--- title: Filtering slug: neurons-api/filtering createdAt: 2026-08-19T08:34:10.100Z --- :::hint{type="info"} Complex fields, such as sub collections and nested json objects with child properties, are not filterable. See the descriptions of the [cve](docId\:VWzHdvV7uiw8NtwjuUZ3p), [notification](docId\:Mjf7s-U4YmNDNQX6GRhmi) and [patch](docId\:ZrTaYnkOHm7gEw9DY-0h5) endpoints to learn which fields are not filterable. ::: Data resources can be filtered using the **filter** query string parameter. By default, all basic fields are filterable. | Operation | Function | Example | Supported Data Types | | ---------------------- | ---------- | -------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Contains | contains | ?filter=contains(Field, 'Bar') | String | | Ends With | endswith | ?filter=endswith(Field, "Bar') | String | | Equals | eq | ?filter=Field eq "Foo" | all | | Greater Than or Equals | ge | ?filter=Field ge 150 | DateTime, Decimal, Double, Float, Guid, Int32, Int64, String | | Greater Than | gt | ?filter=Field gt 150 | DateTime, Decimal, Double, Float, Guid, Int32, Int64, String | | In | in | ?filter=in(CollectionField, \['Foo', 'Bar']) | Guid, Int32 and String Array Types. Values should be comma separated within opening and closing brackets. | | Is Null (or default) | isnull | ?filter=isnull(Field) | Boolean, DateTime, Decimal, Double, Float, Guid, Int32, Int64, String.
Note: If the underlying data storage type is not nullable, an equality comparison is done against the default value (i.e. Integer, Double, Decimal = 0, DateTime = DateTime.MinValue, Guid = Guid.Empty) | | Less Than or Equals | le | ?filter=Field le 150 | DateTime, Decimal, Double, Float, Guid, Int32, Int64, String | | Less Than | lt | ?filter=Field lt 150 | DateTime, Decimal, Double, Float, Guid, Int32, Int64, String | | Not Equals | ne | ?filter=Field ne "Foo' | all | | Starts With | startswith | ?filter=startswith(Field, 'Bar') | String | The functions **endswith**, **contains** and **startswith** are only supported for String property types. For collection searching, the **in** function is only supported for Guid, Int32 and String property types. Nested properties are not supported.