Api

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 https://cloud.google.com/apis/design/glossary for detailed terminology.

JSON representation 
{
  "name": string,
  "methods": [
    {
      object (Method)
    }
  ],
  "options": [
    {
      object (Option)
    }
  ],
  "version": string,
  "sourceContext": {
    object (SourceContext)
  },
  "mixins": [
    {
      object (Mixin)
    }
  ],
  "syntax": enum (Syntax)
}
Fields
name

string

The fully qualified name of this interface, including package name followed by the interface's simple name.
methods[]

object (Method)

The methods of this interface, in unspecified order.
options[]

object (Option)

Any metadata attached to the interface.
version

string

A version string for this interface. If specified, must have the form major-version.minor-version, as in 1.10. If the minor version is omitted, it defaults to zero. If the entire version field is empty, the major version is derived from the package name, as outlined below. If the field is not empty, the version in the package name will be verified to be consistent with what is provided here.

The versioning schema uses semantic versioning where the major version number indicates a breaking change and the minor version an additive, non-breaking change. Both version numbers are signals to users what to expect from different versions, and should be carefully chosen based on the product plan.

The major version is also reflected in the package name of the interface, which must end in v<major-version>, as in google.feature.v1. For major versions 0 and 1, the suffix can be omitted. Zero major versions must only be used for experimental, non-GA interfaces.
sourceContext

object (SourceContext)

Source context for the protocol buffer service represented by this message.
mixins[]

object (Mixin)

Included interfaces. See Mixin.
syntax

enum (Syntax)

The source syntax of the service.

Method

Method represents a method of an API interface.

JSON representation 
{
  "name": string,
  "requestTypeUrl": string,
  "requestStreaming": boolean,
  "responseTypeUrl": string,
  "responseStreaming": boolean,
  "options": [
    {
      object (Option)
    }
  ],
  "syntax": enum (Syntax)
}
Fields
name

string

The simple name of this method.
requestTypeUrl

string

A URL of the input message type.
requestStreaming

boolean

If true, the request is streamed.
responseTypeUrl

string

The URL of the output message type.
responseStreaming

boolean

If true, the response is streamed.
options[]

object (Option)

Any metadata attached to the method.
syntax

enum (Syntax)

The source syntax of this method.

Option

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

JSON representation 
{
  "name": string,
  "value": {
    "@type": string,
    field1: ...,
    ...
  }
}
Fields
name

string

The option's name. For protobuf built-in options (options defined in descriptor.proto), this is the short name. For example, "mapEntry". For custom options, it should be the fully-qualified name. For example, "google.api.http".
value

object

The option's value packed in an Any message. If the value is a primitive, the corresponding wrapper type defined in google/protobuf/wrappers.proto should be used. If the value is an enum, it should be stored as an int32 value using the google.protobuf.Int32Value type.

An object containing fields of an arbitrary type. An additional field "@type" contains a URI identifying the type. Example: { "id": 1234, "@type": "types.example.com/standard/id" }.

SourceContext

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

JSON representation 
{
  "fileName": string
}
Fields
fileName

string

The path-qualified name of the .proto file that contained the associated protobuf element. For example: "google/protobuf/sourceContext.proto".

Mixin

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";
  }
}

package google.storage.v2;
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:

apis:
- name: google.storage.v2.Storage
  mixins:
  - 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:

apis:
- name: google.storage.v2.Storage
  mixins:
  - 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";
  }
  ...
}
JSON representation 
{
  "name": string,
  "root": string
}
Fields
name

string

The fully qualified name of the interface which is included.
root

string

If non-empty specifies a path under which inherited HTTP paths are rooted.