diff --git a/package.json b/package.json
new file mode 100644
index 00000000..65b07521
--- /dev/null
+++ b/package.json
@@ -0,0 +1,24 @@
+{
+  "name": "multi-agent-chat-platform",
+  "version": "0.1.0",
+  "description": "Multi-agent interactive chat platform",
+  "scripts": {
+    "test": "jest",
+    "lint": "eslint . --ext .ts"
+  },
+  "dependencies": {
+    "typescript": "^4.5.4"
+  },
+  "devDependencies": {
+    "@types/jest": "^27.4.0",
+    "jest": "^27.4.7",
+    "ts-jest": "^27.1.2",
+    "eslint": "^8.6.0",
+    "@typescript-eslint/parser": "^5.8.1",
+    "@typescript-eslint/eslint-plugin": "^5.8.1"
+  },
+  "jest": {
+    "preset": "ts-jest",
+    "testEnvironment": "node"
+  }
+}
\ No newline at end of file
diff --git a/src/interfaces/system-interfaces.ts b/src/interfaces/system-interfaces.ts
new file mode 100644
index 00000000..d263e1ff
--- /dev/null
+++ b/src/interfaces/system-interfaces.ts
@@ -0,0 +1,87 @@
+/**
+ * Comprehensive system-wide interfaces for multi-agent chat platform
+ * Defines core interfaces and type contracts for each component
+ */
+
+// Personality Profile Interface
+export interface PersonalityProfile {
+  id: string;
+  name: string;
+  description: string;
+  tone: string;
+  samplePrompts: string[];
+  version: string;
+}
+
+// Chat Message Interface
+export interface ChatMessage {
+  id: string;
+  sessionId: string;
+  agentId: string;
+  content: string;
+  timestamp: number;
+  type: 'user' | 'agent';
+}
+
+// Conversation Session Interface
+export interface ConversationSession {
+  id: string;
+  participants: string[];
+  messages: ChatMessage[];
+  startTime: number;
+  lastActivityTime: number;
+  status: 'active' | 'completed' | 'terminated';
+}
+
+// API Response Interface
+export interface ApiResponse<T> {
+  success: boolean;
+  data?: T;
+  error?: string;
+}
+
+// Engine Adapter Response Interface
+export interface LLMResponse {
+  text: string;
+  confidence: number;
+  tokens: number;
+}
+
+// Agent Deployment Status Interface
+export interface AgentDeploymentStatus {
+  agentId: string;
+  containerStatus: 'running' | 'stopped' | 'error';
+  healthCheck: {
+    cpu: number;
+    memory: number;
+    uptime: number;
+  };
+}
+
+// Validation Utility
+export class InterfaceValidator {
+  static validatePersonalityProfile(profile: PersonalityProfile): boolean {
+    const requiredFields = ['id', 'name', 'description', 'tone'];
+    
+    // Check required fields exist
+    for (const field of requiredFields) {
+      if (!profile[field]) {
+        console.error(`Missing required field: ${field}`);
+        return false;
+      }
+    }
+
+    // Additional validation rules
+    if (profile.name.length < 2 || profile.name.length > 50) {
+      console.error('Invalid name length');
+      return false;
+    }
+
+    if (profile.samplePrompts && profile.samplePrompts.length > 10) {
+      console.error('Too many sample prompts');
+      return false;
+    }
+
+    return true;
+  }
+}
\ No newline at end of file
diff --git a/tests/interface-validation.test.ts b/tests/interface-validation.test.ts
new file mode 100644
index 00000000..019fc635
--- /dev/null
+++ b/tests/interface-validation.test.ts
@@ -0,0 +1,68 @@
+import { 
+  PersonalityProfile, 
+  InterfaceValidator, 
+  ChatMessage, 
+  ConversationSession 
+} from '../src/interfaces/system-interfaces';
+
+describe('System Interface Validation', () => {
+  describe('PersonalityProfile Validation', () => {
+    const validProfile: PersonalityProfile = {
+      id: 'peter_disciple',
+      name: 'Peter',
+      description: 'Passionate apostle',
+      tone: 'zealous',
+      samplePrompts: ['Tell me about faith'],
+      version: '1.0.0'
+    };
+
+    const invalidProfiles = [
+      { ...validProfile, name: 'P' }, // Too short name
+      { ...validProfile, name: '' }, // Empty name
+      { 
+        ...validProfile, 
+        samplePrompts: new Array(15).fill('test prompt') // Too many prompts
+      }
+    ];
+
+    test('Valid profile passes validation', () => {
+      expect(InterfaceValidator.validatePersonalityProfile(validProfile)).toBe(true);
+    });
+
+    test.each(invalidProfiles)('Invalid profile is rejected', (profile) => {
+      expect(InterfaceValidator.validatePersonalityProfile(profile)).toBe(false);
+    });
+  });
+
+  describe('ChatMessage Creation', () => {
+    const validMessage: ChatMessage = {
+      id: 'msg_123',
+      sessionId: 'session_456',
+      agentId: 'peter_disciple',
+      content: 'Hello, I am Peter!',
+      timestamp: Date.now(),
+      type: 'agent'
+    };
+
+    test('Chat message can be created with valid data', () => {
+      expect(validMessage).toBeDefined();
+      expect(validMessage.type).toBe('agent');
+    });
+  });
+
+  describe('Conversation Session Management', () => {
+    const validSession: ConversationSession = {
+      id: 'last_supper_session',
+      participants: ['peter_disciple', 'john_disciple'],
+      messages: [],
+      startTime: Date.now(),
+      lastActivityTime: Date.now(),
+      status: 'active'
+    };
+
+    test('Conversation session initializes correctly', () => {
+      expect(validSession.status).toBe('active');
+      expect(validSession.participants).toHaveLength(2);
+    });
+  });
+});
\ No newline at end of file