www/versioned_docs/version-9.x/server/context.md
The createContext() function is called for each request and the result is propagated to all resolvers. You can use this to pass contextual data down to the resolvers.
import * as trpc from '@trpc/server';
import * as trpcNext from '@trpc/server/adapters/next';
// The app's context - is generated for each incoming request
export async function createContext(opts?: trpcNext.CreateNextContextOptions) {
// Create your context based on the request object
// Will be available as `ctx` in all your resolvers
// This is just an example of something you'd might want to do in your ctx fn
async function getUserFromHeader() {
if (opts?.req.headers.authorization) {
// const user = await decodeJwtToken(req.headers.authorization.split(' ')[1])
// return user;
}
return null;
}
const user = await getUserFromHeader();
return {
user,
};
}
type Context = trpc.inferAsyncReturnType<typeof createContext>;
// Helper function to create a router with your app's context
export function createRouter() {
return trpc.router<Context>();
}