Build a Simple Private Web App That Queries 4 AI APIs in a Relay Sequence (AI platforms)

I'm a business owner looking for a developer to build a small private web application. The concept is simple: I enter one question, and the app automatically runs it through a two-round relay across four AI models (Anthropic Claude, OpenAI ChatGPT, Google Gemini, and xAI Grok) using their official APIs, then gives me one final synthesized answer. The full step-by-step workflow is written out in a spec document I will provide. No design work needed beyond a clean, simple, mobile-friendly page with a text box, a button, and a results area with a copy button. Requirements: Experience with the Anthropic, OpenAI, Google Gemini, and xAI APIs (or ability to learn them quickly — they are all similar) Simple password protection so only I can use it Deployed to a low-cost host under a private URL Spending caps / prepaid credits configured on all four API accounts Brief handoff documentation and a 15-minute walkthrough call I will create and pay for the four API accounts myself; you will wire in the keys. Budget: Fixed price — please quote. I expect this is roughly a weekend-sized project for someone who has worked with these APIs. Timeline: Within 2–3 weeks of hire.