WhatsApp AI Chatbot

We are a solar street light manufacturer receiving inquiries from Facebook Ads through WhatsApp. Previously, we used WATI for WhatsApp automation. However, the monthly cost became too expensive, so we decided to build our own WhatsApp AI system using WhatsApp Cloud API and AI. We already started this project with another developer, but unfortunately he became unavailable unexpectedly and the project was left unfinished. We are now looking for a developer who can review the existing work (if usable) and either continue from the current stage or rebuild the workflow if necessary. Project Goal The purpose of this project is not to build a complex AI agent. The goal is to: * Build a reasonable whatsapp chat bot * Automatically answer common customer questions in client’s language * Support English, Spanish, French, and Arabic inquiries * Collect customer information * Qualify leads before they reach our sales team Our sales team works primarily in English, so customer conversations should be automatically translated and summarized in English internally. AI Knowledge & Conversation Logic I prefer a simple and practical FAQ-first approach. The AI should: 1. Search the FAQ database first. 2. If no suitable FAQ answer is found, search company documents and product information. 3. If the answer is still unclear, do not guess or generate speculative information. Instead, collect the customer’s contact information and create a lead for manual sales follow-up. The objective is to provide accurate answers while continuously improving the FAQ database over time. Whenever our sales team manually answers a new question, we can later add that question and answer to the FAQ database so the AI can handle similar inquiries automatically in the future. This approach is easier to maintain, more reliable, and more suitable for our business than a complex autonomous AI agent. Previous Setup The previous developer was using: * Railway * WhatsApp Cloud API * Qwen API * Resend (email notifications) You are welcome to continue using the same stack or recommend a better alternative. My main concerns are: * Reliability * Ease of maintenance * Low operating cost What I Need From You Please let me know: 1. Have you built WhatsApp Cloud API projects before? 2. Have you built FAQ-based or RAG-based AI systems before? 3. Can you review and continue an existing project? 4. What technology stack would you recommend? 5. What would be your estimated timeline? 6. How long is your post-deployment support period? Long-term reliability and communication are very important to me, as my previous developer became unavailable during the project.