nestrs-lambda - Nestrs

NestJS serverless guides wrap Express or Fastify. nestrs is Axum-only (ADR-0001). nestrs-lambda takes the router from NestApplication::into_router and serves it with lambda_http (API Gateway HTTP API, REST API, ALB, Function URL).

Install

[dependencies]
nestrs = "1.3.0"
nestrs-lambda = "1.3.0"
tokio = { version = "1", features = ["macros", "rt-multi-thread"] }

The crate enables lambda_http features apigw_http and apigw_rest.

Listen on Lambda

Do not call listen / listen_graceful. Those bind a TCP socket. On Lambda, hand the router to listen_lambda:

use nestrs::prelude::*;
use nestrs_lambda::{lambda_http, listen_lambda};

#[module(controllers = [HealthController], providers = [AppState])]
struct AppModule;

#[derive(Default)]
#[injectable]
struct AppState;

#[controller(prefix = "/health")]
struct HealthController;

#[routes(state = AppState)]
impl HealthController {
    #[get("/")]
    async fn live() -> &'static str {
        "ok"
    }
}

#[tokio::main]
async fn main() -> Result<(), lambda_http::Error> {
    let router = NestFactory::create::<AppModule>().into_router();
    listen_lambda(router).await
}

Local vs Lambda

Environment	Entry point
Process / container	`NestFactory::create::<M>().listen_graceful(3000)`
AWS Lambda	`listen_lambda(NestFactory::create::<M>().into_router())`

Share the same AppModule. Swap only main.

PathNormalization and some listen-only builders apply in listen, not into_router. If you rely on trailing-slash rewriting, wrap the router yourself after into_router.

API

Item	Role
`listen_lambda(router)`	`lambda_http::run(router).await`
`lambda_http`	Re-export of the AWS runtime crate