Context

The context object contains all the variables related to the current request. It's passed as an argument to the resolver function of a procedure so that you can interact with the context in your API routes.

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To learn how you can add conditional properties to the context object, see the middleware documentation.

Defining your context

Earlier in our quick start guide, we created a new Aetheris server and defined a base router with no context. By default, the context will only have access to properties such as input, params, path, etc. If you want, you can add custom properties to the context object by creating a context creator function. This function may vary depending on the http framework you are using Aetheris with, but the concept remains the same.

The context creator can be useful if you need to past information from the underlying frameworks api to your Aetheris server, such as from middleware that may be exclusive to that framework. It can also add custom additional properties to the context object that may be useful in your API routes.

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The request object type from Next.js is not mandatory, but can be useful if you need to access the request object in your API routes.

src/server/index.ts

import { createAetheris, router } from "@aetheris/server";
import { NextRequest } from "next/server";
 
// Create the context creator function
export const createContext = (req: NextRequest) => ({
    logger: (message: string) => {
        console.log(`[${new Date().toISOString()}] ${message}`);
    },
})
 
const aether = createAetheris<typeof createContext>();
 
export const app = router({
    // Access the context in your resolver
    helloWorld: aether.handler({
        resolver: ({ logger }) => {
            logger(`helloWorld was called.`);
            return `Hello, World!`;
        },
    }),
});
 
export type App = typeof app;

In order for the context creator to be used, it has to passed to the handler creator function when creating the handler for your respective framework. For example, in Next.js, you would pass the context creator to the createHandler function.

src/app/api/[[...slug]]/route.ts

import { createNextHandler } from "@aetheris/server/adapters/next";
import { app, createContext } from "@/server";
 
const handler = createNextHandler({
    app,
    createContext,
    prefix: "/api",
});
 
export const POST = handler;

Now the logger will be called as expected when the helloWorld procedure is called.

Concepts Validation