Introduction

agnostic-io provides runtime-agnostic I/O traits following the Sans-I/O design philosophy. It defines standardized async I/O interfaces that work across tokio, smol, and other runtimes without coupling your protocol implementations to specific I/O primitives.

What is Sans-I/O?

Sans-I/O (French for "without I/O") is a design pattern that separates protocol logic from I/O implementation. Instead of tightly coupling your code to specific I/O libraries, you:

1. Define abstract I/O traits (what agnostic-io provides)
2. Implement your protocol logic against these traits
3. Let runtime-specific implementations handle the actual I/O

This approach makes your code:

• Testable: Mock I/O without real sockets
• Portable: Works with any async runtime
• Reusable: Protocol implementations work everywhere
• Maintainable: Changes to I/O layer don't affect protocol logic

Key Features

• Runtime Agnostic: Works with tokio, smol, and more
• no_std Compatible: Can be used in embedded environments
• Zero-Cost: Trait-based design compiles away
• Comprehensive: AsyncRead, AsyncWrite, AsyncSeek, and more
• Tokio Compatible: Optional compatibility layer for tokio traits

Installation

[dependencies]
agnostic-io = "0.2"

Feature Flags

# Standard library support (default)
agnostic-io = { version = "0.1", features = ["std"] }

# Allocation support without std
agnostic-io = { version = "0.1", default-features = false, features = ["alloc"] }

# Tokio I/O trait compatibility
agnostic-io = { version = "0.1", features = ["tokio"] }

# no_std without allocations
agnostic-io = { version = "0.1", default-features = false }

Tokio Compatibility

When using the tokio feature, agnostic-io provides compatibility with tokio::io traits:

[dependencies]
agnostic-io = { version = "0.1", features = ["tokio"] }

Feature Flags

• std (default): Standard library support
• alloc: Allocation support without std
• tokio: Compatibility with tokio::io traits

License

agnostic-io is under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE, LICENSE-MIT for details.

Copyright (c) 2025 Al Liu.