Resource Bar Contexts (resource_bar_context)

A context extracts the current value, the minimum, the maximum and the last-changed tick from an entity or from client state, and builds a display name out of the value ID it is given. It is written in the context of an inline bars entry of a resource.

This family is registered by the mod; a data pack picks one, it cannot add a new one. The environmental storage maximum of an aura chunk is a separate family, see aura maximum types.

A context is picked by an ID string, not by a type object: it goes in the context field of a resource bar, and that ID string is all you write there. An omitted context counts as mxt:self_hud. A context has no JSON fields, and a data pack cannot add a sixth one.

ID	Layout	Description
mxt:self_hud	Self HUD	Reads the value stored on the entity
mxt:target_overlay	Target overlay	Reads the value stored on the entity
mxt:boss_overlay	Boss overlay	Reads the value stored on the entity
mxt:environment_concentration	Self HUD	Reads the environmental aura template synchronized to the client, excluding chunk stock and block or formation contributions
mxt:actual_concentration	Self HUD	Reads the final concentration synchronized to the client, with environment, stock, blocks and formations all counted

{
  "bars": [
    {
      "context": "mxt:self_hud",
      "anchor": "left",
      "renderer": {"type": "mxt:boss_bar", "bar_index": 1}
    }
  ]
}

The three contexts that read a stored value report nothing while that value has not been initialized, and the bar is not drawn. The two concentration contexts need a matching aura definition for the value: with no definition, or when both the maximum and the current value of that pool are not positive, they report nothing either.

Both concentration contexts always report a minimum of 0 and have no change time, so mxt:recently_changed never holds for them. Display names are built from the value name: mxt:self_hud uses it as is, mxt:target_overlay and mxt:boss_overlay prefix it with target or boss, and the two concentration contexts add an environmental or actual prefix plus a concentration suffix, so a value named "Aura" shows as "Environmental Aura Concentration" and "Actual Aura Concentration".

mxt:target_overlay and mxt:boss_overlay are drawn in two passes split by anchor, so a target bar written with anchor: right is drawn on the right.