Platforms and transports

SDK surfaces

Surface	Installation	Deployment requirements
React Native	`npm install @offline-protocol/mesh-sdk@0.33.0`	Native iOS or Android app; not Expo Go or a browser.
Python	`pip install offline-protocol-sdk` (0.33.0)	Python 3.10 to 3.13 on macOS 14+ arm64, Linux x86_64 or aarch64 with glibc 2.34+, or Windows x86_64. Other hosts build from source.
Python local API	`offline-protocol-service`, in the Python package	One engine shared by several local applications over JSON-RPC, on every transport the configuration enables. See local API service.
HTTP front	`pip install 'offline-protocol-sdk[lan,http]'`, then `offline-protocol-service --http`; or the published image `ghcr.io/offline-protocol/offline-protocol-service:0.33.0`	Programs that do not use the SDK call services on other devices over plain HTTP. The image runs the service with the front for linux/amd64 and linux/arm64. See HTTP front.
Swift (preview)	SwiftPM: `https://github.com/Offline-Protocol/offline-protocol-swift.git`, from 0.33.0	iOS 13+, iOS only. Storage providers are not yet public; the app wires transports to the engine.
Android (preview)	Maven Central: `implementation("com.offlineprotocol:offline-protocol-sdk:0.33.0")`	Android 7+ (API 24). Kotlin bindings, native libraries for four ABIs, and the Android transport and storage classes; the app wires them to the engine. See native packages.
Flutter (preview)	Path dependency on `bindings/flutter/offline_protocol` in the SDK repository at `v0.33.0`; not on pub.dev	Flutter 3.10+, iOS 13+, Android 7+ (API 24). `MeshSdk` carries the React Native module’s native surface: messaging, groups, documents, services, files, telemetry and every transport, with the Android foreground service. See Flutter plugin.
Java	Maven Central: `implementation("com.offlineprotocol:offline-protocol-java:0.33.0")`, with the native library from the GitHub release	JDK 22+ on Linux x86_64 or aarch64, macOS arm64 or Windows x86_64. The host supplies transports and storage. See Java binding.
C	`offline_protocol.h` and the native library in the GitHub release’s desktop archives	Linux x86_64 or aarch64, macOS arm64 or Windows x86_64, from C or any language that calls C. The host supplies transports and storage. See C binding.
Ruby	RubyGems: `gem "offline_protocol", "0.33.0"`, with the native library from the GitHub release	Ruby 3.3+ and the `ffi` gem on Linux x86_64 or aarch64, macOS arm64 or Windows x86_64. The host supplies transports and storage. See Ruby binding.
C# (preview)	Project reference to `bindings/csharp` in the SDK repository at `v0.33.0`, with the native library from the GitHub release; not on NuGet	.NET 8+ on Windows x86_64, Linux x86_64 or aarch64, or macOS arm64, over the C API. The host supplies transports and storage. See C# binding.
Browser (experimental)	Build `bindings/web` from the SDK repository at `v0.33.0`; the engine is the `offline-protocol-web` crate on crates.io	A full node in a Web Worker with OPFS storage, in a secure context. Links tabs, devices on one network over WebRTC, phones and boards over Web Bluetooth (Chromium), and any device over the application’s Nostr relays. See browser binding.
Rust	`offline-protocol@=0.33.0` from crates.io	Supply transport I/O and storage for the target.
Constrained leaf	`offline-protocol-leaf@=0.33.0` from crates.io	Firmware integration, entropy, storage and radio I/O; a full peer participates in session setup. Compiles for Cortex-M33, ESP32 RISC-V, Cortex-M0 and WASI; see build targets.

Transport compatibility

Path	React Native	Python / embedded considerations
Bluetooth LE	iOS and Android native bridges	Central via `bleak`, peripheral via `bless` (installed by default except on Windows). The SDK starts a peripheral when BLE is enabled; qualify host support and permissions.
Wi-Fi / peer streams	Android: Wi-Fi Direct, with optional group formation by the SDK on Android 10+, and from v0.29.0 the Wi-Fi network it is on. iOS: Network framework over the local network or AWDL. Both carry authenticated streams from v0.28.0. See phone Wi-Fi peer streams.	Python’s `wifi_direct` slot carries authenticated TCP peer streams over an existing IP network and reaches iPhones and, from v0.29.0, Android phones on the same Wi-Fi network. It does not create a Wi-Fi Direct group.
Internet relay	WebSocket connection to a configured relay	Python includes a client. A constrained MCU requires its own relay client or a companion full peer.
Reticulum	Requires a configured daemon/gateway that the SDK package does not ship	Python integrations must provide the working transport callback; enabling a flag alone does not supply the bridge.
Nostr	Requires reachable relays	Python integrations must provide the working transport callback. Nostr relay access requires a network path.

A shared transport name does not establish cross-platform interoperability. In particular, the iOS peer stream does not reach an Android Wi-Fi Direct group; an iPhone and an Android phone on 0.29.0 or later meet over that slot only on a shared Wi-Fi network that allows multicast. An iPhone on 0.28.0 or later does not see one on 0.27 or earlier over that slot. Qualify the exact device pair and path; use BLE for the phone quickstart.

Before you deploy

Confirm radio roles, permissions, background execution, payload size, battery use, storage capacity and restart behaviour on the actual hardware. Test internet loss separately from peer-link loss. A simulator build checks application integration, not radio delivery. See React Native installation, Python, Java, C, Ruby, the browser and embedded integration.

Obtain relay access

Turn on the hosted relay with offline apps features enable relay, or with Hosted relay in the application’s Mesh SDK tab in the developer portal. Every plan includes relay deliveries (10,000 a month on Free), and usage beyond the quota is billed at the published rate; see hosted plans and usage. Each device authenticates to the relay with its signed-in user’s OfflineID session token as authToken. Guest sessions, portal API keys, and developer or admin tokens are not accepted. Then set the relay WebSocket serverAddress to wss://relay.offlineprotocol.com. Local peer-to-peer traffic is never metered on any plan.

Start here

Workflows

Examples and integrations

Operate and ship

Developer portal

Support

SDK surfaces

Transport compatibility

Before you deploy

Obtain relay access