LICENSE_KEY`, verified against the external `https://enterprise-api.classroomio.dev`. Without a key, `requireLicense` returns 403.
- Polar billing and PostHog/Umami analytics are off.
- **Cloud (`PUBLIC_IS_SELFHOSTED` unset or `false`)**:
- Multi-tenant: multiple orgs per user, "add org" shown; org is resolved from the **subdomain** (`acme.<PRIVATE_APP_HOST>`) or a custom domain. Locally there are no subdomains, so an org public site is simulated with the `?org=<siteName>` query param (sets the `_orgSiteName` cookie — see `layout-setup.ts`).
- The license gate is a **no-op**, so all enterprise features are unlocked **without** a `LICENSE_KEY` — i.e. cloud mode is the easiest way to exercise SSO/token-auth/multi-org in dev.
- Polar billing and analytics activate but are themselves gated by their own keys (absent keys just no-op), so they don't block startup.
Non-obvious gotcha: the README local-dev setup only sets `PUBLIC_IS_SELFHOSTED=true` in `apps/dashboard/.env`; `apps/api/.env` leaves it unset, so the **API behaves as cloud** (license no-op, 2nd org allowed) while the **dashboard UI is self-hosted**. To exercise a coherent mode, set the flag the same way in both files. The flag is read at process start, so restart the dev servers after editing it.
### Seeded tenants (good for multi-tenant testing)
The seed (`packages/db/src/utils/seed/organizationmember.ts`) creates **three independent organizations**, each with its own admin + student. All accounts use password `123456`:
| Udemy Test (`udemy-test`) | `admin@test.com` | `student@test.com` | Modern Web Development with React; Getting started with MVC; Data Science with Python and Pandas |
In cloud mode you can demonstrate tenant isolation on the single local instance by visiting each org's public catalog via the `?org=<siteName>` param, e.g. `http://localhost:5173/?org=coursera-test` vs `?org=udemy-test` vs `?org=skillshare-test` — each renders its own branded catalog and courses. (Note: a user enrolled in courses across orgs becomes a member of multiple tenants, so after login the dashboard may open whichever org that user most recently used.)