Hi, Please, how should I modify the mapping to be able to parse the following example? -=-=-=- rectangleJson := '{ "origin" : null, "corner" : null }'. (NeoJSONReader on: rectangleJson readStream) mapInstVarsFor: Point; for: Rectangle do: [ :mapping | (mapping mapInstVar: #origin) valueSchema: Point. (mapping mapInstVar: #corner) valueSchema: Point ]; nextAs: Rectangle. -=-=-=- I receive from a server JSON messages including null values. Can we say use Point value schema or null? How? In the documentation I can see the example: -=-=-=- String streamContents: [ :stream | (NeoJSONWriter on: stream) mapAllInstVarsFor: Point; writeNil: true; nextPut: Point new ]. -=-=-=- that produces {"x":null,"y":null} But I do not see how to apply this for the following example: -=-=-=- String streamContents: [ :stream | (NeoJSONWriter on: stream) mapAllInstVarsFor: Point; for: Rectangle do: [ :mapping | (mapping mapInstVar: #origin) valueSchema: Point. (mapping mapInstVar: #corner) valueSchema: Point ]; writeNil: true; nextPut: Rectangle new ]. -=-=-=- Thanks, Juraj