Skip to main content

Documentation Index

Fetch the complete documentation index at: https://mintlify.com/jlucaso1/whatsapp-rust/llms.txt

Use this file to discover all available pages before exploring further.

​
Overview

WhatsApp-Rust is a high-performance, async Rust library for the WhatsApp Web API. The project follows a modular, layered architecture that separates protocol concerns from runtime concerns, enabling platform-agnostic core logic with pluggable backends.

​
Workspace Structure

The project is organized as a Cargo workspace with multiple crates: 
whatsapp-rust/
├── src/                          # Main client library
├── wacore/                       # Platform-agnostic core
│   ├── binary/                   # WhatsApp binary protocol
│   ├── libsignal/                # Signal Protocol implementation
│   ├── appstate/                 # App state management
│   ├── noise/                    # Noise Protocol handshake
│   └── derive/                   # Derive macros
├── waproto/                      # Protocol Buffers definitions
├── storages/sqlite-storage/      # SQLite backend
├── transports/tokio-transport/   # Tokio WebSocket transport
└── http_clients/ureq-client/     # HTTP client for media

​
Three Main Crates

​
wacore - Platform-Agnostic Core

Location: wacore/ Purpose: Contains core logic for the WhatsApp binary protocol, cryptography primitives, IQ protocol types, and state management traits. Key Features:
  • No runtime dependencies on Tokio or specific databases
  • Pure protocol implementation
  • Cryptographic operations (Signal Protocol, Noise Protocol)
  • Type-safe protocol node builders
Key Modules: 
wacore/
├── binary/           // Binary protocol encoding/decoding
├── libsignal/        // E2E encryption
├── noise/            // Noise Protocol handshake
├── appstate/         // App state sync protocol
├── iq/               // Type-safe IQ protocol types
├── protocol.rs       // ProtocolNode trait
├── types/
│   ├── events.rs     // Event definitions
│   └── message.rs    // Message types
└── store/
    ├── traits.rs     // Storage trait definitions
    └── device.rs     // Device state model

​
waproto - Protocol Buffers

Location: waproto/ Purpose: Houses WhatsApp’s Protocol Buffers definitions compiled to Rust structs. Build Process: 
// build.rs uses prost to compile .proto files
prost_build::compile_protos(&["src/whatsapp.proto"], &["src/"])?;
Generated Types:
  • Message - All message types
  • WebMessageInfo - Message metadata
  • HistorySync - Chat history
  • SyncActionValue - App state mutations

​
whatsapp-rust - Main Client

Location: src/ Purpose: Integrates wacore with the Tokio runtime, provides high-level client API, and manages storage. Key Features:
  • Asynchronous operations with Tokio
  • SQLite persistence (pluggable)
  • Event bus system
  • Feature modules (groups, media, etc.)

​
Key Components

​
Client

Location: src/client.rs Purpose: Orchestrates connection lifecycle, event bus, and high-level operations. 
pub struct Client {
    pub(crate) core: wacore::client::CoreClient,
    pub(crate) persistence_manager: Arc<PersistenceManager>,
    pub(crate) media_conn: Arc<RwLock<Option<MediaConn>>>,
    pub(crate) noise_socket: Arc<Mutex<Option<Arc<NoiseSocket>>>>,
    // ... connection state, caches, locks
}
Responsibilities:
  • Connection management
  • Request/response routing
  • Event dispatching
  • Session management

​
PersistenceManager

Location: src/store/persistence_manager.rs Purpose: Manages all state changes and persistence. 
pub struct PersistenceManager {
    device: Arc<RwLock<Device>>,
    backend: Arc<dyn Backend>,
    dirty: Arc<AtomicBool>,
    save_notify: Arc<Notify>,
}
Critical Pattern:
  • Never modify Device state directly
  • Use DeviceCommand + process_command()
  • For read-only: get_device_snapshot()

​
Signal Protocol

Location: wacore/libsignal/ & src/store/signal*.rs Purpose: End-to-end encryption via Signal Protocol implementation. Features:
  • Double Ratchet algorithm
  • Pre-key bundles
  • Session management
  • Sender keys for groups

​
Socket & Handshake

Location: src/socket/, src/handshake.rs Purpose: WebSocket connection and Noise Protocol handshake. Flow:
  1. WebSocket connection
  2. Noise handshake (XX pattern)
  3. Encrypted frame exchange

​
Module Interactions

​
Layer Responsibilities

​
wacore Layer (Platform-Agnostic)

  • Protocol logic
  • State traits
  • Cryptographic helpers
  • Data models
Example: IQ Protocol 
// wacore/src/iq/groups.rs
pub struct GroupQueryIq {
    group_jid: Jid,
}

impl IqSpec for GroupQueryIq {
    type Response = GroupInfoResponse;
    fn build_iq(&self) -> InfoQuery<'static> { /* ... */ }
    fn parse_response(&self, response: &Node) -> Result<Self::Response> { /* ... */ }
}

​
whatsapp-rust Layer (Runtime)

  • Runtime orchestration
  • Storage integration
  • User-facing API
Example: Feature API 
// src/features/groups.rs
impl Client {
    pub async fn get_group_info(&self, jid: &Jid) -> Result<GroupInfoResponse> {
        self.execute(GroupQueryIq::new(jid)).await
    }
}

​
Protocol Entry Points

​
Incoming Messages

Flow: src/message.rs → Signal decryption → Event dispatch 
// src/message.rs
pub async fn handle_message(client: &Arc<Client>, node: &Node) {
    // 1. Extract encrypted message
    // 2. Decrypt via Signal Protocol
    // 3. Dispatch Event::Message
}

​
Outgoing Messages

Flow: src/send.rs → Signal encryption → Socket send 
// src/send.rs
pub async fn send_message(client: &Arc<Client>, msg: &Message) {
    // 1. Encrypt via Signal Protocol
    // 2. Build protocol node
    // 3. Send via NoiseSocket
}

​
Socket Communication

Flow: src/socket/ → Noise framing → Transport 
// src/socket/mod.rs
impl NoiseSocket {
    pub async fn send_node(&self, node: Node) -> Result<()> {
        // 1. Marshal to binary
        // 2. Encrypt with Noise
        // 3. Frame and send
    }
}

​
Concurrency Patterns

​
Per-Chat Message Queues

Prevents race conditions where a later message is processed before the PreKey message: 
pub(crate) message_queues: Cache<String, mpsc::Sender<Arc<Node>>>,

​
Per-Device Session Locks

Prevents concurrent Signal protocol operations on the same session: 
pub(crate) session_locks: Cache<String, Arc<tokio::sync::Mutex<()>>>,

​
Background Saver

Periodic persistence with dirty flag optimization: 
impl PersistenceManager {
    pub fn run_background_saver(self: Arc<Self>, interval: Duration) {
        tokio::spawn(async move {
            loop {
                // Wait for notification or interval
                self.save_to_disk().await;
            }
        });
    }
}

​
Feature Organization

Location: src/features/ 
features/
├── mod.rs              // Feature exports
├── groups.rs           // Group management
├── presence.rs         // Presence updates
├── media.rs            // Media upload/download
└── contacts.rs         // Contact operations
Pattern: 
impl Client {
    /// High-level feature method
    pub async fn create_group(&self, subject: &str, participants: &[Jid]) -> Result<Jid> {
        // Use wacore IqSpec for protocol
        let spec = CreateGroupIq::new(subject, participants)?;
        self.execute(spec).await
    }
}

​
State Management Flow

​
Best Practices

​
State Management

// Use DeviceCommand for state changes
client.persistence_manager
    .process_command(DeviceCommand::SetPushName(name))
    .await;

​
Async Operations

// Wrap blocking I/O in spawn_blocking
let result = tokio::task::spawn_blocking(move || {
    // Heavy crypto or blocking HTTP
    expensive_operation()
}).await?;

​
Error Handling

use thiserror::Error;
use anyhow::Result;

#[derive(Debug, Error)]
pub enum SocketError {
    #[error("connection closed")]
    Closed,
    #[error("encryption failed: {0}")]
    Encryption(String),
}

// Use anyhow::Result for functions with multiple error types
pub async fn complex_operation() -> Result<()> {
    // Automatically converts errors with ?
    socket_operation()?;
    storage_operation()?;
    Ok(())
}

Authentication

Learn about QR code and pair code flows

Events

Understand the event system and handlers

Storage

Explore storage backends and state management

Getting Started

Build your first WhatsApp bot

Build docs developers (and LLMs) love

Get started for freeTalk to us