Achievements may look daunting with their short names, but they are not as difficult as they look. Here's the important parts of the structure:

interface Achievement {
    art: 0 | 1 | 2;
    category: string;
    deci: number;
    desc: string;
    hidden: boolean;
    k: number;
    min: number;
    name: string;
    o: number;
    object: string;
    rt:
        | 1
        | 2
        | 3
        | 4
        | 5
        | 6;
    vt:
        | 0
        | 1
        | 2
        | 3
        | 4
        | 5
        | 6;
}

Properties

art: 0 | 1 | 2

The AR type of this achievement:

category: string

The category of the achievement.

deci: number

The amount of decimal placed to show.

desc: string

The flavor text of the achievement.

hidden: boolean

Whether this achievement is usually not shown.

k: number

The Achievement ID, for every type of achievement.

min: number

The minimum score required to obtain the achievement.

name: string

The primary name of the achievement.

o: number

The order of this achievement in its category.

object: string

The objective of the achievement.

rt:
    | 1
    | 2
    | 3
    | 4
    | 5
    | 6

The rank type of this achievement:

vt:
    | 0
    | 1
    | 2
    | 3
    | 4
    | 5
    | 6

The value type of this achievement: