Add axum middleware example

Cargo.toml

@@ -37,3 +37,7 @@ serde_json = "1.0.120"
 [dev-dependencies]
 jiff = { version = "0.1.4", features = ["serde"] }
 tokio = { version = "1.37.0", features = ["macros", "test-util", "rt-multi-thread"] }
+# Used in examples
+axum = "0.7.9"
+svix = "1.42.0"
+http-body-util = "0.1.2"

examples/axum-verify-event-middleware.rs

@@ -0,0 +1,64 @@
+// axum = "0.7.9"
+// svix = "1.42.0"
+// http-body-util = "0.1.2"
+
+use axum::{
+    body::Body,
+    extract::Request,
+    http,
+    middleware::{self, Next},
+    response::{IntoResponse, Response},
+    routing::post,
+    Router,
+};
+
+use http::{HeaderMap, StatusCode};
+
+use resend_rs::events::try_parse_event;
+use svix::webhooks::Webhook;
+
+#[allow(clippy::unwrap_used)]
+#[tokio::main]
+async fn main() {
+    let app = Router::new()
+        .route("/", post(handler))
+        .layer(middleware::from_fn(verify_middleware));
+
+    let listener = tokio::net::TcpListener::bind("127.0.0.1:3000")
+        .await
+        .unwrap();
+
+    println!("listening on {}", listener.local_addr().unwrap());
+
+    axum::serve(listener, app).await.unwrap();
+}
+
+async fn handler(data: String) -> StatusCode {
+    // Put your normal endpoint code here
+    let event = try_parse_event(&data);
+    println!("{event:?}");
+
+    StatusCode::OK
+}
+
+async fn verify_middleware(
+    headers: HeaderMap,
+    request: Request,
+    next: Next,
+) -> Result<impl IntoResponse, Response> {
+    let (parts, body) = request.into_parts();
+
+    let bytes = http_body_util::BodyExt::collect(body)
+        .await
+        .map_err(|err| (StatusCode::INTERNAL_SERVER_ERROR, err.to_string()).into_response())?
+        .to_bytes();
+
+    let secret = "<YOUR RESEND SIGNING SECRET HERE>".to_string();
+    let wh = Webhook::new(&secret).expect("Invalid secret");
+    wh.verify(&bytes, &headers)
+        .map_err(|err| (StatusCode::INTERNAL_SERVER_ERROR, err.to_string()).into_response())?;
+
+    let request = Request::from_parts(parts, Body::from(bytes));
+
+    Ok(next.run(request).await)
+}

src/events.rs

@@ -1,4 +1,7 @@
 //! Parsing for Resend's Events.
+//! 
+//! For an example on how to add (Axum) middleware that verifies incoming event signatures,
+//! check out [this example](https://github.com/resend/resend-rust/examples/axum-verify-event-middleware.rs).
 
 #![allow(dead_code)]