Collect leads with a conversational GPT-4.1 chatbot and Google Sheets

Description A natural conversational AI chatbot that collects lead information (Name, Phone, Email, Message) one question at a time without feeling like a form. Uses session-based memory to track conversations, intelligently asks only for missing details, and saves complete leads to Google Sheets automatically. --- What this workflow does This workflow creates a human-like booking assistant that gathers lead information through natural conversation instead of traditional forms. The AI chatbot asks ONE question at a time, remembers previous answers using session memory, never repeats questions, and only saves data to Google Sheets when all four required fields (Name, Phone Number, Email Address, User Message) are confidently collected. The conversation feels natural and friendly—users engage with the bot as if chatting with a real person, dramatically improving completion rates compared to static forms. Perfect for booking systems, consultation requests, event registrations, customer support intake, or any scenario where you need to collect contact information without friction. --- Key features One question at a time: The AI never overwhelms users with multiple questions. It asks for Name, then Phone, then Email, then Message—sequentially and naturally, based on what's still missing from the conversation. Session-based memory: Uses timestamp-based session tracking so the AI remembers the entire conversation context. If a user says "My name is John" in message 1, the AI won't ask for the name again in message 5. Smart field detection: The AI automatically detects which details have been collected and which are still missing. It adapts the conversation flow dynamically instead of following a rigid script. Natural language processing: Handles variations in user input ("John Doe", "I'm John", "Call me John") and validates data intelligently before saving. Complete data guarantee: Only writes to Google Sheets when all 4 required fields are present. No partial or incomplete leads clutter your tracking sheet. Webhook-based integration: Works with any website, app, or platform that can send HTTP requests. Integrate with chatbots, contact forms, booking widgets, or custom applications. Instant responses: Real-time conversation with sub-second response times. Users get immediate replies, maintaining engagement throughout the lead collection process. --- How it works 1. User initiates conversation via webhook A user sends a message through your website chat widget, contact form, or booking interface. This triggers a webhook that passes the message along with query parameters (name, email, phone, message, timestamp, source) to n8n. 2. AI Agent analyzes conversation state The Conversational Lead Collection Agent receives the user's message and checks the current state: - Which fields are already collected (from previous messages in this session)? - Which fields are still missing? - What should be asked next? The AI uses the system prompt to understand its role as a booking assistant for "Spark Writers' Retreat" and follows strict conversation rules. 3. Session memory tracks context The Buffer Window Memory node uses the timestamp from the webhook as a unique session ID. This allows the AI to: - Remember all previous messages in this conversation - Access previously collected information (name, phone, email) - Never ask the same question twice - Maintain conversation continuity even if the user takes breaks 4. One question at a time Based on what's missing, the AI asks exactly ONE question in natural, friendly language: - If Name is missing → "Hi! What's your name?" - If Phone is missing → "Great! And what's your phone number?" - If Email is missing → "Perfect! Could you share your email address?" - If Message is missing → "Thanks! How can I help you today?" The AI adapts its language based on previous conversation flow—it doesn't sound robotic or repetitive. 5. Data validation and collection As the user responds, the AI: - Validates input (