# AGENTS.md

This document defines the laws, principles, and rule sets that govern this codebase. Any agent or developer making changes has to adhere to these rules.

**Before starting off** — Read the README.md file to understand the project's goals and objectives.

---

## Agent Rules (Override Everything)

1. **No testing by yourself** — All testing is done by the team.
2. **No assumptions about code or domain logic** — Always confirm and be sure before making changes.
3. **No running scripts** — Do not run build, dev, test, or migrate scripts unless explicitly approved.

More rules are only to be added by the human, in case such a suggestion becomes viable.

---

## 1. Project Overview

- **Monorepo**: Turbo repo
- **Package Manager**: pnpm
- **Language**: TypeScript everywhere
- **Node**: >= 24

> **Note**: The monorepo architecture is currently in flux. Some patterns are being refined; follow existing conventions and confirm before introducing new ones.

### Applications

| App              | Purpose                                                                             |
| ---------------- | ----------------------------------------------------------------------------------- |
| `apps/main`      | SvelteKit UI — the primary user-facing application                                  |
| `apps/processor` | Hono web server — intended for asynchronous processing (jobs, workers). Currently minimal; structure is evolving. |

### Packages

Packages live under `packages/` and are **standalone, modular** pieces consumed by apps:

| Package       | Purpose                                      |
| ------------- | -------------------------------------------- |
| `@pkg/logic`  | Domain logic (DDD, controllers, repositories) |
| `@pkg/db`     | Drizzle schema, database access              |
| `@pkg/logger` | Logging, `getError` for error construction   |
| `@pkg/result` | Result type, `ERROR_CODES`, `tryCatch`        |
| `@pkg/keystore` | Redis instance (sessions, 2FA, etc.)       |
| `@pkg/settings` | App settings / env config                   |

### Data Stores

- **PostgreSQL (Drizzle)** — Primary relational data (auth, users, accounts, etc.)
- **Redis (Valkey)** — Sessions, 2FA verification state (via `@pkg/keystore`)

Additional stores (NoSQL DBs, R2, etc.) may be introduced later. Follow existing domain patterns when adding new data access.

---

## 2. The Logic Package: DDD + Layered Architecture

The `@pkg/logic` package contains **all domain logic**. It follows:

1. **Domain-Driven Design (DDD)** — Bounded contexts as domains
2. **Layered architecture** — Clear separation of concerns
3. **Result-style error handling** — Errors as values; avoid try-catch in domain code

### Domain Structure

Each domain is a folder under `packages/logic/domains/`:

```
domains/
  <domain-name>/
    data.ts        # Types, schemas (Valibot)
    repository.ts  # Data access
    controller.ts  # Use cases / application logic
    router.ts      # HTTP routes (when exposed via API)
    errors.ts      # Domain-specific error constructors (using getError)
```

Not every domain has a router (e.g. auth uses `config.base.ts` with better-auth). Add new domains as needed; mirror existing patterns.

### Path Aliases (logic package)

- `@/*` → `./*`
- `@domains/*` → `./domains/*`
- `@core/*` → `./core/*`

### Flow Execution Context

Domain operations receive a `FlowExecCtx` (`fctx`) for tracing and audit:

```ts
type FlowExecCtx = {
  flowId: string;
  userId?: string;
  sessionId?: string;
};
```

---

## 3. Error Handling: Result Pattern (neverthrow)

Errors are **values**, not exceptions. The codebase uses Result-style handling.

### Current Conventions

1. **Logic package** — Uses `neverthrow` (`ResultAsync`, `okAsync`, `errAsync`) for async operations that may fail.
2. **`@pkg/result`** — Provides `Result<T, Err>`, `ERROR_CODES`, and `tryCatch()`. The `Result` type is legacy; as the project is moving toward neverthrow. Use `ERROR_CODES` for consistent error codes.
3. **`getError()`** — From `@pkg/logger`. Use at boundaries when converting a thrown error to an `Err` object:  
   `return getError({ code: ERROR_CODES.XXX, message: "...", description: "...", detail: "..." }, e)`.
4. **Domain errors** — Each domain has an `errors.ts` that exports error constructors built with `getError`. Use these instead of ad-hoc error objects.
5. **Check before use** — Always check `result.isOk()` / `result.isErr()` before using `result.value`; never assume success.

### Err Shape

```ts
type Err = {
  flowId?: string;
  code: string;
  message: string;
  description: string;
  detail: string;
  actionable?: boolean;
  error?: any;
};
```

---

## 4. Frontend (Main App)

The main app is a **SvelteKit** application with a domain-driven UI structure.

### Structure

- **Routes**: File-based routing under `src/routes/`. Layout groups (e.g. `(main)`, `auth`) wrap related pages.
- **Domain-driven UI**: Feature code lives under `src/lib/domains/<domain>/` — each domain has its own folder with view models and components.
- **View Model (VM) pattern**: Domain logic and state for a screen live in `*.vm.svelte.ts` classes. VMs hold reactive state (`$state`), orchestrate API calls, and expose methods. Pages import and use a VM instance.
- **API layer**: A typed Hono client (`hc`) is used against a Router composed from logic package routers. The API is defined in `$lib/api.ts` and proxied through SvelteKit route handlers at `/api/v1/[...paths]`. Auth/session context is injected at the proxy layer.

### Context Injection

Logic routers receive `user`, `session`, and `fCtx` via `c.env.locals`. The shape is defined in `HonoContext` (`@core/hono.helpers`). The API proxy builds this context from the session before forwarding requests.

### Global Stores

Shared state (e.g. `apiClient`, `user`, `session`, `breadcrumbs`) lives in `$lib/global.stores.ts`.

### Conventions

- Pages are thin: they mount a VM, render components, and wire up lifecycle.
- VMs own async flows, polling, and error handling for their domain.
- UI components under `$lib/components/` are shared; domain-specific components live in `$lib/domains/<domain>/`.

---

## 5. Processor App

The processor is a **Hono** server intended for **background workers** and async jobs. Its structure is still evolving.

### Current State

- Minimal Hono server; no BullMQ or job processors yet.
- When workers are added, processing logic should live under `src/domains/<domain>/` and call into `@pkg/logic` controllers and repositories.
- HTTP routes will expose internal APIs (e.g. task status, webhooks), secured (e.g. API key), for use by the main app or external services.
- Async work should be triggered by calling the processor HTTP API, not by importing job queues in the main app or logic package.

### Conventions (when implemented)

- The worker processes jobs; do not block it with long-running HTTP logic.
- Job payloads should be validated before processing.
- Follow existing domain patterns for controllers and repositories.

---

## 6. Validation & Schemas

- **Valibot** is used for schema validation in the logic package.
- Domain data types are defined in `data.ts` per domain.
- Use `v.InferOutput<typeof Schema>` for TypeScript types.
- Routers use `sValidator` from `@hono/standard-validator` with Valibot schemas for request validation.

---

## 7. Package Naming

- Apps: `@apps/*` (e.g. `@apps/main`, `@apps/processor`)
- Packages: `@pkg/*` (e.g. `@pkg/logic`, `@pkg/db`, `@pkg/logger`)