Namespace Google.Protobuf.WellKnownTypes (3.23.0)



Any contains an arbitrary serialized protocol buffer message along with a URL that describes the type of the serialized message.

Protobuf library provides support to pack/unpack Any values in the form of utility functions or additional generated methods of the Any type.

Example 1: Pack and unpack a message in C++.

Foo foo = ...;
Any any;
if (any.UnpackTo(&foo)) {

Example 2: Pack and unpack a message in Java.

Foo foo = ...;
Any any = Any.pack(foo);
if ( {
  foo = any.unpack(Foo.class);
// or ...
if (any.isSameTypeAs(Foo.getDefaultInstance())) {
  foo = any.unpack(Foo.getDefaultInstance());

Example 3: Pack and unpack a message in Python.

foo = Foo(...)
any = Any()
if any.Is(Foo.DESCRIPTOR):

Example 4: Pack and unpack a message in Go

 foo := &pb.Foo{...}
 any, err := anypb.New(foo)
 if err != nil {
 foo := &pb.Foo{}
 if err := any.UnmarshalTo(foo); err != nil {

The pack methods provided by protobuf library will by default use '' as the type URL and the unpack methods only use the fully qualified type name after the last '/' in the type URL, for example "" will yield type name "y.z".


The JSON representation of an Any value uses the regular representation of the deserialized, embedded message, with an additional field @type which contains the type URL. Example:

package google.profile;
message Person {
  string first_name = 1;
  string last_name = 2;

  "@type": "",
  "firstName": <string>,
  "lastName": <string>

If the embedded message type is well-known and has a custom JSON representation, that representation will be embedded adding a field value which holds the custom JSON in addition to the @type field. Example (for message [google.protobuf.Duration][]):

  "@type": "",
  "value": "1.212s"


Holder for reflection information generated from google/protobuf/any.proto


Api is a light-weight descriptor for an API Interface.

Interfaces are also described as "protocol buffer services" in some contexts, such as by the "service" keyword in a .proto file, but they are different from API Services, which represent a concrete implementation of an interface as opposed to simply a description of methods and bindings. They are also sometimes simply referred to as "APIs" in other contexts, such as the name of this message itself. See for detailed terminology.


Holder for reflection information generated from google/protobuf/api.proto


Wrapper message for bool.

The JSON representation for BoolValue is JSON true and false.


Wrapper message for bytes.

The JSON representation for BytesValue is JSON string.


Wrapper message for double.

The JSON representation for DoubleValue is JSON number.


A Duration represents a signed, fixed-length span of time represented as a count of seconds and fractions of seconds at nanosecond resolution. It is independent of any calendar and concepts like "day" or "month". It is related to Timestamp in that the difference between two Timestamp values is a Duration and it can be added or subtracted from a Timestamp. Range is approximately +-10,000 years.


Example 1: Compute Duration from two Timestamps in pseudo code.

Timestamp start = ...;
Timestamp end = ...;
Duration duration = ...;

duration.seconds = end.seconds - start.seconds;
duration.nanos = end.nanos - start.nanos;

if (duration.seconds < 0 && duration.nanos > 0) {
  duration.seconds += 1;
  duration.nanos -= 1000000000;
} else if (duration.seconds > 0 && duration.nanos < 0) {
  duration.seconds -= 1;
  duration.nanos += 1000000000;

Example 2: Compute Timestamp from Timestamp + Duration in pseudo code.

Timestamp start = ...;
Duration duration = ...;
Timestamp end = ...;

end.seconds = start.seconds + duration.seconds;
end.nanos = start.nanos + duration.nanos;

if (end.nanos < 0) {
  end.seconds -= 1;
  end.nanos += 1000000000;
} else if (end.nanos >= 1000000000) {
  end.seconds += 1;
  end.nanos -= 1000000000;

Example 3: Compute Duration from datetime.timedelta in Python.

td = datetime.timedelta(days=3, minutes=10)
duration = Duration()

JSON Mapping

In JSON format, the Duration type is encoded as a string rather than an object, where the string ends in the suffix "s" (indicating seconds) and is preceded by the number of seconds, with nanoseconds expressed as fractional seconds. For example, 3 seconds with 0 nanoseconds should be encoded in JSON format as "3s", while 3 seconds and 1 nanosecond should be expressed in JSON format as "3.000000001s", and 3 seconds and 1 microsecond should be expressed in JSON format as "3.000001s".


Holder for reflection information generated from google/protobuf/duration.proto


A generic empty message that you can re-use to avoid defining duplicated empty messages in your APIs. A typical example is to use it as the request or the response type of an API method. For instance:

service Foo {
  rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty);


Holder for reflection information generated from google/protobuf/empty.proto


Enum type definition.


Enum value definition.


A single field of a message type.


Container for nested types declared in the Field message type.


FieldMask represents a set of symbolic field paths, for example:

paths: "f.a"
paths: "f.b.d"

Here f represents a field in some root message, a and b fields in the message found in f, and d a field found in the message in f.b.

Field masks are used to specify a subset of fields that should be returned by a get operation or modified by an update operation. Field masks also have a custom JSON encoding (see below).

Field Masks in Projections

When used in the context of a projection, a response message or sub-message is filtered by the API to only contain those fields as specified in the mask. For example, if the mask in the previous example is applied to a response message as follows:

f {
  a : 22
  b {
    d : 1
    x : 2
  y : 13
z: 8

The result will not contain specific values for fields x,y and z (their value will be set to the default, and omitted in proto text output):

f {
  a : 22
  b {
    d : 1

A repeated field is not allowed except at the last position of a paths string.

If a FieldMask object is not present in a get operation, the operation applies to all fields (as if a FieldMask of all fields had been specified).

Note that a field mask does not necessarily apply to the top-level response message. In case of a REST get operation, the field mask applies directly to the response, but in case of a REST list operation, the mask instead applies to each individual message in the returned resource list. In case of a REST custom method, other definitions may be used. Where the mask applies will be clearly documented together with its declaration in the API. In any case, the effect on the returned resource/resources is required behavior for APIs.

Field Masks in Update Operations

A field mask in update operations specifies which fields of the targeted resource are going to be updated. The API is required to only change the values of the fields as specified in the mask and leave the others untouched. If a resource is passed in to describe the updated values, the API ignores the values of all fields not covered by the mask.

If a repeated field is specified for an update operation, new values will be appended to the existing repeated field in the target resource. Note that a repeated field is only allowed in the last position of a paths string.

If a sub-message is specified in the last position of the field mask for an update operation, then new value will be merged into the existing sub-message in the target resource.

For example, given the target message:

f {
  b {
    d: 1
    x: 2
  c: [1]

And an update message:

f {
  b {
    d: 10
  c: [2]

then if the field mask is:

paths: ["f.b", "f.c"]

then the result will be:

f {
  b {
    d: 10
    x: 2
  c: [1, 2]

An implementation may provide options to override this default behavior for repeated and message fields.

In order to reset a field's value to the default, the field must be in the mask and set to the default value in the provided resource. Hence, in order to reset all fields of a resource, provide a default instance of the resource and set all fields in the mask, or do not provide a mask as described below.

If a field mask is not present on update, the operation applies to all fields (as if a field mask of all fields has been specified). Note that in the presence of schema evolution, this may mean that fields the client does not know and has therefore not filled into the request will be reset to their default. If this is unwanted behavior, a specific service may require a client to always specify a field mask, producing an error if not.

As with get operations, the location of the resource which describes the updated values in the request message depends on the operation kind. In any case, the effect of the field mask is required to be honored by the API.

Considerations for HTTP REST

The HTTP kind of an update operation which uses a field mask must be set to PATCH instead of PUT in order to satisfy HTTP semantics (PUT must only be used for full updates).

JSON Encoding of Field Masks

In JSON, a field mask is encoded as a single string where paths are separated by a comma. Fields name in each path are converted to/from lower-camel naming conventions.

As an example, consider the following message declarations:

message Profile {
  User user = 1;
  Photo photo = 2;
message User {
  string display_name = 1;
  string address = 2;

In proto a field mask for Profile may look as such:

mask {
  paths: "user.display_name"
  paths: "photo"

In JSON, the same mask is represented as below:

  mask: "user.displayName,photo"

Field Masks and Oneof Fields

Field masks treat fields in oneofs just as regular fields. Consider the following message:

message SampleMessage {
  oneof test_oneof {
    string name = 4;
    SubMessage sub_message = 9;

The field mask can be:

mask {
  paths: "name"


mask {
  paths: "sub_message"

Note that oneof type names ("test_oneof" in this case) cannot be used in paths.

Field Mask Verification

The implementation of any API method which has a FieldMask type field in the request should verify the included field paths, and return an INVALID_ARGUMENT error if any path is unmappable.


Options to customize merging behavior.


Holder for reflection information generated from google/protobuf/field_mask.proto


Wrapper message for float.

The JSON representation for FloatValue is JSON number.


Wrapper message for int32.

The JSON representation for Int32Value is JSON number.


Wrapper message for int64.

The JSON representation for Int64Value is JSON string.


ListValue is a wrapper around a repeated field of values.

The JSON representation for ListValue is JSON array.


Method represents a method of an API interface.


Declares an API Interface to be included in this interface. The including interface must redeclare all the methods from the included interface, but documentation and options are inherited as follows:

  • If after comment and whitespace stripping, the documentation string of the redeclared method is empty, it will be inherited from the original method.

  • Each annotation belonging to the service config (http, visibility) which is not set in the redeclared method will be inherited.

  • If an http annotation is inherited, the path pattern will be modified as follows. Any version prefix will be replaced by the version of the including interface plus the [root][] path if specified.

Example of a simple mixin:

package google.acl.v1;
service AccessControl {
  // Get the underlying ACL object.
  rpc GetAcl(GetAclRequest) returns (Acl) {
    option (google.api.http).get = "/v1/{resource=**}:getAcl";

service Storage {
  rpc GetAcl(GetAclRequest) returns (Acl);

  // Get a data record.
  rpc GetData(GetDataRequest) returns (Data) {
    option (google.api.http).get = "/v2/{resource=**}";

Example of a mixin configuration:

- name:
  - name: google.acl.v1.AccessControl

The mixin construct implies that all methods in AccessControl are also declared with same name and request/response types in Storage. A documentation generator or annotation processor will see the effective Storage.GetAcl method after inherting documentation and annotations as follows:

service Storage {
  // Get the underlying ACL object.
  rpc GetAcl(GetAclRequest) returns (Acl) {
    option (google.api.http).get = "/v2/{resource=**}:getAcl";

Note how the version in the path pattern changed from v1 to v2.

If the root field in the mixin is specified, it should be a relative path under which inherited HTTP paths are placed. Example:

- name:
  - name: google.acl.v1.AccessControl
    root: acls

This implies the following inherited HTTP annotation:

service Storage {
  // Get the underlying ACL object.
  rpc GetAcl(GetAclRequest) returns (Acl) {
    option (google.api.http).get = "/v2/acls/{resource=**}:getAcl";


A protocol buffer option, which can be attached to a message, field, enumeration, etc.


SourceContext represents information about the source of a protobuf element, like the file in which it is defined.


Holder for reflection information generated from google/protobuf/source_context.proto


Wrapper message for string.

The JSON representation for StringValue is JSON string.


Struct represents a structured data value, consisting of fields which map to dynamically typed values. In some languages, Struct might be supported by a native representation. For example, in scripting languages like JS a struct is represented as an object. The details of that representation are described together with the proto support for the language.

The JSON representation for Struct is JSON object.


Holder for reflection information generated from google/protobuf/struct.proto


Extension methods on BCL time-related types, converting to protobuf types.


A Timestamp represents a point in time independent of any time zone or local calendar, encoded as a count of seconds and fractions of seconds at nanosecond resolution. The count is relative to an epoch at UTC midnight on January 1, 1970, in the proleptic Gregorian calendar which extends the Gregorian calendar backwards to year one.

All minutes are 60 seconds long. Leap seconds are "smeared" so that no leap second table is needed for interpretation, using a 24-hour linear smear.

The range is from 0001-01-01T00:00:00Z to 9999-12-31T23:59:59.999999999Z. By restricting to that range, we ensure that we can convert to and from RFC 3339 date strings.


Example 1: Compute Timestamp from POSIX time().

Timestamp timestamp;

Example 2: Compute Timestamp from POSIX gettimeofday().

struct timeval tv;
gettimeofday(&tv, NULL);

Timestamp timestamp;
timestamp.set_nanos(tv.tv_usec * 1000);

Example 3: Compute Timestamp from Win32 GetSystemTimeAsFileTime().

UINT64 ticks = (((UINT64)ft.dwHighDateTime) << 32) | ft.dwLowDateTime;

// A Windows tick is 100 nanoseconds. Windows epoch 1601-01-01T00:00:00Z
// is 11644473600 seconds before Unix epoch 1970-01-01T00:00:00Z.
Timestamp timestamp;
timestamp.set_seconds((INT64) ((ticks / 10000000) - 11644473600LL));
timestamp.set_nanos((INT32) ((ticks % 10000000) * 100));

Example 4: Compute Timestamp from Java System.currentTimeMillis().

long millis = System.currentTimeMillis();

Timestamp timestamp = Timestamp.newBuilder().setSeconds(millis / 1000)
    .setNanos((int) ((millis % 1000) * 1000000)).build();

Example 5: Compute Timestamp from Java

Instant now =;

Timestamp timestamp =

Example 6: Compute Timestamp from current time in Python.

timestamp = Timestamp()

JSON Mapping

In JSON format, the Timestamp type is encoded as a string in the RFC 3339 format. That is, the format is "{year}-{month}-{day}T{hour}:{min}:{sec}[.{frac_sec}]Z" where {year} is always expressed using four digits while {month}, {day}, {hour}, {min}, and {sec} are zero-padded to two digits each. The fractional seconds, which can go up to 9 digits (i.e. up to 1 nanosecond resolution), are optional. The "Z" suffix indicates the timezone ("UTC"); the timezone is required. A proto3 JSON serializer should always use UTC (as indicated by "Z") when printing the Timestamp type and a proto3 JSON parser should be able to accept both UTC and other timezones (as indicated by an offset).

For example, "2017-01-15T01:30:15.01Z" encodes 15.01 seconds past 01:30 UTC on January 15, 2017.

In JavaScript, one can convert a Date object to this format using the standard toISOString() method. In Python, a standard datetime.datetime object can be converted to this format using strftime with the time format spec '%Y-%m-%dT%H:%M:%S.%fZ'. Likewise, in Java, one can use the Joda Time's ISODateTimeFormat.dateTime() to obtain a formatter capable of generating timestamps in this format.


Holder for reflection information generated from google/protobuf/timestamp.proto


A protocol buffer message type.


Holder for reflection information generated from google/protobuf/type.proto


Wrapper message for uint32.

The JSON representation for UInt32Value is JSON number.


Wrapper message for uint64.

The JSON representation for UInt64Value is JSON string.


Value represents a dynamically typed value which can be either null, a number, a string, a boolean, a recursive struct value, or a list of values. A producer of value is expected to set one of these variants. Absence of any variant indicates an error.

The JSON representation for Value is JSON value.


Holder for reflection information generated from google/protobuf/wrappers.proto



Whether a field is optional, required, or repeated.


Basic field types.


NullValue is a singleton enumeration to represent the null value for the Value type union.

The JSON representation for NullValue is JSON null.


The syntax in which a protocol buffer element is defined.


Enum of possible cases for the "kind" oneof.