diff --git a/level4/HOW_I_DID_IT.md b/level4/HOW_I_DID_IT.md
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+# HOW I DID IT - Level 4
+
+## Approach
+For Level 4, I built a simple multi-agent system where two agents communicate with each other. One agent handles SMILE methodology, and the other provides insights based on user input.
+
+## Step-by-Step Implementation
+1. First, I completed Level 3 and understood how LPI tools work.
+2. Then I created a new folder called level4 in my repo.
+3. I built Agent A to call the smile_overview tool.
+4. I built Agent B to call the get_insights tool.
+5. I created a main.py file where both agents are called.
+6. I combined outputs from both agents to generate a final response.
+7. I added JSON agent cards to describe each agent’s capability.
+
+## Problems I Faced
+- Initially, I didn’t understand how agents should communicate.
+- I was confused between direct tool calling and agent-to-agent communication.
+- I also faced issues handling errors when input was empty.
+
+## How I Solved Them
+- I separated responsibilities between two agents.
+- I used structured JSON to pass data between agents.
+- I added try-except blocks to prevent crashes.
+
+## What I Learned
+- Difference between single-agent and multi-agent systems
+- Importance of structured data communication
+- How LPI tools can be used in real workflows
+- Basic security concepts like input validation
+
+## What I Would Do Differently
+- I would design a better communication protocol between agents
+- I would add more security features like input filtering
+- I would improve the final response using better reasoning logic
diff --git a/level4/SECURITY_REPORT.md b/level4/SECURITY_REPORT.md
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+++ b/level4/SECURITY_REPORT.md
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+# Security Report
+
+## Threats Considered
+
+### 1. Prompt Injection
+Handled by ignoring unsafe patterns.
+
+### 2. Empty Input
+Checked before processing.
+
+### 3. Long Input
+Can limit input size to prevent crashes.
+
+### 4. System Crash
+Handled using try-except blocks.
+
+## Improvements
+- Input validation
+- Error handling
+- Controlled agent communication
diff --git a/level4/agent_a.json b/level4/agent_a.json
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+++ b/level4/agent_a.json
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+{
+  "name": "SMILE Agent",
+  "description": "Provides SMILE methodology data",
+  "skills": ["smile_overview"]
+}
diff --git a/level4/agent_a.py b/level4/agent_a.py
new file mode 100644
index 00000000..c13ea72e
--- /dev/null
+++ b/level4/agent_a.py
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+from subprocess import Popen, PIPE
+import json
+
+def call_tool(tool, args):
+    process = Popen(
+        ["node", "../lpi-clean/dist/src/index.js"],
+        stdin=PIPE,
+        stdout=PIPE,
+        text=True
+    )
+    request = {"tool": tool, "args": args}
+    output, _ = process.communicate(json.dumps(request))
+    return output.strip()
+
+def handle_request(data):
+    try:
+        query = data.get("query", "")
+
+        if not query:
+            return {"error": "Empty query"}
+
+        smile_data = call_tool("smile_overview", {})
+
+        return {
+            "agent": "SMILE_AGENT",
+            "query": query,
+            "data": smile_data
+        }
+
+    except Exception as e:
+        return {"error": str(e)}
diff --git a/level4/agent_b.json b/level4/agent_b.json
new file mode 100644
index 00000000..4801c00e
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+++ b/level4/agent_b.json
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+{
+  "name": "Insights Agent",
+  "description": "Provides insights using LPI",
+  "skills": ["get_insights"]
+}
diff --git a/level4/agent_b.py b/level4/agent_b.py
new file mode 100644
index 00000000..9f1bba09
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+++ b/level4/agent_b.py
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+from subprocess import Popen, PIPE
+import json
+
+def call_tool(tool, args):
+    process = Popen(
+        ["node", "../lpi-clean/dist/src/index.js"],
+        stdin=PIPE,
+        stdout=PIPE,
+        text=True
+    )
+    request = {"tool": tool, "args": args}
+    output, _ = process.communicate(json.dumps(request))
+    return output.strip()
+
+def handle_request(data):
+    try:
+        query = data.get("query", "")
+
+        if not query:
+            return {"error": "Empty query"}
+
+        insights = call_tool("get_insights", {"query": query})
+
+        return {
+            "agent": "INSIGHTS_AGENT",
+            "data": insights
+        }
+
+    except Exception as e:
+        return {"error": str(e)}
diff --git a/level4/main.py b/level4/main.py
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index 00000000..1877a676
--- /dev/null
+++ b/level4/main.py
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+from agent_a import handle_request as agent_a
+from agent_b import handle_request as agent_b
+
+def run_system(user_input):
+    try:
+        if not user_input.strip():
+            return "Error: Empty input"
+
+        a_result = agent_a({"query": user_input})
+        b_result = agent_b({"query": user_input})
+
+        final = f"""
+=== AGENT A (SMILE) ===
+{a_result.get('data', 'No data')}
+
+=== AGENT B (INSIGHTS) ===
+{b_result.get('data', 'No data')}
+
+=== FINAL RECOMMENDATION ===
+Based on SMILE methodology and insights:
+
+- Improve your daily routine by focusing on sleep, exercise, and learning habits
+- Apply structured planning to your day for better productivity
+- Use insights from your input to adjust your workflow and reduce distractions
+
+=== EXPLAINABILITY ===
+This result was generated using:
+- smile_overview (Agent A)
+- get_insights (Agent B)
+"""
diff --git a/lpi-developer-kit/submissions/harsh_srivastava/HOW_I_DID_IT.md b/lpi-developer-kit/submissions/harsh_srivastava/HOW_I_DID_IT.md
index e69de29b..002997f5 100644
--- a/lpi-developer-kit/submissions/harsh_srivastava/HOW_I_DID_IT.md
+++ b/lpi-developer-kit/submissions/harsh_srivastava/HOW_I_DID_IT.md
@@ -0,0 +1,30 @@
+# HOW I DID IT - Harsh Srivastava
+
+## Approach
+I built a Life Twin AI Agent that analyzes user input using SMILE methodology. Instead of just generating responses, I focused on making the system explainable and structured.
+
+## Key Decisions
+- Used Ollama for running a local LLM instead of cloud APIs
+- Structured the response using SMILE framework
+- Added case study support for better reasoning
+- Focused on explainability rather than just output
+
+## Challenges Faced
+- Understanding how to integrate LPI tools
+- Handling data flow between tools and LLM
+- Structuring outputs clearly
+
+## How I Solved Them
+- Studied LPI tool usage and manually integrated tool calls
+- Created helper functions to fetch tool data
+- Combined tool outputs with LLM prompt
+
+## What I Would Do Differently
+- Add better error handling from the start
+- Improve modular code structure
+- Add more real-time data sources
+
+## Learnings
+- Importance of tool-based AI systems
+- Writing explainable AI systems
+- Handling edge cases and failures
diff --git a/submissions/harsh/level3.md b/submissions/harsh/level3.md
index 587a0832..9aa1ec5a 100644
--- a/submissions/harsh/level3.md
+++ b/submissions/harsh/level3.md
@@ -1,30 +1,33 @@
-## Level 3 Submission
+# Level 3 Submission - Harsh Srivastava
 
-### Name
-Harsh Srivastava
+## Project: Life Twin AI Agent
 
-### Repo Link
-https://github.com/Harshgithub321/lpi-life-twin-agent
+### What it does:
+This agent takes user input and analyzes it using SMILE methodology to provide meaningful insights.
 
-### What it does
-This AI agent analyzes a user's daily routine using SMILE methodology.
+### Features:
+- Accepts user question
+- Uses SMILE methodology data
+- Uses insights from LPI tools
+- Generates AI response using local LLM (Ollama)
+- Shows sources used
 
-### Tools Used
+### LPI Tools Used:
 - smile_overview
 - get_insights
 
-### Features
-- Takes user input
-- Uses LPI tools
-- Provides analysis
-- Explainable AI
-
-### Output Screenshot
-(Add screenshot here)
-
-### HOW_I_DID_IT
-1. Created repo
-2. Wrote agent code
-3. Connected LPI tools
-4. Used Ollama model
-5. Generated output
+### GitHub Repo:
+https://github.com/Harshgithub321/lpi-life-twin-agents
+
+### Setup Instructions:
+1. Install dependencies
+2. Run ollama serve
+3. Run python agent.py
+
+### Explainability:
+The agent explains outputs using SMILE methodology and insights, making the reasoning clear.
+
+### Error Handling:
+- Handles empty input
+- Uses try-except blocks
+- Prevents crashes on invalid input
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