diff --git a/package.json b/package.json
new file mode 100644
index 00000000..0ba1ac77
--- /dev/null
+++ b/package.json
@@ -0,0 +1,20 @@
+{
+  "name": "multi-agent-chat-platform",
+  "version": "0.1.0",
+  "description": "Multi-agent interactive chat platform",
+  "scripts": {
+    "test": "jest",
+    "lint": "eslint . --ext .ts"
+  },
+  "dependencies": {},
+  "devDependencies": {
+    "@types/jest": "^29.5.3",
+    "jest": "^29.6.1",
+    "ts-jest": "^29.1.1",
+    "typescript": "^5.1.6"
+  },
+  "jest": {
+    "preset": "ts-jest",
+    "testEnvironment": "node"
+  }
+}
\ No newline at end of file
diff --git a/src/interfaces/chat.interface.ts b/src/interfaces/chat.interface.ts
new file mode 100644
index 00000000..ecceb766
--- /dev/null
+++ b/src/interfaces/chat.interface.ts
@@ -0,0 +1,26 @@
+// Chat message interface
+export interface ChatMessage {
+  id: string;
+  sessionId: string;
+  sender: string;
+  content: string;
+  timestamp: Date;
+}
+
+// Chat session interface
+export interface ChatSession {
+  id: string;
+  participants: string[];
+  messages: ChatMessage[];
+  createdAt: Date;
+  lastActiveAt: Date;
+}
+
+// Chat response interface
+export interface ChatResponse {
+  sessionId: string;
+  replies: {
+    agentId: string;
+    message: string;
+  }[];
+}
\ No newline at end of file
diff --git a/src/interfaces/personality.interface.ts b/src/interfaces/personality.interface.ts
new file mode 100644
index 00000000..36332f2d
--- /dev/null
+++ b/src/interfaces/personality.interface.ts
@@ -0,0 +1,31 @@
+// Interface for Personality Profile
+export interface PersonalityProfile {
+  id: string;
+  name: string;
+  description: string;
+  tone: string;
+  samplePrompts: string[];
+  
+  // Metadata for versioning
+  version: number;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+// Validation function for Personality Profile
+export function validatePersonalityProfile(profile: PersonalityProfile): boolean {
+  // Basic validation checks
+  if (!profile.id || profile.id.trim() === '') {
+    return false;
+  }
+  
+  if (!profile.name || profile.name.trim() === '') {
+    return false;
+  }
+  
+  if (profile.samplePrompts.length === 0) {
+    return false;
+  }
+  
+  return true;
+}
\ No newline at end of file
diff --git a/tests/chat.test.ts b/tests/chat.test.ts
new file mode 100644
index 00000000..e62a9355
--- /dev/null
+++ b/tests/chat.test.ts
@@ -0,0 +1,42 @@
+import { ChatMessage, ChatSession, ChatResponse } from '../src/interfaces/chat.interface';
+
+describe('Chat Interfaces', () => {
+  const sampleMessage: ChatMessage = {
+    id: 'msg-001',
+    sessionId: 'session-001',
+    sender: 'peter',
+    content: 'I will never deny you',
+    timestamp: new Date()
+  };
+
+  const sampleSession: ChatSession = {
+    id: 'session-001',
+    participants: ['peter', 'jesus'],
+    messages: [sampleMessage],
+    createdAt: new Date(),
+    lastActiveAt: new Date()
+  };
+
+  const sampleResponse: ChatResponse = {
+    sessionId: 'session-001',
+    replies: [
+      { agentId: 'peter', message: 'Master, I am ready to follow you' },
+      { agentId: 'jesus', message: 'Before the rooster crows, you will deny me three times' }
+    ]
+  };
+
+  test('chat message interface should be valid', () => {
+    expect(sampleMessage.sender).toBe('peter');
+    expect(sampleMessage.content).toBe('I will never deny you');
+  });
+
+  test('chat session should track messages and participants', () => {
+    expect(sampleSession.participants).toHaveLength(2);
+    expect(sampleSession.messages).toHaveLength(1);
+  });
+
+  test('chat response should include multiple agent replies', () => {
+    expect(sampleResponse.replies).toHaveLength(2);
+    expect(sampleResponse.replies[0].agentId).toBe('peter');
+  });
+});
\ No newline at end of file
diff --git a/tests/personality.test.ts b/tests/personality.test.ts
new file mode 100644
index 00000000..b2551081
--- /dev/null
+++ b/tests/personality.test.ts
@@ -0,0 +1,33 @@
+import { PersonalityProfile, validatePersonalityProfile } from '../src/interfaces/personality.interface';
+
+describe('Personality Profile Validation', () => {
+  const validProfile: PersonalityProfile = {
+    id: 'peter-apostle',
+    name: 'Peter the Apostle',
+    description: 'Fisherman turned disciple',
+    tone: 'passionate',
+    samplePrompts: ['Tell me about walking on water', 'What was it like following Jesus?'],
+    version: 1,
+    createdAt: new Date(),
+    updatedAt: new Date()
+  };
+
+  test('should validate a correct personality profile', () => {
+    expect(validatePersonalityProfile(validProfile)).toBe(true);
+  });
+
+  test('should reject profile with empty id', () => {
+    const invalidProfile = { ...validProfile, id: '' };
+    expect(validatePersonalityProfile(invalidProfile)).toBe(false);
+  });
+
+  test('should reject profile with empty name', () => {
+    const invalidProfile = { ...validProfile, name: '' };
+    expect(validatePersonalityProfile(invalidProfile)).toBe(false);
+  });
+
+  test('should reject profile with no sample prompts', () => {
+    const invalidProfile = { ...validProfile, samplePrompts: [] };
+    expect(validatePersonalityProfile(invalidProfile)).toBe(false);
+  });
+});
\ No newline at end of file