What is altterminal-backend?

AltTerminal-Backend is the server-side component for ALTTerminal, a trading interface for the alt.fun platform running on HyperEVM (a blockchain environment). The frontend of ALTTerminal is a static web app that users interact with directly, but it needs this backend for three specific reasons the README explains clearly. First, it hides the upstream RPC key. RPC (Remote Procedure Call) is how browser-based apps read data from a blockchain node. The Alchemy API key needed to connect to HyperEVM must stay private on the server, if it were in the browser, anyone could extract and abuse it. The backend exposes a proxy endpoint so the browser routes its blockchain reads through the server. Second, it caches the data feed from alt.fun's indexer. The frontend polls for new trades and token data every one to three seconds per open browser tab. Without a cache, each user would generate one database request per second, with this backend, all users share a single cache that refreshes about once per second total. Third, it mirrors token and trade data into a Turso database (a lightweight SQL database) for long-term persistence, and pre-joins token symbols into trade records so the frontend doesn't need extra lookups. Caching uses a stale-while-revalidate strategy: if the upstream indexer goes down, the backend keeps serving the last good data for a grace period rather than returning errors. The cache layers from fastest to slowest are: in-process memory (under 1ms), Turso (~50-100ms), then the live indexer (~200-500ms). The project is written in TypeScript and is designed to deploy on Railway or any Node 22 host.