Rust Configuration

Client Builder

The Rust SDK uses a builder pattern for configuration:

use flags_rs::{Auth, Client};

let client = Client::builder()
    .with_auth(Auth {
        project_id: "your-project-id".to_string(),
        agent_id: "your-agent-id".to_string(),
        environment_id: "your-environment-id".to_string(),
    })
    .with_base_url("https://custom-api.flags.gg")
    .with_max_retries(5)
    .with_memory_cache()
    .build();

Builder Methods

Method	Default	Description
with_auth(Auth)	—	Required. Set authentication credentials
with_base_url(&str)	https://api.flags.gg	Custom API endpoint
with_max_retries(u32)	3	Max retry attempts
with_memory_cache()	Memory	Use in-memory cache

Error Types

The SDK defines a FlagError enum:

Variant	Description
HttpError	Network or HTTP errors
CacheError	Cache operation errors
AuthError	Authentication errors
ApiError	API response errors
BuilderError	Configuration errors

The client gracefully degrades — it falls back to cached or default values rather than panicking.

Async Runtime

The SDK uses tokio for async operations. All flag checks and list operations are async:

let enabled = client.is("flag").enabled().await;
let flags = client.list().await?;