Welcome to Day 4 of the n8n Zero to Hero course! 🤖 Today we build our FIRST AI Agent – not just a basic chatbot! Create a Fitness Journal AI that understands natural language, extracts workout data, and automatically logs everything to Google Sheets.

🔗 Resources & Links
📌 Download workflow JSON:
📌 System Prompt template Included in the workflow itself

🕒 TIMESTAMPS
0:00 – 0:21 – Day 4 Introduction: First AI Agent Bot
0:22 – 1:19 – Project Overview: Fitness Tracker with AI Coach
1:20 – 2:24 – Setting Up Google Sheets (Date, Activity, Duration, Calories, Mood, Notes)
2:25 – 3:38 – Adding Chat Trigger (WhatsApp/Telegram Integration)
3:39 – 4:33 – Building AI Agent Node & System Prompt
4:34 – 5:42 – Connecting Gemini AI (Free API Setup)
5:43 – 6:18 – Testing AI Coach: Natural Conversation
6:19 – 6:45 – Adding IF Node for JSON Detection
6:46 – 7:10 – Testing Complete workflow & Wrap-Up

📋 Project: AI Fitness Journal & Coach
Build an intelligent fitness tracking system that:
✅ Chats with you naturally about workouts
✅ Asks follow-up questions when details are missing
✅ Extracts: activity, duration, reps, calories, mood, notes
✅ Acts as a ruthless fitness mentor
✅ Outputs structured JSON when ready to log
✅ Validates JSON format automatically
✅ Transforms data for Google Sheets
✅ Logs workouts automatically
✅ Works via chat interface (web/WhatsApp/Telegram)
✅ Provides motivational coaching notes
Real-world application: Personal fitness tracking, habit journaling, client coaching systems, automated data logging!

🎯 Key Concepts Covered

AI Agent Fundamentals:

Chat triggers for conversational interfaces
System prompts for AI personality & behavior
Natural language understanding
Structured data extraction from conversations
JSON output formatting
Follow-up question logic
Ruthless mentor personality design

Gemini AI Integration:

Free API access (aistudio.google.com)
API key generation
Gemini 2.5 Pro for better instruction adherence
Model selection & configuration

Data Processing:

IF nodes for conditional routing
Regex pattern matching for JSON validation
Code nodes for data transformation
Parsing AI outputs
Error handling and iteration
Schema mapping for Google Sheets

Advanced Techniques:

Multi-stage conversations
Context retention
Data validation before logging
True/False branch routing
Manual column mapping for reliability
Debugging AI outputs with LLMs

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