diff --git a/Makefile b/Makefile index fe0f7ad4..496d9e5f 100644 --- a/Makefile +++ b/Makefile @@ -1,4 +1,8 @@ .PHONY : build + +default: + @dune build + build : @dune build -p dream-pure,dream-httpaf,dream --no-print-directory @install diff --git a/dream-httpaf.opam b/dream-httpaf.opam index 443479ee..12bb4683 100644 --- a/dream-httpaf.opam +++ b/dream-httpaf.opam @@ -16,9 +16,7 @@ depends: [ "dune" {>= "2.7.0"} # --instrument-with. "lwt" "lwt_ppx" {>= "1.2.2"} - "lwt_ssl" "ocaml" {>= "4.08.0"} - "ssl" {>= "0.5.8"} # Ssl.get_negotiated_alpn_protocol. # Currently vendored. # "gluten" diff --git a/dream-pure.opam b/dream-pure.opam index 6f6b7f26..b3a44e28 100644 --- a/dream-pure.opam +++ b/dream-pure.opam @@ -22,6 +22,7 @@ depends: [ "ocaml" {>= "4.08.0"} "ptime" {>= "0.8.1"} # Ptime.weekday. "uri" {>= "4.2.0"} + "eio" {>= "0.2"} # Testing, development. "alcotest" {with-test} diff --git a/dream.opam b/dream.opam index 198b9bcd..c9f79833 100644 --- a/dream.opam +++ b/dream.opam @@ -61,7 +61,6 @@ depends: [ "graphql-lwt" "lwt" "lwt_ppx" {>= "1.2.2"} - "lwt_ssl" "logs" {>= "0.5.0"} "magic-mime" "mirage-clock" @@ -70,9 +69,10 @@ depends: [ "multipart_form" {>= "0.3.0"} "ocaml" {>= "4.08.0"} "ptime" {>= "0.8.1"} # Ptime.v. - "ssl" {>= "0.5.8"} # Ssl.get_negotiated_alpn_protocol. "uri" {>= "4.2.0"} "yojson" # ... + "eio_main" {>= "0.2"} + "lwt_eio" {>= "0.1"} # Testing, development. "alcotest" {with-test} diff --git a/example/1-hello/README.md b/example/1-hello/README.md index 64ef42f6..542bba40 100644 --- a/example/1-hello/README.md +++ b/example/1-hello/README.md @@ -6,8 +6,10 @@ This project is so simple that it doesn't even log requests! ```ocaml let () = - Dream.run (fun _ -> - Dream.html "Good morning, world!") + Eio_main.run (fun env -> + Dream.run env (fun _ -> + Dream.html "Good morning, world!") + ) ```
@@ -39,6 +41,11 @@ name of the `.ml` file, but with `.ml` changed to `.exe`.
+A Dream server runs in an [Eio](https://github.com/ocaml-multicore/eio) event loop, +which is created by `Eio_main.run`. + +
+ **Next steps:** - The next example, [**`2-middleware`**](../2-middleware#files), adds a logger diff --git a/example/1-hello/hello.ml b/example/1-hello/hello.ml index 5411c9ee..83de636c 100644 --- a/example/1-hello/hello.ml +++ b/example/1-hello/hello.ml @@ -1,3 +1,5 @@ let () = - Dream.run (fun _ -> - Dream.html "Good morning, world!") + Eio_main.run (fun env -> + Dream.run env (fun _ -> + Dream.html "Good morning, world!") + ) diff --git a/example/2-middleware/README.md b/example/2-middleware/README.md index 5ec6b67e..3949861e 100644 --- a/example/2-middleware/README.md +++ b/example/2-middleware/README.md @@ -9,9 +9,10 @@ middlewares, the [*logger*](https://aantron.github.io/dream/#val-logger): ```ocaml let () = - Dream.run - (Dream.logger (fun _ -> - Dream.html "Good morning, world!")) + Eio_main.run (fun env -> + Dream.run env + (Dream.logger (fun _ -> + Dream.html "Good morning, world!"))) ```
@@ -25,7 +26,8 @@ in this example looks like this: ```ocaml let () = - Dream.run + Eio_main.run @@ fun env -> + Dream.run env @@ Dream.logger @@ fun _ -> Dream.html "Good morning, world!" ``` diff --git a/example/2-middleware/middleware.ml b/example/2-middleware/middleware.ml index a35eb21d..c04d64f5 100644 --- a/example/2-middleware/middleware.ml +++ b/example/2-middleware/middleware.ml @@ -1,4 +1,5 @@ let () = - Dream.run + Eio_main.run @@ fun env -> + Dream.run env @@ Dream.logger @@ fun _ -> Dream.html "Good morning, world!" diff --git a/example/3-router/router.ml b/example/3-router/router.ml index 0c0c410f..faff8819 100644 --- a/example/3-router/router.ml +++ b/example/3-router/router.ml @@ -1,5 +1,6 @@ let () = - Dream.run + Eio_main.run @@ fun env -> + Dream.run env @@ Dream.logger @@ Dream.router [ diff --git a/example/4-counter/counter.ml b/example/4-counter/counter.ml index 0f4c9d50..3d1a5756 100644 --- a/example/4-counter/counter.ml +++ b/example/4-counter/counter.ml @@ -5,7 +5,8 @@ let count_requests inner_handler request = inner_handler request let () = - Dream.run + Eio_main.run @@ fun env -> + Dream.run env @@ Dream.logger @@ count_requests @@ Dream.router [ diff --git a/example/5-promise/README.md b/example/5-promise/README.md index 60110392..821daa08 100644 --- a/example/5-promise/README.md +++ b/example/5-promise/README.md @@ -1,29 +1,30 @@ # `5-promise` +(note this example is now badly named, as it doesn't use any promises) +
[**`4-counter`**](../4-counter#files) was limited to counting requests *before* -passing them on to the rest of the app. With the promise library -[Lwt](https://github.com/ocsigen/lwt), we can await responses, and do something -*after*. In this example, we separately count requests that were handled -successfully, and those that caused an exception: +passing them on to the rest of the app. We can also await responses, and do +something *after*. In this example, we separately count requests that were +handled successfully, and those that caused an exception: ```ocaml let successful = ref 0 let failed = ref 0 let count_requests inner_handler request = - try%lwt - let%lwt response = inner_handler request in + try + let response = inner_handler request in successful := !successful + 1; - Lwt.return response - + response with exn -> failed := !failed + 1; raise exn let () = - Dream.run + Eio_main.run @@ fun env -> + Dream.run env @@ Dream.logger @@ count_requests @@ Dream.router [ @@ -49,49 +50,13 @@ Try it in the [playground](http://dream.as/5-promise).
-As you can see, the -[core constructs](https://ocsigen.org/lwt/latest/api/Ppx_lwt) of Lwt are: - -- `let%lwt` to await the result of a promise. -- `try%lwt` to catch both exceptions and rejections. Lwt promises can only be - rejected with exceptions, of OCaml type `exn`. -- `Lwt.return` to resolve a promise. - -Besides these, Lwt has a lot of [convenience -functions](https://ocsigen.org/lwt/latest/api/Lwt), and an [asychronous -I/O library](https://ocsigen.org/lwt/latest/api/Lwt_unix). +As you can see, we use `try` to catch both exceptions and rejections.
-To use `let%lwt`, we need to modify our -[`dune`](https://github.com/aantron/dream/blob/master/example/5-promise/dune) -file a bit to include `lwt_ppx`: - -
(executable
- (name promise)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
-
- -There are other ways to write *await* and *catch* in Lwt that don't require -`lwt_ppx`, but `lwt_ppx` is presently the best for preserving nice stack traces. -For example, `let%lwt` is equivalent to... - -- [`Lwt.bind`](https://github.com/ocsigen/lwt/blob/c5f895e35a38df2d06f19fd23bf553129b9e95b3/src/core/lwt.mli#L475), - which is almost never used directly. -- [`>>=`](https://github.com/ocsigen/lwt/blob/c5f895e35a38df2d06f19fd23bf553129b9e95b3/src/core/lwt.mli#L1395) - from module `Lwt.Infix`. -- [`let*`](https://github.com/ocsigen/lwt/blob/c5f895e35a38df2d06f19fd23bf553129b9e95b3/src/core/lwt.mli#L1511) - from module `Lwt.Syntax`, which is showcased in Lwt's - [README](https://github.com/ocsigen/lwt#readme). - -We will stick to `let%lwt` in the examples and keep things tidy. - -
- **Next steps:** - [**`6-echo`**](../6-echo#files) uses Dream and Lwt to read a request body. diff --git a/example/5-promise/dune b/example/5-promise/dune index 438ffc03..b5b1aa57 100644 --- a/example/5-promise/dune +++ b/example/5-promise/dune @@ -1,6 +1,5 @@ (executable (name promise) - (libraries dream) - (preprocess (pps lwt_ppx))) + (libraries dream)) (data_only_dirs _esy esy.lock lib node_modules) diff --git a/example/5-promise/promise.ml b/example/5-promise/promise.ml index 34bc200c..91769d02 100644 --- a/example/5-promise/promise.ml +++ b/example/5-promise/promise.ml @@ -2,17 +2,17 @@ let successful = ref 0 let failed = ref 0 let count_requests inner_handler request = - try%lwt - let%lwt response = inner_handler request in + try + let response = inner_handler request in successful := !successful + 1; - Lwt.return response - + response with exn -> failed := !failed + 1; raise exn let () = - Dream.run + Eio_main.run @@ fun env -> + Dream.run env @@ Dream.logger @@ count_requests @@ Dream.router [ diff --git a/example/6-echo/dune b/example/6-echo/dune index aeebe713..8784a629 100644 --- a/example/6-echo/dune +++ b/example/6-echo/dune @@ -1,6 +1,5 @@ (executable (name echo) - (libraries dream) - (preprocess (pps lwt_ppx))) + (libraries dream)) (data_only_dirs _esy esy.lock lib node_modules) diff --git a/example/6-echo/echo.ml b/example/6-echo/echo.ml index fbdca6fe..27907306 100644 --- a/example/6-echo/echo.ml +++ b/example/6-echo/echo.ml @@ -1,10 +1,11 @@ let () = - Dream.run + Eio_main.run @@ fun env -> + Dream.run env @@ Dream.logger @@ Dream.router [ Dream.post "/echo" (fun request -> - let%lwt body = Dream.body request in + let body = Dream.body request in Dream.respond ~headers:["Content-Type", "application/octet-stream"] body); diff --git a/example/7-template/README.md b/example/7-template/README.md index 4162f6c0..4fcc5ea5 100644 --- a/example/7-template/README.md +++ b/example/7-template/README.md @@ -43,8 +43,7 @@ file to run the template preprocessor: 
(executable
  (name template)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (rule
  (targets template.ml)
diff --git a/example/7-template/template.eml.ml b/example/7-template/template.eml.ml
index 27e7e351..3fedf055 100644
--- a/example/7-template/template.eml.ml
+++ b/example/7-template/template.eml.ml
@@ -6,7 +6,8 @@ let render param =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
diff --git a/example/8-debug/debug.ml b/example/8-debug/debug.ml
index b1aed12e..6fed9a35 100644
--- a/example/8-debug/debug.ml
+++ b/example/8-debug/debug.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run ~error_handler:Dream.debug_error_handler
+  Eio_main.run @@ fun env ->
+  Dream.run ~error_handler:Dream.debug_error_handler env
   @@ Dream.logger
   @@ Dream.router [
 
diff --git a/example/9-error/error.eml.ml b/example/9-error/error.eml.ml
index 515091cf..67937346 100644
--- a/example/9-error/error.eml.ml
+++ b/example/9-error/error.eml.ml
@@ -12,9 +12,10 @@ let my_error_template _error debug_info suggested_response =
     
     
   end;
-  Lwt.return suggested_response
+  suggested_response
 
 let () =
-  Dream.run ~error_handler:(Dream.error_template my_error_template)
+  Eio_main.run @@ fun env ->
+  Dream.run ~error_handler:(Dream.error_template my_error_template) env
   @@ Dream.logger
   @@ Dream.not_found
diff --git a/example/a-log/log.ml b/example/a-log/log.ml
index 7afc7e21..a66a5c47 100644
--- a/example/a-log/log.ml
+++ b/example/a-log/log.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
diff --git a/example/b-session/dune b/example/b-session/dune
index 0087f76d..557b34a4 100644
--- a/example/b-session/dune
+++ b/example/b-session/dune
@@ -1,6 +1,5 @@
 (executable
  (name session)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/b-session/session.ml b/example/b-session/session.ml
index b1d981b5..57cb238b 100644
--- a/example/b-session/session.ml
+++ b/example/b-session/session.ml
@@ -1,13 +1,14 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ fun request ->
 
     match Dream.session "user" request with
     | None ->
-      let%lwt () = Dream.invalidate_session request in
-      let%lwt () = Dream.put_session "user" "alice" request in
+      Dream.invalidate_session request;
+      Dream.put_session "user" "alice" request;
       Dream.html "You weren't logged in; but now you are!"
 
     | Some username ->
diff --git a/example/c-cookie/cookie.ml b/example/c-cookie/cookie.ml
index 73435ada..fcc56b60 100644
--- a/example/c-cookie/cookie.ml
+++ b/example/c-cookie/cookie.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.set_secret "foo"
   @@ Dream.logger
   @@ fun request ->
@@ -13,4 +14,4 @@ let () =
       let response = Dream.response "Set language preference; come again!" in
       Dream.add_header response "Content-Type" Dream.text_html;
       Dream.set_cookie response "ui.language" "ut-OP" request;
-      Lwt.return response
+      response
diff --git a/example/d-form/dune b/example/d-form/dune
index 6918056c..d8ba1e88 100644
--- a/example/d-form/dune
+++ b/example/d-form/dune
@@ -1,7 +1,6 @@
 (executable
  (name form)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (rule
  (targets form.ml)
diff --git a/example/d-form/form.eml.ml b/example/d-form/form.eml.ml
index 7ee950b5..4b9650e4 100644
--- a/example/d-form/form.eml.ml
+++ b/example/d-form/form.eml.ml
@@ -16,7 +16,8 @@ let show_form ?message request =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ Dream.router [
@@ -27,7 +28,7 @@ let () =
 
     Dream.post "/"
       (fun request ->
-        match%lwt Dream.form request with
+        match Dream.form request with
         | `Ok ["message", message] ->
           Dream.html (show_form ~message request)
         | _ ->
diff --git a/example/e-json/README.md b/example/e-json/README.md
index fc26a1cf..08002072 100644
--- a/example/e-json/README.md
+++ b/example/e-json/README.md
@@ -44,7 +44,7 @@ To get this working, we have to add `ppx_yojson_conv` to our
 
(executable
  (name json)
  (libraries dream)
- (preprocess (pps lwt_ppx ppx_yojson_conv)))
+ (preprocess (pps ppx_yojson_conv)))
 

 
 and to
diff --git a/example/e-json/dune b/example/e-json/dune
index 15568cec..dc82cfd9 100644
--- a/example/e-json/dune
+++ b/example/e-json/dune
@@ -1,6 +1,6 @@
 (executable
  (name json)
  (libraries dream)
- (preprocess (pps lwt_ppx ppx_yojson_conv)))
+ (preprocess (pps ppx_yojson_conv)))
 
 (data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/e-json/json.ml b/example/e-json/json.ml
index fa8fad05..2fa3a2d6 100644
--- a/example/e-json/json.ml
+++ b/example/e-json/json.ml
@@ -3,17 +3,16 @@ type message_object = {
 } [@@deriving yojson]
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.origin_referrer_check
   @@ Dream.router [
 
     Dream.post "/"
       (fun request ->
-        let%lwt body = Dream.body request in
-
         let message_object =
-          body
+          Dream.body request
           |> Yojson.Safe.from_string
           |> message_object_of_yojson
         in
diff --git a/example/f-static/static.ml b/example/f-static/static.ml
index 2ede0c2c..7e365e2e 100644
--- a/example/f-static/static.ml
+++ b/example/f-static/static.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/static/**" (Dream.static ".")
diff --git a/example/g-upload/dune b/example/g-upload/dune
index 72f71e70..b5700e4e 100644
--- a/example/g-upload/dune
+++ b/example/g-upload/dune
@@ -1,7 +1,6 @@
 (executable
  (name upload)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (rule
  (targets upload.ml)
diff --git a/example/g-upload/upload.eml.ml b/example/g-upload/upload.eml.ml
index 5c2a1752..cb22653b 100644
--- a/example/g-upload/upload.eml.ml
+++ b/example/g-upload/upload.eml.ml
@@ -23,7 +23,8 @@ let report files =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ Dream.router [
@@ -32,7 +33,7 @@ let () =
       Dream.html (home request));
 
     Dream.post "/" (fun request ->
-      match%lwt Dream.multipart request with
+      match Dream.multipart request with
       | `Ok ["files", files] -> Dream.html (report files)
       | _ -> Dream.empty `Bad_Request);
 
diff --git a/example/h-sql/sql.eml.ml b/example/h-sql/sql.eml.ml
index fe406b97..f33389f7 100644
--- a/example/h-sql/sql.eml.ml
+++ b/example/h-sql/sql.eml.ml
@@ -33,20 +33,21 @@ let render comments request =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.sql_pool "sqlite3:db.sqlite"
   @@ Dream.sql_sessions
   @@ Dream.router [
 
     Dream.get "/" (fun request ->
-      let%lwt comments = Dream.sql request list_comments in
+      let comments = Dream.sql request list_comments in
       Dream.html (render comments request));
 
     Dream.post "/" (fun request ->
-      match%lwt Dream.form request with
+      match Dream.form request with
       | `Ok ["text", text] ->
-        let%lwt () = Dream.sql request (add_comment text) in
+        Dream.sql request (add_comment text);
         Dream.redirect request "/"
       | _ ->
         Dream.empty `Bad_Request);
diff --git a/example/i-graphql/graphql.ml b/example/i-graphql/graphql.ml
index 27a68c7c..de46fec9 100644
--- a/example/i-graphql/graphql.ml
+++ b/example/i-graphql/graphql.ml
@@ -36,7 +36,8 @@ let default_query =
   "{\\n  users {\\n    name\\n    id\\n  }\\n}\\n"
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.origin_referrer_check
   @@ Dream.router [
diff --git a/example/j-stream/dune b/example/j-stream/dune
index 9cf43884..dedf8f7b 100644
--- a/example/j-stream/dune
+++ b/example/j-stream/dune
@@ -1,6 +1,5 @@
 (executable
  (name stream)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/j-stream/stream.ml b/example/j-stream/stream.ml
index 3f9c2477..089871c9 100644
--- a/example/j-stream/stream.ml
+++ b/example/j-stream/stream.ml
@@ -1,22 +1,23 @@
 let echo request response =
   let rec loop () =
-    match%lwt Dream.read request with
+    match Dream.read request with
     | None ->
       Dream.close response
     | Some chunk ->
-      let%lwt () = Dream.write response chunk in
-      let%lwt () = Dream.flush response in
+      Dream.write response chunk;
+      Dream.flush response;
       loop ()
   in
   loop ()
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
     Dream.post "/echo" (fun request ->
-      Dream.stream
+      Dream.stream request
         ~headers:["Content-Type", "application/octet-stream"]
         (echo request));
 
diff --git a/example/k-websocket/dune b/example/k-websocket/dune
index 2e18f039..2ad9a331 100644
--- a/example/k-websocket/dune
+++ b/example/k-websocket/dune
@@ -1,7 +1,6 @@
 (executable
  (name websocket)
- (libraries dream)
- (preprocess (pps lwt_ppx)))
+ (libraries dream))
 
 (rule
  (targets websocket.ml)
diff --git a/example/k-websocket/websocket.eml.ml b/example/k-websocket/websocket.eml.ml
index 1166c93e..b05877a5 100644
--- a/example/k-websocket/websocket.eml.ml
+++ b/example/k-websocket/websocket.eml.ml
@@ -18,7 +18,8 @@ let home =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
@@ -27,11 +28,11 @@ let () =
         Dream.html home);
 
     Dream.get "/websocket"
-      (fun _ ->
-        Dream.websocket (fun response ->
-          match%lwt Dream.read response with
+      (fun request ->
+        Dream.websocket request (fun response ->
+          match Dream.read response with
           | Some "Hello?" ->
-            let%lwt () = Dream.write response "Good-bye!" in
+            Dream.write response "Good-bye!";
             Dream.close response
           | _ ->
             Dream.close response));
diff --git a/example/l-https/https.ml b/example/l-https/https.ml
index d9f4a077..7e76651f 100644
--- a/example/l-https/https.ml
+++ b/example/l-https/https.ml
@@ -1,4 +1,5 @@
 let () =
-  Dream.run ~https:true
+  Eio_main.run @@ fun env ->
+  Dream.run ~https:true env
   @@ Dream.logger
   @@ fun _ -> Dream.html "Good morning, world!"
diff --git a/example/r-advanced-template/template.eml.re b/example/r-advanced-template/template.eml.re
index 94ad8e49..da357d2a 100644
--- a/example/r-advanced-template/template.eml.re
+++ b/example/r-advanced-template/template.eml.re
@@ -38,7 +38,8 @@ let tasks = [
 ];
 
 let () =
-  Dream.run
+  Eio_main.run @@ env =>
+  Dream.run(env)
   @@ Dream.logger
   @@ Dream.router([
     Dream.get("/", _ => render_home(tasks) |> Dream.html),
diff --git a/example/r-fullstack-melange/server/server.eml.re b/example/r-fullstack-melange/server/server.eml.re
index c55429b6..9cbe627c 100644
--- a/example/r-fullstack-melange/server/server.eml.re
+++ b/example/r-fullstack-melange/server/server.eml.re
@@ -8,7 +8,8 @@ let home = {
 };
 
 let () =
-  Dream.run
+  Eio_main.run @@ env =>
+  Dream.run(env)
   @@ Dream.logger
   @@ Dream.router([
 
diff --git a/example/r-graphql/graphql.re b/example/r-graphql/graphql.re
index cd129b1b..768c95f4 100644
--- a/example/r-graphql/graphql.re
+++ b/example/r-graphql/graphql.re
@@ -47,7 +47,8 @@ let default_query =
   "{\\n  users {\\n    name\\n    id\\n  }\\n}\\n";
 
 let () =
-  Dream.run
+  Eio_main.run @@ env =>
+  Dream.run(env)
   @@ Dream.logger
   @@ Dream.origin_referrer_check
   @@ Dream.router([
diff --git a/example/r-hello/hello.re b/example/r-hello/hello.re
index d6fdbaf3..7ac71b66 100644
--- a/example/r-hello/hello.re
+++ b/example/r-hello/hello.re
@@ -1,3 +1,4 @@
 let () =
-  Dream.run(_ =>
+  Eio_main.run @@ env =>
+  Dream.run(env, _ =>
     Dream.html("Good morning, reasonable world!"));
diff --git a/example/r-template-files/server.re b/example/r-template-files/server.re
index 656b6c13..63b229c7 100644
--- a/example/r-template-files/server.re
+++ b/example/r-template-files/server.re
@@ -1,5 +1,6 @@
 let () =
-  Dream.run @@
+  Eio_main.run @@ env =>
+  Dream.run(env) @@
   Dream.logger @@
   Dream.router([
     Dream.get("/:word", request =>
diff --git a/example/r-template-stream/template_stream.eml.re b/example/r-template-stream/template_stream.eml.re
index e51238b3..7a4f4ac8 100644
--- a/example/r-template-stream/template_stream.eml.re
+++ b/example/r-template-stream/template_stream.eml.re
@@ -1,16 +1,16 @@
 let render = response => {
-  let%lwt () = {
+  let () = {
     %% response
     
     
 
 %     let rec paragraphs = index => {
         
<%i index %>

-%       let%lwt () = Dream.flush(response);
-%       let%lwt () = Lwt_unix.sleep(1.);
-%       paragraphs(index + 1);
+%       Dream.flush(response);
+%       Eio_unix.sleep(1.);
+%       if (index < 10) paragraphs(index + 1);
 %     };
-%     let%lwt () = paragraphs(0);
+%     paragraphs(0);
 
     
     
@@ -19,6 +19,7 @@ let render = response => {
 };
 
 let () =
-  Dream.run
+  Eio_main.run @@ env =>
+  Dream.run(env)
   @@ Dream.logger
-  @@ _ => Dream.stream(~headers=[("Content-Type", Dream.text_html)], render);
+  @@ request => Dream.stream(~headers=[("Content-Type", Dream.text_html)], request, render);
diff --git a/example/r-template/template.eml.re b/example/r-template/template.eml.re
index 5fe9eaaa..b7fbd522 100644
--- a/example/r-template/template.eml.re
+++ b/example/r-template/template.eml.re
@@ -7,7 +7,8 @@ let greet = who => {
 };
 
 let () =
-  Dream.run
+  Eio_main.run @@ env =>
+  Dream.run(env)
   @@ Dream.logger
   @@ Dream.router([
 
diff --git a/example/r-tyxml/tyxml.re b/example/r-tyxml/tyxml.re
index e89a44a9..c0d06328 100644
--- a/example/r-tyxml/tyxml.re
+++ b/example/r-tyxml/tyxml.re
@@ -12,7 +12,8 @@ let html_to_string = html =>
   Format.asprintf("%a", Tyxml.Html.pp(), html);
 
 let () =
-  Dream.run
+  Eio_main.run @@ env =>
+  Dream.run(env)
   @@ Dream.logger
   @@ Dream.router([
 
diff --git a/example/w-advanced-template/template.eml.ml b/example/w-advanced-template/template.eml.ml
index 6d17bd81..7e26831e 100644
--- a/example/w-advanced-template/template.eml.ml
+++ b/example/w-advanced-template/template.eml.ml
@@ -37,7 +37,8 @@ let tasks = [
 ]
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/"
diff --git a/example/w-chat/chat.eml.ml b/example/w-chat/chat.eml.ml
index 28d15b52..8d71e7cc 100644
--- a/example/w-chat/chat.eml.ml
+++ b/example/w-chat/chat.eml.ml
@@ -1,3 +1,5 @@
+open Eio.Std
+
 let home =
   
   
@@ -44,16 +46,19 @@ let forget client_id =
   Hashtbl.remove clients client_id
 
 let send message =
+  Switch.run @@ fun sw ->
   Hashtbl.to_seq_values clients
   |> List.of_seq
-  |> Lwt_list.iter_p (fun client -> Dream.write client message)
+  |> List.iter (fun client ->
+      Fiber.fork ~sw (fun () -> Dream.write client message)
+    )
 
 let handle_client client =
   let client_id = track client in
   let rec loop () =
-    match%lwt Dream.read client with
+    match Dream.read client with
     | Some message ->
-      let%lwt () = send message in
+      send message;
       loop ()
     | None ->
       forget client_id;
@@ -62,7 +67,8 @@ let handle_client client =
   loop ()
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
@@ -70,7 +76,7 @@ let () =
       (fun _ -> Dream.html home);
 
     Dream.get "/websocket"
-      (fun _ -> Dream.websocket handle_client);
+      (fun request -> Dream.websocket request handle_client);
 
   ]
   @@ Dream.not_found
diff --git a/example/w-content-security-policy/content_security_policy.eml.ml b/example/w-content-security-policy/content_security_policy.eml.ml
index 257442b8..78460b98 100644
--- a/example/w-content-security-policy/content_security_policy.eml.ml
+++ b/example/w-content-security-policy/content_security_policy.eml.ml
@@ -6,7 +6,8 @@ let home =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
@@ -21,7 +22,7 @@ let () =
         "You should not be able to see this inside a frame!");
 
     Dream.post "/violation" (fun request ->
-      let%lwt report = Dream.body request in
+      let report = Dream.body request in
       Dream.error (fun log -> log "%s" report);
       Dream.empty `OK);
 
diff --git a/example/w-esy/hello.ml b/example/w-esy/hello.ml
index a35eb21d..c04d64f5 100644
--- a/example/w-esy/hello.ml
+++ b/example/w-esy/hello.ml
@@ -1,4 +1,5 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ fun _ -> Dream.html "Good morning, world!"
diff --git a/example/w-flash/flash.eml.ml b/example/w-flash/flash.eml.ml
index 1b9cd121..b0edf034 100644
--- a/example/w-flash/flash.eml.ml
+++ b/example/w-flash/flash.eml.ml
@@ -19,7 +19,8 @@ let result request =
 
 let () =
   Dream.set_log_level "dream.flash" `Debug;
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ Dream.flash_messages
@@ -31,9 +32,9 @@ let () =
 
     Dream.post "/"
       (fun request ->
-        match%lwt Dream.form request with
+        match Dream.form request with
         | `Ok ["text", text] ->
-          let () = Dream.put_flash request "Info" text in
+          Dream.put_flash request "Info" text;
           Dream.redirect request "/result"
         | _ ->
           Dream.redirect request "/");
diff --git a/example/w-fswatch/hello.ml b/example/w-fswatch/hello.ml
index a35eb21d..c04d64f5 100644
--- a/example/w-fswatch/hello.ml
+++ b/example/w-fswatch/hello.ml
@@ -1,4 +1,5 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ fun _ -> Dream.html "Good morning, world!"
diff --git a/example/w-fullstack-jsoo/.gitignore b/example/w-fullstack-jsoo/.gitignore
deleted file mode 100644
index 980c8512..00000000
--- a/example/w-fullstack-jsoo/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-static/
diff --git a/example/w-fullstack-jsoo/README.md b/example/w-fullstack-jsoo/README.md
deleted file mode 100644
index d5bf7b8a..00000000
--- a/example/w-fullstack-jsoo/README.md
+++ /dev/null
@@ -1,84 +0,0 @@
-# `w-fullstack-jsoo`
-
-

-
-This example shares a toy function between client and server using
-[js_of_ocaml](https://ocsigen.org/js_of_ocaml/latest/manual/overview). The
-function is in
-[common/common.ml](https://github.com/aantron/dream/blob/master/example/w-fullstack-jsoo/common/common.ml).
-
-```ocaml
-let greet = function
-  | `Server -> "Hello..."
-  | `Client -> "...world!"
-```
-
-The first part of the message is printed by the server, in
-[server/server.eml.ml](https://github.com/aantron/dream/blob/master/example/w-fullstack-jsoo/server/server.eml.ml):
-
-```ocaml
-let home =
-  
-    
-      
<%s Common.greet `Server %>

-      
-    
-  
-
-let () =
-  Dream.run
-  @@ Dream.logger
-  @@ Dream.router [
-
-    Dream.get "/"
-      (fun _ -> Dream.html home);
-
-    Dream.get "/static/**"
-      (Dream.static "./static");
-
-  ]
-  @@ Dream.not_found
-```
-
-The rest is printed by the client, in
-[client/client.ml](https://github.com/aantron/dream/blob/master/example/w-fullstack-jsoo/client/client.ml):
-
-```ocaml
-open Js_of_ocaml
-
-let () =
-  let body = Dom_html.getElementById_exn "body" in
-  let p = Dom_html.(createP document) in
-  p##.innerHTML := Js.string (Common.greet `Client);
-  Dom.appendChild body p
-```
-
-To run the example, do
-
-
cd example/w-fullstack-jsoo
-dune build --root . client/client.bc.js
-mkdir -p static
-cp _build/default/client/client.bc.js static/client.js
-dune exec --root . server/server.exe
-

-
-You can also trigger it all with esy with
-
-
$ cd example/w-fullstack-jsoo
-$ npm install esy && npx esy
-$ npx esy start

-
-Then visit [http://localhost:8080](http://localhost:8080), and you will see...
-
-![Full-stack greeting](https://raw.githubusercontent.com/aantron/dream/master/docs/asset/fullstack.png)
-
-

-
-**See also:**
-
-- [**`w-one-binary`**](../w-one-binary#files) for bundling assets into a
-  self-contained binary.
-
-

-
-[Up to the example index](../#full-stack)
diff --git a/example/w-fullstack-jsoo/client/client.ml b/example/w-fullstack-jsoo/client/client.ml
deleted file mode 100644
index 50b65562..00000000
--- a/example/w-fullstack-jsoo/client/client.ml
+++ /dev/null
@@ -1,7 +0,0 @@
-open Js_of_ocaml
-
-let () =
-  let body = Dom_html.getElementById_exn "body" in
-  let p = Dom_html.(createP document) in
-  p##.innerHTML := Js.string (Common.greet `Client);
-  Dom.appendChild body p
diff --git a/example/w-fullstack-jsoo/client/dune b/example/w-fullstack-jsoo/client/dune
deleted file mode 100644
index 45f19c4d..00000000
--- a/example/w-fullstack-jsoo/client/dune
+++ /dev/null
@@ -1,5 +0,0 @@
-(executable
- (name client)
- (modes js)
- (libraries common js_of_ocaml)
- (preprocess (pps js_of_ocaml-ppx)))
diff --git a/example/w-fullstack-jsoo/common/common.ml b/example/w-fullstack-jsoo/common/common.ml
deleted file mode 100644
index 6a1a1208..00000000
--- a/example/w-fullstack-jsoo/common/common.ml
+++ /dev/null
@@ -1,3 +0,0 @@
-let greet = function
-  | `Server -> "Hello..."
-  | `Client -> "...world!"
diff --git a/example/w-fullstack-jsoo/common/dune b/example/w-fullstack-jsoo/common/dune
deleted file mode 100644
index 35b99062..00000000
--- a/example/w-fullstack-jsoo/common/dune
+++ /dev/null
@@ -1,2 +0,0 @@
-(library
- (name common))
diff --git a/example/w-fullstack-jsoo/dune b/example/w-fullstack-jsoo/dune
deleted file mode 100644
index 8ab777a7..00000000
--- a/example/w-fullstack-jsoo/dune
+++ /dev/null
@@ -1 +0,0 @@
-(data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/w-fullstack-jsoo/dune-project b/example/w-fullstack-jsoo/dune-project
deleted file mode 100644
index 929c696e..00000000
--- a/example/w-fullstack-jsoo/dune-project
+++ /dev/null
@@ -1 +0,0 @@
-(lang dune 2.0)
diff --git a/example/w-fullstack-jsoo/esy.json b/example/w-fullstack-jsoo/esy.json
deleted file mode 100644
index 37d63a63..00000000
--- a/example/w-fullstack-jsoo/esy.json
+++ /dev/null
@@ -1,28 +0,0 @@
-{
-  "dependencies": {
-    "@opam/dream": "1.0.0~alpha2",
-    "@opam/dune": "^2.0",
-    "@opam/js_of_ocaml": "*",
-    "@opam/js_of_ocaml-ppx": "*",
-    "ocaml": "4.12.x"
-  },
-  "devDependencies": {
-    "@opam/ocaml-lsp-server": "*"
-  },
-  "resolutions": {
-    "@opam/conf-libev": "esy-packages/libev:package.json#0b5eb6685b688649045aceac55dc559f6f21b829",
-    "esy-openssl": "esy-packages/esy-openssl#619ae2d46ca981ec26ab3287487ad98b157a01d1"
-  },
-  "esy": {
-    "buildsInSource": "unsafe",
-    "build": [
-      "dune build --root . client/client.bc.js",
-      "mkdir -p static",
-      "cp _build/default/client/client.bc.js static/client.js",
-      "dune build --root . server/server.exe"
-    ]
-  },
-  "scripts": {
-    "start": "dune exec --root . server/server.exe"
-  }
-}
diff --git a/example/w-fullstack-jsoo/server/dune b/example/w-fullstack-jsoo/server/dune
deleted file mode 100644
index e167254b..00000000
--- a/example/w-fullstack-jsoo/server/dune
+++ /dev/null
@@ -1,8 +0,0 @@
-(executable
- (name server)
- (libraries common dream))
-
-(rule
- (targets server.ml)
- (deps server.eml.ml)
- (action (run dream_eml %{deps} --workspace %{workspace_root})))
diff --git a/example/w-fullstack-jsoo/server/server.eml.ml b/example/w-fullstack-jsoo/server/server.eml.ml
deleted file mode 100644
index a9be889e..00000000
--- a/example/w-fullstack-jsoo/server/server.eml.ml
+++ /dev/null
@@ -1,21 +0,0 @@
-let home =
-  
-    
-      
<%s Common.greet `Server %>

-      
-    
-  
-
-let () =
-  Dream.run
-  @@ Dream.logger
-  @@ Dream.router [
-
-    Dream.get "/"
-      (fun _ -> Dream.html home);
-
-    Dream.get "/static/**"
-      (Dream.static "./static");
-
-  ]
-  @@ Dream.not_found
diff --git a/example/w-fullstack-rescript/server/server.eml.ml b/example/w-fullstack-rescript/server/server.eml.ml
index 0827f76b..b1f69f6b 100644
--- a/example/w-fullstack-rescript/server/server.eml.ml
+++ b/example/w-fullstack-rescript/server/server.eml.ml
@@ -7,7 +7,8 @@ let home =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
diff --git a/example/w-graphql-subscription/graphql_subscription.ml b/example/w-graphql-subscription/graphql_subscription.ml
index 7f7d304f..f00d94e9 100644
--- a/example/w-graphql-subscription/graphql_subscription.ml
+++ b/example/w-graphql-subscription/graphql_subscription.ml
@@ -29,7 +29,8 @@ let default_query =
   "subscription {\\n  count(until: 3)\\n}\\n"
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.origin_referrer_check
   @@ Dream.router [
diff --git a/example/w-live-reload/live_reload.ml b/example/w-live-reload/live_reload.ml
index 9750d90f..70c748a0 100644
--- a/example/w-live-reload/live_reload.ml
+++ b/example/w-live-reload/live_reload.ml
@@ -33,11 +33,11 @@ socket.onclose = function(event) {
 |js}
 
 let inject_live_reload_script inner_handler request =
-  let%lwt response = inner_handler request in
+  let response = inner_handler request in
 
   match Dream.header response "Content-Type" with
   | Some "text/html; charset=utf-8" ->
-    let%lwt body = Dream.body response in
+    let body = Dream.body response in
     let soup =
       Markup.string body
       |> Markup.parse_html ~context:`Document
@@ -47,19 +47,20 @@ let inject_live_reload_script inner_handler request =
 
     begin match Soup.Infix.(soup $? "head") with
     | None ->
-      Lwt.return response
+      response
     | Some head ->
       Soup.create_element "script" ~inner_text:live_reload_script
       |> Soup.append_child head;
       Dream.set_body response (Soup.to_string soup);
-      Lwt.return response
+      response
     end
 
   | _ ->
-    Lwt.return response
+    response
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ inject_live_reload_script
   @@ Dream.router [
@@ -70,9 +71,9 @@ let () =
       |> Printf.sprintf "Good morning, world! Random tag: %s"
       |> Dream.html);
 
-    Dream.get "/_live-reload" (fun _ ->
-      Dream.websocket (fun socket ->
-        let%lwt _ = Dream.read socket in
+    Dream.get "/_live-reload" (fun request ->
+      Dream.websocket request (fun socket ->
+        let _ = Dream.read socket in
         Dream.close socket));
 
   ]
diff --git a/example/w-long-polling/long_polling.eml.ml b/example/w-long-polling/long_polling.eml.ml
index 6562c838..cc9f07c4 100644
--- a/example/w-long-polling/long_polling.eml.ml
+++ b/example/w-long-polling/long_polling.eml.ml
@@ -1,3 +1,5 @@
+open Eio.Std
+
 let home =
   
   
@@ -34,44 +36,47 @@ let server_state =
 let last_message =
   ref 0
 
-let rec message_loop () =
-  let%lwt () = Lwt_unix.sleep (Random.float 2.) in
-  incr last_message;
-
-  let message = string_of_int !last_message in
-  Dream.log "Generated message %s" message;
-
-  begin match !server_state with
-  | Client_waiting f ->
-    server_state := Messages_accumulating [];
-    f message
-  | Messages_accumulating list ->
-    server_state := Messages_accumulating (message::list)
-  end;
+let message_loop () =
+  while true do
+    Eio_unix.sleep (Random.float 2.);
+    incr last_message;
 
-  message_loop ()
+    let message = string_of_int !last_message in
+    Dream.log "Generated message %s" message;
 
-let () =
-  Lwt.async message_loop;
-
-  Dream.run
-  @@ Dream.logger
-  @@ Dream.router [
-
-    Dream.get "/" (fun _ -> Dream.html home);
-
-    Dream.get "/poll" (fun _ ->
-      match !server_state with
-      | Client_waiting _ ->
-        Dream.empty `Unauthorized
-      | Messages_accumulating [] ->
-        let response_promise, respond = Lwt.wait () in
-        server_state := Client_waiting (fun message ->
-          Lwt.wakeup_later respond (Dream.response message));
-        response_promise
-      | Messages_accumulating messages ->
+    begin match !server_state with
+      | Client_waiting f ->
         server_state := Messages_accumulating [];
-        Dream.html (String.concat "\n" (List.rev messages)));
+        f message
+      | Messages_accumulating list ->
+        server_state := Messages_accumulating (message::list)
+    end
+  done
 
-  ]
-  @@ Dream.not_found
+let () =
+  Eio_main.run @@ fun env ->
+  Fiber.both
+    message_loop
+    (fun () ->
+       Dream.run env
+       @@ Dream.logger
+       @@ Dream.router [
+
+         Dream.get "/" (fun _ -> Dream.html home);
+
+         Dream.get "/poll" (fun _ ->
+             match !server_state with
+             | Client_waiting _ ->
+               Dream.empty `Unauthorized
+             | Messages_accumulating [] ->
+               let response_promise, respond = Promise.create () in
+               server_state := Client_waiting (fun message ->
+                   Promise.resolve respond (Dream.response message));
+               Promise.await response_promise
+             | Messages_accumulating messages ->
+               server_state := Messages_accumulating [];
+               Dream.html (String.concat "\n" (List.rev messages)));
+
+       ]
+       @@ Dream.not_found
+    )
diff --git a/example/w-multipart-dump/multipart_dump.eml.ml b/example/w-multipart-dump/multipart_dump.eml.ml
index 6521436c..b4754cfe 100644
--- a/example/w-multipart-dump/multipart_dump.eml.ml
+++ b/example/w-multipart-dump/multipart_dump.eml.ml
@@ -10,7 +10,8 @@ let home request =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ Dream.router [
@@ -19,7 +20,7 @@ let () =
       Dream.html (home request));
 
     Dream.post "/" (fun request ->
-      let%lwt body = Dream.body request in
+      let body = Dream.body request in
       Dream.respond
         ~headers:["Content-Type", "text/plain"]
         body);
diff --git a/example/w-nginx/server.eml.ml b/example/w-nginx/server.eml.ml
index 0a9905bd..ba5f4b46 100644
--- a/example/w-nginx/server.eml.ml
+++ b/example/w-nginx/server.eml.ml
@@ -9,7 +9,8 @@ let home =
   
 
 let () =
-  Dream.run ~interface:"0.0.0.0" ~port:8081
+  Eio_main.run @@ fun env ->
+  Dream.run ~interface:"0.0.0.0" ~port:8081 env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/" (fun _request -> Dream.html home)
diff --git a/example/w-one-binary/one_binary.ml b/example/w-one-binary/one_binary.ml
index ac200fb1..7d287b61 100644
--- a/example/w-one-binary/one_binary.ml
+++ b/example/w-one-binary/one_binary.ml
@@ -4,7 +4,8 @@ let loader _root path _request =
   | Some asset -> Dream.respond asset
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/assets/**" (Dream.static ~loader "")
diff --git a/example/w-postgres/postgres.eml.ml b/example/w-postgres/postgres.eml.ml
index 52ecd53c..54acddf8 100644
--- a/example/w-postgres/postgres.eml.ml
+++ b/example/w-postgres/postgres.eml.ml
@@ -33,20 +33,21 @@ let render comments request =
   
 
 let () =
-  Dream.run ~interface:"0.0.0.0"
+  Eio_main.run @@ fun env ->
+  Dream.run ~interface:"0.0.0.0" env
   @@ Dream.logger
   @@ Dream.sql_pool "postgresql://dream:password@postgres/dream"
   @@ Dream.sql_sessions
   @@ Dream.router [
 
     Dream.get "/" (fun request ->
-      let%lwt comments = Dream.sql request list_comments in
+      let comments = Dream.sql request list_comments in
       Dream.html (render comments request));
 
     Dream.post "/" (fun request ->
-      match%lwt Dream.form request with
+      match Dream.form request with
       | `Ok ["text", text] ->
-        let%lwt () = Dream.sql request (add_comment text) in
+        Dream.sql request (add_comment text);
         Dream.redirect request "/"
       | _ ->
         Dream.empty `Bad_Request);
diff --git a/example/w-query/query.ml b/example/w-query/query.ml
index 0dbff411..b5d06342 100644
--- a/example/w-query/query.ml
+++ b/example/w-query/query.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run (fun request ->
+  Eio_main.run @@ fun env ->
+  Dream.run env (fun request ->
     match Dream.query "echo" request with
     | None ->
       Dream.html "Use ?echo=foo to give a message to echo!"
diff --git a/example/w-server-sent-events/server_sent_events.eml.ml b/example/w-server-sent-events/server_sent_events.eml.ml
index 12a6dad2..7621bd45 100644
--- a/example/w-server-sent-events/server_sent_events.eml.ml
+++ b/example/w-server-sent-events/server_sent_events.eml.ml
@@ -1,3 +1,5 @@
+open Eio.Std
+
 let home =
   
   
@@ -26,17 +28,17 @@ let notify =
 let last_message =
   ref 0
 
-let rec message_loop () =
-  let%lwt () = Lwt_unix.sleep (Random.float 2.) in
-
-  incr last_message;
-  let message = string_of_int !last_message in
-  Dream.log "Generated message %s" message;
+let message_loop () =
+  while true do
+    Eio_unix.sleep (Random.float 2.);
 
-  server_state := message::!server_state;
-  !notify ();
+    incr last_message;
+    let message = string_of_int !last_message in
+    Dream.log "Generated message %s" message;
 
-  message_loop ()
+    server_state := message::!server_state;
+    !notify ()
+  done
 
 let rec forward_messages response =
   let%lwt messages =
@@ -58,23 +60,28 @@ let rec forward_messages response =
   |> List.map (Printf.sprintf "data: %s\n\n")
   |> String.concat ""
   |> fun text ->
-    let%lwt () = Dream.write response text in
-    let%lwt () = Dream.flush response in
+    Dream.write response text;
+    Dream.flush response;
     forward_messages response
 
-let () =
-  Lwt.async message_loop;
-
-  Dream.run
-  @@ Dream.logger
-  @@ Dream.router [
+let forward_messages response = Lwt_eio.Promise.await_lwt (forward_messages response)
 
-    Dream.get "/" (fun _ -> Dream.html home);
-
-    Dream.get "/push" (fun _ ->
-      Dream.stream
-        ~headers:["Content-Type", "text/event-stream"]
-        forward_messages);
-
-  ]
-  @@ Dream.not_found
+let () =
+  Eio_main.run @@ fun env ->
+  Fiber.both
+    message_loop
+    (fun () ->
+       Dream.run env
+       @@ Dream.logger
+       @@ Dream.router [
+
+         Dream.get "/" (fun _ -> Dream.html home);
+
+         Dream.get "/push" (fun request ->
+             Dream.stream request
+               ~headers:["Content-Type", "text/event-stream"]
+               forward_messages);
+
+       ]
+       @@ Dream.not_found
+    )
diff --git a/example/w-stress-response/stress_response.ml b/example/w-stress-response/stress_response.ml
index 29854159..d4013b4a 100644
--- a/example/w-stress-response/stress_response.ml
+++ b/example/w-stress-response/stress_response.ml
@@ -1,3 +1,5 @@
+open Eio.Std
+
 let show_heap_size () =
   Gc.((quick_stat ()).heap_words) * 8
   |> float_of_int
@@ -14,23 +16,22 @@ let stress ?(megabytes = 1024) ?(chunk = 64) response =
   let start = Unix.gettimeofday () in
 
   let rec loop sent =
-    if sent >= limit then
-      let%lwt () = Dream.flush response in
-      let%lwt () = Dream.close response in
-      Lwt.return (Unix.gettimeofday () -. start)
-    else
-      let%lwt () = Dream.write response chunk_a in
-      let%lwt () = Dream.write response chunk_b in
-      let%lwt () = Lwt.pause () in
+    if sent >= limit then (
+      Dream.flush response;
+      Dream.close response;
+      (Unix.gettimeofday () -. start)
+    ) else (
+      Dream.write response chunk_a;
+      Dream.write response chunk_b;
+      Fiber.yield ();
       loop (sent + chunk + chunk)
+    )
   in
-  let%lwt elapsed = loop 0 in
+  let elapsed = loop 0 in
 
   Dream.log "%.0f MB/s over %.1f s"
     ((float_of_int megabytes) /. elapsed) elapsed;
-  show_heap_size ();
-
-  Lwt.return_unit
+  show_heap_size ()
 
 let query_int name request =
   Dream.query name request |> Option.map int_of_string
@@ -38,12 +39,13 @@ let query_int name request =
 let () =
   show_heap_size ();
 
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
     Dream.get "/" (fun request ->
-      Dream.stream
+      Dream.stream request
         ~headers:["Content-Type", "application/octet-stream"]
         (stress
           ?megabytes:(query_int "mb" request)
diff --git a/example/w-stress-websocket-send/stress_websocket_send.eml.ml b/example/w-stress-websocket-send/stress_websocket_send.eml.ml
index 9e17de31..ee401093 100644
--- a/example/w-stress-websocket-send/stress_websocket_send.eml.ml
+++ b/example/w-stress-websocket-send/stress_websocket_send.eml.ml
@@ -1,5 +1,7 @@
 (* TODO Definitely needs flow control. *)
 
+open Eio.Std
+
 let home =
   
     
@@ -41,27 +43,27 @@ let stress websocket =
   let limit = 1024 * 1024 * 1024 in
   let start = Unix.gettimeofday () in
   let rec loop sent =
-    if sent >= limit then
-      let%lwt () = Dream.close websocket in
-      Lwt.return (Unix.gettimeofday () -. start)
-    else
-      let%lwt () = Dream.write websocket frame_a ~kind:`Binary in
-      let%lwt () = Dream.write websocket frame_b ~kind:`Binary in
-      let%lwt () = Lwt.pause () in
+    if sent >= limit then (
+      Dream.close websocket;
+      (Unix.gettimeofday () -. start)
+    ) else (
+      Dream.write websocket frame_a ~kind:`Binary;
+      Dream.write websocket frame_b ~kind:`Binary;
+      Fiber.yield ();
       loop (sent + frame + frame)
+    )
   in
-  let%lwt elapsed = loop 0 in
+  let elapsed = loop 0 in
 
   Dream.log "%.0f MB/s over %.1f s"
     ((float_of_int limit) /. elapsed /. 1024. /. 1024.) elapsed;
-  show_heap_size ();
-
-  Lwt.return_unit
+  show_heap_size ()
 
 let () =
   show_heap_size ();
 
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
@@ -69,7 +71,7 @@ let () =
       (fun _ -> Dream.html home);
 
     Dream.get "/websocket"
-      (fun _ -> Dream.websocket stress);
+      (fun request -> Dream.websocket request stress);
 
   ]
   @@ Dream.not_found
diff --git a/example/w-template-files/server.ml b/example/w-template-files/server.ml
index 0f56c2f8..6cab8853 100644
--- a/example/w-template-files/server.ml
+++ b/example/w-template-files/server.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
diff --git a/example/w-template-stream/template_stream.eml.ml b/example/w-template-stream/template_stream.eml.ml
index c8033744..db390873 100644
--- a/example/w-template-stream/template_stream.eml.ml
+++ b/example/w-template-stream/template_stream.eml.ml
@@ -1,16 +1,16 @@
 let render response =
-  let%lwt () =
+  let () =
     %% response
     
     
 
 %     let rec paragraphs index =
         
<%i index %>

-%       let%lwt () = Dream.flush response in
-%       let%lwt () = Lwt_unix.sleep 1. in
-%       paragraphs (index + 1)
+%       Dream.flush response;
+%       Eio_unix.sleep 1.;
+%       if index < 10 then paragraphs (index + 1)
 %     in
-%     let%lwt () = paragraphs 0 in
+%     paragraphs 0;
 
     
     
@@ -18,6 +18,7 @@ let render response =
   Dream.close response
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
-  @@ fun _ -> Dream.stream ~headers:["Content-Type", Dream.text_html] render
+  @@ fun request -> Dream.stream ~headers:["Content-Type", Dream.text_html] request render
diff --git a/example/w-tyxml/tyxml.ml b/example/w-tyxml/tyxml.ml
index ce23849d..fa17b22c 100644
--- a/example/w-tyxml/tyxml.ml
+++ b/example/w-tyxml/tyxml.ml
@@ -12,7 +12,8 @@ let html_to_string html =
   Format.asprintf "%a" (Tyxml.Html.pp ()) html
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.router [
 
diff --git a/example/w-upload-stream/upload_stream.eml.ml b/example/w-upload-stream/upload_stream.eml.ml
index 743f5960..4a3e3bab 100644
--- a/example/w-upload-stream/upload_stream.eml.ml
+++ b/example/w-upload-stream/upload_stream.eml.ml
@@ -23,7 +23,8 @@ let report files =
   
 
 let () =
-  Dream.run
+  Eio_main.run @@ fun env ->
+  Dream.run env
   @@ Dream.logger
   @@ Dream.memory_sessions
   @@ Dream.router [
@@ -33,11 +34,11 @@ let () =
 
     Dream.post "/" (fun request ->
       let rec receive file_sizes =
-        match%lwt Dream.upload request with
+        match Dream.upload request with
         | None -> Dream.html (report (List.rev file_sizes))
         | Some (_, filename, _) ->
           let rec count_size size =
-            match%lwt Dream.upload_part request with
+            match Dream.upload_part request with
             | None -> receive ((filename, size)::file_sizes)
             | Some chunk -> count_size (size + String.length chunk)
           in
diff --git a/example/z-docker-esy/app.ml b/example/z-docker-esy/app.ml
index e2c65265..57bdc8b8 100644
--- a/example/z-docker-esy/app.ml
+++ b/example/z-docker-esy/app.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run ~interface:"0.0.0.0"
+  Eio_main.run @@ fun env ->
+  Dream.run ~interface:"0.0.0.0" env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/" (fun _ ->
diff --git a/example/z-docker-opam/app.ml b/example/z-docker-opam/app.ml
index e7af6315..269d1c68 100644
--- a/example/z-docker-opam/app.ml
+++ b/example/z-docker-opam/app.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run ~interface:"0.0.0.0"
+  Eio_main.run @@ fun env ->
+  Dream.run ~interface:"0.0.0.0" env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/" (fun _ ->
diff --git a/example/z-fly/app.ml b/example/z-fly/app.ml
index 2184ee89..77188580 100644
--- a/example/z-fly/app.ml
+++ b/example/z-fly/app.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run ~interface:"0.0.0.0"
+  Eio_main.run @@ fun env ->
+  Dream.run ~interface:"0.0.0.0" env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/" (fun _ -> Dream.html "Dream deployed on Fly!");
diff --git a/example/z-heroku/app.ml b/example/z-heroku/app.ml
index c2c86bdb..2cd99b3b 100644
--- a/example/z-heroku/app.ml
+++ b/example/z-heroku/app.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run ~interface:"0.0.0.0" ~port:(int_of_string (Sys.getenv "PORT"))
+  Eio_main.run @@ fun env ->
+  Dream.run ~interface:"0.0.0.0" ~port:(int_of_string (Sys.getenv "PORT")) env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/" (fun _ -> Dream.html "Dream running in Heroku!");
diff --git a/example/z-playground/.gitignore b/example/z-playground/.gitignore
deleted file mode 100644
index 3189f954..00000000
--- a/example/z-playground/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-!package-lock.json
diff --git a/example/z-playground/README.md b/example/z-playground/README.md
deleted file mode 100644
index 112aa46c..00000000
--- a/example/z-playground/README.md
+++ /dev/null
@@ -1,24 +0,0 @@
-# `z-playground`
-
-

-
-This “example” is, in fact, the Dream online playground, running at
-[http://dream.as](http://dream.as).
-
-It's a simple, one-page app that uses a WebSocket to communicates with its
-server. The server starts and stops Docker containers that run visitors' code.
-An `
-
-
-
-
-
-
diff --git a/example/z-playground/client/dune b/example/z-playground/client/dune
deleted file mode 100644
index 6c6dcf4f..00000000
--- a/example/z-playground/client/dune
+++ /dev/null
@@ -1,8 +0,0 @@
-(library
- (name client)
- (libraries dream))
-
-(rule
- (targets client.ml)
- (deps client.eml.html)
- (action (run dream_eml %{deps} --workspace %{workspace_root})))
diff --git a/example/z-playground/client/playground.css b/example/z-playground/client/playground.css
deleted file mode 100644
index 0e0f462a..00000000
--- a/example/z-playground/client/playground.css
+++ /dev/null
@@ -1,312 +0,0 @@
-/* This file is part of Dream, released under the MIT license. See LICENSE.md
-  for details, or visit https://github.com/aantron/dream.
-
-  Copyright 2021 Anton Bachin */
-
-/*
-
-Playground layout: 2 panels with normal element and fluid
-┌──────────────────────────────────────────────────┐
-│                                                  │
-│ body (desktop)                                   │
-│                                                  │
-│ ┌───────────────────────┐ ┌────────────────────┐ │
-│ │                       │ │                    │ │
-│ │ ┌───────────────────┐ │ │ ┌────────────────┐ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │ .panel-element    │ │ │ │ .panel-element │ │ │
-│ │ ├───────────────────┤ │ │ ├────────────────┤ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │ .panel-fluid      │ │ │ │ .panel-fluid   │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ │                   │ │ │ │                │ │ │
-│ │ └───────────────────┘ │ │ └────────────────┘ │ │
-│ │                       │ │                    │ │
-│ │                       │ │                    │ │
-│ └───────────────────────┘ └────────────────────┘ │
-│                                                  │
-└──────────────────────────────────────────────────┘
-
-This is on mobile or when pressing Change
-┌──────────────────────────────────────────────────┐
-│                                                  │
-│ body (mobile/Change view actived)                │
-│ ┌──────────────────────────────────────────────┐ │
-│ │                                              │ │
-│ │ ┌──────────────────────────────────────────┐ │ │
-│ │ │ .panel-element                           │ │ │
-│ │ │                                          │ │ │
-│ │ ├──────────────────────────────────────────┤ │ │
-│ │ │ .panel-fluid                             │ │ │
-│ │ │                                          │ │ │
-│ │ │                                          │ │ │
-│ │ │                                          │ │ │
-│ │ │                                          │ │ │
-│ │ └──────────────────────────────────────────┘ │ │
-│ │                                              │ │
-│ ├──────────────────────────────────────────────┤ │
-│ │                                              │ │
-│ │ ┌──────────────────────────────────────────┐ │ │
-│ │ │ .panel-element                           │ │ │
-│ │ │                                          │ │ │
-│ │ ├──────────────────────────────────────────┤ │ │
-│ │ │ .panel-fluid                             │ │ │
-│ │ │                                          │ │ │
-│ │ │                                          │ │ │
-│ │ │                                          │ │ │
-│ │ └──────────────────────────────────────────┘ │ │
-│ │                                              │ │
-│ └──────────────────────────────────────────────┘ │
-│                                                  │
-└──────────────────────────────────────────────────┘
- */
-body {
-  margin: 0;
-  font-size: 14px;
-  line-height: 21px;
-  color: #ddd;
-  font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Oxygen, Ubuntu, Cantarell, Open Sans, Helvetica Neue, Helvetica, Arial, sans-serif;
-  display: flex;
-  height: 100vh;
-  overflow-y: hidden;
-}
-
-@supports (-webkit-touch-callout: none) {
-  body {
-    /* The hack for Safari Mobile hack */
-    height: -webkit-fill-available;
-  }
-}
-
-.panel {
-  flex: 0 0 50%;
-  width: 50%;
-  display: flex;
-  flex-direction: column;
-}
-.panel-fluid {
-  flex: 1 0 auto;
-  min-height: 300px;
-}
-
-/*
- * Change view activation and mobile mode is the same
- * Please ensure that they are in perfect sync
- */
-body.full-editor {
-  flex-direction: column;
-  overflow-y: auto;
-  height: auto;
-}
-
-.full-editor .panel {
-  width: 100%;
-}
-
-@media (max-width: 1100px) {
-  body {
-    flex-direction: column;
-    overflow-y: auto;
-    height: auto;
-  }
-  .panel {
-    width: 100%;
-  }
-}
-
-#textarea {
-  position: relative;
-}
-#textarea .CodeMirror {
-  height: 100%;
-  position: absolute;
-  top: 0;
-  bottom: 0;
-  left: 0;
-  right: 0;
-}
-
-header {
-  height: 64px;
-  display: flex;
-  align-items: center
-}
-/* Editor */
-
-h1 {
-  margin: 0;
-  display: inline-block;
-  margin-left: 24px;
-  font-weight: normal;
-}
-
-#log {
-  height: 100px;
-  margin: 0;
-  overflow-x: hidden;
-  padding-left: 34px;
-  padding-top: 14px;
-  overflow: auto;
-}
-
-.CodeMirror, #log {
-  font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, monospace;
-}
-
-#editor button {
-  font: inherit;
-  color: inherit;
-  margin-left: 2em;
-  background-color: #4338CA;
-  font-weight: bold;
-  border: none;
-  padding: 4px 8px;
-  border-radius: 4px;
-}
-
-#editor button:hover {
-  cursor: pointer;
-  background-color: #3730A3;
-}
-
-#editor header > a {
-  color: inherit;
-  text-decoration: none;
-  flex: 1;
-  text-align: right;
-  margin-right: 24px;
-}
-
-@media (max-width: 550px) {
-  #editor header > a {
-    display: none;
-  }
-}
-
-/* width */
-::-webkit-scrollbar {
-  width: 10px;
-  height: 10px;
-  opacity: 0.2;
-}
-
-/* Track */
-::-webkit-scrollbar-track {
-  background: rgba(255, 255, 255, 0.2);
-}
-
-/* Handle */
-::-webkit-scrollbar-thumb {
-  background: #888;
-}
-
-/* Handle on hover */
-::-webkit-scrollbar-thumb:hover {
-  background: #555;
-}
-
-/* Client */
-
-#client header {
-  background-color: #eee;
-  box-sizing: border-box;
-  border-bottom: 1px solid #ccc;
-  padding: 16px;
-}
-
-#client input {
-  width: 100%;
-  height: 100%;
-  background: none;
-  border: none;
-  border: 1px solid #aaa;
-  padding: 8px;
-}
-
-#client input:focus {
-  outline: none;
-}
-
-#client iframe {
-  border: 0;
-  width: 100%;
-  background-color: white;
-}
-
-
-/* Syntax */
-
-.cm-s-dream.CodeMirror, body {
-  background-color: #181b1e;
-}
-
-.cm-s-dream.CodeMirror, #editor > header {
-  border-bottom: 1px solid #263838;
-  box-sizing: border-box;
-}
-
-.cm-s-dream.CodeMirror {
-  color: #ddd;
-  border-bottom: 1px solid #2a2a26;
-}
-
-#log {
-  color: #ddd;
-}
-
-.cm-s-dream .CodeMirror-gutters {
-  background: none;
-  border-right: 1px solid #262626;
-}
-
-.cm-s-dream .CodeMirror-linenumber {
-  color: #999;
-}
-
-.cm-s-dream .cm-keyword, .t-magenta {
-  color: #ff6c9b;
-}
-
-.cm-s-dream .cm-operator, .t-cyan {
-  color: #8dc5ff;
-}
-
-.cm-s-dream .cm-string, .t-yellow {
-  color: #e3db7a;
-}
-
-.cm-s-dream .cm-variable {
-  color: #ddd;
-}
-
-.cm-s-dream .cm-variable-2, .t-green {
-  color: #70df5c;
-}
-
-.t-dim {
-  color: #999;
-  display: none;
-}
-
-.t-white {
-  color: #ddd;
-}
-
-.t-red {
-  color: #ff2300;
-}
-
-.t-blue {
-  color: #81a2ff;
-}
diff --git a/example/z-playground/client/playground.js b/example/z-playground/client/playground.js
deleted file mode 100644
index aded91d8..00000000
--- a/example/z-playground/client/playground.js
+++ /dev/null
@@ -1,113 +0,0 @@
-// This file is part of Dream, released under the MIT license. See LICENSE.md
-// for details, or visit https://github.com/aantron/dream.
-//
-// Copyright 2021 Anton Bachin *)
-
-
-
-var editor = document.querySelector("#textarea");
-var run = document.querySelector("#run");
-var refresh = document.querySelector("#refresh");
-var address = document.querySelector("input");
-var iframe = document.querySelector("iframe");
-var pre = document.querySelector("pre");
-var chview = document.querySelector("#chview");
-
-var codemirror = CodeMirror(editor, {
-  theme: "material dream",
-  lineNumbers: true,
-  tabSize: 2,
-  extraKeys: {
-    "Tab": function (editor) {
-      if (editor.somethingSelected())
-        editor.execCommand("indentMore");
-      else
-        editor.execCommand("insertSoftTab");
-    }
-  }
-});
-
-function colorizeLog(string) {
-  return string
-    .replace(/&/g, "&")
-    .replace(//g, ">")
-    .replace(/"/g, """)
-    .replace(/'/g, "'")
-    .replace(/\033\[\?7l/g, "")
-    .replace(/\033\[2m/g, "")
-    .replace(/\033\[35m\033\[3m/g, "")
-    .replace(/\033\[36m\033\[3m/g, "")
-    .replace(/\033\[37m\033\[3m/g, "")
-    .replace(/\033\[0;35m\033\[0m/g, "")
-    .replace(/\033\[0;36m\033\[0m/g, "")
-    .replace(/\033\[0;37m\033\[0m/g, "")
-    .replace(/\033\[31m/g, "")
-    .replace(/\033\[32m/g, "")
-    .replace(/\033\[33m/g, "")
-    .replace(/\033\[34m/g, "")
-    .replace(/\033\[35m/g, "")
-    .replace(/\033\[36m/g, "")
-    .replace(/\033\[37m/g, "")
-    .replace(/\033\[0m/g, "")
-    ;
-};
-
-var components = window.location.pathname.split("/");
-var sandbox = components[1];
-sandbox = sandbox || "ocaml";
-var socket =
-  new WebSocket("ws://" + window.location.host + "/socket?sandbox=" + sandbox);
-
-var path = components.slice(2).join("/");
-if (path !== "")
-  path = "/" + path;
-
-var firstStart = true;
-
-socket.onmessage = function (e) {
-  var message = JSON.parse(e.data);
-  switch (message.kind) {
-    case "content":
-      codemirror.setValue(message.payload);
-      pre.innerHTML += "Building image...\n";
-      socket.send(codemirror.getValue());
-      break;
-
-    case "log":
-      pre.innerHTML += colorizeLog(message.payload);
-      pre.scrollTop = pre.scrollHeight;
-      break;
-
-    case "started": {
-      var frame_location =
-        window.location.protocol + "//" +
-        window.location.hostname + ":" + message.port + path + location.search;
-      iframe.src = frame_location;
-      address.value = frame_location;
-      history.replaceState(
-        null, "", "/" + message.sandbox + path + location.search);
-      if (firstStart)
-        firstStart = false;
-      else
-        pre.scrollIntoView();
-      break;
-    }
-  }
-};
-
-run.onclick = function () {
-  pre.innerHTML += "Building image...\n";
-  pre.scrollTop = pre.scrollHeight;
-  socket.send(codemirror.getValue());
-};
-
-chview.onclick = function(){
-  var body = document.body;
-  body.classList.toggle("full-editor")
-}
-
-address.onkeyup = function (event) {
-  if (event.keyCode === 13)
-    iframe.src = this.value;
-};
diff --git a/example/z-playground/dune b/example/z-playground/dune
deleted file mode 100644
index 8ab777a7..00000000
--- a/example/z-playground/dune
+++ /dev/null
@@ -1 +0,0 @@
-(data_only_dirs _esy esy.lock lib node_modules)
diff --git a/example/z-playground/dune-project b/example/z-playground/dune-project
deleted file mode 100644
index 929c696e..00000000
--- a/example/z-playground/dune-project
+++ /dev/null
@@ -1 +0,0 @@
-(lang dune 2.0)
diff --git a/example/z-playground/opam-switch b/example/z-playground/opam-switch
deleted file mode 100644
index 9d51863d..00000000
--- a/example/z-playground/opam-switch
+++ /dev/null
@@ -1,161 +0,0 @@
-opam-version: "2.0"
-compiler: [
-  "base-bigarray.base"
-  "base-threads.base"
-  "base-unix.base"
-  "ocaml.4.12.0"
-  "ocaml-base-compiler.4.12.0"
-  "ocaml-config.2"
-  "ocaml-options-vanilla.1"
-]
-roots: ["multipart_form.git" "ocaml-base-compiler.4.12.0"]
-installed: [
-  "angstrom.0.15.0"
-  "base.v0.14.1"
-  "base-bigarray.base"
-  "base-bytes.base"
-  "base-threads.base"
-  "base-unix.base"
-  "base64.3.5.0"
-  "bigarray-compat.1.0.0"
-  "bigarray-overlap.0.2.0"
-  "bigstringaf.0.7.0"
-  "biniou.1.2.1"
-  "bisect_ppx.2.6.0"
-  "caqti.1.5.0"
-  "caqti-driver-sqlite3.1.5.0"
-  "caqti-lwt.1.3.0"
-  "cmdliner.1.0.4"
-  "conf-libev.4-11"
-  "conf-libssl.3"
-  "conf-pkg-config.2"
-  "conf-sqlite3.1"
-  "cppo.1.6.7"
-  "csexp.1.5.1"
-  "cstruct.6.0.0"
-  "cudf.0.9-1"
-  "digestif.1.0.0"
-  "dune.2.8.5"
-  "dune-configurator.2.8.5"
-  "duration.0.1.3"
-  "easy-format.1.3.2"
-  "eqaf.0.7"
-  "extlib.1.7.7-1"
-  "faraday.0.7.2"
-  "faraday-lwt.0.7.2"
-  "faraday-lwt-unix.0.7.2"
-  "fix.20201120"
-  "fmt.0.8.9"
-  "graphql.0.13.0"
-  "graphql-lwt.0.13.0"
-  "graphql_parser.0.13.0"
-  "hmap.0.8.1"
-  "ke.0.4"
-  "logs.0.7.0"
-  "lwt.5.4.0"
-  "lwt_ppx.2.0.2"
-  "lwt_ssl.1.1.3"
-  "magic-mime.1.1.3"
-  "markup.1.0.0-1"
-  "menhir.20210419"
-  "menhirLib.20210419"
-  "menhirSdk.20210419"
-  "merlin-extend.0.6"
-  "mirage-crypto.0.10.1"
-  "mirage-crypto-rng.0.10.1"
-  "mmap.1.1.0"
-  "mtime.1.2.0"
-  "multipart-form-data.0.3.0"
-  "multipart_form.git"
-  "ocaml.4.12.0"
-  "ocaml-base-compiler.4.12.0"
-  "ocaml-compiler-libs.v0.12.3"
-  "ocaml-config.2"
-  "ocaml-migrate-parsetree.2.1.0"
-  "ocaml-options-vanilla.1"
-  "ocaml-syntax-shims.1.0.0"
-  "ocamlbuild.0.14.0"
-  "ocamlfind.1.9.1"
-  "ocamlgraph.2.0.0"
-  "ocplib-endian.1.1"
-  "octavius.1.2.2"
-  "opam-core.2.1.0~beta4"
-  "opam-file-format.2.1.2"
-  "opam-format.2.1.0~beta4"
-  "opam-installer.2.1.0~beta4"
-  "pecu.0.5"
-  "ppx_derivers.1.2.1"
-  "ppx_js_style.v0.14.0"
-  "ppx_yojson_conv.v0.14.0"
-  "ppx_yojson_conv_lib.v0.14.0"
-  "ppxlib.0.22.0"
-  "prettym.0.0.1"
-  "psq.0.2.0"
-  "ptime.0.8.5"
-  "re.1.9.0"
-  "reason.3.7.0"
-  "result.1.5"
-  "rresult.0.6.0"
-  "seq.base"
-  "sexplib0.v0.14.0"
-  "sqlite3.5.0.3"
-  "ssl.0.5.10"
-  "stdlib-shims.0.3.0"
-  "stringext.1.6.0"
-  "topkg.1.0.3"
-  "tyxml.4.5.0"
-  "tyxml-jsx.4.5.0"
-  "tyxml-ppx.4.5.0"
-  "tyxml-syntax.4.5.0"
-  "uchar.0.0.2"
-  "unstrctrd.0.2"
-  "uri.4.2.0"
-  "uutf.1.0.2"
-  "yojson.1.7.0"
-]
-pinned: "multipart_form.git"
-package "multipart_form" {
-  opam-version: "2.0"
-  version: "git"
-  synopsis: "Multipart-form: RFC2183, RFC2388 & RFC7578"
-  description: """
-Implementation of RFC7578 in OCaml
-
-Returning values from forms: multipart/form-data"""
-  maintainer: "Romain Calascibetta "
-  authors: "Romain Calascibetta "
-  license: "MIT"
-  homepage: "https://github.com/dinosaure/multipart_form"
-  doc: "https://dinosaure.github.io/multipart_form/"
-  bug-reports: "https://github.com/dinosaure/multipart_form/issues"
-  depends: [
-    "ocaml" {>= "4.08.0"}
-    "dune" {>= "2.0.0"}
-    "angstrom" {>= "0.14.0"}
-    "base64"
-    "unstrctrd" {>= "0.2"}
-    "rresult"
-    "uutf"
-    "stdlib-shims"
-    "pecu" {>= "0.4"}
-    "lwt"
-    "prettym"
-    "fmt"
-    "logs"
-    "ke" {>= "0.4"}
-    "alcotest" {with-test}
-    "rosetta" {with-test}
-    "bigarray-compat" {>= "1.0.0"}
-    "bigstringaf" {>= "0.7.0"}
-    "result" {>= "1.5"}
-  ]
-  build: [
-    ["dune" "build" "-p" name "-j" jobs]
-    ["dune" "runtest" "-p" name "-j" jobs] {with-test}
-  ]
-  dev-repo: "git+https://github.com/dinosaure/multipart_form.git"
-  url {
-    src:
-      "git+https://github.com/dinosaure/multipart_form.git#8f5b6cb77af1a385155b0aeac40437dba6e56577"
-  }
-}
diff --git a/example/z-playground/package-lock.json b/example/z-playground/package-lock.json
deleted file mode 100644
index f34206be..00000000
--- a/example/z-playground/package-lock.json
+++ /dev/null
@@ -1,12 +0,0 @@
-{
-  "name": "dream-playground",
-  "requires": true,
-  "lockfileVersion": 1,
-  "dependencies": {
-    "codemirror": {
-      "version": "5.61.0",
-      "resolved": "https://registry.npmjs.org/codemirror/-/codemirror-5.61.0.tgz",
-      "integrity": "sha512-D3wYH90tYY1BsKlUe0oNj2JAhQ9TepkD51auk3N7q+4uz7A/cgJ5JsWHreT0PqieW1QhOuqxQ2reCXV1YXzecg=="
-    }
-  }
-}
diff --git a/example/z-playground/package.json b/example/z-playground/package.json
deleted file mode 100644
index 224b9483..00000000
--- a/example/z-playground/package.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "name": "dream-playground",
-  "dependencies": {
-    "codemirror": "*"
-  },
-  "scripts": {
-    "start": "npm run bundle && opam exec -- dune exec server/playground.exe"
-  }
-}
diff --git a/example/z-playground/playground.opam b/example/z-playground/playground.opam
deleted file mode 100644
index d3ea9a3e..00000000
--- a/example/z-playground/playground.opam
+++ /dev/null
@@ -1,9 +0,0 @@
-opam-version: "2.0"
-
-depends: [
-  "caqti-driver-sqlite3"
-  "dune" {>= "2.0.0"}
-  "ocaml"
-  "ppx_yojson_conv"
-  "reason"
-]
diff --git a/example/z-playground/runtime/dune b/example/z-playground/runtime/dune
deleted file mode 100644
index 0a30838c..00000000
--- a/example/z-playground/runtime/dune
+++ /dev/null
@@ -1,9 +0,0 @@
-(library
- (name runtime)
- (wrapped false)
- (libraries dream))
-
-(rule
- (targets playground.ml)
- (deps playground.eml.ml)
- (action (run dream_eml %{deps} --workspace %{workspace_root})))
diff --git a/example/z-playground/runtime/playground.eml.ml b/example/z-playground/runtime/playground.eml.ml
deleted file mode 100644
index c959f54f..00000000
--- a/example/z-playground/runtime/playground.eml.ml
+++ /dev/null
@@ -1,62 +0,0 @@
-(* This file is part of Dream, released under the MIT license. See LICENSE.md
-   for details, or visit https://github.com/aantron/dream.
-
-   Copyright 2021 Anton Bachin *)
-
-
-
-let welcome =
-  
-  
-  
-  
-  
-  
-  
-  
-  
Welcome to the Dream Playground!

-  

-    Edit the code to the left, and press Run to recompile! Use
-    the navigation bar above to visit different paths on your server. Many of
-    the 
-    examples are loaded into the playground. For example, try
-    dream.as/2-middleware.
-  

-  
Links:

-  
-  
Loaded examples:

-  
-  
-  
diff --git a/example/z-playground/runtime/runtime.opam b/example/z-playground/runtime/runtime.opam
deleted file mode 100644
index 0d2ac090..00000000
--- a/example/z-playground/runtime/runtime.opam
+++ /dev/null
@@ -1,11 +0,0 @@
-opam-version: "2.0"
-
-depends: [
-  "dream"
-  "dune" {>= "2.0.0"}
-  "ocaml"
-]
-
-build: [
-  ["dune" "build" "-p" name "-j" jobs]
-]
diff --git a/example/z-playground/sandbox/ocaml/keep b/example/z-playground/sandbox/ocaml/keep
deleted file mode 100644
index e69de29b..00000000
diff --git a/example/z-playground/sandbox/ocaml/server.eml.ml b/example/z-playground/sandbox/ocaml/server.eml.ml
deleted file mode 100644
index 4876aa13..00000000
--- a/example/z-playground/sandbox/ocaml/server.eml.ml
+++ /dev/null
@@ -1,7 +0,0 @@
-let () =
-  Dream.run ~interface:"0.0.0.0"
-  @@ Dream.logger
-  @@ Dream.router [
-    Dream.get "/" (fun _ -> Dream.html Playground.welcome);
-  ]
-  @@ Dream.not_found
diff --git a/example/z-playground/sandbox/reason/keep b/example/z-playground/sandbox/reason/keep
deleted file mode 100644
index e69de29b..00000000
diff --git a/example/z-playground/sandbox/reason/server.eml.re b/example/z-playground/sandbox/reason/server.eml.re
deleted file mode 100644
index 03f3fbca..00000000
--- a/example/z-playground/sandbox/reason/server.eml.re
+++ /dev/null
@@ -1,7 +0,0 @@
-let () =
-  Dream.run(~interface="0.0.0.0")
-  @@ Dream.logger
-  @@ Dream.router([
-    Dream.get("/", _ => Dream.html(Playground.welcome)),
-  ])
-  @@ Dream.not_found
diff --git a/example/z-playground/server/build.sh b/example/z-playground/server/build.sh
deleted file mode 100644
index 9e5e4101..00000000
--- a/example/z-playground/server/build.sh
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/bin/bash
-
-set -e
-set -x
-
-mkdir -p static
-cp node_modules/codemirror/lib/codemirror.js static/
-cp node_modules/codemirror/lib/codemirror.css static/
-cp node_modules/codemirror/theme/material.css static/
-cp node_modules/codemirror/mode/mllike/mllike.js static/
-cp client/playground.css static/
-cp client/playground.js static/
-opam exec -- dune build server/playground.exe
diff --git a/example/z-playground/server/deploy.sh b/example/z-playground/server/deploy.sh
deleted file mode 100644
index ba2ba326..00000000
--- a/example/z-playground/server/deploy.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-
-set -e
-set -x
-
-sudo cp \
-  /home/playground/playground/example/z-playground/server/playground.service \
-  /etc/systemd/system
-sudo chmod a-x /etc/systemd/system/playground.service
-sudo systemctl daemon-reload
-sudo systemctl stop playground
-(cd /home/playground/playground/example/z-playground \
-  && sudo -H -u playground bash server/build.sh)
-sudo cp \
-  /home/playground/playground/_build/default/example/z-playground/server/playground.exe \
-  /usr/local/bin/playground
-sudo chown root:root /usr/local/bin/playground
-sudo systemctl start playground
diff --git a/example/z-playground/server/dune b/example/z-playground/server/dune
deleted file mode 100644
index ce57b96e..00000000
--- a/example/z-playground/server/dune
+++ /dev/null
@@ -1,4 +0,0 @@
-(executable
- (name playground)
- (libraries client dream)
- (preprocess (pps lwt_ppx)))
diff --git a/example/z-playground/server/playground.ml b/example/z-playground/server/playground.ml
deleted file mode 100644
index 39f3c111..00000000
--- a/example/z-playground/server/playground.ml
+++ /dev/null
@@ -1,563 +0,0 @@
-(* This file is part of Dream, released under the MIT license. See LICENSE.md
-   for details, or visit https://github.com/aantron/dream.
-
-   Copyright 2021 Anton Bachin *)
-
-
-
-(* Sandboxes. *)
-
-type syntax = [ `OCaml | `Reason ]
-
-let (//) = Filename.concat
-
-let sandbox_root = "sandbox"
-
-let sandbox_dune = {|(executable
- (name server)
- (libraries caqti caqti-driver-sqlite3 dream runtime tyxml)
- (preprocess (pps lwt_ppx ppx_yojson_conv)))
-
-(rule
- (targets server.ml)
- (deps server.eml.ml)
- (action (run dream_eml %{deps} --workspace %{workspace_root})))
-|}
-
-let sandbox_dune_re = {|(executable
- (name server)
- (libraries caqti caqti-driver-sqlite3 dream runtime tyxml)
- (preprocess (pps lwt_ppx ppx_yojson_conv)))
-
-(rule
- (targets server.re)
- (deps server.eml.re)
- (action (run dream_eml %{deps} --workspace %{workspace_root})))
-|}
-
-let sandbox_dune_no_eml = {|(executable
- (name server)
- (libraries caqti caqti-driver-sqlite3 dream runtime tyxml)
- (preprocess (pps lwt_ppx ppx_yojson_conv tyxml-jsx tyxml-ppx)))
-|}
-
-let base_dockerfile = {|FROM ubuntu:focal-20210416
-RUN apt update && apt install -y openssl libev4 libsqlite3-0
-WORKDIR /www
-COPY db.sqlite db.sqlite
-RUN chmod -R 777 .
-USER 112:3000
-ENTRYPOINT /www/server.exe
-|}
-
-let base_dockerignore = {|*
-!db.sqlite|}
-
-let sandbox_dockerfile = {|FROM base:base
-COPY server.exe server.exe
-|}
-
-let exec format =
-  Printf.ksprintf (fun command -> Lwt_process.(exec (shell command))) format
-
-let create_sandboxes_directory () =
-  match%lwt Lwt_unix.mkdir sandbox_root 0o755 with
-  | () -> Lwt.return_unit
-  | exception Unix.(Unix_error (EEXIST, _, _)) -> Lwt.return_unit
-
-let exists sandbox =
-  Lwt_unix.file_exists (sandbox_root // sandbox)
-
-let write_file sandbox file content =
-  Lwt_io.(with_file
-    ~mode:Output (sandbox_root // sandbox // file) (fun channel ->
-      write channel content))
-
-let create_named sandbox syntax eml code =
-  Dream.info (fun log -> log "Sandbox %s: creating" sandbox);
-  begin match%lwt Lwt_unix.mkdir (sandbox_root // sandbox) 0o755 with
-  | () -> Lwt.return_unit
-  | exception Unix.(Unix_error (EEXIST, _, _)) -> Lwt.return_unit
-  end;%lwt
-  let filename =
-    match syntax, eml with
-    | `OCaml, false -> "server.ml"
-    | `Reason, false -> "server.re"
-    | `OCaml, true -> "server.eml.ml"
-    | `Reason, true -> "server.eml.re"
-  in
-  write_file sandbox filename code;%lwt
-  Lwt.return sandbox
-
-let rec create ?(attempts = 3) syntax eml code =
-  match attempts with
-  | 0 -> failwith "Unable to create sandbox directory"
-  | attempts ->
-    let sandbox = Dream.random 9 |> Dream.to_base64url in
-    match sandbox.[0] with
-    | '_' | '-' -> create ~attempts syntax eml code
-    | _ ->
-      match%lwt exists sandbox with
-      | true -> create ~attempts:(attempts - 1) syntax eml code
-      | false -> create_named sandbox syntax eml code
-
-let read sandbox =
-  let%lwt no_eml_exists =
-    Lwt_unix.file_exists (sandbox_root // sandbox // "no-eml") in
-  let eml = not no_eml_exists in
-  let base = if eml then "server.eml" else "server" in
-  let ocaml_promise =
-    Lwt_io.(with_file
-      ~mode:Input (sandbox_root // sandbox // base ^ ".ml") read)
-  in
-  match%lwt ocaml_promise with
-  | content -> Lwt.return (content, `OCaml, eml)
-  | exception _ ->
-    let%lwt content =
-      Lwt_io.(with_file
-        ~mode:Input (sandbox_root // sandbox // base ^ ".re") read)
-    in
-    Lwt.return (content, `Reason, eml)
-
-let init_client socket content =
-  `Assoc [
-    "kind", `String "content";
-    "payload", `String content;
-  ]
-  |> Yojson.Basic.to_string
-  |> Dream.write socket
-
-let validate_id sandbox =
-  String.length sandbox > 0 && Dream.from_base64url sandbox <> None
-
-
-
-(* Session state transitions. *)
-
-type container = {
-  container_id : string;
-  port : int;
-}
-
-type session = {
-  mutable container : container option;
-  mutable sandbox : string;
-  syntax : syntax;
-  eml : bool;
-  socket : Dream.response;
-}
-
-let allocated_ports =
-  Hashtbl.create 1024
-
-let kill_container session =
-  match session.container with
-  | None -> Lwt.return_unit
-  | Some {container_id; port} ->
-    session.container <- None;
-    Dream.info (fun log ->
-      log "Sandbox %s: killing container %s" session.sandbox container_id);
-    let%lwt _status =
-      exec "docker kill %s > /dev/null 2> /dev/null" container_id in
-    Hashtbl.remove allocated_ports port;
-    Lwt.return_unit
-
-let min_port = 9000
-let max_port = 9999
-
-let next_port =
-  ref min_port
-
-(* This can fail if there is a huge number of sandboxes, or very large spikes in
-   sandbox creation. However, the failure is not catastrophic. *)
-let rec allocate_port () =
-  let port = !next_port in
-  incr next_port;
-  let%lwt () =
-    if !next_port > max_port then begin
-      next_port := min_port;
-      Lwt.pause ()
-    end
-    else
-      Lwt.return_unit
-  in
-  if Hashtbl.mem allocated_ports port then
-    allocate_port ()
-  else begin
-    Hashtbl.replace allocated_ports port ();
-    Lwt.return port
-  end
-
-let client_log ?(add_newline = false) session message =
-  let message =
-    if add_newline then message ^ "\n"
-    else message
-  in
-  `Assoc [
-    "kind", `String "log";
-    "payload", `String message;
-  ]
-  |> Yojson.Basic.to_string
-  |> Dream.write session.socket
-
-let build_sandbox sandbox syntax eml =
-  let dune =
-    match syntax, eml with
-    | _, false -> sandbox_dune_no_eml
-    | `OCaml, true -> sandbox_dune
-    | `Reason, true -> sandbox_dune_re
-  in
-  write_file sandbox "dune" dune;%lwt
-  begin
-    if eml then
-      Lwt.return_unit
-    else
-      write_file sandbox "no-eml" ""
-  end;%lwt
-  let%lwt _status = exec "rm -f %s/server.exe" (sandbox_root // sandbox) in
-  let process =
-    Printf.sprintf
-      "cd %s && opam exec %s -- dune build %s ./server.exe 2>&1"
-      (sandbox_root // sandbox) "--color=always" "--no-print-directory"
-    |> Lwt_process.shell
-    |> new Lwt_process.process_in in
-  let%lwt output = Lwt_io.read process#stdout in
-  match%lwt process#close with
-  | Unix.WEXITED 0 ->
-    let%lwt _status =
-      exec
-        "cp ../../_build/default/example/z-playground/%s/server.exe %s"
-        (sandbox_root // sandbox) (sandbox_root // sandbox)
-    in
-    Lwt.return None
-  | _ ->
-    Lwt.return (Some output)
-
-let build session =
-  match%lwt build_sandbox session.sandbox session.syntax session.eml with
-  | None ->
-    Dream.info (fun log -> log "Sandbox %s: build succeeded" session.sandbox);
-    Lwt.return_true
-  | Some output ->
-    Dream.info (fun log ->
-      log "Sandbox %s: sending build output" session.sandbox);
-    client_log session output;%lwt
-    Lwt.return_false
-
-let image_exists sandbox =
-  match%lwt exec "docker image inspect sandbox:%s 2>&1 > /dev/null" sandbox with
-  | Unix.WEXITED 0 -> Lwt.return_true
-  | _ -> Lwt.return_false
-
-let image_sandbox sandbox =
-  write_file sandbox "Dockerfile" sandbox_dockerfile;%lwt
-  let%lwt _status =
-    exec "cd %s && docker build -t sandbox:%s . 2>&1"
-      (sandbox_root // sandbox) sandbox in
-  Lwt.return_unit
-
-let image session =
-  image_sandbox session.sandbox;%lwt
-  Dream.info (fun log -> log "Sandbox %s: built image" session.sandbox);
-  Lwt.return_unit
-
-let started session port =
-  `Assoc [
-    "kind", `String "started";
-    "sandbox", `String session.sandbox;
-    "port", `Int port;
-  ]
-  |> Yojson.Basic.to_string
-  |> Dream.write session.socket
-
-let rec make_container_id () =
-  let candidate = Dream.random 9 |> Dream.to_base64url in
-  match candidate.[0] with
-  | '_' | '-' -> make_container_id ()
-  | _ -> candidate
-
-let run session =
-  let alive, signal_alive = Lwt.wait () in
-  let signalled = ref false in
-  let signal_alive () =
-    if !signalled then
-      ()
-    else begin
-      signalled := true;
-      Lwt.wakeup_later signal_alive ()
-    end
-  in
-  let%lwt port = allocate_port () in
-  let container_id = make_container_id () in
-  session.container <- Some {container_id; port};
-  Lwt.async begin fun () ->
-    Printf.sprintf
-      "docker run -p %i:8080 --name %s --rm -t sandbox:%s 2>&1"
-      port container_id session.sandbox
-    |> Lwt_process.shell
-    |> Lwt_process.pread_lines
-    |> Lwt_stream.iter_s (fun line ->
-      signal_alive ();
-      client_log ~add_newline:true session line)
-  end;
-  alive;%lwt
-  started session port;%lwt
-  Dream.info (fun log ->
-    log "Sandbox %s: started %s on port %i" session.sandbox container_id port);
-  Lwt.return_unit
-
-let kill session =
-  let%lwt () = kill_container session in
-  Dream.close session.socket
-
-
-
-(* Main loop for each connected client WebSocket. *)
-
-let gc_running =
-  ref None
-
-let notify_gc =
-  ref ignore
-
-let sandbox_users =
-  ref 0
-
-let sandbox_locks =
-  Hashtbl.create 256
-
-let lock_sandbox sandbox f =
-  begin match !gc_running with
-  | None -> Lwt.return_unit
-  | Some finished -> finished
-  end;%lwt
-
-  incr sandbox_users;
-  let mutex =
-    match Hashtbl.find_opt sandbox_locks sandbox with
-    | Some mutex -> mutex
-    | None ->
-      let mutex = Lwt_mutex.create () in
-      Hashtbl.add sandbox_locks sandbox mutex;
-      mutex
-  in
-  Lwt.finalize
-    (fun () -> Lwt_mutex.with_lock mutex f)
-    (fun () ->
-      decr sandbox_users;
-      if !sandbox_users = 0 then
-        !notify_gc ();
-      Lwt.return_unit)
-
-let rec listen session =
-  match%lwt Dream.read session.socket with
-  | None ->
-    Dream.info (fun log -> log "WebSocket closed by client");
-    kill session
-  | Some code ->
-
-  Dream.info (fun log -> log "Sandbox %s: code update" session.sandbox);
-  ignore (kill_container session);
-
-  lock_sandbox session.sandbox begin fun () ->
-
-    let%lwt current_code, _, _ = read session.sandbox in
-    if code = current_code then
-      Lwt.return_unit
-    else begin
-      let%lwt sandbox = create session.syntax session.eml code in
-      session.sandbox <- sandbox;
-      Lwt.return_unit
-    end;%lwt
-
-    match%lwt image_exists session.sandbox with
-    | true -> run session
-    | false ->
-      match%lwt build session with
-      | false -> Lwt.return_unit
-      | true ->
-        image session;%lwt
-        run session
-  end;%lwt
-
-  listen session
-
-let listen session =
-  try%lwt
-    listen session
-  with exn ->
-    kill session;%lwt
-    raise exn
-
-
-
-let rec gc ?(initial = true) () =
-  let next = Lwt_unix.sleep 3600. in
-
-  let%lwt keep =
-    Lwt_process.shell "ls sandbox/*/keep | awk -F / '{print $2}'"
-    |> Lwt_process.pread_lines
-    |> Lwt_stream.to_list in
-
-  let can_start, signal_can_start = Lwt.wait () in
-  let finished, signal_finished = Lwt.wait () in
-
-  gc_running := Some finished;
-
-  if !sandbox_users = 0 then
-    Lwt.return_unit
-  else begin
-    notify_gc :=
-      (fun () -> Lwt.wakeup_later signal_can_start (); notify_gc := ignore);
-    can_start
-  end;%lwt
-
-  Lwt.finalize begin fun () ->
-    Dream.log "Running playground GC";
-
-    let%lwt images =
-      Lwt_process.shell "docker images | awk '{print $1, $2, $3}'"
-      |> Lwt_process.pread_lines
-      |> Lwt_stream.to_list
-    in
-
-    let images =
-      images
-      |> List.tl
-      |> List.map (String.split_on_char ' ')
-      |> List.filter_map (function
-        | ["base"; _; _] -> None
-        | ["ubuntu"; _; ] -> None
-        | ["sandbox"; tag; _] when List.mem tag keep -> None
-        | [_; _; id] -> Some id
-        | _ -> None)
-    in
-
-    let%lwt _status = exec "docker rmi %s" (String.concat " " images) in
-
-    Lwt_unix.files_of_directory "sandbox"
-    |> Lwt_stream.iter_n ~max_concurrency:16 begin fun sandbox ->
-      if List.mem sandbox keep then
-        Lwt.return_unit
-      else
-        let%lwt _status = exec "rm -rf sandbox/%s/_build" sandbox in
-        Lwt.return_unit
-    end;%lwt
-
-    Hashtbl.reset sandbox_locks;
-
-    Lwt.return_unit
-  end
-    (fun () ->
-      gc_running := None;
-      Lwt.wakeup_later signal_finished ();
-      Lwt.return_unit);%lwt
-
-  Dream.log "Warming caches";
-
-  keep |> Lwt_list.iteri_s begin fun index sandbox ->
-    Lwt_unix.sleep 1.;%lwt
-    if initial then
-      Dream.log "Warming %s (%i/%i)" sandbox (index + 1) (List.length keep);
-    lock_sandbox sandbox (fun () ->
-      if%lwt image_exists sandbox then
-        Lwt.return_unit
-      else begin
-        let%lwt _, syntax, eml = read sandbox in
-        let%lwt _ = build_sandbox sandbox syntax eml in
-        image_sandbox sandbox
-      end)
-  end;%lwt
-
-  next;%lwt
-  gc ~initial:false ()
-
-
-
-(* Entry point. *)
-
-let () =
-  Dream.log "Starting playground";
-
-  (* Stop when systemd sends SIGTERM. *)
-  let stop, signal_stop = Lwt.wait () in
-  Lwt_unix.on_signal Sys.sigterm (fun _signal ->
-    Lwt.wakeup_later signal_stop ())
-  |> ignore;
-
-  (* Build the base image. *)
-  Lwt_main.run begin
-    Lwt_io.(with_file ~mode:Output "Dockerfile" (fun channel ->
-      write channel base_dockerfile));%lwt
-    Lwt_io.(with_file ~mode:Output ".dockerignore" (fun channel ->
-      write channel base_dockerignore));%lwt
-    let%lwt _status = exec "docker build -t base:base . 2>&1" in
-    Lwt.return_unit
-  end;
-
-  (* Start the sandbox gc. *)
-  Lwt.async gc;
-
-  (* Start the Web server. *)
-  let playground_handler request =
-    let sandbox = Dream.param request "id" in
-    match validate_id sandbox with
-    | false -> Dream.empty `Not_Found
-    | true ->
-    match%lwt exists sandbox with
-    | false -> Dream.empty `Not_Found
-    | true ->
-    let%lwt example =
-      match sandbox.[1] with
-      | '-' ->
-        if%lwt Lwt_unix.file_exists (sandbox_root // sandbox // "keep") then
-          Lwt.return (Some sandbox)
-        else
-          Lwt.return_none
-      | _ -> Lwt.return_none
-      | exception _ -> Lwt.return_none
-    in
-    Dream.html (Client.html example)
-  in
-
-  Dream.run ~interface:"0.0.0.0" ~port:80 ~stop ~adjust_terminal:false
-  @@ Dream.logger
-  @@ Dream.router [
-
-    (* The client will send a default sandbox id in this case. *)
-    Dream.get "/" (fun _ ->
-      Dream.html (Client.html None));
-
-    (* Upon request for /socket?sandbox=id, send the code in the sandbox to the
-       client, and then enter the "REPL." Not bothering with nice replies or
-       nice error handling here, because a valid client won't trigger them. If
-       they occur, they are harmless to the server. *)
-    Dream.get "/socket" (fun request ->
-      match Dream.query "sandbox" request with
-      | None -> Dream.empty `Bad_Request
-      | Some sandbox ->
-      match validate_id sandbox with
-      | false -> Dream.empty `Bad_Request
-      | true ->
-      (* Read the sandbox. If the requested sandbox doesn't exist, this will
-         raise an exception, causing a 500 reply to the JavaScript client. *)
-      let%lwt content, syntax, eml = read sandbox in
-      Dream.websocket (fun socket ->
-        init_client socket content;%lwt
-        Dream.info (fun log ->
-          log "Sandbox %s: content sent to client" sandbox);
-        listen {container = None; sandbox; syntax; eml; socket}));
-
-    (* Serve scripts and CSS. *)
-    Dream.get "/static/**" (Dream.static "./static");
-
-    (* For sandbox ids, respond with the sandbox page. *)
-    Dream.get "/:id" playground_handler;
-    Dream.get "/:id/**" playground_handler;
-
-  ]
-  @@ Dream.not_found;
-
-  Dream.log "Killing all containers";
-  Sys.command "docker kill $(docker ps -q)" |> ignore;
-  Dream.log "Exiting"
diff --git a/example/z-playground/server/playground.service b/example/z-playground/server/playground.service
deleted file mode 100644
index 732c14d6..00000000
--- a/example/z-playground/server/playground.service
+++ /dev/null
@@ -1,17 +0,0 @@
-[Unit]
-Description=Dream Playground
-After=network.target
-Requires=docker.service
-
-[Service]
-Type=simple
-User=playground
-Restart=on-failure
-RestartSec=1
-StandardOutput=journal
-WorkingDirectory=/home/playground/playground/example/z-playground
-ExecStart=/usr/local/bin/playground
-AmbientCapabilities=CAP_NET_BIND_SERVICE
-
-[Install]
-WantedBy=multi-user.target
diff --git a/example/z-playground/server/setup.sh b/example/z-playground/server/setup.sh
deleted file mode 100644
index 2657f90b..00000000
--- a/example/z-playground/server/setup.sh
+++ /dev/null
@@ -1,53 +0,0 @@
-#!/bin/bash
-
-# Upon getting a fresh Droplet (virtual machine), the system packages inside the
-# image it was made from are likely somewhat out of date. Upgrade them
-# immediately.
-sudo apt update
-sudo apt -y upgrade
-
-# A restart is likely needed, as there is often a kernel upgrade.
-sudo init 6
-
-# Install the latest Docker. We use an APT repository for the absolute latest
-# release, including all the latest security features. The commands are based on
-# https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-ubuntu-20-04
-curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
-sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu focal stable"
-sudo apt update
-sudo apt install -y docker-ce
-
-# Install packages required for building OCaml projects and opam, including a C
-# compiler as part of build-essential.
-sudo apt install -y build-essential m4 unzip bubblewrap pkg-config
-
-# Install opam itself.
-wget -O opam https://github.com/ocaml/opam/releases/download/2.0.8/opam-2.0.8-x86_64-linux
-sudo mv opam /usr/local/bin/
-sudo chmod a+x /usr/local/bin/opam
-
-# Install npm, which we use to build the client.
-sudo apt install -y npm
-
-# Install system libraries that will be needed by Dream.
-sudo apt install -y libev-dev libsqlite3-dev libssl-dev pkg-config
-
-# Create users. User playground is used for building and running the playground.
-# The reason there isn't a separate user for buulding it is that the playground
-# itself will use the build setup to build the sandboxes. User sandbox is for
-# the containers.
-sudo adduser --disabled-password playground
-sudo usermod -a -G docker playground
-sudo -H -u playground mkdir /home/playground/.ssh -m 700
-sudo cp .ssh/authorized_keys /home/playground/.ssh/
-sudo chown playground:playground /home/playground/.ssh/authorized_keys
-sudo adduser --system sandbox
-
-# Initialize opam and install a compiler.
-sudo -H -u playground opam init --no-setup --bare
-sudo -H -u playground opam switch create 4.12.0
-
-# Set up UFW.
-sudo ufw allow ssh
-sudo ufw allow http
-sudo ufw enable
diff --git a/example/z-playground/server/sync.sh b/example/z-playground/server/sync.sh
deleted file mode 100644
index 43b1db92..00000000
--- a/example/z-playground/server/sync.sh
+++ /dev/null
@@ -1,104 +0,0 @@
-#!/bin/bash
-
-set -e
-set -x
-
-HOST=$1
-DIR=playground/example/z-playground
-
-rsync -v $HOST:$DIR/package-lock.json $HOST:$DIR/opam-switch . || true
-rsync -rlv --exclude node_modules \
-  ../../dream.opam ../../dune-project ../../src $HOST:playground
-ssh $HOST "mkdir -p $DIR"
-rsync -rlv . $HOST:$DIR
-
-set +x
-
-mkdir -p ./sync-temp/runtime
-echo "let list = [" > ./sync-temp/runtime/examples.ml
-
-function index_example {
-  EXAMPLE=$1
-  echo "  \"$EXAMPLE\";" >> ./sync-temp/runtime/examples.ml
-}
-
-function example {
-  EXAMPLE=$1
-  mkdir -p ./sync-temp/sandbox/$1
-  cat ../$1/*.ml | sed 's/Dream\.run/Dream\.run ~interface:"0.0.0.0"/g' \
-    > ./sync-temp/sandbox/$1/server.eml.ml
-  touch ./sync-temp/sandbox/$1/keep
-  index_example $EXAMPLE
-}
-example 1-hello
-example 2-middleware
-example 3-router
-example 4-counter
-example 5-promise
-example 6-echo
-example 7-template
-example 8-debug
-example 9-error
-example a-log
-example b-session
-example c-cookie
-example d-form
-example e-json
-example g-upload
-example h-sql
-example i-graphql
-example j-stream
-example k-websocket
-example w-graphql-subscription
-example w-flash
-example w-content-security-policy
-example w-long-polling
-example w-multipart-dump
-example w-query
-example w-server-sent-events
-example w-template-stream
-example w-tyxml
-example w-upload-stream
-example w-chat
-touch ./sync-temp/sandbox/w-tyxml/no-eml
-mv ./sync-temp/sandbox/w-tyxml/server.eml.ml \
-  ./sync-temp/sandbox/w-tyxml/server.ml
-
-function example_re {
-  EXAMPLE=$1
-  mkdir -p ./sync-temp/sandbox/$1
-  cat ../$1/*.re \
-    | sed 's/Dream\.run(/Dream\.run(~interface="0.0.0.0", /g' \
-    | sed 's/Dream\.run$/Dream\.run(~interface="0.0.0.0")/g' \
-    > ./sync-temp/sandbox/$1/server.eml.re
-  touch ./sync-temp/sandbox/$1/keep
-  index_example $EXAMPLE
-}
-example_re r-hello
-example_re r-template
-example_re r-template-stream
-example_re r-graphql
-example_re r-tyxml
-touch ./sync-temp/sandbox/r-tyxml/no-eml
-mv ./sync-temp/sandbox/r-tyxml/server.eml.re \
-  ./sync-temp/sandbox/r-tyxml/server.re
-
-echo "]" >> ./sync-temp/runtime/examples.ml
-
-cp ../h-sql/db.sqlite ./sync-temp/
-
-set -x
-
-rsync -rlv ./sync-temp/* $HOST:$DIR
-rm -rf sync-temp
-ssh $HOST "touch playground/dune-workspace"
-
-set +x
-
-echo
-echo "If this is the first sync, run as playground@$HOST in ~/playground:"
-echo "  opam install --deps-only ."
-echo "  opam switch export opam-switch"
-echo "  npm install"
-echo "Then, as root@$HOST:"
-echo "  systemctl enable playground"
diff --git a/example/z-systemd/app.ml b/example/z-systemd/app.ml
index 98261d50..1feda01c 100644
--- a/example/z-systemd/app.ml
+++ b/example/z-systemd/app.ml
@@ -1,5 +1,6 @@
 let () =
-  Dream.run ~interface:"0.0.0.0" ~port:80
+  Eio_main.run @@ fun env ->
+  Dream.run ~interface:"0.0.0.0" ~port:80 env
   @@ Dream.logger
   @@ Dream.router [
     Dream.get "/" (fun _ -> Dream.html "Dream started by systemd!");
diff --git a/src/dream.ml b/src/dream.ml
index 72d291cb..b0adff18 100644
--- a/src/dream.ml
+++ b/src/dream.ml
@@ -147,12 +147,12 @@ let all_cookies = Cookie.all_cookies
 
 (* Bodies *)
 
-let body = Message.body
+let body x = Lwt_eio.Promise.await_lwt (Message.body x)
 let set_body = Message.set_body
-let read = Message.read
-let write = Message.write
-let flush = Message.flush
-let close = Message.close
+let read body = Lwt_eio.Promise.await_lwt (Message.read body)
+let write ?kind response data = Lwt_eio.Promise.await_lwt (Message.write ?kind response data)
+let flush response = Lwt_eio.Promise.await_lwt (Message.flush response)
+let close ?code msg = Lwt_eio.Promise.await_lwt (Message.close ?code msg)
 type buffer = Stream.buffer
 type stream = Stream.stream
 let client_stream = Message.client_stream
@@ -178,12 +178,12 @@ let origin_referrer_check = Origin_referrer_check.origin_referrer_check
 (* Forms *)
 
 type 'a form_result = 'a Form.form_result
-let form = Form.form ~now
+let form ?csrf x = Lwt_eio.Promise.await_lwt (Form.form ~now ?csrf x)
 type multipart_form = Upload.multipart_form
-let multipart = Upload.multipart ~now
+let multipart ?csrf x = Lwt_eio.Promise.await_lwt (Upload.multipart ~now ?csrf x)
 type part = Upload.part
-let upload = Upload.upload
-let upload_part = Upload.upload_part
+let upload request = Lwt_eio.Promise.await_lwt (Upload.upload request)
+let upload_part request = Lwt_eio.Promise.await_lwt (Upload.upload_part request)
 type csrf_result = Csrf.csrf_result
 let csrf_token = Csrf.csrf_token ~now
 let verify_csrf_token = Csrf.verify_csrf_token ~now
@@ -265,7 +265,7 @@ let graphiql = Graphql.graphiql
 (* SQL *)
 
 let sql_pool = Sql.sql_pool
-let sql = Sql.sql
+let sql req fn = Lwt_eio.Promise.await_lwt (Sql.sql req fn)
 
 
 
@@ -370,7 +370,11 @@ let test ?(prefix = "") handler request =
     @@ handler
   in
 
-  Lwt_main.run (app request)
+  let result = ref None in
+  Eio_main.run (fun _env ->
+      result := Some (app request)
+    );
+  Option.get !result
 
 let sort_headers = Message.sort_headers
 let echo = Echo.echo
diff --git a/src/dream.mli b/src/dream.mli
index 24ca0863..786f8d04 100644
--- a/src/dream.mli
+++ b/src/dream.mli
@@ -4,7 +4,6 @@
    Copyright 2021 Anton Bachin *)
 
 
-
 (** {1 Types}
 
     Dream is built on just five types. The first two are the data types of
@@ -19,7 +18,7 @@ and response = server message
 
 (** The remaining three types are for building up Web apps. *)
 
-and handler = request -> response promise
+and handler = request -> response
 (** Handlers are asynchronous functions from requests to responses. Example
     {{:https://github.com/aantron/dream/tree/master/example/1-hello#files}
     [1-hello]} \[{{:http://dream.as/1-hello} playground}\] shows the simplest
@@ -471,7 +470,7 @@ val respond :
   ?status:[< status ] ->
   ?code:int ->
   ?headers:(string * string) list ->
-    string -> response promise
+    string -> response
 (** Same as {!Dream.val-response}, but the new {!type-response} is wrapped in a
     {!type-promise}. *)
 
@@ -479,7 +478,7 @@ val html :
   ?status:[< status ] ->
   ?code:int ->
   ?headers:(string * string) list ->
-    string -> response promise
+    string -> response
 (** Same as {!Dream.respond}, but adds [Content-Type: text/html; charset=utf-8].
     See {!Dream.text_html}.
 
@@ -493,7 +492,7 @@ val json :
   ?status:[< status ] ->
   ?code:int ->
   ?headers:(string * string) list ->
-    string -> response promise
+    string -> response
 (** Same as {!Dream.respond}, but adds [Content-Type: application/json]. See
     {!Dream.application_json}. *)
 
@@ -501,7 +500,7 @@ val redirect :
   ?status:[< redirection ] ->
   ?code:int ->
   ?headers:(string * string) list ->
-    request -> string -> response promise
+    request -> string -> response
 (** Creates a new {!type-response}. Adds a [Location:] header with the given
     string. The default status code is [303 See Other], for a temporary
     redirection. Use [~status:`Moved_Permanently] or [~code:301] for a permanent
@@ -515,14 +514,14 @@ val redirect :
 
 val empty :
   ?headers:(string * string) list ->
-    status -> response promise
+    status -> response
 (** Same as {!Dream.val-response} with the empty string for a body. *)
 
 val stream :
   ?status:[< status ] ->
   ?code:int ->
   ?headers:(string * string) list ->
-    (response -> unit promise) -> response promise
+    request -> (response -> unit) -> response
 (** Same as {!Dream.val-respond}, but calls {!Dream.set_stream} internally to
     prepare the response for stream writing, and then runs the callback
     asynchronously to do it. See example
@@ -531,14 +530,14 @@ val stream :
 
     {[
       fun request ->
-        Dream.stream (fun response ->
-          let%lwt () = Dream.write response "foo" in
+        Dream.stream request (fun response ->
+          Dream.write response "foo";
           Dream.close_stream response)
     ]} *)
 
 val websocket :
   ?headers:(string * string) list ->
-    (response -> unit promise) -> response promise
+    request -> (response -> unit) -> response
 (** Creates a fresh [101 Switching Protocols] response. Once this response is
     returned to Dream's HTTP layer, the callback is passed a new
     {!type-websocket}, and the application can begin using it. See example
@@ -746,7 +745,7 @@ val all_cookies : request -> (string * string) list
 
 (** {1 Bodies} *)
 
-val body : 'a message -> string promise
+val body : 'a message -> string
 (** Retrieves the entire body. See example
     {{:https://github.com/aantron/dream/tree/master/example/6-echo#files}
     [6-echo]}. *)
@@ -764,7 +763,7 @@ https://aantron.github.io/dream/#val-set_body
 
 (** {2 Streaming} *)
 
-val read : 'a message -> string option promise
+val read : 'a message -> string option
 (** Retrieves a body chunk. The chunk is not buffered, thus it can only be read
     once. See example
     {{:https://github.com/aantron/dream/tree/master/example/j-stream#files}
@@ -780,15 +779,15 @@ https://aantron.github.io/dream/#val-set_stream
 "]
 (**/**)
 
-val write : ?kind:[< `Text | `Binary ] -> response -> string -> unit promise
+val write : ?kind:[< `Text | `Binary ] -> response -> string -> unit
 (** Streams out the string. The promise is fulfilled when the response can
     accept more writes. *)
 (* TODO Document clearly which of the writing functions can raise exceptions. *)
 
-val flush : response -> unit promise
+val flush : response -> unit
 (** Flushes write buffers. Data is sent to the client. *)
 
-val close : ?code:int -> 'a message -> unit promise
+val close : ?code:int -> 'a message -> unit
 (** Finishes the response stream. *)
 (* TODO Fix comment. *)
 
@@ -857,7 +856,7 @@ val close_stream :
 
 (**/**)
 val write_buffer :
-  ?offset:int -> ?length:int -> response -> buffer -> unit promise
+  ?offset:int -> ?length:int -> response -> buffer -> unit
 [@@ocaml.deprecated
 "Use Dream.write_stream. See
 https://aantron.github.io/dream/#val-write_stream
@@ -952,7 +951,7 @@ type 'a form_result = [
     activity, or tokens so old that decryption keys have since been rotated on
     the server. *)
 
-val form : ?csrf:bool -> request -> (string * string) list form_result promise
+val form : ?csrf:bool -> request -> (string * string) list form_result
 (** Parses the request body as a form. Performs CSRF checks. Use
     {!Dream.form_tag} in a template to transparently generate forms that will
     pass these checks. See {!section-templates} and example
@@ -1043,7 +1042,7 @@ type multipart_form =
     OWASP {i File Upload Cheat Sheet}} for security precautions for upload
     forms. *)
 
-val multipart : ?csrf:bool -> request -> multipart_form form_result promise
+val multipart : ?csrf:bool -> request -> multipart_form form_result
 (** Like {!Dream.form}, but also reads files, and [Content-Type:] must be
     [multipart/form-data]. The [
] tag and CSRF token can be generated in a
     template with
@@ -1076,7 +1075,7 @@ type part = string option * string option * ((string * string) list)
     Note that, in the general case, [filename] and [headers] are not reliable.
     [name] is the form field name. *)
 
-val upload : request -> part option promise
+val upload : request -> part option
 (** Retrieves the next upload part.
 
     Upon getting [Some (name, filename, headers)] from this function, the user
@@ -1095,7 +1094,7 @@ val upload : request -> part option promise
       [FormData]} in the client to submit [multipart/form-data] by AJAX, and
       include a custom header. *)
 
-val upload_part : request -> string option promise
+val upload_part : request -> string option
 (** Retrieves a part chunk. *)
 
 (** {2 CSRF tokens}
@@ -1501,14 +1500,14 @@ val mime_lookup : string -> (string * string) list
 val session : string -> request -> string option
 (** Value from the request's session. *)
 
-val put_session : string -> string -> request -> unit promise
+val put_session : string -> string -> request -> unit
 (** Mutates a value in the request's session. The back end may commit the value
     to storage immediately, so this function returns a promise. *)
 
 val all_session_values : request -> (string * string) list
 (** Full session dictionary. *)
 
-val invalidate_session : request -> unit promise
+val invalidate_session : request -> unit
 (** Invalidates the request's session, replacing it with a fresh, empty
     pre-session. *)
 
@@ -1579,7 +1578,7 @@ https://aantron.github.io/dream/#type-stream
 (**/**)
 
 (**/**)
-val send : ?kind:[< `Text | `Binary ] -> response -> string -> unit promise
+val send : ?kind:[< `Text | `Binary ] -> response -> string -> unit
 [@@ocaml.deprecated
 "Use Dream.write. See
 https://aantron.github.io/dream/#val-write
@@ -1596,7 +1595,7 @@ https://aantron.github.io/dream/#val-write
     {{:https://developer.mozilla.org/en-US/docs/Web/API/WebSocket/binaryType}
     MDN, [WebSocket.binaryType]}. *)
 
-val receive : response -> string option promise
+val receive : response -> string option
 [@@ocaml.deprecated
 "Use Dream.read. See
 https://aantron.github.io/dream/#val-read
@@ -1606,7 +1605,7 @@ https://aantron.github.io/dream/#val-read
 (**/**)
 
 (**/**)
-val close_websocket : ?code:int -> response -> unit promise
+val close_websocket : ?code:int -> response -> unit
 [@@ocaml.deprecated
 "Use Dream.close. See
 https://aantron.github.io/dream/#val-close
@@ -1731,7 +1730,7 @@ val graphiql : ?default_query:string -> string -> handler
 val sql_pool : ?size:int -> string -> middleware
 (** Makes an SQL connection pool available to its inner handler. *)
 
-val sql : request -> (Caqti_lwt.connection -> 'a promise) -> 'a promise
+val sql : request -> (Caqti_lwt.connection -> 'a promise) -> 'a
 (** Runs the callback with a connection from the SQL pool. See example
     {{:https://github.com/aantron/dream/tree/master/example/h-sql#files}
     [h-sql]}.
@@ -2006,7 +2005,7 @@ type error = {
     [true].
     }} *)
 
-type error_handler = error -> response option promise
+type error_handler = error -> response option
 (** Error handlers log errors and convert them into responses. Ignore if using
     {!Dream.error_template}.
 
@@ -2022,7 +2021,7 @@ type error_handler = error -> response option promise
 (* TODO Get rid of the option? *)
 
 val error_template :
-  (error -> string -> response -> response promise) -> error_handler
+  (error -> string -> response -> response) -> error_handler
 (** Builds an {!error_handler} from a template. See example
     {{:https://github.com/aantron/dream/tree/master/example/9-error#files}
     [9-error]} \[{{:http://dream.as/9-error} playground}\].
@@ -2067,7 +2066,7 @@ val debug_error_handler : error_handler
 (** An {!error_handler} for showing extra information about requests and
     exceptions, for use during development. *)
 
-val catch : (error -> response promise) -> middleware
+val catch : (error -> response) -> middleware
 (** Forwards exceptions, rejections, and [4xx], [5xx] responses from the
     application to the error handler. See {!section-errors}. *)
 (* TODO Error handler should not return an option, and then the type can be
@@ -2080,7 +2079,6 @@ val catch : (error -> response promise) -> middleware
 val run :
   ?interface:string ->
   ?port:int ->
-  ?stop:unit promise ->
   ?error_handler:error_handler ->
   ?https:bool ->
   ?certificate_file:string ->
@@ -2088,6 +2086,7 @@ val run :
   ?builtins:bool ->
   ?greeting:bool ->
   ?adjust_terminal:bool ->
+  < clock:#Eio.Time.clock; net:#Eio.Net.t; ..> ->
     handler -> unit
 (** Runs the Web application represented by the {!handler}, by default at
     {{:http://localhost:8080} http://localhost:8080}.
@@ -2099,10 +2098,6 @@ val run :
     - [~interface] is the network interface to listen on. Defaults to
       ["localhost"]. Use ["0.0.0.0"] to listen on all interfaces.
     - [~port] is the port to listen on. Defaults to [8080].
-    - [~stop] is a promise that causes the server to stop accepting new
-      requests, and {!Dream.run} to return. Requests that have already entered
-      the Web application continue to be processed. The default value is a
-      promise that never resolves. However, see also [~stop_on_input].
     - [~debug:true] enables debug information in error templates. See
       {!Dream.error_template}. The default is [false], to prevent accidental
       deployment with debug output turned on. See example
@@ -2139,13 +2134,13 @@ val run :
 val serve :
   ?interface:string ->
   ?port:int ->
-  ?stop:unit promise ->
   ?error_handler:error_handler ->
   ?https:bool ->
   ?certificate_file:string ->
   ?key_file:string ->
   ?builtins:bool ->
-    handler -> unit promise
+  net:#Eio.Net.t ->
+    handler -> unit
 (** Like {!Dream.run}, but returns a promise that does not resolve until the
     server stops listening, instead of calling
     {{:https://ocsigen.org/lwt/latest/api/Lwt_main#VALrun} [Lwt_main.run]}.
@@ -2460,7 +2455,7 @@ val request :
   ?target:string ->
   ?version:int * int ->
   ?headers:(string * string) list ->
-    string -> request
+  string -> request
 (** [Dream.request body] creates a fresh request with the given body for
     testing. The optional arguments set the corresponding {{!requests} request
     fields}. *)
diff --git a/src/eml/eml.ml b/src/eml/eml.ml
index 1ea43f96..dc19826a 100644
--- a/src/eml/eml.ml
+++ b/src/eml/eml.ml
@@ -688,17 +688,16 @@ struct
     init = (fun () ->
       print "let ___eml_write string = Dream.write response string in\n");
 
-    finish = (fun () ->
-      print "Lwt.return_unit\n");
+    finish = ignore;
 
     text =
-      Printf.ksprintf print "let%%lwt () = ___eml_write %S in\n";
+      Printf.ksprintf print "___eml_write %S;\n";
 
     format =
-      Printf.ksprintf print "let%%lwt () = Printf.ksprintf ___eml_write %S ";
+      Printf.ksprintf print "Printf.ksprintf ___eml_write %S ";
 
     format_end = (fun () ->
-      print " in\n");
+      print ";\n");
   }
 
   let stream_reason print = {
@@ -707,14 +706,13 @@ struct
     init = (fun () ->
       print "let ___eml_write = string => Dream.write(response, string);\n");
 
-    finish = (fun () ->
-      print "Lwt.return_unit\n");
+    finish = ignore;
 
     text =
-      Printf.ksprintf print "let%%lwt () = ___eml_write(%S);\n";
+      Printf.ksprintf print "___eml_write(%S);\n";
 
     format =
-      Printf.ksprintf print "let%%lwt () = Printf.ksprintf(___eml_write, %S)";
+      Printf.ksprintf print "Printf.ksprintf(___eml_write, %S)";
 
     format_end = (fun () ->
       print ";\n");
diff --git a/src/graphql/graphql.ml b/src/graphql/graphql.ml
index c09b3f46..eaa092a3 100644
--- a/src/graphql/graphql.ml
+++ b/src/graphql/graphql.ml
@@ -115,6 +115,7 @@ let complete_message id =
 (* TODO Take care to pass around the request Lwt.key in async, etc. *)
 (* TODO Test client complete racing against a stream. *)
 let handle_over_websocket make_context schema subscriptions request response =
+  Lwt_eio.Promise.await_lwt @@
   let rec loop inited =
     match%lwt Message.read response with
     | None ->
@@ -279,47 +280,50 @@ let graphql make_context schema = fun request ->
     | Some "websocket", Some "graphql-transport-ws" ->
       Helpers.websocket
         ~headers:["Sec-WebSocket-Protocol", "graphql-transport-ws"]
+        request
         (handle_over_websocket make_context schema (Hashtbl.create 16) request)
     | _ ->
       log.warning (fun log -> log ~request "Upgrade: websocket header missing");
       Message.response ~status:`Not_Found Stream.empty Stream.null
-      |> Lwt.return
     end
 
   | `POST ->
     begin match Message.header request "Content-Type" with
     | Some "application/json" ->
-      let%lwt body = Message.body request in
-      (* TODO This almost certainly raises exceptions... *)
-      let json = Yojson.Basic.from_string body in
-
-      begin match%lwt run_query make_context schema request json with
-      | Error json ->
-        Yojson.Basic.to_string json
-        |> Helpers.json
-
-      | Ok (`Response json) ->
-        Yojson.Basic.to_string json
-        |> Helpers.json
-
-      | Ok (`Stream _) ->
-        make_error "Subscriptions and streaming should use WebSocket transport"
-        |> Yojson.Basic.to_string
-        |> Helpers.json
-      end
+      Lwt_eio.Promise.await_lwt (
+        let%lwt body = Message.body request in
+        (* TODO This almost certainly raises exceptions... *)
+        let json = Yojson.Basic.from_string body in
+
+        begin match%lwt run_query make_context schema request json with
+          | Error json ->
+            Yojson.Basic.to_string json
+            |> Helpers.json
+            |> Lwt.return
+
+          | Ok (`Response json) ->
+            Yojson.Basic.to_string json
+            |> Helpers.json
+            |> Lwt.return
+
+          | Ok (`Stream _) ->
+            make_error "Subscriptions and streaming should use WebSocket transport"
+            |> Yojson.Basic.to_string
+            |> Helpers.json
+            |> Lwt.return
+        end
+      )
 
     | _ ->
       log.warning (fun log -> log ~request
         "Content-Type not 'application/json'");
       Message.response ~status:`Bad_Request Stream.empty Stream.null
-      |> Lwt.return
     end
 
   | method_ ->
     log.error (fun log -> log ~request
       "Method %s; must be GET or POST" (Method.method_to_string method_));
     Message.response ~status:`Not_Found Stream.empty Stream.null
-    |> Lwt.return
 
 
 
diff --git a/src/http/dune b/src/http/dune
index 386935c7..4b6faf12 100644
--- a/src/http/dune
+++ b/src/http/dune
@@ -17,8 +17,8 @@
   dream-httpaf.httpaf-lwt-unix
   lwt
   lwt.unix
-  lwt_ssl
-  ssl
+  lwt_eio
+  eio_main
   dream-httpaf.websocketaf
  )
  (preprocess (pps lwt_ppx))
diff --git a/src/http/error_handler.ml b/src/http/error_handler.ml
index f9c49efb..678faeeb 100644
--- a/src/http/error_handler.ml
+++ b/src/http/error_handler.ml
@@ -159,7 +159,7 @@ let customize template (error : Catch.error) =
      Then, call the template, and return the response. *)
 
   if not error.will_send_response then
-    Lwt.return_none
+    None
 
   else
     let debug_dump = dump error in
@@ -179,13 +179,13 @@ let customize template (error : Catch.error) =
     (* No need to catch errors when calling the template, because every call
        site of the error handler already has error handlers for catching double
        faults. *)
-    let%lwt response = template error debug_dump response in
-    Lwt.return (Some response)
+    let response = template error debug_dump response in
+    Some response
 
 
 
 let default_template _error _debug_dump response =
-  Lwt.return response
+  response
 
 let debug_template _error debug_dump response =
   let status = Message.status response in
@@ -193,7 +193,7 @@ let debug_template _error debug_dump response =
   and reason = Status.status_to_string status in
   Message.set_header response "Content-Type" Dream_pure.Formats.text_html;
   Message.set_body response (Error_template.render ~debug_dump ~code ~reason);
-  Lwt.return response
+  response
 
 let default =
   customize default_template
@@ -228,17 +228,19 @@ let double_faults f default =
    is a programming error, so it's probably fine to return a generic server
    error. *)
 let respond_with_option f =
+  Lwt_eio.Promise.await_lwt @@
   double_faults
     (fun () ->
-      f ()
-      |> Lwt.map (function
-        | Some response -> response
-        | None ->
-          Message.response
-            ~status:`Internal_Server_Error Stream.empty Stream.null))
+      Lwt_eio.run_eio @@ fun () ->
+      match f () with
+      | Some response -> response
+      | None ->
+        Message.response
+          ~status:`Internal_Server_Error Stream.empty Stream.null)
     (fun () ->
       Message.response ~status:`Internal_Server_Error Stream.empty Stream.null
-      |> Lwt.return)
+      |> Lwt.return
+    )
 
 
 
@@ -304,7 +306,7 @@ let httpaf
 
   Lwt.async begin fun () ->
     double_faults begin fun () ->
-      let%lwt response = user's_error_handler error in
+      let%lwt response = Lwt_eio.run_eio (fun () -> user's_error_handler error) in
 
       let response =
         match response with
@@ -362,7 +364,7 @@ let h2
 
   Lwt.async begin fun () ->
     double_faults begin fun () ->
-      let%lwt response = user's_error_handler error in
+      let%lwt response = Lwt_eio.run_eio (fun () -> user's_error_handler error) in
 
       let response =
         match response with
@@ -403,7 +405,7 @@ let tls
 
   Lwt.async (fun () ->
     double_faults
-      (fun () -> Lwt.map ignore (user's_error_handler error))
+      (fun () -> Lwt_eio.run_eio (fun () -> user's_error_handler error |> ignore))
       Lwt.return)
 
 
@@ -434,7 +436,7 @@ let websocket
 
   Lwt.async (fun () ->
     double_faults
-      (fun () -> Lwt.map ignore (user's_error_handler error))
+      (fun () -> Lwt_eio.run_eio (fun () -> user's_error_handler error |> ignore))
       Lwt.return)
 
 
diff --git a/src/http/error_handler.mli b/src/http/error_handler.mli
index 285469b5..7ab26b64 100644
--- a/src/http/error_handler.mli
+++ b/src/http/error_handler.mli
@@ -17,7 +17,7 @@ module Message = Dream_pure.Message
 val default : Catch.error_handler
 val debug_error_handler : Catch.error_handler
 val customize :
-  (Catch.error -> string -> Message.response -> Message.response Lwt.t) ->
+  (Catch.error -> string -> Message.response -> Message.response) ->
     Catch.error_handler
 
 
@@ -35,7 +35,7 @@ val customize :
 
 val app :
   Catch.error_handler ->
-    (Catch.error -> Message.response Lwt.t)
+    (Catch.error -> Message.response)
 
 val httpaf :
   Catch.error_handler ->
@@ -57,7 +57,7 @@ val websocket :
 
 val websocket_handshake :
   Catch.error_handler ->
-    (Message.request -> Message.response -> string -> Message.response Lwt.t)
+    (Message.request -> Message.response -> string -> Message.response)
 
 
 
diff --git a/src/http/http.ml b/src/http/http.ml
index df0e9660..8ca61eea 100644
--- a/src/http/http.ml
+++ b/src/http/http.ml
@@ -4,6 +4,7 @@
    Copyright 2021 Anton Bachin *)
 
 
+open Eio.Std
 
 module Catch = Dream__server.Catch
 module Content_length = Dream__server.Content_length
@@ -274,7 +275,7 @@ let websocket_handler response socket =
    that ordinarily shouldn't be relied on by the user - this is just our last
    chance to tell the user that something is wrong with their app. *)
 (* TODO Rename conn like in the body branch. *)
-let wrap_handler
+let wrap_handler ~sw
     https
     (user's_error_handler : Catch.error_handler)
     (user's_dream_handler : Message.handler) =
@@ -319,7 +320,7 @@ let wrap_handler
       Stream.stream body Stream.no_writer in
 
     let request : Message.request =
-      Helpers.request ~client ~method_ ~target ~https ~version ~headers body in
+      Helpers.request ~sw ~client ~method_ ~target ~https ~version ~headers body in
 
     (* Call the user's handler. If it raises an exception or returns a promise
        that rejects with an exception, pass the exception up to Httpaf. This
@@ -334,7 +335,7 @@ let wrap_handler
     Lwt.async begin fun () ->
       Lwt.catch begin fun () ->
         (* Do the big call. *)
-        let%lwt response = user's_dream_handler request in
+        let%lwt response = Lwt_eio.run_eio (fun () -> user's_dream_handler request) in
 
         (* Extract the Dream response's headers. *)
 
@@ -389,7 +390,7 @@ let wrap_handler
           |> function
           | Ok () -> Lwt.return_unit
           | Error error_string ->
-            let%lwt response =
+            let response =
               Error_handler.websocket_handshake
                 user's_error_handler request response error_string
             in
@@ -410,7 +411,7 @@ let wrap_handler
 
 
 (* TODO Factor out what is in common between the http/af and h2 handlers. *)
-let wrap_handler_h2
+let wrap_handler_h2 ~sw
     https
     (_user's_error_handler : Catch.error_handler)
     (user's_dream_handler : Message.handler) =
@@ -449,7 +450,7 @@ let wrap_handler_h2
       Stream.stream body Stream.no_writer in
 
     let request : Message.request =
-      Helpers.request ~client ~method_ ~target ~https ~version ~headers body in
+      Helpers.request ~sw ~client ~method_ ~target ~https ~version ~headers body in
 
     (* Call the user's handler. If it raises an exception or returns a promise
        that rejects with an exception, pass the exception up to Httpaf. This
@@ -464,7 +465,7 @@ let wrap_handler_h2
     Lwt.async begin fun () ->
       Lwt.catch begin fun () ->
         (* Do the big call. *)
-        let%lwt response = user's_dream_handler request in
+        let%lwt response = Lwt_eio.run_eio (fun () -> user's_dream_handler request) in
 
         (* Extract the Dream response's headers. *)
 
@@ -517,6 +518,7 @@ type tls_library = {
     key_file:string ->
     handler:Message.handler ->
     error_handler:Catch.error_handler ->
+    sw:Switch.t ->
       Unix.sockaddr ->
       Lwt_unix.file_descr ->
         unit Lwt.t;
@@ -526,15 +528,18 @@ let no_tls = {
   create_handler = begin fun
       ~certificate_file:_ ~key_file:_
       ~handler
-      ~error_handler ->
+      ~error_handler
+      ~sw ->
     Httpaf_lwt_unix.Server.create_connection_handler
       ?config:None
-      ~request_handler:(wrap_handler false error_handler handler)
+      ~request_handler:(wrap_handler ~sw false error_handler handler)
       ~error_handler:(Error_handler.httpaf error_handler)
   end;
 }
 
 let openssl = {
+  create_handler = fun ~certificate_file:_ -> failwith "https://github.com/savonet/ocaml-ssl/issues/76"
+(*
   create_handler = begin fun
       ~certificate_file ~key_file
       ~handler
@@ -543,15 +548,15 @@ let openssl = {
     let httpaf_handler =
       Httpaf_lwt_unix.Server.SSL.create_connection_handler
         ?config:None
-      ~request_handler:(wrap_handler true error_handler handler)
-      ~error_handler:(Error_handler.httpaf error_handler)
+      ~request_handler:(wrap_handler ~sw true error_handler handler)
+      ~error_handler:(Error_handler.httpaf ~sw error_handler)
     in
 
     let h2_handler =
       H2_lwt_unix.Server.SSL.create_connection_handler
         ?config:None
       ~request_handler:(wrap_handler_h2 true error_handler handler)
-      ~error_handler:(Error_handler.h2 error_handler)
+      ~error_handler:(Error_handler.h2 ~sw error_handler)
     in
 
     let perform_tls_handshake =
@@ -590,6 +595,7 @@ let openssl = {
         | Some _ ->
           assert false
   end;
+*)
 }
 
 (* TODO LATER Add ALPN + HTTP/2.0 with ocaml-tls, too. *)
@@ -597,11 +603,12 @@ let ocaml_tls = {
   create_handler = fun
       ~certificate_file ~key_file
       ~handler
-      ~error_handler ->
+      ~error_handler
+      ~sw ->
     Httpaf_lwt_unix.Server.TLS.create_connection_handler_with_default
       ~certfile:certificate_file ~keyfile:key_file
       ?config:None
-      ~request_handler:(wrap_handler true error_handler handler)
+      ~request_handler:(wrap_handler ~sw true error_handler handler)
       ~error_handler:(Error_handler.httpaf error_handler)
 }
 
@@ -616,12 +623,22 @@ let built_in_middleware error_handler =
 
 
 
+let of_unix_addr = function
+  | Unix.ADDR_INET (host, port) -> `Tcp (Eio_unix.Ipaddr.of_unix host, port)
+  | Unix.ADDR_UNIX path -> `Unix path
+
+let to_unix_addr = function
+  | `Tcp (host, port) -> Unix.ADDR_INET (Eio_unix.Ipaddr.to_unix host, port)
+  | `Unix path -> Unix.ADDR_UNIX path
+
+
+
 let serve_with_details
     caller_function_for_error_messages
     tls_library
+    ~net
     ~interface
     ~port
-    ~stop
     ~error_handler
     ~certificate_file
     ~key_file
@@ -665,36 +682,40 @@ let serve_with_details
      be pattern matching on the exception (but that might introduce dependency
      coupling), or the upstream should be patched to distinguish the errors in
      some useful way. *)
-  let httpaf_connection_handler client_address socket =
-    Lwt.catch
-      (fun () ->
-        httpaf_connection_handler client_address socket)
-      (fun exn ->
-        tls_error_handler client_address exn;
-        Lwt.return_unit)
+  let httpaf_connection_handler ~sw flow client_address =
+    let client_address = to_unix_addr client_address in
+    try
+      let fd = Eio_unix.FD.take flow |> Option.get in
+      let socket = Lwt_unix.of_unix_file_descr fd in
+      Lwt_eio.Promise.await_lwt @@
+      httpaf_connection_handler ~sw client_address socket
+    with exn ->
+      tls_error_handler client_address exn
   in
 
-  (* Look up the low-level address corresponding to the interface. Hopefully,
-     this is a local interface. *)
-  let%lwt addresses = Lwt_unix.getaddrinfo interface (string_of_int port) [] in
-  match addresses with
-  | [] ->
-    Printf.ksprintf failwith "Dream.%s: no interface with address %s"
-      caller_function_for_error_messages interface
-  | address::_ ->
-  let listen_address = Lwt_unix.(address.ai_addr) in
-
-
-  (* Bring up the HTTP server. Wait for the server to actually get started.
-     Then, wait for the ~stop promise. If the ~stop promise ever resolves, stop
-     the server. *)
-  let%lwt server =
-    Lwt_io.establish_server_with_client_socket
-      listen_address
-      httpaf_connection_handler in
+  let listen_address = Lwt_eio.Promise.await_lwt @@
+    (* Look up the low-level address corresponding to the interface. Hopefully,
+       this is a local interface. *)
+    let%lwt addresses = Lwt_unix.getaddrinfo interface (string_of_int port) [] in
+    match addresses with
+    | [] ->
+      Printf.ksprintf failwith "Dream.%s: no interface with address %s"
+        caller_function_for_error_messages interface
+    | address::_ ->
+      Lwt.return (of_unix_addr Lwt_unix.(address.ai_addr))
+  in
 
-  let%lwt () = stop in
-  Lwt_io.shutdown_server server
+  (* Bring up the HTTP server. *)
+  Switch.run @@ fun sw ->
+  let socket =
+    Eio.Net.listen ~sw net listen_address
+      ~reuse_addr:true
+      ~backlog:(Lwt_unix.somaxconn () [@ocaml.warning "-3"])
+  in
+  while true do
+    Eio.Net.accept_sub ~sw socket httpaf_connection_handler
+      ~on_error:(fun ex -> !Lwt.async_exception_hook ex)
+  done
 
 
 
@@ -705,15 +726,15 @@ let serve_with_maybe_https
     caller_function_for_error_messages
     ~interface
     ~port
-    ~stop
     ~error_handler
     ~https
     ?certificate_file ?key_file
     ?certificate_string ?key_string
     ~builtins
+    ~net
     user's_dream_handler =
 
-  try%lwt
+  try
     (* This check will at least catch secrets like "foo" when used on a public
        interface. *)
     (* if not (is_localhost interface) then
@@ -729,9 +750,9 @@ let serve_with_maybe_https
       serve_with_details
         caller_function_for_error_messages
         no_tls
+        ~net
         ~interface
         ~port
-        ~stop
         ~error_handler
         ~certificate_file:""
         ~key_file:""
@@ -794,9 +815,9 @@ let serve_with_maybe_https
         serve_with_details
           caller_function_for_error_messages
           tls_library
+          ~net
           ~interface
           ~port
-          ~stop
           ~error_handler
           ~certificate_file
           ~key_file
@@ -804,6 +825,7 @@ let serve_with_maybe_https
           user's_dream_handler
 
       | `Memory (certificate_string, key_string, verbose_or_silent) ->
+        Lwt_eio.Promise.await_lwt @@
         Lwt_io.with_temp_file begin fun (certificate_file, certificate_stream) ->
         Lwt_io.with_temp_file begin fun (key_file, key_stream) ->
 
@@ -819,16 +841,17 @@ let serve_with_maybe_https
         let%lwt () = Lwt_io.close certificate_stream in
         let%lwt () = Lwt_io.close key_stream in
 
+        Lwt_eio.run_eio @@ fun () ->
         serve_with_details
           caller_function_for_error_messages
           tls_library
           ~interface
           ~port
-          ~stop
           ~error_handler
           ~certificate_file
           ~key_file
           ~builtins
+          ~net
           user's_dream_handler
 
         end
@@ -847,28 +870,27 @@ let serve_with_maybe_https
 
 let default_interface = "localhost"
 let default_port = 8080
-let never = fst (Lwt.wait ())
 
 
 
 let serve
     ?(interface = default_interface)
     ?(port = default_port)
-    ?(stop = never)
     ?(error_handler = Error_handler.default)
     ?(https = false)
     ?certificate_file
     ?key_file
     ?(builtins = true)
+    ~net
     user's_dream_handler =
 
   serve_with_maybe_https
     "serve"
+    ~net
     ~interface
     ~port
-    ~stop
     ~error_handler
-    ~https:(if https then `OpenSSL else `No)
+    ~https:(if https then `OCaml_TLS else `No)
     ?certificate_file
     ?key_file
     ?certificate_string:None
@@ -881,7 +903,6 @@ let serve
 let run
     ?(interface = default_interface)
     ?(port = default_port)
-    ?(stop = never)
     ?(error_handler = Error_handler.default)
     ?(https = false)
     ?certificate_file
@@ -889,6 +910,7 @@ let run
     ?(builtins = true)
     ?(greeting = true)
     ?(adjust_terminal = true)
+    env
     user's_dream_handler =
 
   let () = if Sys.unix then
@@ -953,14 +975,15 @@ let run
   end;
 
   try
-    Lwt_main.run begin
+    begin
+      Lwt_eio.with_event_loop ~clock:env#clock @@ fun () ->
       serve_with_maybe_https
         "run"
+        ~net:env#net
         ~interface
         ~port
-        ~stop
         ~error_handler
-        ~https:(if https then `OpenSSL else `No)
+        ~https:(if https then `OCaml_TLS else `No)
         ?certificate_file ?key_file
         ?certificate_string:None ?key_string:None
         ~builtins
diff --git a/src/mirage/adapt.ml b/src/mirage/adapt.ml
deleted file mode 100644
index bf5d7e54..00000000
--- a/src/mirage/adapt.ml
+++ /dev/null
@@ -1,79 +0,0 @@
-(* This file is part of Dream, released under the MIT license. See LICENSE.md
-   for details, or visit https://github.com/aantron/dream.
-
-   Copyright 2021 Anton Bachin
-
-   XXX(dinosaure): same as [src/http/adapt.ml] without [address_to_string] - which
-   depends on [Unix]. *)
-
-module Dream = Dream__pure.Inmost
-module Stream = Dream__pure.Stream
-
-(* TODO Write a test simulating client exit during SSE; this was killing the
-   server at some point. *)
-(* TODO LATER Will also need to monitor buffer accumulation and use flush. *)
-(* TODO Rewrite using Dream.next. *)
-let forward_body_general
-    (response : Dream.response)
-    (_write_string : ?off:int -> ?len:int -> string -> unit)
-    (write_buffer : ?off:int -> ?len:int -> Stream.buffer -> unit)
-    http_flush
-    close =
-  let bytes_since_flush = ref 0 in
-
-  let rec send () =
-    Dream.body_stream response
-    |> fun stream ->
-      Stream.read
-        stream
-        ~data
-        ~close
-        ~flush
-        ~ping
-        ~pong
-
-  and data chunk off len _binary _fin =
-    write_buffer ~off ~len chunk;
-    bytes_since_flush := !bytes_since_flush + len;
-    if !bytes_since_flush >= 4096 then begin
-      bytes_since_flush := 0;
-      http_flush send
-    end
-    else
-      send ()
-
-  and flush () =
-    bytes_since_flush := 0;
-    http_flush send
-
-  and ping _buffer _offset _length =
-    send ()
-
-  and pong _buffer _offset _length =
-    send ()
-
-  in
-
-  send ()
-
-let forward_body
-    (response : Dream.response)
-    (body : Httpaf.Body.Writer.t) =
-
-  forward_body_general
-    response
-    (Httpaf.Body.Writer.write_string body)
-    (Httpaf.Body.Writer.write_bigstring body)
-    (Httpaf.Body.Writer.flush body)
-    (fun _code -> Httpaf.Body.Writer.close body)
-
-let forward_body_h2
-    (response : Dream.response)
-    (body : [ `write ] H2.Body.t) =
-
-  forward_body_general
-    response
-    (H2.Body.write_string body)
-    (H2.Body.write_bigstring body)
-    (H2.Body.flush body)
-    (fun _code -> H2.Body.close_writer body)
diff --git a/src/mirage/dune b/src/mirage/dune
deleted file mode 100644
index 6f9f8613..00000000
--- a/src/mirage/dune
+++ /dev/null
@@ -1,20 +0,0 @@
-(library
- (public_name dream-mirage)
- (name dream__mirage)
- (libraries
-  bigarray-compat
-  bigstringaf
-  digestif
-  dream.cipher
-  dream.localhost
-  dream.middleware
-  dream-pure
-  dream.h2
-  dream.httpaf
-  lwt
-  dream-mirage.paf
-  dream-mirage.paf.alpn
-  dream-mirage.paf.mirage
- )
- (preprocess (pps lwt_ppx))
- (instrumentation (backend bisect_ppx)))
diff --git a/src/mirage/error_handler.ml b/src/mirage/error_handler.ml
deleted file mode 100644
index de42ac3e..00000000
--- a/src/mirage/error_handler.ml
+++ /dev/null
@@ -1,252 +0,0 @@
-module Dream = Dream__pure.Inmost
-
-let log =
-  Dream__middleware.Log.sub_log "dream.mirage"
-
-let select_log = function
-  | `Error -> log.error
-  | `Warning -> log.warning
-  | `Info -> log.info
-  | `Debug -> log.debug
-
-let dump (error : Dream.error) =
-  let buffer = Buffer.create 4096 in
-  let p format = Printf.bprintf buffer format in
-
-  begin match error.condition with
-  | `Response response ->
-    let status = Dream.status response in
-    p "%i %s\n" (Dream.status_to_int status) (Dream.status_to_string status)
-
-  | `String "" ->
-    p "(Library error without description payload)\n"
-
-  | `String string ->
-    p "%s\n" string
-
-  | `Exn exn ->
-    let backtrace = Printexc.get_backtrace () in
-    p "%s\n" (Printexc.to_string exn);
-    backtrace |> Dream__middleware.Log.iter_backtrace (p "%s\n")
-  end;
-
-  p "\n";
-
-  let layer =
-    match error.layer with
-    | `TLS -> "TLS library"
-    | `HTTP -> "HTTP library"
-    | `HTTP2 -> "HTTP2 library"
-    | `WebSocket -> "WebSocket library"
-    | `App -> "Application"
-  in
-
-  let blame =
-    match error.caused_by with
-    | `Server -> "Server"
-    | `Client -> "Client"
-  in
-
-  let severity =
-    match error.severity with
-    | `Error -> "Error"
-    | `Warning -> "Warning"
-    | `Info -> "Info"
-    | `Debug -> "Debug"
-  in
-
-  p "From: %s\n" layer;
-  p "Blame: %s\n" blame;
-  p "Severity: %s" severity;
-
-  begin match error.client with
-  | None -> ()
-  | Some client -> p "\n\nClient: %s" client
-  end;
-
-  begin match error.request with
-  | None -> ()
-  | Some request ->
-    let last = Dream.last request in
-
-    let major, minor = Dream.version last in
-    p "\n\n%s %s HTTP/%i.%i"
-      (Dream.method_to_string (Dream.method_ last))
-      (Dream.target last)
-      major minor;
-
-    Dream.all_headers last
-    |> List.iter (fun (name, value) -> p "\n%s: %s" name value);
-
-    let show_variables kind =
-      kind (fun name value first ->
-        if first then
-          p "\n";
-        p "\n%s: %s" name value;
-        false)
-        true
-        request
-      |> ignore
-    in
-    show_variables Dream.fold_locals;
-    show_variables Dream.fold_globals
-  end;
-
-  Buffer.contents buffer
-
-let customize template (error : Dream.error) =
-
-  (* First, log the error. *)
-
-  begin match error.condition with
-  | `Response _ -> ()
-  | `String _ | `Exn _ as condition ->
-
-    let client =
-      match error.client with
-      | None -> ""
-      | Some client ->  " (" ^ client ^ ")"
-    in
-
-    let layer =
-      match error.layer with
-      | `TLS -> ["TLS" ^ client]
-      | `HTTP -> ["HTTP" ^ client]
-      | `HTTP2 -> ["HTTP/2" ^ client]
-      | `WebSocket -> ["WebSocket" ^ client]
-      | `App -> []
-    in
-
-    let description, backtrace =
-      match condition with
-      | `String string -> string, ""
-      | `Exn exn ->
-        let backtrace = Printexc.get_backtrace () in
-        Printexc.to_string exn, backtrace
-    in
-
-    let message = String.concat ": " (layer @ [description]) in
-
-    select_log error.severity (fun log ->
-      log ?request:error.request "%s" message);
-    backtrace |> Dream__middleware.Log.iter_backtrace (fun line ->
-      select_log error.severity (fun log ->
-        log ?request:error.request "%s" line))
-  end;
-
-  (* If Dream will not send a response for this error, we are done after
-     logging. Otherwise, if debugging is enabled, gather a bunch of information.
-     Then, call the template, and return the response. *)
-
-  if not error.will_send_response then
-    Lwt.return_none
-
-  else
-    let debug_dump =
-      match error.debug with
-      | false -> None
-      | true -> Some (dump error)
-    in
-
-    let response =
-      match error.condition with
-      | `Response response -> response
-      | _ ->
-        let status =
-          match error.caused_by with
-          | `Server -> `Internal_Server_Error
-          | `Client -> `Bad_Request
-        in
-        Dream.response ~status ""
-    in
-
-    (* No need to catch errors when calling the template, because every call
-       site of the error handler already has error handlers for catching double
-       faults. *)
-    response
-    |> template debug_dump
-    |> Lwt.map (fun response -> Some response)
-
-let default_response = function
-  | `Server -> Dream.response ~status:`Internal_Server_Error ""
-  | `Client -> Dream.response ~status:`Bad_Request ""
-
-let default_template debug_dump response =
-  match debug_dump with
-  | None -> Lwt.return response
-  | Some debug_dump ->
-    let status = Dream.status response in
-    let code = Dream.status_to_int status
-    and reason = Dream.status_to_string status in
-    response
-    |> Dream.with_header "Content-Type" Dream__pure.Formats.text_html
-    |> Dream.with_body
-      (Dream__middleware.Error_template.render ~debug_dump ~code ~reason)
-    |> Lwt.return
-
-let default =
-  customize default_template
-
-let double_faults f default =
-  Lwt.catch f begin fun exn ->
-    let backtrace = Printexc.get_backtrace () in
-    log.error (fun log -> log "Error handler raised: %s" (Printexc.to_string exn));
-    backtrace
-    |> Dream__middleware.Log.iter_backtrace (fun line ->
-      log.error (fun log -> log "%s" line));
-    default ()
-  end
-
-let httpaf app user's_error_handler = fun client_address ?request:_ error start_response ->
-  let condition, severity, caused_by = match error with
-    | `Exn exn ->
-      `Exn exn,
-      `Error,
-      `Server
-    | `Bad_request
-    | `Bad_gateway ->
-      `String "Bad request",
-      `Warning,
-      `Client
-    | `Internal_server_error ->
-      `String "Content-Length missing or negative",
-      `Error,
-      `Server in
-  let error = {
-    Dream.condition;
-    layer = `HTTP;
-    caused_by;
-    request = None;
-    response = None;
-    client= Some client_address;
-    severity;
-    debug = Dream.debug app;
-    will_send_response = true;
-  } in
-
-  Lwt.async begin fun () ->
-    double_faults begin fun () ->
-      let%lwt response = user's_error_handler error in
-      let response = match response with
-        | Some response -> response
-        | None -> default_response caused_by in
-      let headers = Httpaf.Headers.of_list (Dream.all_headers response) in
-      let body = start_response headers in
-      Adapt.forward_body response body;
-      Lwt.return_unit
-    end
-      Lwt.return
-  end
-
-let respond_with_option f =
-  double_faults
-    (fun () ->
-       f ()
-       |> Lwt.map (function
-         | Some response -> response
-         | None -> Dream.response ~status:`Internal_Server_Error ""))
-    (fun () ->
-       Dream.empty `Internal_Server_Error)
-
-let app user's_error_handler = fun error ->
-  respond_with_option (fun () -> user's_error_handler error)
diff --git a/src/mirage/mirage.ml b/src/mirage/mirage.ml
deleted file mode 100644
index 003abcc0..00000000
--- a/src/mirage/mirage.ml
+++ /dev/null
@@ -1,254 +0,0 @@
-module Dream = Dream__pure.Inmost
-
-open Rresult
-open Lwt.Infix
-
-let to_dream_method meth = Httpaf.Method.to_string meth |> Dream.string_to_method
-let to_httpaf_status status = Dream.status_to_int status |> Httpaf.Status.of_code
-let to_h2_status status = Dream.status_to_int status |> H2.Status.of_code
-let sha1 str = Digestif.SHA1.(to_raw_string (digest_string str))
-let const x = fun _ -> x
-let ( >>? ) = Lwt_result.bind
-
-let wrap_handler_httpaf app _user's_error_handler user's_dream_handler =
-  let httpaf_request_handler = fun client reqd ->
-    let httpaf_request = Httpaf.Reqd.request reqd in
-    let method_ = to_dream_method httpaf_request.meth in
-    let target  = httpaf_request.target in
-    let version = (httpaf_request.version.major, httpaf_request.version.minor) in
-    let headers = Httpaf.Headers.to_list httpaf_request.headers in
-    let body    = Httpaf.Reqd.request_body reqd in
-
-    let read ~data ~close ~flush:_ ~ping:_ ~pong:_ =
-      Httpaf.Body.Reader.schedule_read
-        body
-        ~on_eof:(fun () -> close 1000)
-        ~on_read:(fun buffer ~off ~len -> data buffer off len true false)
-    in
-    let close _close =
-      Httpaf.Body.Reader.close body in
-    let body =
-      Dream__pure.Stream.read_only ~read ~close in
-
-    let request = Dream.request_from_http ~app ~client ~method_ ~target ~version ~headers body in
-
-    (* Call the user's handler. If it raises an exception or returns a promise
-       that rejects with an exception, pass the exception up to Httpaf. This
-       will cause it to call its (low-level) error handler with variand `Exn _.
-       A well-behaved Dream app should catch all of its own exceptions and
-       rejections in one of its top-level middlewares.
-
-       We don't try to log exceptions here because the behavior is not
-       customizable here. The handler itself is customizable (to catch all)
-       exceptions, and the error callback that gets leaked exceptions is also
-       customizable. *)
-    Lwt.async begin fun () ->
-      Lwt.catch begin fun () ->
-        (* Do the big call. *)
-        let%lwt response = user's_dream_handler request in
-
-        (* Extract the Dream response's headers. *)
-
-        (* This is the default function that translates the Dream response to an
-           http/af response and sends it. We pre-define the function, however,
-           because it is called from two places:
-
-           1. Upon a normal response, the function is called unconditionally.
-           2. Upon failure to establish a WebSocket, the function is called to
-              transmit the resulting error response. *)
-        let forward_response response =
-          let headers =
-            Httpaf.Headers.of_list (Dream.all_headers response) in
-
-          (* let version =
-            match Dream.version_override response with
-            | None -> None
-            | Some (major, minor) -> Some Httpaf.Version.{major; minor}
-          in *)
-          let status =
-            to_httpaf_status (Dream.status response) in
-          (* let reason =
-            Dream.reason_override response in *)
-
-          let httpaf_response =
-            Httpaf.Response.create ~headers status in
-          let body =
-            Httpaf.Reqd.respond_with_streaming reqd httpaf_response in
-
-          Adapt.forward_body response body;
-
-          Lwt.return_unit
-        in
-
-        forward_response response
-      end
-      @@ fun exn ->
-        (* TODO LATER There was something in the fork changelogs about not
-           requiring report_exn. Is it relevant to this? *)
-        Httpaf.Reqd.report_exn reqd exn;
-        Lwt.return_unit
-    end
-  in
-
-  httpaf_request_handler
-
-let request_handler
-  : Dream.app -> Dream.error_handler -> Dream.handler -> string -> Alpn.reqd -> unit
-  = fun app
-      (user's_error_handler : Dream.error_handler)
-      (user's_dream_handler : Dream.handler) -> ();
-    fun client_address -> function
-    | Alpn.Reqd_HTTP_1_1 reqd -> wrap_handler_httpaf app user's_error_handler user's_dream_handler client_address reqd
-    | _ -> assert false
-
-let error_handler
-  : Dream.app -> Dream.error_handler -> string -> ?request:Alpn.request -> Alpn.server_error ->
-    (Alpn.headers -> Alpn.body) -> unit
-  = fun app
-      (user's_error_handler : Dream.error_handler) -> ();
-    fun client ?request error start_response ->
-  match request with
-  | Some (Alpn.Request_HTTP_1_1 request) ->
-    let start_response hdrs : Httpaf.Body.Writer.t = match start_response Alpn.(Headers_HTTP_1_1 hdrs) with
-      | Alpn.Body_HTTP_1_1 (Alpn.Wr, Alpn.Body_wr body) -> body
-      | _ -> Fmt.failwith "Impossible to respond with an h2 respond to an HTTP/1.1 client" in
-    Error_handler.httpaf app user's_error_handler client ?request:(Some request) error start_response
-  | _ -> assert false (* TODO *)
-
-module Make (Pclock : Mirage_clock.PCLOCK) (Time : Mirage_time.S) (Stack : Mirage_stack.V4V6) = struct
-  include Dream__pure.Stream
-  include Dream__pure.Inmost
-
-  include Dream__middleware.Log
-  include Dream__middleware.Log.Make (Pclock)
-  include Dream__middleware.Echo
-  
-  let default_log =
-    Dream__middleware.Log.sub_log (Logs.Src.name Logs.default)
-  
-  let error = default_log.error
-  let warning = default_log.warning
-  let info = default_log.info
-  let debug = default_log.debug
-  
-  include Dream__middleware.Router
-  
-  include Dream__middleware.Session
-  include Dream__middleware.Session.Make (Pclock)
-
-  include Dream__middleware.Origin_referrer_check
-  include Dream__middleware.Form
-  include Dream__middleware.Upload
-  include Dream__middleware.Csrf
-  
-  let content_length =
-    Dream__middleware.Content_length.content_length
-  
-  include Dream__middleware.Lowercase_headers
-  include Dream__middleware.Catch
-  include Dream__middleware.Request_id
-  include Dream__middleware.Site_prefix
-
-  let error_template =
-    Error_handler.customize
-
-  let random =
-    Dream__cipher.Random.random
-
-  include Dream__pure.Formats
-
-  let log =
-    Dream__middleware.Log.convenience_log
-
-  include Dream__middleware.Tag
-
-  let now () = Ptime.to_float_s (Ptime.v (Pclock.now_d_ps ()))
-
-  let form = form ~now
-  let multipart = multipart ~now
-  let csrf_token = csrf_token ~now
-  let verify_csrf_token = verify_csrf_token ~now
-  let form_tag = form_tag ~now
-  
-  include Dream__pure.Formats
-
-  include Paf_mirage.Make (Time) (Stack)
-
-  let alpn =
-    let module R = (val Mimic.repr tls_protocol) in
-    let alpn (_, flow) = match TLS.epoch flow with
-      | Ok { Tls.Core.alpn_protocol; _ } -> alpn_protocol
-      | Error _ -> None in
-    let peer ((ipaddr, port), _) = Fmt.str "%a:%d" Ipaddr.pp ipaddr port in
-    let injection (_, flow) = R.T flow in
-    { Alpn.alpn; peer; injection; }
-
-  let built_in_middleware =
-    Dream__pure.Inmost.pipeline [
-      Dream__middleware.Lowercase_headers.lowercase_headers;
-      Dream__middleware.Content_length.content_length;
-      Dream__middleware.Catch.catch_errors;
-      Dream__middleware.Request_id.assign_request_id;
-      Dream__middleware.Site_prefix.chop_site_prefix;
-    ]
-
-  let localhost_certificate =
-    let crts = Rresult.R.failwith_error_msg
-      (X509.Certificate.decode_pem_multiple (Cstruct.of_string Dream__localhost.certificate)) in
-    let key = Rresult.R.failwith_error_msg
-      (X509.Private_key.decode_pem (Cstruct.of_string Dream__localhost.key)) in
-    `Single (crts, key)
-
-  let https ?stop ~port ?(prefix= "") stack
-    ?(cfg= Tls.Config.server ~certificates:localhost_certificate ())
-    ?error_handler:(user's_error_handler : error_handler = Error_handler.default) (user's_dream_handler : handler) =
-    let prefix = prefix
-      |> Dream__pure.Formats.from_path
-      |> Dream__pure.Formats.drop_trailing_slash in
-    initialize ~setup_outputs:ignore ;    
-    let app = Dream__pure.Inmost.new_app (Error_handler.app user's_error_handler) prefix in
-    let accept t = accept t >>? fun flow ->
-      let edn = Stack.TCP.dst flow in
-      TLS.server_of_flow cfg flow >>= function
-      | Ok flow -> Lwt.return_ok (edn, flow)
-      | Error err -> Lwt.return (R.error_msgf "%a" TLS.pp_write_error err) in
-    let user's_dream_handler =
-      built_in_middleware user's_dream_handler in
-    let error_handler = error_handler app user's_error_handler in
-    let request_handler =
-      request_handler app user's_error_handler user's_dream_handler in
-    let service = Alpn.service alpn ~error_handler ~request_handler accept close in
-    init ~port stack >>= fun t ->
-    let `Initialized th = serve ?stop service t in th
-
-  let alpn protocol =
-    let protocol = match protocol with
-      | `H2 -> "h2"
-      | `HTTP_1_1 -> "http/1.1" in
-    let module R = (val Mimic.repr tcp_protocol) in
-    let alpn _ = Some protocol in
-    let peer ((ipaddr, port), _) = Fmt.str "%a:%d" Ipaddr.pp ipaddr port in
-    let injection (_, flow) = R.T flow in
-    { Alpn.alpn; peer; injection; }
-
-  let http ?stop ~port ?(prefix= "") ?(protocol= `HTTP_1_1) stack
-    ?error_handler:(user's_error_handler= Error_handler.default)
-    user's_dream_handler =
-    let prefix = prefix
-      |> Dream__pure.Formats.from_path
-      |> Dream__pure.Formats.drop_trailing_slash in
-    initialize ~setup_outputs:ignore ;
-    let app = Dream__pure.Inmost.new_app (Error_handler.app user's_error_handler) prefix in
-    let accept t = accept t >>? fun flow ->
-      let edn = Stack.TCP.dst flow in
-      Lwt.return_ok (edn, flow) in
-    let user's_dream_handler =
-      built_in_middleware user's_dream_handler in
-    let error_handler = error_handler app user's_error_handler in
-    let request_handler = request_handler app user's_error_handler user's_dream_handler in
-    let service = Alpn.service (alpn protocol) ~error_handler ~request_handler accept close in
-    init ~port stack >>= fun t ->
-    let `Initialized th = serve ?stop service t in th
-end
-
-include Dream
diff --git a/src/mirage/mirage.mli b/src/mirage/mirage.mli
deleted file mode 100644
index 658a6215..00000000
--- a/src/mirage/mirage.mli
+++ /dev/null
@@ -1,204 +0,0 @@
-type incoming
-type outgoing
-
-type 'a message
-
-type request = incoming message
-type response = outgoing message
-
-type handler = request -> response Lwt.t
-type middleware = handler -> handler
-
-module Make
-  (Pclock : Mirage_clock.PCLOCK)
-  (Time : Mirage_time.S)
-  (Stack : Mirage_stack.V4V6) : sig
-
-  type route
-
-  type method_ =
-    [ `GET
-    | `POST
-    | `PUT
-    | `DELETE
-    | `HEAD
-    | `CONNECT
-    | `OPTIONS
-    | `TRACE
-    | `PATCH
-    | `Method of string ]
-
-  type informational =
-    [ `Continue
-    | `Switching_Protocols ]
-  
-  type successful =
-    [ `OK
-    | `Created
-    | `Accepted
-    | `Non_Authoritative_Information
-    | `No_Content
-    | `Reset_Content
-    | `Partial_Content ]
-  
-  type redirection =
-    [ `Multiple_Choices
-    | `Moved_Permanently
-    | `Found
-    | `See_Other
-    | `Not_Modified
-    | `Temporary_Redirect
-    | `Permanent_Redirect ]
-  
-  type client_error =
-    [ `Bad_Request
-    | `Unauthorized
-    | `Payment_Required
-    | `Forbidden
-    | `Not_Found
-    | `Method_Not_Allowed
-    | `Not_Acceptable
-    | `Proxy_Authentication_Required
-    | `Request_Timeout
-    | `Conflict
-    | `Gone
-    | `Length_Required
-    | `Precondition_Failed
-    | `Payload_Too_Large
-    | `URI_Too_Long
-    | `Unsupported_Media_Type
-    | `Range_Not_Satisfiable
-    | `Expectation_Failed
-    | `Misdirected_Request
-    | `Too_Early
-    | `Upgrade_Required
-    | `Precondition_Required
-    | `Too_Many_Requests
-    | `Request_Header_Fields_Too_Large
-    | `Unavailable_For_Legal_Reasons ]
-  
-  type server_error =
-    [ `Internal_Server_Error
-    | `Not_Implemented
-    | `Bad_Gateway
-    | `Service_Unavailable
-    | `Gateway_Timeout
-    | `HTTP_Version_Not_Supported ]
-  
-  type standard_status =
-    [ informational
-    | successful
-    | redirection
-    | client_error
-    | server_error ]
-
-  type status =
-    [ standard_status
-    | `Status of int ]
-
-  val random : int -> string
-
-  val log : ('a, Format.formatter, unit, unit) format4 -> 'a
-
-  type ('a, 'b) conditional_log =
-    ((?request:request ->
-     ('a, Format.formatter, unit, 'b) format4 -> 'a) -> 'b) ->
-      unit
-
-  type log_level = [ `Error | `Warning | `Info | `Debug ]
-
-  val error     : ('a, unit) conditional_log
-  val warning   : ('a, unit) conditional_log
-  val info      : ('a, unit) conditional_log
-  (* val debug     : ('a, unit) conditional_log *)
-
-  val html : ?status:status -> ?code:int -> ?headers:(string * string) list -> string -> response Lwt.t
-
-  val param : string -> request -> string
-
-  type csrf_result =
-    [ `Ok
-    | `Expired of float
-    | `Wrong_session
-    | `Invalid ]
-
-  val csrf_token : ?valid_for:float -> request -> string
-  val verify_csrf_token : request -> string -> csrf_result Lwt.t
-
-  type 'a form_result =
-    [ `Ok            of 'a
-    | `Expired       of 'a * float
-    | `Wrong_session of 'a
-    | `Invalid_token of 'a
-    | `Missing_token of 'a
-    | `Many_tokens   of 'a
-    | `Wrong_content_type ]
-
-  type multipart_form =
-    (string * ((string option * string) list)) list
-
-  val form : ?csrf:bool -> request -> (string * string) list form_result Lwt.t
-  val multipart : ?csrf:bool -> request -> multipart_form form_result Lwt.t
-
-  val form_tag :
-    ?method_:method_ ->
-    ?target:string ->
-    ?enctype:[ `Multipart_form_data ] ->
-    ?csrf_token:bool ->
-      action:string -> request -> string
-
-  val lowercase_headers : middleware
-  val content_length : middleware
-
-  val logger : middleware
-  val router : route list -> middleware
-
-  val get : string -> handler -> route
-  val not_found : handler
-
-  type error =
-    { condition :
-        [ `Response of response
-        | `String of string
-        | `Exn of exn ]
-    ; layer :
-        [ `App
-        | `HTTP
-        | `HTTP2
-        | `TLS
-        | `WebSocket ]
-    ; caused_by :
-        [ `Server
-        | `Client ]
-    ; request : request option
-    ; response : response option
-    ; client : string option
-    ; severity : log_level
-    ; debug : bool
-    ; will_send_response : bool }
-
-  type error_handler = error -> response option Lwt.t
-
-  val error_template :
-    (string option -> response -> response Lwt.t) -> error_handler
-
-  val https :
-       ?stop:Lwt_switch.t
-    -> port:int
-    -> ?prefix:string
-    -> Stack.TCP.t
-    -> ?cfg:Tls.Config.server
-    -> ?error_handler:error_handler
-    -> handler
-    -> unit Lwt.t
-
-  val http :
-       ?stop:Lwt_switch.t
-    -> port:int
-    -> ?prefix:string
-    -> ?protocol:[ `H2 | `HTTP_1_1 ]
-    -> Stack.TCP.t
-    -> ?error_handler:error_handler
-    -> handler
-    -> unit Lwt.t
-end
diff --git a/src/pure/dune b/src/pure/dune
index 76415568..ef00d0e2 100644
--- a/src/pure/dune
+++ b/src/pure/dune
@@ -6,6 +6,7 @@
   bigstringaf
   hmap
   lwt
+  eio
   uri
   ptime
  )
diff --git a/src/pure/message.ml b/src/pure/message.ml
index 24debd91..a2c336cd 100644
--- a/src/pure/message.ml
+++ b/src/pure/message.ml
@@ -4,7 +4,6 @@
    Copyright 2021 Anton Bachin *)
 
 
-
 (* Type abbreviations and modules used in defining the primary types *)
 
 type 'a promise = 'a Lwt.t
@@ -54,7 +53,7 @@ type response = server message
 
 (* Functions of messages *)
 
-type handler = request -> response Lwt.t
+type handler = request -> response
 type middleware = handler -> handler
 
 
diff --git a/src/pure/message.mli b/src/pure/message.mli
index 330d1270..f1b28372 100644
--- a/src/pure/message.mli
+++ b/src/pure/message.mli
@@ -16,7 +16,7 @@ type request = client message
 type response = server message
 
 type 'a promise = 'a Lwt.t
-type handler = request -> response promise
+type handler = request -> response
 type middleware = handler -> handler
 
 
diff --git a/src/server/catch.ml b/src/server/catch.ml
index da550b78..a02d37aa 100644
--- a/src/server/catch.ml
+++ b/src/server/catch.ml
@@ -34,7 +34,7 @@ type error = {
   will_send_response : bool;
 }
 
-type error_handler = error -> Message.response option Message.promise
+type error_handler = error -> Message.response option
 
 (* This error handler actually *is* a middleware, but it is just one pathway for
    reaching the centralized error handler provided by the user, so it is built
@@ -43,12 +43,8 @@ type error_handler = error -> Message.response option Message.promise
 (* TODO The option return value thing is pretty awkward. *)
 let catch error_handler next_handler request =
 
-  Lwt.try_bind
-
-    (fun () ->
-      next_handler request)
-
-    (fun response ->
+  match next_handler request with
+  | response ->
       let status = Message.status response in
 
       (* TODO Overfull hbox. *)
@@ -74,13 +70,13 @@ let catch error_handler next_handler request =
         error_handler error
       end
       else
-        Lwt.return response)
+        response
 
     (* This exception handler is partially redundant, in that the HTTP-level
        handlers will also catch exceptions. However, this handler is able to
        capture more relevant context. We leave the HTTP-level handlers for truly
        severe protocol-level errors and integration mistakes. *)
-    (fun exn ->
+  | exception exn ->
       let error = {
         condition = `Exn exn;
         layer = `App;
@@ -92,4 +88,4 @@ let catch error_handler next_handler request =
         will_send_response = true;
       } in
 
-      error_handler error)
+      error_handler error
diff --git a/src/server/content_length.ml b/src/server/content_length.ml
index 4c411ea8..81568c65 100644
--- a/src/server/content_length.ml
+++ b/src/server/content_length.ml
@@ -18,7 +18,7 @@ let content_length next_handler request =
   if fst (Message.version request) <> 1 then
     next_handler request
   else
-    let%lwt (response : Message.response) = next_handler request in
+    let (response : Message.response) = next_handler request in
     if not (Message.has_header response "Transfer-Encoding") then
       Message.add_header response "Transfer-Encoding" "chunked";
-    Lwt.return response
+    response
diff --git a/src/server/dune b/src/server/dune
index 9afd04a3..6a15a7ae 100644
--- a/src/server/dune
+++ b/src/server/dune
@@ -16,6 +16,7 @@
   unstrctrd
   uri
   yojson
+  lwt_eio
  )
  (preprocess (pps lwt_ppx))
  (instrumentation (backend bisect_ppx)))
diff --git a/src/server/echo.ml b/src/server/echo.ml
index 093c652d..0a26c6c6 100644
--- a/src/server/echo.ml
+++ b/src/server/echo.ml
@@ -12,4 +12,3 @@ module Stream = Dream_pure.Stream
 
 let echo request =
   Message.response (Message.server_stream request) Stream.null
-  |> Lwt.return
diff --git a/src/server/flash.ml b/src/server/flash.ml
index 254c2567..6248e106 100644
--- a/src/server/flash.ml
+++ b/src/server/flash.ml
@@ -77,7 +77,7 @@ let flash_messages inner_handler request =
   let outbox = ref [] in
   Message.set_field request storage_field outbox;
   let existing = Cookie.cookie request flash_cookie in
-  let%lwt response = inner_handler request in
+  let response = inner_handler request in
   let entries = List.rev !outbox in
   let () =
     match existing, entries with
@@ -101,4 +101,4 @@ let flash_messages inner_handler request =
       Cookie.set_cookie
         response flash_cookie value request ~max_age:five_minutes
   in
-  Lwt.return response
+  response
diff --git a/src/server/helpers.ml b/src/server/helpers.ml
index dae6cfdd..19bbbaeb 100644
--- a/src/server/helpers.ml
+++ b/src/server/helpers.ml
@@ -4,6 +4,7 @@
    Copyright 2021 Anton Bachin *)
 
 
+open Eio.Std
 
 module Formats = Dream_pure.Formats
 module Message = Dream_pure.Message
@@ -46,10 +47,17 @@ let set_https request https =
 
 
 
-let request ~client ~method_ ~target ~https ~version ~headers server_stream =
+let switch_field =
+  Message.new_field
+    ~name:"dream.switch"
+    ~show_value:(Fmt.to_to_string Switch.dump)
+    ()
+
+let request ~sw ~client ~method_ ~target ~https ~version ~headers server_stream =
   let request =
     Message.request
       ~method_ ~target ~version ~headers Stream.null server_stream in
+  Message.set_field request switch_field sw;
   set_client request client;
   set_https request https;
   request
@@ -64,20 +72,19 @@ let html ?status ?code ?headers body =
   let response =
     Message.response ?status ?code ?headers (Stream.string body) Stream.null in
   Message.set_header response "Content-Type" Formats.text_html;
-  Lwt.return response
+  response
 
 let json ?status ?code ?headers body =
   let response =
     Message.response ?status ?code ?headers (Stream.string body) Stream.null in
   Message.set_header response "Content-Type" Formats.application_json;
-  Lwt.return response
+  response
 
 let response_with_body ?status ?code ?headers body =
   Message.response ?status ?code ?headers (Stream.string body) Stream.null
 
 let respond ?status ?code ?headers body =
   Message.response ?status ?code ?headers (Stream.string body) Stream.null
-  |> Lwt.return
 
 (* TODO Actually use the request and extract the site prefix. *)
 let redirect ?status ?code ?headers _request location =
@@ -90,9 +97,15 @@ let redirect ?status ?code ?headers _request location =
   let response =
     Message.response ?status ?code ?headers Stream.empty Stream.null in
   Message.set_header response "Location" location;
-  Lwt.return response
+  response
+
+let get_switch request =
+  match Message.field request switch_field with
+  | Some sw -> sw
+  | None -> failwith "Missing switch field on request!"
 
-let stream ?status ?code ?headers callback =
+let stream ?status ?code ?headers request callback =
+  let sw = get_switch request in
   let reader, writer = Stream.pipe () in
   let client_stream = Stream.stream reader Stream.no_writer
   and server_stream = Stream.stream Stream.no_reader writer in
@@ -100,9 +113,9 @@ let stream ?status ?code ?headers callback =
     Message.response ?status ?code ?headers client_stream server_stream in
   (* TODO Should set up an error handler for this. YES. *)
   (* TODO Make sure the request id is propagated to the callback. *)
-  let wrapped_callback _ = Lwt.async (fun () -> callback response) in
+  let wrapped_callback _ = Fiber.fork ~sw (fun () -> callback response) in
   Stream.ready server_stream ~close:wrapped_callback wrapped_callback;
-  Lwt.return response
+  response
 
 let websocket_field =
   Message.new_field
@@ -116,7 +129,8 @@ let is_websocket response =
   | _ -> false
 
 (* TODO Mark the request as a WebSocket request for HTTP. *)
-let websocket ?headers callback =
+let websocket ?headers request callback =
+  let sw = get_switch request in
   let in_reader, in_writer = Stream.pipe ()
   and out_reader, out_writer = Stream.pipe () in
   let client_stream = Stream.stream out_reader in_writer
@@ -126,9 +140,9 @@ let websocket ?headers callback =
       ~status:`Switching_Protocols ?headers client_stream server_stream in
   Message.set_field response websocket_field true;
   (* TODO Make sure the request id is propagated to the callback. *)
-  let wrapped_callback _ = Lwt.async (fun () -> callback response) in
+  let wrapped_callback _ = Fiber.fork ~sw (fun () -> callback response) in
   Stream.ready server_stream ~close:wrapped_callback wrapped_callback;
-  Lwt.return response
+  response
 
 let empty ?headers status =
   respond ?headers ~status ""
diff --git a/src/server/log.ml b/src/server/log.ml
index f2a664f2..bd4064e6 100644
--- a/src/server/log.ml
+++ b/src/server/log.ml
@@ -493,11 +493,8 @@ struct
         user_agent);
 
     (* Call the rest of the app. *)
-    Lwt.try_bind
-      (fun () ->
-        Lwt.with_value id_lwt_key (Some id) (fun () ->
-          next_handler request))
-      (fun response ->
+    match Lwt.with_value id_lwt_key (Some id) (fun () -> next_handler request) with
+    | response ->
         (* Log the elapsed time. If the response is a redirection, log the
            target. *)
         let location =
@@ -531,21 +528,20 @@ struct
               log.info report
         end;
 
-        Lwt.return response)
-
-      (fun exn ->
-        let backtrace = Printexc.get_backtrace () in
-        (* In case of exception, log the exception. We alsp log the backtrace
-           here, even though it is likely to be redundant, because some OCaml
-           libraries install exception printers that will clobber the backtrace
-           right during Printexc.to_string! *)
-        log.warning (fun log ->
+        response
+    | exception exn ->
+      let backtrace = Printexc.get_backtrace () in
+      (* In case of exception, log the exception. We alsp log the backtrace
+         here, even though it is likely to be redundant, because some OCaml
+         libraries install exception printers that will clobber the backtrace
+         right during Printexc.to_string! *)
+      log.warning (fun log ->
           log ~request "Aborted by: %s" (Printexc.to_string exn));
 
-        backtrace
-        |> iter_backtrace (fun line -> log.warning (fun log -> log "%s" line));
+      backtrace
+      |> iter_backtrace (fun line -> log.warning (fun log -> log "%s" line));
 
-        Lwt.fail exn)
+      raise exn
 end
 
 
diff --git a/src/server/lowercase_headers.ml b/src/server/lowercase_headers.ml
index b3ff584f..fec6dced 100644
--- a/src/server/lowercase_headers.ml
+++ b/src/server/lowercase_headers.ml
@@ -15,9 +15,9 @@ module Message = Dream_pure.Message
 (* TODO This can be optimized not to convert a header if it is already
    lowercase. Another option is to use memoization to reduce GC pressure. *)
 let lowercase_headers inner_handler request =
-  let%lwt response = inner_handler request in
+  let response = inner_handler request in
   if fst (Message.version request) <> 1 then
     Message.all_headers response
     |> List.map (fun (name, value) -> String.lowercase_ascii name, value)
     |> Message.set_all_headers response;
-  Lwt.return response
+  response
diff --git a/src/server/origin_referrer_check.ml b/src/server/origin_referrer_check.ml
index beb9fd55..9306a612 100644
--- a/src/server/origin_referrer_check.ml
+++ b/src/server/origin_referrer_check.ml
@@ -32,7 +32,6 @@ let origin_referrer_check inner_handler request =
       log.warning (fun log -> log ~request
         "Origin and Referer headers both missing");
       Message.response ~status:`Bad_Request Stream.empty Stream.null
-      |> Lwt.return
 
     (* TODO Also recommend Uri to users. *)
     | Some origin ->
@@ -41,7 +40,6 @@ let origin_referrer_check inner_handler request =
       | None ->
         log.warning (fun log -> log ~request "Host header missing");
         Message.response ~status:`Bad_Request Stream.empty Stream.null
-        |> Lwt.return
 
       | Some host ->
 
@@ -76,5 +74,4 @@ let origin_referrer_check inner_handler request =
           log.warning (fun log -> log ~request
             "Origin-Host mismatch: '%s' vs. '%s'" origin host);
           Message.response ~status:`Bad_Request Stream.empty Stream.null
-          |> Lwt.return
         end
diff --git a/src/server/session.ml b/src/server/session.ml
index 45289987..19084f35 100644
--- a/src/server/session.ml
+++ b/src/server/session.ml
@@ -20,10 +20,10 @@ type 'a back_end = {
 }
 
 let middleware field back_end = fun inner_handler request ->
-  let%lwt session = back_end.load request in
+  let session = Lwt_eio.Promise.await_lwt (back_end.load request) in
   Message.set_field request field session;
-  let%lwt response = inner_handler request in
-  back_end.send session request response
+  let response = inner_handler request in
+  Lwt_eio.Promise.await_lwt (back_end.send session request response)
 
 let getter field request =
   match Message.field request field with
@@ -56,8 +56,8 @@ type session = {
 }
 
 type operations = {
-  put : string -> string -> unit Lwt.t;
-  invalidate : unit -> unit Lwt.t;
+  put : string -> string -> unit;
+  invalidate : unit -> unit;
   mutable dirty : bool;
 }
 
@@ -124,14 +124,12 @@ struct
     session.payload
     |> List.remove_assoc name
     |> fun dictionary -> (name, value)::dictionary
-    |> fun dictionary -> session.payload <- dictionary;
-    Lwt.return_unit
+    |> fun dictionary -> session.payload <- dictionary
 
   let invalidate hash_table ~now lifetime operations session =
     Hashtbl.remove hash_table !session.id;
     session := create hash_table (now () +. lifetime);
-    operations.dirty <- true;
-    Lwt.return_unit
+    operations.dirty <- true
 
   let operations ~now hash_table lifetime session dirty =
     let rec operations = {
@@ -213,13 +211,11 @@ struct
     |> List.remove_assoc name
     |> fun dictionary -> (name, value)::dictionary
     |> fun dictionary -> session.payload <- dictionary;
-    operations.dirty <- true;
-    Lwt.return_unit
+    operations.dirty <- true
 
   let invalidate ~now lifetime operations session =
     session := create (now () +. lifetime);
-    operations.dirty <- true;
-    Lwt.return_unit
+    operations.dirty <- true
 
   let operations ~now lifetime session dirty =
     let rec operations = {
diff --git a/src/server/site_prefix.ml b/src/server/site_prefix.ml
index 6a41d2f6..e425d028 100644
--- a/src/server/site_prefix.ml
+++ b/src/server/site_prefix.ml
@@ -36,7 +36,6 @@ let with_site_prefix prefix =
     match match_site_prefix prefix (Router.path request) with
     | None ->
       Message.response ~status:`Bad_Gateway Stream.empty Stream.null
-      |> Lwt.return
     | Some path ->
       (* TODO This doesn't need to be recomputed on each request - can cache the
          result in the app. *)
diff --git a/src/sql/session.ml b/src/sql/session.ml
index 57b44929..ab070a3c 100644
--- a/src/sql/session.ml
+++ b/src/sql/session.ml
@@ -119,15 +119,19 @@ let put request (session : Session.session) name value =
   |> List.remove_assoc name
   |> fun dictionary -> (name, value)::dictionary
   |> fun dictionary -> session.payload <- dictionary;
-  Sql.sql request (fun db -> update db session)
+  Lwt_eio.Promise.await_lwt begin
+    Sql.sql request (fun db -> update db session)
+  end
 
 let invalidate request lifetime operations (session : Session.session ref) =
-  Sql.sql request begin fun db ->
-    let%lwt () = remove db !session.id in
-    let%lwt new_session = create db (Unix.gettimeofday () +. lifetime) 1 in
-    session := new_session;
-    operations.Session.dirty <- true;
-    Lwt.return_unit
+  Lwt_eio.Promise.await_lwt begin
+    Sql.sql request begin fun db ->
+      let%lwt () = remove db !session.id in
+      let%lwt new_session = create db (Unix.gettimeofday () +. lifetime) 1 in
+      session := new_session;
+      operations.Session.dirty <- true;
+      Lwt.return_unit
+    end
   end
 
 let operations request lifetime (session : Session.session ref) dirty =
diff --git a/src/unix/static.ml b/src/unix/static.ml
index c3c0470c..06e8764a 100644
--- a/src/unix/static.ml
+++ b/src/unix/static.ml
@@ -28,16 +28,16 @@ let mime_lookup filename =
 
 let from_filesystem local_root path _ =
   let file = Filename.concat local_root path in
-  Lwt.catch
-    (fun () ->
+  try
+    Lwt_eio.Promise.await_lwt (
       Lwt_io.(with_file ~mode:Input file) (fun channel ->
-        let%lwt content = Lwt_io.read channel in
-        Message.response
-          ~headers:(mime_lookup path) (Stream.string content) Stream.null
-        |> Lwt.return))
-    (fun _exn ->
-      Message.response ~status:`Not_Found Stream.empty Stream.null
-      |> Lwt.return)
+          let%lwt content = Lwt_io.read channel in
+          Message.response
+            ~headers:(mime_lookup path) (Stream.string content) Stream.null
+          |> Lwt.return)
+    )
+  with _exn ->
+    Message.response ~status:`Not_Found Stream.empty Stream.null
 
 (* TODO Add ETag handling. *)
 (* TODO Add Content-Length handling? *)
@@ -76,16 +76,14 @@ let static ?(loader = from_filesystem) local_root = fun request ->
 
   if not @@ Method.methods_equal (Message.method_ request) `GET then
     Message.response ~status:`Not_Found Stream.empty Stream.null
-    |> Lwt.return
 
   else
     match validate_path request with
     | None ->
       Message.response ~status:`Not_Found Stream.empty Stream.null
-      |> Lwt.return
 
     | Some path ->
-      let%lwt response = loader local_root path request in
+      let response = loader local_root path request in
       if not (Message.has_header response "Content-Type") then begin
         match Message.status response with
         | `OK
@@ -97,4 +95,4 @@ let static ?(loader = from_filesystem) local_root = fun request ->
         | _ ->
           ()
       end;
-      Lwt.return response
+      response
diff --git a/src/vendor/dune b/src/vendor/dune
index ac440a8b..1feae9e3 100644
--- a/src/vendor/dune
+++ b/src/vendor/dune
@@ -1,39 +1,6 @@
 (data_only_dirs *)
 
 
-
-(subdir paf/lib
- (library
-  (name paf)
-  (public_name dream-mirage.paf)
-  (modules paf)
-  (libraries faraday bigstringaf ke mimic)))
-
-(subdir paf/lib
- (library
-  (name alpn)
-  (public_name dream-mirage.paf.alpn)
-  (modules alpn)
-  (libraries dream-mirage.paf dream-httpaf.httpaf dream-httpaf.h2)))
-
-(subdir paf/lib
- (library
-  (name paf_mirage)
-  (public_name dream-mirage.paf.mirage)
-  (modules paf_mirage)
-  (libraries dream-mirage.paf tls-mirage mirage-time mirage-stack dream-mirage.paf.alpn)))
-
-(subdir paf/lib
- (library
-  (name le)
-  (wrapped false)
-  (public_name dream-mirage.paf.le)
-  (modules lE)
-  (libraries dream-httpaf.httpaf dream-mirage.paf mirage-time mirage-stack duration tls-mirage emile
-    letsencrypt)))
-
-
-
 (subdir gluten/lib
  (library
   (name gluten)
@@ -61,7 +28,7 @@
    (select
     ssl_io.ml
     from
-    (lwt_ssl -> ssl_io.real.ml)
+    (lwt_ssl_disabled -> ssl_io.real.ml)
     (-> ssl_io.dummy.ml))
    (select
     tls_io.ml
diff --git a/test/expect/pure/stream/dune b/test/expect/pure/stream/dune
deleted file mode 100644
index b012b025..00000000
--- a/test/expect/pure/stream/dune
+++ /dev/null
@@ -1,5 +0,0 @@
-(library
- (name test_expect_pure_stream)
- (libraries test_expect_pure)
- (inline_tests)
- (preprocess (pps lwt_ppx ppx_expect)))
diff --git a/test/expect/pure/stream/stream.ml b/test/expect/pure/stream/stream.ml
deleted file mode 100644
index 90a89410..00000000
--- a/test/expect/pure/stream/stream.ml
+++ /dev/null
@@ -1,298 +0,0 @@
-(* This file is part of Dream, released under the MIT license. See LICENSE.md
-   for details, or visit https://github.com/aantron/dream.
-
-   Copyright 2021 Anton Bachin *)
-
-
-
-module Stream = Dream_pure.Stream
-
-
-
-let read_and_dump stream =
-  Stream.read stream
-    ~data:(fun buffer offset length binary fin ->
-      Printf.printf "read: data: BINARY=%b FIN=%b %s\n"
-        binary fin (Bigstringaf.substring buffer ~off:offset ~len:length))
-    ~close:(fun code ->
-      Printf.printf "read: close: CODE=%i\n" code)
-    ~flush:(fun () ->
-      print_endline "read: flush")
-    ~ping:(fun buffer offset length ->
-      Printf.printf "read: ping: %s\n"
-        (Bigstringaf.substring buffer ~off:offset ~len:length))
-    ~pong:(fun buffer offset length ->
-      Printf.printf "read: pong: %s\n"
-        (Bigstringaf.substring buffer ~off:offset ~len:length))
-
-let flush_and_dump stream =
-  Stream.flush stream
-    ~close:(fun code ->
-      Printf.printf "flush: close: CODE=%i\n" code)
-    (fun () ->
-      print_endline "flush: ok")
-
-let write_and_dump stream buffer offset length binary fin =
-  Stream.write stream buffer offset length binary fin
-    ~close:(fun code ->
-      Printf.printf "write: close: CODE=%i\n" code)
-    (fun () ->
-      print_endline "write: ok")
-
-let ping_and_dump payload stream =
-  let length = String.length payload in
-  Stream.ping stream (Bigstringaf.of_string ~off:0 ~len:length payload) 0 length
-    ~close:(fun code ->
-      Printf.printf "ping: close: CODE=%i\n" code)
-    (fun () ->
-      print_endline "ping: ok")
-
-let pong_and_dump payload stream =
-  let length = String.length payload in
-  Stream.pong stream (Bigstringaf.of_string ~off:0 ~len:length payload) 0 length
-    ~close:(fun code ->
-      Printf.printf "pong: close: CODE=%i\n" code)
-    (fun () ->
-      print_endline "pong: ok")
-
-
-
-(* Read-only streams. *)
-
-let%expect_test _ =
-  let stream = Stream.(stream empty no_writer) in
-  read_and_dump stream;
-  read_and_dump stream;
-  Stream.close stream 1005;
-  read_and_dump stream;
-  [%expect {|
-    read: close: CODE=1000
-    read: close: CODE=1000
-    read: close: CODE=1000 |}]
-
-let%expect_test _ =
-  let stream = Stream.(stream empty no_writer) in
-  Stream.close stream 1005;
-  read_and_dump stream;
-  [%expect {| read: close: CODE=1000 |}]
-
-let%expect_test _ =
-  let stream = Stream.(stream (string "foo") no_writer) in
-  read_and_dump stream;
-  read_and_dump stream;
-  read_and_dump stream;
-  Stream.close stream 1005;
-  read_and_dump stream;
-  [%expect {|
-    read: data: BINARY=true FIN=true foo
-    read: close: CODE=1000
-    read: close: CODE=1000
-    read: close: CODE=1000 |}]
-
-let%expect_test _ =
-  let stream = Stream.(stream (string "") no_writer) in
-  read_and_dump stream;
-  read_and_dump stream;
-  [%expect {|
-    read: close: CODE=1000
-    read: close: CODE=1000 |}]
-
-let%expect_test _ =
-  let stream = Stream.(stream (string "foo") no_writer) in
-  Stream.close stream 1005;
-  read_and_dump stream;
-  [%expect {| read: close: CODE=1000 |}]
-
-let%expect_test _ =
-  let stream = Stream.(stream empty no_writer) in
-  (try write_and_dump stream Bigstringaf.empty 0 0 false false
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  (try flush_and_dump stream
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  (try ping_and_dump "foo" stream
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  (try pong_and_dump "bar" stream
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  [%expect {|
-    (Failure "write to a read-only stream")
-    (Failure "flush of a read-only stream")
-    (Failure "ping on a read-only stream")
-    (Failure "pong on a read-only stream") |}]
-
-
-
-(* Pipe: double read. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  read_and_dump stream;
-  try read_and_dump stream
-  with Failure _ as exn -> print_endline (Printexc.to_string exn);
-  [%expect {| (Failure "stream read: the previous read has not completed") |}]
-
-
-
-(* Pipe: interactions between read and close. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  read_and_dump stream;
-  print_endline "checkpoint 1";
-  Stream.close stream 1005;
-  print_endline "checkpoint 2";
-  read_and_dump stream;
-  print_endline "checkpoint 3";
-  Stream.close stream 1000;
-  [%expect {|
-    checkpoint 1
-    read: close: CODE=1005
-    checkpoint 2
-    read: close: CODE=1005
-    checkpoint 3 |}]
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  Stream.close stream 1005;
-  read_and_dump stream;
-  read_and_dump stream;
-  [%expect {|
-    read: close: CODE=1005
-    read: close: CODE=1005 |}]
-
-
-
-(* Pipe: interactions between read and flush. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  read_and_dump stream;
-  print_endline "checkpoint 1";
-  flush_and_dump stream;
-  (try flush_and_dump stream
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  read_and_dump stream;
-  flush_and_dump stream;
-  [%expect {|
-    checkpoint 1
-    read: flush
-    (Failure "stream flush: the previous write has not completed")
-    flush: ok
-    read: flush |}]
-
-
-
-(* Pipe: interactions between read and write. *)
-
-let buffer =
-  Bigstringaf.of_string ~off:0 ~len:3 "foo"
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  read_and_dump stream;
-  print_endline "checkpoint 1";
-  write_and_dump stream buffer 0 3 false true;
-  (try write_and_dump stream buffer 1 1 true false
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  read_and_dump stream;
-  write_and_dump stream buffer 0 3 true true;
-  [%expect {|
-    checkpoint 1
-    read: data: BINARY=false FIN=true foo
-    (Failure "stream write: the stream is not ready")
-    write: ok
-    read: data: BINARY=true FIN=true foo |}]
-
-
-
-(* Pipe: interactions between read and ping. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  read_and_dump stream;
-  print_endline "checkpoint 1";
-  ping_and_dump "foo" stream;
-  (try ping_and_dump "bar" stream
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  read_and_dump stream;
-  ping_and_dump "baz" stream;
-  [%expect {|
-    checkpoint 1
-    read: ping: foo
-    (Failure "stream ping: the previous write has not completed")
-    ping: ok
-    read: ping: baz |}]
-
-
-
-(* Pipe: interactions between read and pong. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  read_and_dump stream;
-  print_endline "checkpoint 1";
-  pong_and_dump "foo" stream;
-  (try pong_and_dump "bar" stream
-  with Failure _ as exn -> print_endline (Printexc.to_string exn));
-  read_and_dump stream;
-  pong_and_dump "baz" stream;
-  [%expect {|
-    checkpoint 1
-    read: pong: foo
-    (Failure "stream pong: the previous write has not completed")
-    pong: ok
-    read: pong: baz |}]
-
-
-
-(* Pipe: interactions between flush and close. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  Stream.close stream 1005;
-  flush_and_dump stream;
-  [%expect {|
-    flush: close: CODE=1005 |}]
-
-
-
-(* Pipe: interactions between write and close. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  Stream.close stream 1005;
-  write_and_dump stream buffer 0 3 true false;
-  [%expect {|
-    write: close: CODE=1005 |}]
-
-
-
-(* Pipe: interactions between ping and close. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  Stream.close stream 1005;
-  ping_and_dump "bar" stream;
-  [%expect {|
-    ping: close: CODE=1005 |}]
-
-
-
-(* Pipe: interactions between pong and close. *)
-
-let%expect_test _ =
-  let reader, writer = Stream.pipe () in
-  let stream = Stream.stream reader writer in
-  Stream.close stream 1005;
-  pong_and_dump "bar" stream;
-  [%expect {|
-    pong: close: CODE=1005 |}]