async-graphql/docs/en/src/context.md

Context

The main goal of Context is to acquire global data attached to Schema. Note that if the return value of resolver function is borrowed from Context, you will need to explicitly state the lifetime of the argument.

The following example shows how to borrow data in Context.

use async_graphql::*;

struct Query;

#[Object]
impl Query {
    async fn borrow_from_context_data<'ctx>(
        &self,
        ctx: &'ctx Context<'_>
    ) -> FieldResult<&'ctx String> {
        ctx.data::<String>()
    }
}