capnweb-transport

Transport layer implementations for Cap'n Web protocol (HTTP, WebSocket, WebTransport).

Overview

capnweb-transport provides multiple transport implementations for the Cap'n Web RPC protocol:

• HTTP Batch: Traditional request/response with batching support
• WebSocket: Full-duplex streaming with multiplexing
• WebTransport: Modern HTTP/3-based transport with stream multiplexing

Features

• Pluggable transport abstraction
• Automatic reconnection and error recovery
• Message framing and buffering
• Backpressure handling
• Connection pooling (HTTP)

Usage

Add to your Cargo.toml:

[dependencies]
capnweb-transport = "0.1.0"

Using different transports:

use capnweb_transport::{Transport, HttpBatchTransport, WebSocketTransport};
use capnweb_core::{Message, CallId, CapId};
use serde_json::json;

// Create a message to send
let message = Message::Call {
    id: CallId::new(1),
    target: CapId::new(0),
    method: "echo".to_string(),
    args: vec![json!("hello world")],
};

// HTTP Batch transport
let transport = HttpBatchTransport::new("http://localhost:8080/rpc/batch");
transport.send(message.clone()).await?;
let response = transport.receive().await?;

// Or use WebSocket transport
let transport = WebSocketTransport::connect("ws://localhost:8080/rpc/ws").await?;
transport.send(message).await?;
let response = transport.receive().await?;

Feature Flags

• websocket (default): WebSocket transport support
• http-batch (default): HTTP batch transport support
• webtransport: WebTransport/HTTP3 support (experimental)

Transport Selection

Choose your transport based on your needs:

• HTTP Batch: Simple, firewall-friendly, works everywhere
• WebSocket: Real-time updates, lower latency, persistent connection
• WebTransport: Best performance, multiplexing, requires HTTP/3

License

This project is licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.