RAG as a Service?

I know the various different solutions for building RAG systems using a vector store manually but I'm working on a new project that could benefit from a RAG assisted version of GPT-4o.

I'm aware of the OpenAI Assistants API (still pretty early stage) but I'm wondering if there's any other options out there?

To be specific: I'm looking for an off the shelf solution where I can easily drop in a bunch of documents or a list of URLs and then ask search or summarization type questions on the dataset. I'm trying to avoid building it since it's a bit of distraction from my primary objective. Most of what I've found is pretty simple and DIY and still requires you to figure out document parsing and chunking. I just need something that works for existing web pages (with some non-static content).

My best solution is to download pages after a delay using a Chrome extension and load them into the OpenAI Assistants API but that's limited to returning 20 chunks and can be a bit limited on summarization.