# Eppo Rust SDK
[Eppo](https://www.geteppo.com/) is a modular flagging and experimentation analysis tool. Eppo's Rust SDK is designed to facilitate assignments in multi-user server-side contexts. You will need an Eppo account before proceeding.
## Features
- Feature gates
- Kill switches
- Progressive rollouts
- A/B/n experiments
- Mutually exclusive experiments (Layers)
- Dynamic configuration
## Installation
Add it with cargo:
```sh
cargo add eppo
```
Or add it to `Cargo.toml` manually:
```toml
[dependencies]
eppo = "0.1.0"
```
## Quick Start
Initialize an instance of Eppo's client. Once initialized, the client can be used to make assignments in your app.
### Initialize Client
```rust
use eppo::ClientConfig;
let mut client = ClientConfig::from_api_key("api-key").to_client();
client.start_poller_thread();
```
### Assign Anywhere
```rust
let user = get_current_user();
let assignment = client.get_assignment(
"show-new-feature",
&user.id,
&user.attributes,
);
```
## Assignment Logger
Pass a logging callback function to the `assignment_logger` method in `ClientConfig` when initializing the SDK to capture assignment data for analysis.
```rust
struct MyAssignmentLogger;
impl AssignmentLogger for MyAssignmentLogger {
fn log_assignment(&self, event: AssignmentEvent) {
// Implement assignment logging logic here
}
}
```