Integrate Claude/OpenAI API into Existing App — Add Text Summarizer Feature

We have an existing web application and want to add a single AI-powered feature: a text summarizer. Users will paste or submit text, and the app should return a clean, concise summary using the OpenAI or Claude API. The app is already built and running — we just need someone to bolt on this one capability cleanly. You'll integrate the API, handle the request/response flow, add basic error handling, and make sure it's reliable and cost-efficient. No full rebuild, no new design — just a well-implemented feature that works. Ideal freelancer has done LLM API integrations before and can work within an existing codebase without breaking things. Clear communication and clean, documented code are a must. Deliverables - Working text summarizer feature integrated into our existing app - API integration (OpenAI or Claude) with secure key handling - Basic error handling and input validatio- Optimized prompt for accurate, concise summarie - - - Short documentation on how it works and how to adjust it