Pluskode Expo Client SDK

Expo-optimized client SDK for Pluskode Backend Framework.

Status

✅ Ready - Optimized for Expo managed workflow

Features

• ✅ HTTP client (HTTPS required in production)
• ✅ WebSocket client (WSS required in production)
• ✅ SSE client
• ✅ gRPC client (via gRPC-Web)
• ✅ MQTT client (over WebSocket)
• ✅ Binary stream support (via WebSocket binary frames)
• ✅ Automatic HTTPS/WSS enforcement
• ✅ App Store/Play Store compliant
• ✅ Pure JavaScript/TypeScript (no native modules)

Installation

npm install @pluskode/client-expo
# or
yarn add @pluskode/client-expo

Usage

Basic Setup

import { PluskodeExpoClient } from '@pluskode/client-expo';

// Production (HTTPS required)
const client = new PluskodeExpoClient({
    baseURL: 'https://api.example.com',
    timeout: 30000,
    retries: 3
});

// Development (localhost HTTP allowed)
const devClient = new PluskodeExpoClient({
    baseURL: 'http://localhost:3000',
    enforceSecure: false // Allow HTTP for localhost
});

HTTP Requests

// GET request
const users = await client.get('/api/users');

// POST request
const newUser = await client.post('/api/users', {
    name: 'John',
    email: '[email protected]'
});

// PUT, PATCH, DELETE
await client.put('/api/users/123', { name: 'Jane' });
await client.patch('/api/users/123', { email: '[email protected]' });
await client.delete('/api/users/123');

WebSocket

// Subscribe to channel (uses WSS automatically)
const unsubscribe = client.subscribe('chat/room1', (data) => {
    console.log('Message:', data);
});

// Send message
client.send('chat/room1', { text: 'Hello!' });

// Unsubscribe
unsubscribe();

Server-Sent Events (SSE)

const unsubscribe = client.subscribeSSE('/events/stream', (event) => {
    console.log('Event:', event.event, 'Data:', event.data);
});

// Close
unsubscribe();

gRPC (via gRPC-Web)

const user = await client.rpc(
    'UserService',
    'GetUser',
    { id: '123' }
);

MQTT (over WebSocket)

// Subscribe
const unsubscribe = client.subscribeMQTT(
    'sensors/temperature',
    (topic, message, qos) => {
        console.log(`${topic}: ${message} (QoS: ${qos})`);
    },
    { qos: 1 }
);

// Publish
await client.publishMQTT(
    'sensors/temperature',
    '25.5',
    { qos: 1, retain: false }
);

Expo Example

import React, { useEffect, useState } from 'react';
import { View, Text, FlatList } from 'react-native';
import { PluskodeExpoClient } from '@pluskode/client-expo';

const client = new PluskodeExpoClient({
    baseURL: __DEV__ ? 'http://localhost:3000' : 'https://api.example.com'
});

export function UsersScreen() {
    const [users, setUsers] = useState([]);
    const [messages, setMessages] = useState([]);

    useEffect(() => {
        // Load users
        client.get('/api/users')
            .then(res => setUsers(res.data))
            .catch(err => console.error(err));

        // Subscribe to chat
        const unsubscribe = client.subscribe('chat/room1', (data) => {
            setMessages(prev => [...prev, data]);
        });

        return () => unsubscribe();
    }, []);

    return (
        <View>
            <FlatList
                data={users}
                renderItem={({ item }) => <Text>{item.name}</Text>}
            />
            <FlatList
                data={messages}
                renderItem={({ item }) => <Text>{item.text}</Text>}
            />
        </View>
    );
}

Security & Compliance

HTTPS/WSS Enforcement

• Production: HTTPS/WSS is automatically enforced
• Development: HTTP/WS allowed only for localhost
• App Store/Play Store: Fully compliant

Why HTTPS/WSS?

1. App Store Requirements: iOS requires HTTPS for network requests
2. Play Store Requirements: Android requires secure connections
3. Security: Protects data in transit
4. Expo Managed Workflow: No native modules, pure JS/TS

Differences from React Native Client

| Feature | Expo Client | React Native Client | |---------|-------------|---------------------| | Native Modules | ❌ Not supported | ✅ Can use native modules | | HTTPS Enforcement | ✅ Automatic | ⚠️ Manual | | Managed Workflow | ✅ Optimized | ⚠️ May require custom native code | | App Store Ready | ✅ Yes | ⚠️ Depends on setup |

Limitations

Since Expo managed workflow doesn't support custom native modules:

• gRPC: Uses gRPC-Web (via HTTP/HTTPS) instead of native gRPC
• MQTT: Uses MQTT over WebSocket instead of native MQTT
• Binary Streams: Uses WebSocket binary frames instead of raw TCP

These limitations are acceptable for most use cases and ensure App Store/Play Store compliance.

Requirements

• Expo SDK 45.0+
• React Native 0.60+
• TypeScript 5.0+ (optional)

License

MIT

Note: This client is optimized for Expo managed workflow. For bare React Native projects, use @pluskode/client-react-native instead.