I just released an open source project to help blockchain developers with RPC access. This project lets you configure an RPC proxy, where you can support multiple chains, with failovers and retries for each RPC call. It has a barebones middleware and event handler system that allows you to execute custom code. It currently runs on node, express, bun, cloudflare workers and fastify out of the box, and more platforms are in the works.
My next roadmap item is adding caching. Caching, I believe will significantly reduce outbound RPC calls to proxied node providers, thus significantly reducing your operating costs.
Please take a look and let me know what you think!