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Protocol Buffers are a language-neutral, platform-neutral, extensible way of serializing structured data for use in communications protocols, data storage, and more, originally designed at Google (see).

protobuf.js is a pure JavaScript implementation on top of bytebuffer.js including a .proto parser, message class building and simple encoding and decoding. There is no compilation step required, it’s super easy to use and it works out of the box on .proto files!

Getting started



node.js / CommonJS

$> npm install protobufjs
var ProtoBuf = require("protobufjs");

RequireJS / AMD

Requires bytebuffer.js. Optionally depends on long.js for long (int64) support. If you do not require long support, you can skip the Long.js config. RequireJS example:

require(["protobuf"], function(ProtoBuf) {

Or as a module dependency:

define("MyModule", ["protobuf"], function(ProtoBuf) {


Requires bytebuffer.js. Optionally depends on long.js for long (int64) support. If you do not require long support, you can skip the Long.js include.

<!-- Order is important -->
<script src="long.min.js"></script>
<script src="bytebuffer.min.js"></script>
<script src="protobuf.min.js"></script>
var ProtoBuf = dcodeIO.ProtoBuf;

Getting started

Note: You’ll need the full build to load .proto data. light builds are able to load JSON only.

Loading .proto files

To load a .proto file, use:

API: ProtoBuf.loadProtoFile(source[, callback[, builder]]):Builder|undefined

// Synchronously
var builder = ProtoBuf.loadProtoFile("path/to/file.proto");

// Asynchronously
ProtoBuf.loadProtoFile("path/to/file.proto", function(err, builder) {

ProtoBuf.loadProtoFile also accepts an object specifying the import root directory and the file to load as its first parameter: {root: string, file: string}. Additionally, an already created and then reused builder can be specified as the last argument, which is useful if all the definitions shall reside in a single namespace.

Loading .proto strings

API: ProtoBuf.loadProto(source[, builder][, filename]):Builder

var builder = ProtoBuf.loadProto(...protoString..., "myproto.proto");

Loading JSON files and strings

To load the (raw) JSON counterpart generated through pbjs, use ProtoBuf.loadJsonFile respectively ProtoBuf.loadJson. It’s the same API.

If you generated classes or modules with it, loading is done just by including respectively requiring the resulting file. Loading is handled transparently in this case.

When using JSON only, you can use protobuf-light.js or protobuf-light.min.js instead, which do NOT include the ProtoBuf.DotProto package for parsing and are therefore smaller.

Command line

Since ProtoBuf.js 4.0.0 the library ships with the pbjs command line utility. With it it’s possible to convert between .proto and JSON descriptors and even to generate the code required to access runtime structures as pure JS (classes), an AMD module or a CommonJS module.

 _ |_ . _
|_)|_)|_)           ProtoBuf.js v4.0.0-b3
|     '

CLI utility to convert between .proto and JSON syntax / to generate classes.

Usage: pbjs <filename> [options] [> outFile]

  --help, -h        Show help  [boolean]
  --version, -v     Show version number  [boolean]
  --source, -s      Specifies the source format. Valid formats are:

                       json       Plain JSON descriptor
                       proto      Plain .proto descriptor

  --target, -t      Specifies the target format. Valid formats are:

                       amd        Runtime structures as AMD module
                       commonjs   Runtime structures as CommonJS module
                       js         Runtime structures
                       json       Plain JSON descriptor
                       proto      Plain .proto descriptor

  --using, -u       Specifies an option to apply to the volatile builder
                    loading the source, e.g. convertFieldsToCamelCase.
  --min, -m         Minifies the output.  [default: false]
  --path, -p        Adds a directory to the include path.
  --legacy, -l      Includes legacy descriptors from google/protobuf/ if
                    explicitly referenced.  [default: false]
  --quiet, -q       Suppresses any informatory output to stderr.  [default: false]
  --use, -i         Specifies an option to apply to the emitted builder
                    utilized by your program, e.g. populateAccessors.
  --exports, -e     Specifies the namespace to export. Defaults to export
                    the root namespace.
  --dependency, -d  Library dependency to use when generating classes.
                    Defaults to 'protobufjs' for CommonJS, 'ProtoBuf' for
                    AMD modules and 'dcodeIO.ProtoBuf' for classes.




CDN usage

<script src="//"></script>

With the version pointing to the exact release your project depends upon.

License: Apache License, Version 2.0