diff --git a/rpc-toolkit-macro-internals/src/command/build.rs b/rpc-toolkit-macro-internals/src/command/build.rs
index 6c6778b..0d0f91f 100644
--- a/rpc-toolkit-macro-internals/src/command/build.rs
+++ b/rpc-toolkit-macro-internals/src/command/build.rs
@@ -444,7 +444,9 @@ fn rpc_handler(
             quote! { args.#field_name }
         }
         ParamType::Context(_) => quote! { ctx },
-        _ => unreachable!(),
+        ParamType::Request => quote! { request },
+        ParamType::Response => quote! { response },
+        ParamType::None => unreachable!(),
     });
     match opt {
         Options::Leaf(opt) if matches!(opt.exec_ctx, ExecutionContext::CliOnly(_)) => quote! {
@@ -452,6 +454,8 @@ fn rpc_handler(
 
             pub async fn rpc_handler#fn_generics(
                 _ctx: #ctx_ty,
+                _request: &::rpc_toolkit::command_helpers::prelude::RequestParts,
+                _response: &mut ::rpc_toolkit::command_helpers::prelude::ResponseParts,
                 method: &str,
                 _args: Params#param_ty_generics,
             ) -> Result<::rpc_toolkit::command_helpers::prelude::Value, ::rpc_toolkit::command_helpers::prelude::RpcError> {
@@ -480,6 +484,8 @@ fn rpc_handler(
 
                 pub async fn rpc_handler#fn_generics(
                     ctx: #ctx_ty,
+                    request: &::rpc_toolkit::command_helpers::prelude::RequestParts,
+                    response: &mut ::rpc_toolkit::command_helpers::prelude::ResponseParts,
                     method: &str,
                     args: Params#param_ty_generics,
                 ) -> Result<::rpc_toolkit::command_helpers::prelude::Value, ::rpc_toolkit::command_helpers::prelude::RpcError> {
@@ -515,7 +521,7 @@ fn rpc_handler(
                     ),
                 };
                 quote_spanned!{ subcommand.span() =>
-                    [#subcommand::NAME, rest] => #subcommand::#rpc_handler(ctx, rest, ::rpc_toolkit::command_helpers::prelude::from_value(args.rest)?).await
+                    [#subcommand::NAME, rest] => #subcommand::#rpc_handler(ctx, request, response, rest, ::rpc_toolkit::command_helpers::prelude::from_value(args.rest)?).await
                 }
             });
             let subcmd_impl = quote! {
@@ -550,6 +556,8 @@ fn rpc_handler(
 
                         pub async fn rpc_handler#fn_generics(
                             ctx: #ctx_ty,
+                            request: &::rpc_toolkit::command_helpers::prelude::RequestParts,
+                            response: &mut ::rpc_toolkit::command_helpers::prelude::ResponseParts,
                             method: &str,
                             args: Params#param_ty_generics,
                         ) -> Result<::rpc_toolkit::command_helpers::prelude::Value, ::rpc_toolkit::command_helpers::prelude::RpcError> {
@@ -569,6 +577,8 @@ fn rpc_handler(
 
                         pub async fn rpc_handler#fn_generics(
                             ctx: #ctx_ty,
+                            request: &::rpc_toolkit::command_helpers::prelude::RequestParts,
+                            response: &mut ::rpc_toolkit::command_helpers::prelude::ResponseParts,
                             method: &str,
                             args: Params#param_ty_generics,
                         ) -> Result<::rpc_toolkit::command_helpers::prelude::Value, ::rpc_toolkit::command_helpers::prelude::RpcError> {
@@ -618,7 +628,9 @@ fn cli_handler(
             quote! { params.#field_name.clone() }
         }
         ParamType::Context(_) => quote! { ctx },
-        _ => unreachable!(),
+        ParamType::Request => quote! { request },
+        ParamType::Response => quote! { response },
+        ParamType::None => unreachable!(),
     });
     let mut param_generics_filter = GenericFilter::new(fn_generics);
     for param in params {
diff --git a/rpc-toolkit-macro-internals/src/command/mod.rs b/rpc-toolkit-macro-internals/src/command/mod.rs
index ba8d4f2..3e458ac 100644
--- a/rpc-toolkit-macro-internals/src/command/mod.rs
+++ b/rpc-toolkit-macro-internals/src/command/mod.rs
@@ -90,4 +90,6 @@ pub enum ParamType {
     None,
     Arg(ArgOptions),
     Context(Type),
+    Request,
+    Response,
 }
diff --git a/rpc-toolkit-macro-internals/src/command/parse.rs b/rpc-toolkit-macro-internals/src/command/parse.rs
index 422df68..3779101 100644
--- a/rpc-toolkit-macro-internals/src/command/parse.rs
+++ b/rpc-toolkit-macro-internals/src/command/parse.rs
@@ -666,6 +666,16 @@ pub fn parse_param_attrs(item: &mut ItemFn) -> Result<Vec<ParamType>> {
                             attr.span(),
                             "`arg` and `context` are mutually exclusive",
                         ));
+                    } else if matches!(ty, ParamType::Request) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`arg` and `request` are mutually exclusive",
+                        ));
+                    } else if matches!(ty, ParamType::Response) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`arg` and `response` are mutually exclusive",
+                        ));
                     }
                 } else if param.attrs[i].path.is_ident("context") {
                     let attr = param.attrs.remove(i);
@@ -681,6 +691,66 @@ pub fn parse_param_attrs(item: &mut ItemFn) -> Result<Vec<ParamType>> {
                             attr.span(),
                             "`arg` and `context` are mutually exclusive",
                         ));
+                    } else if matches!(ty, ParamType::Request) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`context` and `request` are mutually exclusive",
+                        ));
+                    } else if matches!(ty, ParamType::Response) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`context` and `response` are mutually exclusive",
+                        ));
+                    }
+                } else if param.attrs[i].path.is_ident("request") {
+                    let attr = param.attrs.remove(i);
+                    if matches!(ty, ParamType::None) {
+                        ty = ParamType::Request;
+                    } else if matches!(ty, ParamType::Request) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`request` attribute may only be specified once",
+                        ));
+                    } else if matches!(ty, ParamType::Arg(_)) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`arg` and `request` are mutually exclusive",
+                        ));
+                    } else if matches!(ty, ParamType::Context(_)) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`context` and `request` are mutually exclusive",
+                        ));
+                    } else if matches!(ty, ParamType::Response) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`request` and `response` are mutually exclusive",
+                        ));
+                    }
+                } else if param.attrs[i].path.is_ident("response") {
+                    let attr = param.attrs.remove(i);
+                    if matches!(ty, ParamType::None) {
+                        ty = ParamType::Response;
+                    } else if matches!(ty, ParamType::Response) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`response` attribute may only be specified once",
+                        ));
+                    } else if matches!(ty, ParamType::Arg(_)) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`arg` and `response` are mutually exclusive",
+                        ));
+                    } else if matches!(ty, ParamType::Context(_)) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`context` and `response` are mutually exclusive",
+                        ));
+                    } else if matches!(ty, ParamType::Request) {
+                        return Err(Error::new(
+                            attr.span(),
+                            "`request` and `response` are mutually exclusive",
+                        ));
                     }
                 } else {
                     i += 1;
diff --git a/rpc-toolkit-macro-internals/src/rpc_server/build.rs b/rpc-toolkit-macro-internals/src/rpc_server/build.rs
index 48c901c..c590361 100644
--- a/rpc-toolkit-macro-internals/src/rpc_server/build.rs
+++ b/rpc-toolkit-macro-internals/src/rpc_server/build.rs
@@ -54,29 +54,30 @@ pub fn build(args: RpcServerArgs) -> TokenStream {
                                     Err(res) => return Ok(res),
                                 };
                             )*
-                            let rpc_req = ::rpc_toolkit::rpc_server_helpers::make_request(&mut req).await;
+                            let (mut req_parts, req_body) = req.into_parts();
+                            let (mut res_parts, _) = ::rpc_toolkit::hyper::Response::new(()).into_parts();
+                            let rpc_req = ::rpc_toolkit::rpc_server_helpers::make_request(&req_parts, req_body).await;
                             match rpc_req {
                                 Ok(mut rpc_req) => {
                                     #(
-                                        let #middleware_name_post = match #middleware_name_pre2(&mut rpc_req).await? {
+                                        let #middleware_name_post = match #middleware_name_pre2(&mut req_parts, &mut rpc_req).await? {
                                             Ok(a) => a,
                                             Err(res) => return Ok(res),
                                         };
                                     )*
-                                    let mut rpc_res = #command(
-                                        ctx,
-                                        ::rpc_toolkit::yajrc::RpcMethod::as_str(&rpc_req.method),
-                                        rpc_req.params,
-                                    )
-                                    .await;
+                                    let mut rpc_res = match ::rpc_toolkit::serde_json::from_value(::rpc_toolkit::serde_json::Value::Object(rpc_req.params)) {
+                                        Ok(params) => #command(ctx, &req_parts, &mut res_parts, ::rpc_toolkit::yajrc::RpcMethod::as_str(&rpc_req.method), params).await,
+                                        Err(e) => Err(e.into())
+                                    };
                                     #(
-                                        let #middleware_name = match #middleware_name_post_inv(&mut rpc_res).await? {
+                                        let #middleware_name = match #middleware_name_post_inv(&mut res_parts, &mut rpc_res).await? {
                                             Ok(a) => a,
                                             Err(res) => return Ok(res),
                                         };
                                     )*
                                     let mut res = ::rpc_toolkit::rpc_server_helpers::to_response(
-                                        &req,
+                                        &req_parts.headers,
+                                        res_parts,
                                         Ok((
                                             rpc_req.id,
                                             rpc_res,
@@ -89,7 +90,8 @@ pub fn build(args: RpcServerArgs) -> TokenStream {
                                     Ok::<_, ::rpc_toolkit::hyper::http::Error>(res)
                                 }
                                 Err(e) => ::rpc_toolkit::rpc_server_helpers::to_response(
-                                    &req,
+                                    &req_parts.headers,
+                                    res_parts,
                                     Err(e),
                                     status_fn,
                                 ),
diff --git a/rpc-toolkit/src/command_helpers.rs b/rpc-toolkit/src/command_helpers.rs
index 23e8eca..30c06e3 100644
--- a/rpc-toolkit/src/command_helpers.rs
+++ b/rpc-toolkit/src/command_helpers.rs
@@ -16,6 +16,8 @@ pub mod prelude {
     pub use std::marker::PhantomData;
 
     pub use clap::{App, AppSettings, Arg, ArgMatches};
+    pub use hyper::http::request::Parts as RequestParts;
+    pub use hyper::http::response::Parts as ResponseParts;
     pub use serde::{Deserialize, Serialize};
     pub use serde_json::{from_value, to_value, Value};
     pub use tokio::runtime::Runtime;
diff --git a/rpc-toolkit/src/rpc_server_helpers.rs b/rpc-toolkit/src/rpc_server_helpers.rs
index 174b435..bf8b2b3 100644
--- a/rpc-toolkit/src/rpc_server_helpers.rs
+++ b/rpc-toolkit/src/rpc_server_helpers.rs
@@ -3,13 +3,15 @@ use std::future::Future;
 use futures::future::BoxFuture;
 use futures::FutureExt;
 use hyper::body::Buf;
+use hyper::header::HeaderValue;
+use hyper::http::request::Parts as RequestParts;
+use hyper::http::response::Parts as ResponseParts;
 use hyper::http::Error as HttpError;
 use hyper::server::conn::AddrIncoming;
 use hyper::server::{Builder, Server};
-use hyper::{Body, Request, Response, StatusCode};
+use hyper::{Body, HeaderMap, Request, Response, StatusCode};
 use lazy_static::lazy_static;
-use serde::Deserialize;
-use serde_json::Value;
+use serde_json::{Map, Value};
 use url::Host;
 use yajrc::{AnyRpcMethod, GenericRpcMethod, Id, RpcError, RpcRequest, RpcResponse};
 
@@ -33,16 +35,15 @@ pub fn make_builder<Ctx: Context>(ctx: &Ctx) -> Builder<AddrIncoming> {
     Server::bind(&addr)
 }
 
-pub async fn make_request<Params: for<'de> Deserialize<'de> + 'static>(
-    req: &mut Request<Body>,
-) -> Result<RpcRequest<GenericRpcMethod<String, Params>>, RpcError> {
-    let body = hyper::body::aggregate(std::mem::replace(req.body_mut(), Body::empty()))
-        .await?
-        .reader();
-    let rpc_req: RpcRequest<GenericRpcMethod<String, Params>>;
+pub async fn make_request(
+    req_parts: &RequestParts,
+    req_body: Body,
+) -> Result<RpcRequest<GenericRpcMethod<String, Map<String, Value>>>, RpcError> {
+    let body = hyper::body::aggregate(req_body).await?.reader();
+    let rpc_req: RpcRequest<GenericRpcMethod<String, Map<String, Value>>>;
     #[cfg(feature = "cbor")]
-    if req
-        .headers()
+    if req_parts
+        .headers
         .get("content-type")
         .and_then(|h| h.to_str().ok())
         == Some("application/cbor")
@@ -60,7 +61,8 @@ pub async fn make_request<Params: for<'de> Deserialize<'de> + 'static>(
 }
 
 pub fn to_response<F: Fn(i32) -> StatusCode>(
-    req: &Request<Body>,
+    req_headers: &HeaderMap<HeaderValue>,
+    mut res_parts: ResponseParts,
     res: Result<(Option<Id>, Result<Value, RpcError>), RpcError>,
     status_code_fn: F,
 ) -> Result<Response<Body>, HttpError> {
@@ -69,10 +71,8 @@ pub fn to_response<F: Fn(i32) -> StatusCode>(
         Err(e) => e.into(),
     };
     let body;
-    let mut res = Response::builder();
     #[cfg(feature = "cbor")]
-    if req
-        .headers()
+    if req_headers
         .get("accept")
         .and_then(|h| h.to_str().ok())
         .iter()
@@ -81,54 +81,64 @@ pub fn to_response<F: Fn(i32) -> StatusCode>(
         .any(|s| s == "application/cbor")
     // prefer cbor if accepted
     {
-        res = res.header("content-type", "application/cbor");
+        res_parts
+            .headers
+            .insert("content-type", HeaderValue::from_static("application/cbor"));
         body = serde_cbor::to_vec(&rpc_res).unwrap_or_else(|_| CBOR_INTERNAL_ERROR.clone());
     } else {
-        res = res.header("content-type", "application/json");
+        res_parts
+            .headers
+            .insert("content-type", HeaderValue::from_static("application/json"));
         body = serde_json::to_vec(&rpc_res).unwrap_or_else(|_| JSON_INTERNAL_ERROR.clone());
     }
     #[cfg(not(feature = "cbor"))]
     {
-        res.header("content-type", "application/json");
+        res_parts
+            .headers
+            .insert("content-type", HeaderValue::from_static("application/json"));
         body = serde_json::to_vec(&rpc_res).unwrap_or_else(|_| JSON_INTERNAL_ERROR.clone());
     }
-    res = res.header("content-length", body.len());
-    res = res.status(match &rpc_res.result {
+    res_parts.headers.insert(
+        "content-length",
+        HeaderValue::from_str(&format!("{}", body.len()))?,
+    );
+    res_parts.status = match &rpc_res.result {
         Ok(_) => StatusCode::OK,
         Err(e) => status_code_fn(e.code),
-    });
-    res.body(Body::from(body))
+    };
+    Ok(Response::from_parts(res_parts, body.into()))
 }
 
 // &mut Request<Body> -> Result<Result<Future<&mut RpcRequest<...> -> Future<Result<Result<&mut Response<Body> -> Future<Result<(), HttpError>>, Response<Body>>, HttpError>>>, Response<Body>>, HttpError>
-pub type DynMiddleware<Params, Metadata> = Box<
+pub type DynMiddleware<Metadata> = Box<
     dyn for<'a> FnOnce(
             &'a mut Request<Body>,
             Metadata,
         ) -> BoxFuture<
             'a,
-            Result<Result<DynMiddlewareStage2<Params>, Response<Body>>, HttpError>,
+            Result<Result<DynMiddlewareStage2, Response<Body>>, HttpError>,
         > + Send
         + Sync,
 >;
-pub fn noop<Params: for<'de> Deserialize<'de> + 'static, M: Metadata>() -> DynMiddleware<Params, M>
-{
+pub fn noop<M: Metadata>() -> DynMiddleware<M> {
     Box::new(|_, _| async { Ok(Ok(noop2())) }.boxed())
 }
-pub type DynMiddlewareStage2<Params> = Box<
+pub type DynMiddlewareStage2 = Box<
     dyn for<'a> FnOnce(
-            &'a mut RpcRequest<GenericRpcMethod<String, Params>>,
+            &'a mut RequestParts,
+            &'a mut RpcRequest<GenericRpcMethod<String, Map<String, Value>>>,
         ) -> BoxFuture<
             'a,
             Result<Result<DynMiddlewareStage3, Response<Body>>, HttpError>,
         > + Send
         + Sync,
 >;
-pub fn noop2<Params: for<'de> Deserialize<'de> + 'static>() -> DynMiddlewareStage2<Params> {
-    Box::new(|_| async { Ok(Ok(noop3())) }.boxed())
+pub fn noop2() -> DynMiddlewareStage2 {
+    Box::new(|_, _| async { Ok(Ok(noop3())) }.boxed())
 }
 pub type DynMiddlewareStage3 = Box<
     dyn for<'a> FnOnce(
+            &'a mut ResponseParts,
             &'a mut Result<Value, RpcError>,
         ) -> BoxFuture<
             'a,
@@ -137,7 +147,7 @@ pub type DynMiddlewareStage3 = Box<
         + Sync,
 >;
 pub fn noop3() -> DynMiddlewareStage3 {
-    Box::new(|_| async { Ok(Ok(noop4())) }.boxed())
+    Box::new(|_, _| async { Ok(Ok(noop4())) }.boxed())
 }
 pub type DynMiddlewareStage4 = Box<
     dyn for<'a> FnOnce(&'a mut Response<Body>) -> BoxFuture<'a, Result<(), HttpError>>
@@ -153,13 +163,15 @@ pub fn constrain_middleware<
     'b,
     'c,
     'd,
-    Params: for<'de> Deserialize<'de> + 'static,
     M: Metadata,
     ReqFn: Fn(&'a mut Request<Body>, M) -> ReqFut,
     ReqFut: Future<Output = Result<Result<RpcReqFn, Response<Body>>, HttpError>> + 'a,
-    RpcReqFn: FnOnce(&'b mut RpcRequest<GenericRpcMethod<String, Params>>) -> RpcReqFut,
+    RpcReqFn: FnOnce(
+        &'b mut RequestParts,
+        &'b mut RpcRequest<GenericRpcMethod<String, Map<String, Value>>>,
+    ) -> RpcReqFut,
     RpcReqFut: Future<Output = Result<Result<RpcResFn, Response<Body>>, HttpError>> + 'b,
-    RpcResFn: FnOnce(&'c mut Result<Value, RpcError>) -> RpcResFut,
+    RpcResFn: FnOnce(&'c mut ResponseParts, &'c mut Result<Value, RpcError>) -> RpcResFut,
     RpcResFut: Future<Output = Result<Result<ResFn, Response<Body>>, HttpError>> + 'c,
     ResFn: FnOnce(&'d mut Response<Body>) -> ResFut,
     ResFut: Future<Output = Result<(), HttpError>> + 'd,
diff --git a/rpc-toolkit/tests/test.rs b/rpc-toolkit/tests/test.rs
index 65018ec..da3f6de 100644
--- a/rpc-toolkit/tests/test.rs
+++ b/rpc-toolkit/tests/test.rs
@@ -91,18 +91,18 @@ fn dothething2<U: Serialize + for<'a> Deserialize<'a> + FromStr<Err = E>, E: Dis
     ))
 }
 
-async fn cors<Params: for<'de> Deserialize<'de> + 'static, M: Metadata + 'static>(
+async fn cors<M: Metadata + 'static>(
     req: &mut Request<Body>,
     _: M,
-) -> Result<Result<DynMiddlewareStage2<Params>, Response<Body>>, HttpError> {
+) -> Result<Result<DynMiddlewareStage2, Response<Body>>, HttpError> {
     if req.method() == hyper::Method::OPTIONS {
         Ok(Err(Response::builder()
             .header("Access-Control-Allow-Origin", "*")
             .body(Body::empty())?))
     } else {
-        Ok(Ok(Box::new(|_| {
+        Ok(Ok(Box::new(|_, _| {
             async move {
-                let res: DynMiddlewareStage3 = Box::new(|_| {
+                let res: DynMiddlewareStage3 = Box::new(|_, _| {
                     async move {
                         let res: DynMiddlewareStage4 = Box::new(|res| {
                             async move {