sawdog/blueboat

Blueboat is a serverless JavaScript runtime that lets you write simple backend applications without managing servers. Think of it like a platform where you write JavaScript code that responds to web requests, and the platform handles running it at scale. You write routes (like "when someone visits /hello, return this response"), and Blueboat executes them on demand. The key innovation is that Blueboat is built for multi-tenant environments from the ground up. Instead of giving developers direct access to local files, databases, or network sockets, which don't scale well when many users share the same infrastructure, it replaces these with distributed-system equivalents. For example, instead of reading and writing files to disk, you use a key-value store. Instead of running a WebSocket server locally, you publish messages through a pub-sub system. Instead of SQLite, you connect to MySQL or PostgreSQL. This design means your app can run anywhere and scale without friction. A Blueboat application is remarkably simple. You define routes using a Router API, then return Responses. The runtime includes standard web APIs like fetch, Request, and Response, so much of what you know from browser JavaScript or modern Node.js works directly. The README shows examples like handling GET requests, calling external APIs, or working with YAML, all in just a few lines. You can deploy Blueboat two ways: single-tenant mode for local development or self-hosting (where you run one instance just for yourself), or multi-tenant mode where many apps share a single Blueboat cluster. There's also a hosted service called MagicBoat if you don't want to manage your own infrastructure. Developers can use TypeScript, bundle their code with webpack or esbuild, and the project includes type definitions to make development smoother.