feat: add initial backend and frontend structure with models, DTOs, and WebSocket events

apps/backend/prisma/models/character.prisma

@@ -0,0 +1,56 @@
+// Character model and character knowledge
+
+enum ImportSourceType {
+  file
+  url
+  manual
+}
+
+enum ImportStatus {
+  pending
+  processing
+  completed
+  failed
+}
+
+model Character {
+  id                  String   @id @default(uuid())
+  name                String
+  avatarUrl           String?
+  personalityPrompt   String
+  attributes          Json     @default("{}")
+  config              Json     @default("{}")
+  isPublic            Boolean  @default(false)
+  createdAt           DateTime @default(now())
+  updatedAt           DateTime @updatedAt
+
+  userId              String
+  user                User                @relation(fields: [userId], references: [id], onDelete: Cascade)
+  conversations       Conversation[]
+  knowledgeSources    CharacterKnowledge[]
+  vectorMemories      VectorMemory[]
+
+  @@index([userId])
+  @@index([name])
+}
+
+model CharacterKnowledge {
+  id              String           @id @default(uuid())
+  name            String
+  sourceType      ImportSourceType
+  sourceName      String
+  mimeType        String?
+  fileSize        BigInt?
+  rawContent      String?
+  status          ImportStatus     @default(pending)
+  processingInfo  Json?
+  createdAt       DateTime         @default(now())
+  updatedAt       DateTime         @updatedAt
+
+  characterId     String
+  character       Character        @relation(fields: [characterId], references: [id], onDelete: Cascade)
+  vectorMemories  VectorMemory[]
+
+  @@index([characterId])
+  @@index([status])
+}

apps/backend/prisma/models/conversation.prisma

@@ -0,0 +1,38 @@
+// Conversation and participant models
+
+model Conversation {
+  id             String    @id @default(uuid())
+  title          String?
+  messageCount   Int       @default(0)
+  totalTokens    Int       @default(0)
+  settings       Json      @default("{}")
+  createdAt      DateTime  @default(now())
+  updatedAt      DateTime  @updatedAt
+
+  userId         String
+  user           User                 @relation(fields: [userId], references: [id], onDelete: Cascade)
+  characterId    String
+  character      Character            @relation(fields: [characterId], references: [id], onDelete: Cascade)
+  messages       Message[]
+  vectorMemories VectorMemory[]
+  storyBranches  StoryBranch[]
+  participants   ConversationParticipant[]
+
+  @@index([userId])
+  @@index([characterId])
+  @@index([createdAt])
+}
+
+model ConversationParticipant {
+  id              String    @id @default(uuid())
+  isActive        Boolean   @default(true)
+  autoRespond     Boolean   @default(true)
+  createdAt       DateTime  @default(now())
+
+  conversationId  String
+  conversation    Conversation @relation(fields: [conversationId], references: [id], onDelete: Cascade)
+  characterId     String
+
+  @@unique([conversationId, characterId])
+  @@index([conversationId])
+}

apps/backend/prisma/models/importDocument.prisma

@@ -0,0 +1,21 @@
+// General import documents (not linked to characters)
+
+model ImportDocument {
+  id              String           @id @default(uuid())
+  sourceType      ImportSourceType
+  sourceName      String
+  mimeType        String?
+  fileSize        BigInt?
+  content         String?
+  status          ImportStatus     @default(pending)
+  errorMessage    String?
+  metadata        Json?
+  createdAt       DateTime         @default(now())
+  updatedAt       DateTime         @updatedAt
+
+  userId          String
+  user            User             @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@index([userId])
+  @@index([status])
+}

apps/backend/prisma/models/message.prisma

@@ -0,0 +1,24 @@
+// Message model
+
+enum MessageRole {
+  user
+  assistant
+  system
+}
+
+model Message {
+  id              String      @id @default(uuid())
+  role            MessageRole
+  content         String
+  tokensUsed      Int?
+  model           String?
+  metadata        Json?
+  createdAt       DateTime    @default(now())
+
+  conversationId  String
+  conversation    Conversation @relation(fields: [conversationId], references: [id], onDelete: Cascade)
+
+  @@index([conversationId])
+  @@index([createdAt])
+  @@index([conversationId, createdAt])
+}

apps/backend/prisma/models/storyBranch.prisma

@@ -0,0 +1,21 @@
+// Story branching for narrative generation (Phase 2)
+
+model StoryBranch {
+  id              String    @id @default(uuid())
+  title           String?
+  content         String
+  userDirection   String
+  generationParams Json?
+  depth           Int       @default(0)
+  branchOrder     Int       @default(0)
+  createdAt       DateTime  @default(now())
+
+  conversationId  String
+  conversation    Conversation  @relation(fields: [conversationId], references: [id], onDelete: Cascade)
+  parentId        String?
+  parent          StoryBranch?  @relation("BranchTree", fields: [parentId], references: [id], onDelete: Cascade)
+  children        StoryBranch[] @relation("BranchTree")
+
+  @@index([conversationId])
+  @@index([parentId])
+}

apps/backend/prisma/models/user.prisma

@@ -0,0 +1,25 @@
+// User model and related enums
+
+enum UserRole {
+  USER
+  ADMIN
+}
+
+model User {
+  id            String    @id @default(uuid())
+  email         String    @unique
+  username      String    @unique
+  passwordHash  String?
+  keycloakSub   String?   @unique
+  role          UserRole  @default(USER)
+  isActive      Boolean   @default(true)
+  createdAt     DateTime  @default(now())
+  updatedAt     DateTime  @updatedAt
+
+  characters    Character[]
+  conversations Conversation[]
+  importDocs    ImportDocument[]
+
+  @@index([email])
+  @@index([keycloakSub])
+}

apps/backend/prisma/models/vectorMemory.prisma

@@ -0,0 +1,29 @@
+// Vector memory for embeddings (conversation and character knowledge)
+
+enum MemoryType {
+  conversation
+  character
+}
+
+model VectorMemory {
+  id              String    @id @default(uuid())
+  content         String
+  embedding       Unsupported("vector")?
+  memoryType      MemoryType @default(conversation)
+  metadata        Json?
+  createdAt       DateTime  @default(now())
+
+  conversationId  String?
+  conversation    Conversation? @relation(fields: [conversationId], references: [id], onDelete: Cascade)
+  
+  characterId     String?
+  character       Character?    @relation(fields: [characterId], references: [id], onDelete: Cascade)
+  
+  knowledgeId     String?
+  knowledge       CharacterKnowledge? @relation(fields: [knowledgeId], references: [id], onDelete: Cascade)
+
+  @@index([conversationId])
+  @@index([characterId])
+  @@index([knowledgeId])
+  @@index([memoryType])
+}

apps/backend/src/app.module.ts

@@ -0,0 +1,8 @@
+import { Module } from '@nestjs/common';
+
+@Module({
+  imports: [],
+  controllers: [],
+  providers: [],
+})
+export class AppModule {}

apps/backend/src/main.ts

@@ -0,0 +1,20 @@
+import { NestFactory } from '@nestjs/core';
+import { AppModule } from './app.module';
+
+async function bootstrap() {
+  const app = await NestFactory.create(AppModule);
+  
+  app.enableCors({
+    origin: ['http://localhost:5173'],
+    credentials: true,
+  });
+  
+  app.setGlobalPrefix('api');
+  
+  const port = process.env.PORT || 3000;
+  await app.listen(port);
+  
+  console.log(`🚀 Backend running on: http://localhost:${port}/api`);
+}
+
+bootstrap();

apps/frontend/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>DreamChat</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>

apps/frontend/postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+};

apps/frontend/src/App.tsx

@@ -0,0 +1,14 @@
+function App() {
+  return (
+    <div className="min-h-screen bg-background flex items-center justify-center">
+      <div className="text-center">
+        <h1 className="text-4xl font-bold text-primary mb-4">DreamChat</h1>
+        <p className="text-muted-foreground">
+          Character simulation and interactive storytelling platform
+        </p>
+      </div>
+    </div>
+  );
+}
+
+export default App;

apps/frontend/src/main.tsx

@@ -0,0 +1,10 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import App from './App';
+import './styles/globals.css';
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+);

apps/frontend/src/styles/globals.css

@@ -0,0 +1,59 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+@layer base {
+  :root {
+    --background: 0 0% 100%;
+    --foreground: 222.2 84% 4.9%;
+    --card: 0 0% 100%;
+    --card-foreground: 222.2 84% 4.9%;
+    --popover: 0 0% 100%;
+    --popover-foreground: 222.2 84% 4.9%;
+    --primary: 222.2 47.4% 11.2%;
+    --primary-foreground: 210 40% 98%;
+    --secondary: 210 40% 96.1%;
+    --secondary-foreground: 222.2 47.4% 11.2%;
+    --muted: 210 40% 96.1%;
+    --muted-foreground: 215.4 16.3% 46.9%;
+    --accent: 210 40% 96.1%;
+    --accent-foreground: 222.2 47.4% 11.2%;
+    --destructive: 0 84.2% 60.2%;
+    --destructive-foreground: 210 40% 98%;
+    --border: 214.3 31.8% 91.4%;
+    --input: 214.3 31.8% 91.4%;
+    --ring: 222.2 84% 4.9%;
+    --radius: 0.5rem;
+  }
+
+  .dark {
+    --background: 222.2 84% 4.9%;
+    --foreground: 210 40% 98%;
+    --card: 222.2 84% 4.9%;
+    --card-foreground: 210 40% 98%;
+    --popover: 222.2 84% 4.9%;
+    --popover-foreground: 210 40% 98%;
+    --primary: 210 40% 98%;
+    --primary-foreground: 222.2 47.4% 11.2%;
+    --secondary: 217.2 32.6% 17.5%;
+    --secondary-foreground: 210 40% 98%;
+    --muted: 217.2 32.6% 17.5%;
+    --muted-foreground: 215 20.2% 65.1%;
+    --accent: 217.2 32.6% 17.5%;
+    --accent-foreground: 210 40% 98%;
+    --destructive: 0 62.8% 30.6%;
+    --destructive-foreground: 210 40% 98%;
+    --border: 217.2 32.6% 17.5%;
+    --input: 217.2 32.6% 17.5%;
+    --ring: 212.7 26.8% 83.9%;
+  }
+}
+
+@layer base {
+  * {
+    @apply border-border;
+  }
+  body {
+    @apply bg-background text-foreground;
+  }
+}

apps/frontend/tailwind.config.ts

@@ -0,0 +1,38 @@
+import type { Config } from 'tailwindcss';
+
+export default {
+  darkMode: ['class'],
+  content: ['./src/**/*.{js,ts,jsx,tsx}'],
+  theme: {
+    extend: {
+      colors: {
+        border: 'hsl(var(--border))',
+        input: 'hsl(var(--input))',
+        ring: 'hsl(var(--ring))',
+        background: 'hsl(var(--background))',
+        foreground: 'hsl(var(--foreground))',
+        primary: {
+          DEFAULT: 'hsl(var(--primary))',
+          foreground: 'hsl(var(--primary-foreground))',
+        },
+        secondary: {
+          DEFAULT: 'hsl(var(--secondary))',
+          foreground: 'hsl(var(--secondary-foreground))',
+        },
+        destructive: {
+          DEFAULT: 'hsl(var(--destructive))',
+          foreground: 'hsl(var(--destructive-foreground))',
+        },
+        muted: {
+          DEFAULT: 'hsl(var(--muted))',
+          foreground: 'hsl(var(--muted-foreground))',
+        },
+        accent: {
+          DEFAULT: 'hsl(var(--accent))',
+          foreground: 'hsl(var(--accent-foreground))',
+        },
+      },
+    },
+  },
+  plugins: [],
+} satisfies Config;

packages/shared/src/api/dto.ts

@@ -0,0 +1,86 @@
+/**
+ * Shared API DTOs
+ * Used by backend for validation and frontend for type safety
+ */
+
+// Character DTOs
+export interface CreateCharacterDto {
+  name: string;
+  personalityPrompt: string;
+  backstory?: string;
+  attributes?: Record<string, unknown>;
+  avatarUrl?: string;
+  config?: Record<string, unknown>;
+}
+
+export interface UpdateCharacterDto extends Partial<CreateCharacterDto> {}
+
+export interface CharacterResponseDto {
+  id: string;
+  name: string;
+  avatarUrl?: string;
+  personalityPrompt: string;
+  backstory?: string;
+  attributes: Record<string, unknown>;
+  config: Record<string, unknown>;
+  isPublic: boolean;
+  createdAt: string;
+  updatedAt: string;
+}
+
+// Conversation DTOs
+export interface CreateConversationDto {
+  characterId: string;
+  title?: string;
+}
+
+export interface ConversationResponseDto {
+  id: string;
+  title?: string;
+  characterId: string;
+  messageCount: number;
+  totalTokens: number;
+  createdAt: string;
+  updatedAt: string;
+}
+
+// Message DTOs
+export interface CreateMessageDto {
+  content: string;
+}
+
+export interface MessageResponseDto {
+  id: string;
+  role: 'user' | 'assistant' | 'system';
+  content: string;
+  tokensUsed?: number;
+  model?: string;
+  metadata?: Record<string, unknown>;
+  createdAt: string;
+}
+
+// Auth DTOs
+export interface LoginDto {
+  username: string;
+  password: string;
+}
+
+export interface RegisterDto {
+  email: string;
+  username: string;
+  password: string;
+}
+
+export interface AuthResponseDto {
+  accessToken: string;
+  refreshToken: string;
+  expiresIn: number;
+  user: UserResponseDto;
+}
+
+export interface UserResponseDto {
+  id: string;
+  email: string;
+  username: string;
+  role: 'USER' | 'ADMIN';
+}

packages/shared/src/api/index.ts

@@ -0,0 +1 @@
+export * from './dto.js';

packages/shared/src/index.ts

@@ -0,0 +1,2 @@
+export * from './websocket/index.js';
+export * from './api/index.js';

packages/shared/src/websocket/events.ts

@@ -0,0 +1,84 @@
+/**
+ * WebSocket Event Types
+ * Shared between frontend and backend for type-safe communication
+ */
+
+export enum WebSocketEventType {
+  // Client -> Server
+  JOIN_CONVERSATION = 'JOIN_CONVERSATION',
+  LEAVE_CONVERSATION = 'LEAVE_CONVERSATION',
+  SEND_MESSAGE = 'SEND_MESSAGE',
+  STOP_GENERATION = 'STOP_GENERATION',
+
+  // Server -> Client
+  CONVERSATION_JOINED = 'CONVERSATION_JOINED',
+  MESSAGE_ACK = 'MESSAGE_ACK',
+  STREAM_CHUNK = 'STREAM_CHUNK',
+  STREAM_COMPLETE = 'STREAM_COMPLETE',
+  ERROR = 'ERROR',
+}
+
+// Base message interface
+export interface WebSocketMessage<T = unknown> {
+  type: WebSocketEventType;
+  payload: T;
+  timestamp: string;
+  requestId?: string;
+}
+
+// Client -> Server payloads
+export interface JoinConversationPayload {
+  conversationId: string;
+}
+
+export interface LeaveConversationPayload {
+  conversationId: string;
+}
+
+export interface SendMessagePayload {
+  conversationId: string;
+  content: string;
+  streaming?: boolean;
+}
+
+export interface StopGenerationPayload {
+  conversationId: string;
+}
+
+// Server -> Client payloads
+export interface ConversationJoinedPayload {
+  conversationId: string;
+  history: MessageHistoryItem[];
+}
+
+export interface MessageHistoryItem {
+  id: string;
+  role: 'user' | 'assistant' | 'system';
+  content: string;
+  createdAt: string;
+}
+
+export interface MessageAckPayload {
+  messageId: string;
+  status: 'received' | 'processing' | 'error';
+}
+
+export interface StreamChunkPayload {
+  conversationId: string;
+  chunk: string;
+  isComplete: boolean;
+}
+
+export interface StreamCompletePayload {
+  conversationId: string;
+  messageId: string;
+  content: string;
+  tokensUsed?: number;
+  model?: string;
+}
+
+export interface ErrorPayload {
+  code: string;
+  message: string;
+  details?: Record<string, unknown>;
+}

packages/shared/src/websocket/index.ts

@@ -0,0 +1 @@
+export * from './events.js';