---
title: "nym-sdk: Rust SDK for the Nym Mixnet"
description: "Rust SDK reference for building privacy applications on the Nym mixnet. Covers the Mixnet client, Stream multiplexing, Client Pool, FFI bindings, and code examples."
schemaType: "TechArticle"
section: "Developers"
lastUpdated: "2026-05-12"
---

# nym-sdk

import { Callout } from 'nextra/components'

`nym-sdk` is the Rust SDK for the Nym mixnet. All modules share a common `MixnetClient` that manages gateway connections, Sphinx encryption, and cover traffic.

```text
┌──────────────────────────────────────────────────────────────┐
│  Your Rust app (alice)                                       │
│       └─ MixnetClient (Sphinx layering, cover traffic)       │
│            └─ WebSocket to entry gateway                     │
│                 └─ Nym mixnet (entry → 3 mix layers → exit)  │
│                      └─ MixnetClient (bob)                   │
│                           └─ Your Rust app (bob)             │
└──────────────────────────────────────────────────────────────┘
```

Both sides run a `MixnetClient`. Sphinx encryption protects every hop end-to-end; neither gateway nor any mix node can link sender to receiver.

<Callout type="info">
Full API reference: [**docs.rs/nym-sdk**](https://docs.rs/nym-sdk/latest/nym_sdk/)
</Callout>

For an overview of what the SDK can do, see the **[Tour](./rust/tour)**. For setup instructions, see [Installation](./rust/importing).

## Modules

| Module | What it does | Status |
|---|---|---|
| [**Stream**](./rust/stream) | Multiplexed `AsyncRead + AsyncWrite` byte streams over the Mixnet, the closest analogue to TCP sockets. | Recommended |
| [**Mixnet**](./rust/mixnet) | Raw message payloads, independently routed, no connections or ordering. Full control over the communication model. | Stable |
| [**Client Pool**](./rust/client-pool) | Keeps ready-to-use `MixnetClient` instances warm for bursty workloads. | Stable |
| [**TcpProxy**](./rust/tcpproxy) | TCP socket proxying with session management and message ordering. | Deprecated |
| [**FFI**](./rust/ffi) | Go and C/C++ bindings. | Stable |

<Callout type="error">
**TcpProxy is deprecated.** Use the [Stream module](./rust/stream) for new projects.
</Callout>

## Proxy-mode crates

For proxy-mode integrations (reaching third-party services through an Exit Gateway), see also:

- [**`smolmix`**](/developers/smolmix): `TcpStream` and `UdpSocket` over the Mixnet via a userspace IP stack. Compatible with `tokio-rustls`, `hyper`, `tokio-tungstenite`, and the rest of the async Rust ecosystem.
- [**SOCKS Client**](./rust/mixnet): SOCKS4/4a/5 proxy via the Exit Gateway's Network Requester. Works with any SOCKS-capable application without code changes.