react-native-nitro-protobuf

Nitro + Nanopb bridge for fast protobuf encode/decode on iOS and Android.

What it does

• Encodes/decodes protobuf messages in C++ (Nanopb).
• JS inputs/outputs are JSON-like AnyMap objects.
• Binary payloads are passed as ArrayBuffer.

Install

npm install react-native-nitro-protobuf react-native-nitro-modules

cd ios && pod install

Generate Nanopb sources

1. Install protoc and the Nanopb generator:

brew install protobuf nanopb

2. Put your .proto files in your app (example uses ./proto).
3. Add .options files to define max_length, max_size, and max_count.
4. Generate C sources + registry:

npx react-native-nitro-protobuf --protoDir ./proto --outDir ./node_modules/react-native-nitro-protobuf/generated

The generator writes:

• generated/*.pb.h and generated/*.pb.c
• generated/nitro_protobuf_registry.cpp

Usage

import { NitroProtobuf } from 'react-native-nitro-protobuf'

const encoded = NitroProtobuf.encode('nitro.protobuf.UserProfile', {
  id: 1,
  name: 'Ada',
  scores: [10, 20],
  avatar: 'base64...',
  active: true,
})

const decoded = NitroProtobuf.decode('nitro.protobuf.UserProfile', encoded)
const names = NitroProtobuf.listMessages()

Notes and limitations

• Only Nanopb static fields are supported. Use .options to set:
  • max_length for strings
  • max_size for bytes
  • max_count for repeated fields
• oneof and map fields are not supported.
• bytes fields use base64 strings (encode accepts base64 or number[]).
• 64-bit numbers are returned as strings to avoid precision loss.

Example protos

See proto/example.proto and proto/example.options for a minimal setup.

Tests

npm test

Native integration coverage runs automatically when protoc, protoc-gen-nanopb, and a C++ compiler are available. It skips otherwise.