diff --git a/Cargo.lock b/Cargo.lock
index eb30027..6a07fe1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -152,6 +152,12 @@ version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dfc6580bb841c5a68e9ef15c77ccc837b40a7504914d52e47b8b0e9bbda25a1d"
 
+[[package]]
+name = "futures-sink"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9fb8e00e87438d937621c1c6269e53f536c14d3fbd6a042bb24879e57d474fb5"
+
 [[package]]
 name = "futures-task"
 version = "0.3.30"
@@ -525,6 +531,7 @@ dependencies = [
  "nom",
  "serde",
  "tokio",
+ "tokio-util",
  "tower-http",
  "tracing",
  "tracing-subscriber",
@@ -606,6 +613,19 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "tokio-util"
+version = "0.7.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9cf6b47b3771c49ac75ad09a6162f53ad4b8088b76ac60e8ec1455b31a189fe1"
+dependencies = [
+ "bytes",
+ "futures-core",
+ "futures-sink",
+ "pin-project-lite",
+ "tokio",
+]
+
 [[package]]
 name = "tower"
 version = "0.4.13"
diff --git a/Cargo.toml b/Cargo.toml
index b9a2f44..c1b4ff0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,7 +8,8 @@ authors = ["Martin Berg Alstad"]
 # Parsing
 nom = "7.1.3"
 # Async
-tokio = { version = "1.38.0", features = ["macros", "rt-multi-thread"] }
+tokio = { version = "1.38.0", features = ["macros", "rt-multi-thread", "fs"] }
+tokio-util = { version = "0.7.11", features = ["io"] }
 # Serialization / Deserialization
 serde = { version = "1.0.203", features = ["derive", "rc"] }
 # API
diff --git a/http/simplify.http b/http/simplify.http
index babc457..f5108b6 100644
--- a/http/simplify.http
+++ b/http/simplify.http
@@ -1,3 +1,11 @@
+### GET index page
+
+GET {{url}}
+
+### GET OpenAPI page
+
+GET {{url}}/openapi
+
 ### GET Atomic Expression
 GET {{url}}/simplify/A
 
diff --git a/src/routing/index.rs b/src/routing/index.rs
index 16cc8e6..ec1f560 100644
--- a/src/routing/index.rs
+++ b/src/routing/index.rs
@@ -1,11 +1,32 @@
+use axum::body::Body;
+use axum::http::{header, StatusCode};
+use axum::response::{Html, IntoResponse, Response};
 use axum::Router;
 use axum::routing::get;
+use tokio::fs::File;
+use tokio_util::io::ReaderStream;
 
 pub fn router() -> Router {
     Router::new()
         .route("/", get(index))
+        .route("/openapi", get(open_api))
 }
 
 async fn index() -> &'static str {
     "Welcome to the Simplify Truths API!\n"
 }
+
+// TODO open from target dir in release mode.
+async fn open_api() -> Response {
+    let file_path = "./spec/dist/index.html";
+    let file = match File::open(file_path).await {
+        Ok(file) => file,
+        Err(err) => return (StatusCode::NOT_FOUND, format!("File not found: {err}")).into_response(),
+    };
+    // convert the `AsyncRead` into a `Stream`
+    let stream = ReaderStream::new(file);
+    // convert the `Stream` into an `axum::body::HttpBody`
+    let body = Body::from_stream(stream);
+
+    Html(body).into_response()
+}