Value

A message that can hold any of the supported value types.

JSON representation 
{

  // Union field value_type can be only one of the following:
  "nullValue": null,
  "booleanValue": boolean,
  "integerValue": string,
  "doubleValue": number,
  "timestampValue": string,
  "stringValue": string,
  "bytesValue": string,
  "referenceValue": string,
  "geoPointValue": {
    object (LatLng)
  },
  "arrayValue": {
    object (ArrayValue)
  },
  "mapValue": {
    object (MapValue)
  }
  // End of list of possible types for union field value_type.
}
Fields
Union field value_type. Must have a value set. value_type can be only one of the following:
nullValue

null

A null value.
booleanValue

boolean

A boolean value.
integerValue

string (int64 format)

An integer value.
doubleValue

number

A double value.
timestampValue

string (Timestamp format)

A timestamp value.

Precise only to microseconds. When stored, any additional precision is rounded down.

A timestamp in RFC3339 UTC "Zulu" format, with nanosecond resolution and up to nine fractional digits. Examples: "2014-10-02T15:01:23Z" and "2014-10-02T15:01:23.045123456Z".
stringValue

string

A string value.

The string, represented as UTF-8, must not exceed 1 MiB - 89 bytes. Only the first 1,500 bytes of the UTF-8 representation are considered by queries.
bytesValue

string (bytes format)

A bytes value.

Must not exceed 1 MiB - 89 bytes. Only the first 1,500 bytes are considered by queries.

A base64-encoded string.
referenceValue

string

A reference to a document. For example: projects/{project_id}/databases/{databaseId}/documents/{document_path}.
geoPointValue

object (LatLng)

A geo point value representing a point on the surface of Earth.
arrayValue

object (ArrayValue)

An array value.

Cannot directly contain another array value, though can contain an map which contains another array.
mapValue

object (MapValue)

A map value.

MapValue

A map value.

JSON representation 
{
  "fields": {
    string: {
      object (Value)
    },
    ...
  }
}
Fields
fields

map (key: string, value: object (Value))

The map's fields.

The map keys represent field names. Field names matching the regular expression __.*__ are reserved. Reserved field names are forbidden except in certain documented contexts. The map keys, represented as UTF-8, must not exceed 1,500 bytes and cannot be empty.

An object containing a list of "key": value pairs. Example: { "name": "wrench", "mass": "1.3kg", "count": "3" }.