proto2graphql

Converts schema definitions in Protocol Buffer (proto3) to GraphQL. Can be used to help generate a GraphQL API gateway to gRPC backend services.

Installation

npm install -g proto2graphql

Usage

proto2graphql --input [input .proto path] --output [output .graphql path]

Conversions

Messages

Protocol Buffer

message SearchRequest {
  string query = 1;
  int32 page_number = 2;
  int32 result_per_page = 3;
}

GraphQL

type SearchRequest {
  query: String
  pageNumber: Int
  resultPerPage: Int
}

Scalar Value Types

Protocol Buffer	GraphQL
double	Float
float	Float
int32	Int
int64	Int
uint32	Int
uint64	Int
sint32	Int
sint64	Int
fixed32	Int
fixed64	Int
sfixed32	Int
sfixed64	Int
bool	Boolean
string	String
bytes	String

Enumerations

Protocol Buffer

enum Corpus {
  UNIVERSAL = 0;
  WEB = 1;
  IMAGES = 2;
  LOCAL = 3;
  NEWS = 4;
  PRODUCTS = 5;
  VIDEO = 6;
}

GraphQL

enum Corpus {
  UNIVERSAL
  WEB
  IMAGES
  LOCAL
  NEWS
  PRODUCTS
  VIDEO
}

Nested Types

Protocol Buffer

message SearchResponse {
  message Result {
    string url = 1;
    string title = 2;
  }
  Result result = 1;
}

GraphQL

type SearchResponse {
  results: SearchResponse_Result
}

type SearchResponse_Result {
  url: String
  title: String
}

Oneof

Protocol Buffer

message UserAuth {
  message GoogleProvider {
    int32 gid = 1;
  }

  message FacebookProvider {
    string fbid = 1;
  }

  oneof provider {
    GoogleProvider google = 1;
    FacebookProvider facebook = 2;
    string generic = 3;
  }
}

GraphQL

type UserAuth {
  provider: UserAuth_provider
}

union UserAuth_provider =
    UserAuth_GoogleProvider
  | UserAuth_FacebookProvider
  | String

type UserAuth_GoogleProvider {
  gid: Int
}

type UserAuth_FacebookProvider {
  fbid: String
}

Maps

Protocol Buffer

message User {
  map<string, Attribute> attributes = 1;
}

message Attribute {
  string value = 1;
}

GraphQL

type User {
  attributes: [String_Attribute_map]
}

type String_Attribute_map {
  key: String
  value: Attribute
}

type Attribute {
  value: String
}

Packages

Protocol Buffer

package proto2graphql.common;

message TypeA {
  int32 field = 1;
}

GraphQL

type proto2graphql_common_TypeA {
  field: Int
}

Well-Known Types

Protocol Buffer

import "google/protobuf/duration.proto";
import "google/protobuf/timestamp.proto";

message WellKnownTypes {
  google.protobuf.Duration duration_field = 1;
  google.protobuf.Timestamp timestamp_field = 2;
}

GraphQL

type WellKnownTypes {
  durationField: google_protobuf_Duration
  timestampField: google_protobuf_Timestamp
}

type google_protobuf_Duration {
  seconds: Int
  nanos: Int
}

type google_protobuf_Timestamp {
  seconds: Int
  nanos: Int
}