protoc-gen-graphql

protoc-gen-graphql is a highly customizable Protobuf compiler plugin to generate GraphQL schema definition language (SDL) files.

Usage

First, download the plugin and place the executable in your path. Then, run the Protobuf compiler with the --graphql_out flag to enable this plugin. Set the value of this flag to the directory you want the SDL files to be generated into.

protoc -I . --graphql_out=output_dir path/to/file.proto ...

Parameters

The SDL generation can be customized by passing optional parameters to the plugin. Parameters are specified using a comma separated list of parameters before the output directory, separated by a colon. For example:

protoc -I . --graphql_out=root_type_prefix=GRPC,null_wrappers:output_dir path/to/file.proto ...

Note that parameter settings apply to all the generated GraphQL types and files. For settings that apply to single Protobuf objects, like messages and fields, refer to the Protobuf options section below.

Available parameters are:

Key	Values	Default	Description
field_name	lower_camel_case, preserve	lower_camel_case	Transformation from Protobuf field names to GraphQL field names. Default is lowerCamelCase. Use preserve to use the Protobuf name as-is.
trim_prefix	string		Trims the provided prefix from all generated GraphQL type names. Useful if your Protobuf package names have a common prefix you want to omit.
root_type_prefix	string		If set, a gRPC service's mapped query and mutation types will extend some custom root type with name given by the provided prefix plus Query or Mutation. Set to empty string to extend the root Query and Mutation types.
input_mode	all, service, none	service	The input mode determines what GraphQL input objects will be generated. all will generate an input object for each Protobuf message. service will only generate inputs for messages that are transitively used in each gRPC methods' request messages. none will not generate any input objects.
null_wrappers	bool	false	If true, well known wrapper types (e.g. google.protobuf.StringValue) will be mapped to nullable GraphQL scalar types instead of the corresponding object type.
js_64bit_type	string, number	number	Whether to use a String or Float scalar type when mapping 64bit Protobuf types (int64, uint64, sint64, fixed64, sfixed64).
timestamp	string		GraphQL type name to use for the well known google.protobuf.Timestamp type.
duration	string		GraphQL type name to use for the well known google.protobuf.Duration type.
struct	string		GraphQL type name to use for the well known google.protobuf.Struct type.

Protobuf options

Protobuf options file

TODO

Protobuf to GraphQL mapping

TODO

Messages

Maps

Oneofs

Enums

Services