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

`ts
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.