Protocol Buffer Types

Internal

• Protocol Buffer Concepts

String

string some_string = 1;

The default value is empty string (""). The field contains UTF-8 encoded or 7-bit ASCII text.

Boolean

bool some_bool = 1;

The default value is false.

Scalar Number Types

int32

int32 some_int = 1;

The default value is 0.

Bytes

bytes some_bytes = 1;

The default value is the empty byte array.

List (Array)

Use pluralized names for repeated fields.

repeated <some_other_type> <field_name> = <tag>;

Example:

repeated int32 sizes = 1;
repeated string names = 1;

The default value is the empty list.

enum

The enum must start with the tag 0. The default value is the first value. Always start an enum

enums can be defined at the top level of a .proto file or they can be embedded.

enum DayOfTheWeek {
  UNKNOWN_DAY_OF_WEEK = 0;
  MONDAY_DAY_OF_WEEK = 1;
  TUESDAY_DAY_OF_WEEK = 2;
  WEDNESDAY_DAY_OF_WEEK = 3;
  THURSDAY_DAY_OF_WEEK = 4;
  FRIDAY_DAY_OF_WEEK = 5;
  SATURDAY_DAY_OF_WEEK = 6;
  SUNDAY_DAY_OF_WEEK = 7;
}
message Something {
    DayOfTheWeek day_of_the_week = 1;
}

To see what Go code is generated for an enum, go to:

Protocol Buffers Go Code Generation | enums

Other Common Types

Google Common Types

https://github.com/googleapis/googleapis/tree/master/google/type

date

https://github.com/googleapis/googleapis/blob/master/google/type/date.proto

dayofweek

https://github.com/googleapis/googleapis/blob/master/google/type/dayofweek.proto

money

https://github.com/googleapis/googleapis/blob/master/google/type/money.proto