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
}