Runtime Arguments

Cerces implements Web Standards and provides a unified interface for handling HTTP requests across different JavaScript runtimes. Cerces' App.handle method forwards runtime-specific arguments and handles routing, parameter validation, middleware execution, and response generation.

Web Standards Compliance

Cerces follows Web Standards, providing a global argument req: Request on all handlers (routes, dependencies, middleware). This ensures compatibility with the Web Fetch API and allows seamless integration with any runtime that supports standard Request/Response objects.

app.get("/", {
    parameters: {},
    handle: ({ req }) => { 
        // req: Request
        return { message: "Hello World" }
    },
})

Runtime-Specific Arguments

Additional arguments beyond req vary depending on the runtime environment. These are provided by the platform and can include environment variables, execution contexts, or other runtime-specific data.

Runtime arguments are typed through the RuntimeArgs interface, which should be extended in a runtime.d.ts (or similar .d.ts) file. This file is typically created when initializing a project using Cerces templates.

To provide TypeScript support for runtime-specific arguments, extend the RuntimeArgs interface in a declaration file. These are typically already set up if you used a Cerces template to create your project. For example, if you used the bun or cf-workers templates, you would have:

bun

import { Server } from "bun"

declare module "cerces/types" {
    interface RuntimeArgs {
        ctx: Server
    }
}

cf-workers

declare module "cerces/types" {
    interface RuntimeArgs {
        env: Cloudflare.Env
        ctx: ExecutionContext
    }
}

This provides types for additional runtime arguments in handlers:

bun

app.get("/", {
    parameters: {},
    handle: ({ req, ctx }) => { 
        // req: Request; ctx: Server
        return { message: "Hello World" }
    },
})

cf-workers

app.get("/", {
    parameters: {},
    handle: ({ req, env, ctx }) => { 
        // req: Request; env: Cloudflare.Env; ctx: ExecutionContext;
        return { message: "Hello World" }
    },
})

With this setup, handlers automatically receive properly typed runtime arguments without additional configuration.