diff --git a/Cargo.lock b/Cargo.lock
index cee82d3..5cc7e58 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -333,6 +333,16 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "etag"
+version = "4.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b3d0661a2ccddc26cba0b834e9b717959ed6fdd76c7129ee159c170a875bf44"
+dependencies = [
+ "str-buf",
+ "xxhash-rust",
+]
+
 [[package]]
 name = "fastrand"
 version = "2.3.0"
@@ -1325,7 +1335,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_urlencoded",
- "sync_wrapper",
+ "sync_wrapper 1.0.2",
  "system-configuration",
  "tokio",
  "tokio-native-tls",
@@ -1441,6 +1451,7 @@ dependencies = [
  "salvo-jwt-auth",
  "salvo-proxy",
  "salvo_core",
+ "salvo_extra",
 ]
 
 [[package]]
@@ -1523,11 +1534,12 @@ dependencies = [
  "pin-project",
  "rand",
  "regex",
+ "rustls-pemfile",
  "salvo_macros",
  "serde",
  "serde-xml-rs",
  "serde_json",
- "sync_wrapper",
+ "sync_wrapper 1.0.2",
  "tempfile",
  "thiserror 2.0.9",
  "tokio",
@@ -1536,6 +1548,28 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "salvo_extra"
+version = "0.74.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "647f414b9f7cefc341b3c445b65d1226f375e51e469199cfd8caf4996e681610"
+dependencies = [
+ "base64 0.22.1",
+ "etag",
+ "futures-util",
+ "http-body-util",
+ "hyper",
+ "pin-project",
+ "salvo_core",
+ "serde",
+ "serde_json",
+ "tokio",
+ "tokio-tungstenite",
+ "tower",
+ "tracing",
+ "ulid",
+]
+
 [[package]]
 name = "salvo_macros"
 version = "0.74.3"
@@ -1743,6 +1777,12 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
 
+[[package]]
+name = "str-buf"
+version = "3.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ceb97b7225c713c2fd4db0153cb6b3cab244eb37900c3f634ed4d43310d8c34"
+
 [[package]]
 name = "subtle"
 version = "2.6.1"
@@ -1760,6 +1800,12 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "sync_wrapper"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
+
 [[package]]
 name = "sync_wrapper"
 version = "1.0.2"
@@ -1952,6 +1998,18 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "tokio-tungstenite"
+version = "0.24.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "edc5f74e248dc973e0dbb7b74c7e0d6fcc301c694ff50049504004ef4d0cdcd9"
+dependencies = [
+ "futures-util",
+ "log",
+ "tokio",
+ "tungstenite",
+]
+
 [[package]]
 name = "tokio-util"
 version = "0.7.13"
@@ -1982,6 +2040,29 @@ dependencies = [
  "winnow",
 ]
 
+[[package]]
+name = "tower"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2873938d487c3cfb9aed7546dc9f2711d867c9f90c46b889989a2cb84eba6b4f"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "pin-project-lite",
+ "sync_wrapper 0.1.2",
+ "tokio",
+ "tokio-util",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "121c2a6cda46980bb0fcd1647ffaf6cd3fc79a013de288782836f6df9c48780e"
+
 [[package]]
 name = "tower-service"
 version = "0.3.3"
@@ -2051,12 +2132,37 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
+[[package]]
+name = "tungstenite"
+version = "0.24.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18e5b8366ee7a95b16d32197d0b2604b43a0be89dc5fac9f8e96ccafbaedda8a"
+dependencies = [
+ "byteorder",
+ "bytes",
+ "log",
+ "rand",
+ "thiserror 1.0.69",
+ "utf-8",
+]
+
 [[package]]
 name = "typenum"
 version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
 
+[[package]]
+name = "ulid"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04f903f293d11f31c0c29e4148f6dc0d033a7f80cebc0282bea147611667d289"
+dependencies = [
+ "getrandom",
+ "rand",
+ "web-time",
+]
+
 [[package]]
 name = "unicase"
 version = "2.8.0"
@@ -2096,6 +2202,12 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "utf-8"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09cc8ee72d2a9becf2f2febe0205bbed8fc6615b7cb429ad062dc7b7ddd036a9"
+
 [[package]]
 name = "utf16_iter"
 version = "1.0.5"
@@ -2231,6 +2343,16 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "web-time"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a6580f308b1fad9207618087a65c04e7a10bc77e02c8e84e9b00dd4b12fa0bb"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -2392,6 +2514,12 @@ version = "0.8.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea8b391c9a790b496184c29f7f93b9ed5b16abb306c05415b68bcc16e4d06432"
 
+[[package]]
+name = "xxhash-rust"
+version = "0.8.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a08fd76779ae1883bbf1e46c2c46a75a0c4e37c445e68a24b01479d438f26ae6"
+
 [[package]]
 name = "yoke"
 version = "0.7.5"
diff --git a/Cargo.toml b/Cargo.toml
index 3fb003c..e0fd87c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-salvo = "0.74.3"
+salvo = { version = "0.74.3", features = ["affix-state", "logging"] }
 tokio = { version = "1", features = ["macros"] }
 tracing = "0.1"
-tracing-subscriber = "0.3"
\ No newline at end of file
+tracing-subscriber = "0.3"
diff --git a/src/main.rs b/src/main.rs
index d486b93..e3ac953 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,17 +1,127 @@
+use salvo::http::HeaderValue;
+use salvo::logging::Logger;
+
 use salvo::prelude::*;
 
+fn search(buf: &[u8], pattern: &[u8], start_index: usize) -> Option<usize> {
+    let mut i = start_index;
+
+    // If the buffer is empty, the pattern is too long
+    if pattern.len() > buf.len() {
+        return None;
+    }
+
+    // If the pattern is empty
+    if pattern.len() == 0 {
+        return None;
+    }
+
+    // If the starting index is too high
+    if start_index >= buf.len() {
+        return None;
+    }
+
+    while i < buf.len() {
+        for j in 0..pattern.len() {
+            // If the pattern is too long to fit in the buffer anymore
+            if i + j >= buf.len() {
+                return None;
+            }
+
+            // If the pattern stops matching
+            if buf[i + j] != pattern[j] {
+                break;
+            }
+
+            // If the pattern is found
+            if j == pattern.len() - 1 {
+                return Some(i);
+            }
+        }
+
+        i += 1;
+    }
+    None
+}
+
 #[handler]
 async fn hello() -> &'static str {
     "Hello World"
 }
 
+#[handler]
+async fn download(depot: &mut Depot, req: &mut Request, res: &mut Response) {
+    let state = depot.obtain::<State>().unwrap();
+    let data = state.with_key(b"test"); // Clone the data
+
+    if let Err(e) = res.write_body(data) {
+        eprintln!("Error writing body: {}", e);
+    }
+
+    res.headers.insert(
+        "Content-Disposition",
+        HeaderValue::from_static("attachment; filename=demo"),
+    );
+    res.headers.insert(
+        "Content-Type",
+        HeaderValue::from_static("application/octet-stream"),
+    );
+}
+
+#[allow(dead_code)]
+#[derive(Default, Clone, Debug)]
+struct State {
+    data: Vec<u8>,
+    key_start: usize,
+    key_end: usize,
+}
+
+impl State {
+    fn with_key(&self, new_key: &[u8]) -> Vec<u8> {
+        let mut data = self.data.clone();
+
+        // Copy the key into the data
+        for i in 0..new_key.len() {
+            data[self.key_start + i] = new_key[i];
+        }
+
+        // If the new key is shorter than the old key, we just write over the remaining data
+        if new_key.len() < self.key_end - self.key_start {
+            for i in self.key_start + new_key.len()..self.key_end {
+                data[i] = b' ';
+            }
+        }
+
+        return data;
+    }
+}
+
 #[tokio::main]
 async fn main() {
     let port = std::env::var("PORT").unwrap_or_else(|_| "5800".to_string());
     let addr = format!("0.0.0.0:{}", port);
     tracing_subscriber::fmt().init();
 
-    let router = Router::new().get(hello);
+    let path = "./demo/target/release/demo";
+    let data = std::fs::read(&path).expect("Unable to read file");
+
+    let pattern = "a".repeat(1024);
+    let key_start = search(&data, pattern.as_bytes(), 0).unwrap();
+    let key_end = key_start + pattern.len();
+
+    let state = State {
+        data,
+        key_start: key_start,
+        key_end: key_end,
+    };
+
+    let router = Router::new()
+        .hoop(affix_state::inject(state))
+        .get(hello)
+        .push(Router::with_path("download").get(download));
+
+    let service = Service::new(router).hoop(Logger::new());
+
     let acceptor = TcpListener::new(addr).bind().await;
-    Server::new(acceptor).serve(router).await;
+    Server::new(acceptor).serve(service).await;
 }