AI Chatbot for Customer Support (Website + Help Desk Integration) — US-based team preferred

We run an online business based in the US and want to add an AI-powered chatbot to handle customer support. Right now our small team manually answers repetitive questions about orders, shipping, and returns during US business hours (9am to 6pm ET), and we want to automate the first layer of that. What we're looking for: A chatbot that can answer FAQs using our existing knowledge base/help docs Ability to pull basic order status info (we can provide API docs or a mock endpoint) Smooth handoff to a human agent when the bot can't resolve something, with escalations routed to our support team's working hours Embeddable on our website, ideally also able to connect to our help desk tool (currently using Zendesk, open to alternatives) Comfortable with US data handling norms and customer communication style, since this is a US consumer-facing product We're open to your recommended approach, whether that's a RAG setup, an agent built on Claude/GPT, or a no-code/low-code platform, as long as it's reliable and easy for us to maintain afterward. Please include in your proposal: A short explanation of how you'd architect this and why Examples of similar chatbots/agents you've built (links if possible) Rough timeline and price breakdown Whether you'd recommend fixed price or hourly for a project like this Please confirm you are currently based in the United States Skills to add: Chatbot Development, AI Agent Development, RAG, Customer Service Chatbot, Python, API Integration, LangChain, Zendesk