Plug: A WebAssembly Plugin Framework

Features

• Sandboxed WASM Runtime: Isolated memory execution using Wasmer 4.3 (Cranelift). WASI preview1 imports are explicitly allowlisted — only a safe subset of 48 syscalls exposed; dangerous ones (filesystem, network, process) blocked.
• Granular Permissions Model: Enforces manifest-declared permissions at load time (import validation) AND call time (runtime gate) for host imports including host_get_platform. WASI imports blocked unless in explicit allowlist.
• SSRF Protection: net_post enforces HTTPS-only, blocks private/reserved IPs (RFC1918, loopback, link-local), limits response to 1 MiB.
• Multitab: Launch and run multiple independent plugins concurrently in separate workspace tabs.
• Cross-Platform Native UI: Compiles to Windows (Win32 GDI) and Linux (GTK4) with zero browser engine footprint.

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Overview

graph TD
    A[C++ UI Subsystem] -- Input Commands --> B(FFI Interface)
    B -- Parse / Process --> C[Rust Runtime Core]
    C -- Load / Run --> D[Wasmer Sandbox Engine]
    D -- Host Imports / Callbacks --> C
    C -- Control UI --> B
    B -- UI Updates --> A

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Getting Started

Refer to docs/BUILD.md for full toolchain setup.

Quick Build

# Windows
cd plug.cross\windows && .\make.bat

# Linux
cd plug.cross/linux && ./make.sh

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Console Commands

Command	Args	Description
/?	None	Displays help details.
/a	None	Displays system environment and memory statistics.
/tab	None	Spawns a new workspace tab.
/plug*	None	Lists available online registry plugins and hashes.
/plug	[hash]	Downloads and initializes a plugin.
/plug-	[hash]	Unloads the specified plugin.
/e	None	Exits the application.

See All plugins command reference for details.

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Plugin Development

Plugins are compiled targeting wasm32-unknown-unknown.

extern "C" {
    fn get_args(ptr: *mut u8, max_len: usize);
    fn print_info(ptr: *const u8, len: usize);
}

#[no_mangle]
pub extern "C" fn run() {
    let mut buf = [0u8; 128];
    unsafe { get_args(buf.as_mut_ptr(), buf.len()); }
    let msg = "Hello from WASM plugin!";
    unsafe { print_info(msg.as_ptr(), msg.len()); }
}

Refer to docs/PLUGIN_DEVELOPMENT.md for details on permissions configuration (plugin.toml) and FFI imports.

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Security

See docs/SECURITY.md for the complete threat model, sandbox architecture, and security controls summary.