Idempotency — `nestrs-idempotency`

[dependencies]
nestrs = { version = "1.7.1", features = ["idempotency"] }
# Redis store:
nestrs-idempotency = { version = "1.7.1", features = ["cache-redis"] }

use nestrs::idempotency::IdempotencyOptions;
use std::time::Duration;

let opts = IdempotencyOptions {
    // InMemoryIdempotencyStore with 24h TTL by default
    scope: Some("user:42".into()), // ALWAYS scope by principal in multi-tenant APIs
    required: false,               // true → 400 when header missing
    header_name: "idempotency-key".into(),
    ..IdempotencyOptions::in_memory(Duration::from_secs(24 * 3600))
};

use axum::middleware::from_fn_with_state;
use nestrs::idempotency::{idempotency_middleware, IdempotencyOptions};
use std::sync::Arc;

let opts = Arc::new(IdempotencyOptions::default());
let router = router.layer(from_fn_with_state(opts, idempotency_middleware));

#[async_trait]
pub trait IdempotencyStore: Send + Sync {
    async fn begin_or_get(
        &self,
        scope_key: &str,
    ) -> Result<Option<IdempotencyRecord>, IdempotencyBusy>;

    async fn complete(&self, scope_key: &str, record: IdempotencyRecord);
}