diff --git a/DESCRIPTION b/DESCRIPTION
index c280b7b..58e425a 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,14 +1,14 @@
 Package: tower
-Title: Easy Middle Ware Library for Shiny
+Title: Easy Middle Ware Library for 'shiny'
 Version: 0.1.0
 Authors@R: 
     c(person(given = "ixpantia, SRL",
              role = "cph",
              email = "hola@ixpantia.com"),
       person("Andres", "Quintero", , "andres@ixpantia.com", role = c("aut", "cre")))
-Description: The best way to implement middle ware for Shiny Applications. Tower
-    is designed to make implementing behavior on top of Shiny easy with a layering
-    model for incoming HTTP requests and server sessions. Tower is a very minimal
+Description: The best way to implement middle ware for 'shiny' Applications. 'tower'
+    is designed to make implementing behavior on top of 'shiny' easy with a layering
+    model for incoming HTTP requests and server sessions. 'tower' is a very minimal
     package with little overhead, it is mainly meant for other package developers
     to implement new behavior.
 License: MIT + file LICENSE
@@ -16,9 +16,13 @@ Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.2.3
 Imports:
-    compiler
+    compiler,
+    glue,
+    purrr,
+    stringr,
+    curl,
+    jsonlite
 Suggests: 
     testthat (>= 3.0.0),
-    shiny,
-    stringr
+    shiny
 Config/testthat/edition: 3
diff --git a/NAMESPACE b/NAMESPACE
index 5d8ae4b..61b6619 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,8 +1,27 @@
 # Generated by roxygen2: do not edit by hand
 
 S3method(print,tower)
+export(add_body)
+export(add_body_json)
+export(add_cookie)
+export(add_delete_route)
+export(add_get_route)
 export(add_http_layer)
+export(add_patch_route)
+export(add_post_route)
+export(add_put_route)
+export(add_route)
 export(add_server_layer)
 export(app_into_parts)
+export(build_http_cookie)
+export(build_response)
 export(build_tower)
 export(create_tower)
+export(req_body_form)
+export(req_body_json)
+export(req_cookies)
+export(req_query)
+export(response_builder)
+export(set_content_type)
+export(set_header)
+export(set_status)
diff --git a/R/http_helpers.R b/R/http_helpers.R
new file mode 100644
index 0000000..48bc9d3
--- /dev/null
+++ b/R/http_helpers.R
@@ -0,0 +1,203 @@
+#' @title Add an HTTP layer to a tower
+#' @description Adds an HTTP layer to a tower
+#' @param tower A tower object
+#' @param method A string containing the HTTP method to match
+#' @param path A string containing the path to match
+#' @param handler A function to call when the layer is matched
+#' @return A tower object with the layer added
+#' @export
+add_route <- function(tower, method = "GET", path, handler) {
+  handler <- compiler::cmpfun(handler)
+  route_handler <- compiler::cmpfun(function(req) {
+    if (req$REQUEST_METHOD == method && req$PATH_INFO == path) {
+      handler(req)
+    }
+  })
+  return(add_http_layer(tower, route_handler))
+}
+
+#' @title Add a GET route
+#' @description Adds a GET route to a tower
+#' @param tower A tower object
+#' @param path A string containing the path to match
+#' @param handler A function to call when the route is matched
+#' @return A tower object with the route added
+#' @export
+add_get_route <- function(tower, path, handler) {
+  add_route(tower, "GET", path, handler)
+}
+
+#' @title Add a POST route
+#' @description Adds a POST route to a tower
+#' @param tower A tower object
+#' @param path A string containing the path to match
+#' @param handler A function to call when the route is matched
+#' @return A tower object with the route added
+#' @export
+add_post_route <- function(tower, path, handler) {
+  add_route(tower, "POST", path, handler)
+}
+
+#' @title Add a PUT route
+#' @description Adds a PUT route to a tower
+#' @param tower A tower object
+#' @param path A string containing the path to match
+#' @param handler A function to call when the route is matched
+#' @return A tower object with the route added
+#' @export
+add_put_route <- function(tower, path, handler) {
+  add_route(tower, "PUT", path, handler)
+}
+
+#' @title Add a DELETE route
+#' @description Adds a DELETE route to a tower
+#' @param tower A tower object
+#' @param path A string containing the path to match
+#' @param handler A function to call when the route is matched
+#' @return A tower object with the route added
+#' @export
+add_delete_route <- function(tower, path, handler) {
+  add_route(tower, "DELETE", path, handler)
+}
+
+#' @title Add a PATCH route
+#' @description Adds a PATCH route to a tower
+#' @param tower A tower object
+#' @param path A string containing the path to match
+#' @param handler A function to call when the route is matched
+#' @return A tower object with the route added
+#' @export
+add_patch_route <- function(tower, path, handler) {
+  add_route(tower, "PATCH", path, handler)
+}
+
+#' @title Extract the request body from a JSON request
+#' @description Extracts the request body from a JSON request
+#' @param req A request object
+#' @param ... Additional arguments to pass to \code{\link[jsonlite]{fromJSON}}
+#'   when parsing the request body. This will only be used the first time the
+#'   request body is parsed. Subsequent calls will return the cached result.
+#' @return A list containing the request body
+#' @export
+req_body_json <- function(req, ...) {
+  if (!is.null(req[[".parsed.body.json"]])) {
+    return(req[[".parsed.body.json"]])
+  }
+  body <- tryCatch(
+    expr = jsonlite::fromJSON(
+      req$rook.input$read_lines(),
+      ...
+    ),
+    error = function(e) {
+      list()
+    }
+  )
+  req[[".parsed.body.json"]] <- body
+  return(body)
+}
+
+#' @title Extract form data from a request
+#' @description Extracts form data from a request
+#' @param req A request object
+#' @return A list containing the form data
+#' @export
+req_body_form <- function(req) {
+  if (!is.null(req[[".parsed.body.form"]])) {
+    return(req[[".parsed.body.form"]])
+  }
+  form <- tryCatch(
+    expr = shiny::parseQueryString(req[["rook.input"]]$read_lines()),
+    error = function(e) {
+      print(e)
+      list()
+    }
+  )
+  req[[".parsed.body.form"]] <- form
+  return(form)
+}
+
+#' @title Extract query parameters from a request
+#' @description Extracts query parameters from a request
+#' @param req A request object
+#' @return A list containing the query parameters
+#' @export
+req_query <- function(req) {
+  if (!is.null(req[[".parsed.query"]])) {
+    return(req[[".parsed.query"]])
+  }
+  query <- tryCatch(
+    expr = shiny::parseQueryString(req$QUERY_STRING),
+    error = function(e) {
+      list()
+    }
+  )
+  req[[".parsed.query"]] <- query
+  return(query)
+}
+
+#' @keywords internal
+split_cookie_pair <- function(.x) {
+  stringr::str_split(.x, "=", n = 2)
+}
+
+#' @keywords internal
+cookie_unescape <- function(.x) {
+  .x[2] <- curl::curl_unescape(.x[2])
+  stats::setNames(.x[2], .x[1])
+}
+
+#' @title Parse cookies
+#' @description Parses cookies from a string
+#'
+#' @param x A string containing the cookies
+#'
+#' @return A list containing the cookies
+#' @keywords internal
+parse_cookies <- function(x) {
+  if (is.null(x)) {
+    return(list())
+  }
+  cookie_pairs <- stringr::str_split(x, "; ")
+  cookie_pairs <- purrr::map(cookie_pairs, split_cookie_pair)[[1]]
+  cookie_pairs <- purrr::map(cookie_pairs, cookie_unescape)
+  cookie_pairs <- purrr::flatten(cookie_pairs)
+  return(cookie_pairs)
+}
+
+#' @keywords internal
+cookie_to_header <- function(.x, .y) {
+  list(
+    "Set-Cookie" = build_http_cookie(.y, .x)
+  )
+}
+
+#' @title Build a cookie
+#' @description Builds an HttpOnly cookie from a key and value
+#'
+#' @param key A string containing the cookie key
+#' @param value A string containing the cookie value
+#'
+#' @return A string containing the cookie
+#' @export
+build_http_cookie <- function(key, value) {
+  glue::glue("{key}={value}; path=/; SameSite=Lax; HttpOnly")
+}
+
+#' @title Extract cookies from a request
+#' @description Extracts cookies from a request
+#' @param req A request object
+#' @return A list containing the cookies
+#' @export
+req_cookies <- function(req) {
+  if (!is.null(req[[".parsed.cookies"]])) {
+    return(req[[".parsed.cookies"]])
+  }
+  cookies <- tryCatch(
+    expr = parse_cookies(req$HTTP_COOKIE),
+    error = function(e) {
+      list()
+    }
+  )
+  req[[".parsed.cookies"]] <- cookies
+  return(cookies)
+}
diff --git a/R/response_builder.R b/R/response_builder.R
new file mode 100644
index 0000000..b986ca0
--- /dev/null
+++ b/R/response_builder.R
@@ -0,0 +1,161 @@
+#' @title Create a response builder
+#' @description Creates a response builder
+#' @return A response builder object
+#' @export
+response_builder <- function() {
+  resp <- new.env(parent = emptyenv())
+  resp$status <- 200
+  resp$headers <- list()
+  resp$content_type <- NULL
+  resp$cookies <- list()
+  resp$body <- NULL
+  structure(
+    resp,
+    class = "response_builder"
+  )
+}
+
+#' @title Set a header on a response
+#' @description Sets or adds a header to a response
+#' @param res A response builder object
+#' @param name The name of the header
+#' @param value The value of the header
+#' @return The response builder object
+#' @export
+set_header <- function(res, name, value) {
+  res$headers[[name]] <- value
+  return(invisible(res))
+}
+
+#' @title Set the status of a response
+#' @description Sets the status of a response
+#' @param res A response builder object
+#' @param status The status to set
+#' @return The response builder object
+#' @export
+set_status <- function(res, status) {
+  res$status <- status
+  return(invisible(res))
+}
+
+#' @title Add a cookie to a response
+#' @description Adds a cookie to a response
+#' @param res A response builder object
+#' @param name The name of the cookie
+#' @param value The value of the cookie
+#' @return The response builder object
+#' @export
+add_cookie <- function(res, name, value) {
+  res$cookies[[name]] <- value
+  return(invisible(res))
+}
+
+#' @title Set the content type of a response
+#' @description Sets the content type of a response
+#' @param res A response builder object
+#' @param content_type The content type to set
+#' @return The response builder object
+#' @export
+set_content_type <- function(res, content_type) {
+  res$content_type <- content_type
+  return(invisible(res))
+}
+
+#' @keywords internal
+detect_content_type <- function(body) {
+  UseMethod("detect_content_type")
+}
+
+#' @keywords internal
+detect_content_type.default <- function(body) {
+  return("application/json")
+}
+
+#' @keywords internal
+detect_content_type.shiny.tag <- function(body) {
+  return("text/html")
+}
+
+#' @keywords internal
+detect_content_type.shiny.tag.list <- function(body) {
+  return("text/html")
+}
+
+#' @keywords internal
+detect_content_type.list <- function(body) {
+  return("application/json")
+}
+
+#' @keywords internal
+detect_content_type.raw <- function(body) {
+  return("application/octet-stream")
+}
+
+#' @keywords internal
+detect_content_type.character <- function(body) {
+  return("text/plain")
+}
+
+#' @keywords internal
+serialize_body <- function(body, content_type) {
+  switch(
+    content_type,
+    "text/html" = as.character(body),
+    "text/plain" = as.character(body),
+    "application/json" = as.character(jsonlite::toJSON(body)),
+    "application/octet-stream" = as.raw(body)
+  )
+}
+
+#' @title Add a body to a response
+#' @description Adds a body to a response, if no content type is set, it will be detected
+#' @param res A response builder object
+#' @param body The body to add
+#' @return The response builder object
+#' @export
+add_body <- function(res, body) {
+  if (is.null(res$content_type)) {
+    set_content_type(res, detect_content_type(body))
+  }
+  res$body <- body
+  return(invisible(res))
+}
+
+#' @title Add a body to a response as JSON
+#' @description Adds a body to a response as JSON
+#' @param res A response builder object
+#' @param body The body to add
+#' @return The response builder object
+#' @export
+add_body_json <- function(res, body) {
+  set_content_type(res, "application/json")
+  res$body <- body
+  return(invisible(res))
+}
+
+#' @title Build a response
+#' @description Builds a response
+#' @param res A response builder object
+#' @return A response object
+#' @export
+build_response <- function(res) {
+  content_type <- ifelse(
+    is.null(res$content_type),
+    "text/plain",
+    res$content_type
+  )
+  body <- serialize_body(res$body, content_type)
+  status <- res$status
+  headers <- res$headers
+  cookies <- res$cookies |>
+    purrr::imap(cookie_to_header) |>
+    purrr::flatten()
+  headers <- append(headers, cookies)
+
+  shiny::httpResponse(
+    status = status,
+    headers = headers,
+    content_type = content_type,
+    content = body
+  )
+}
diff --git a/R/service.R b/R/service.R
index efbce45..cc7a146 100644
--- a/R/service.R
+++ b/R/service.R
@@ -3,7 +3,7 @@ compiler_options <- list(optimize = 3L)
 
 #' @title Create a new tower
 #' @description Create a new tower to build upon.
-#' @param app A shiny app object
+#' @param app A 'shiny' app object
 #' @return A new tower
 #' @export
 create_tower <- function(app) {
@@ -31,7 +31,7 @@ print.tower <- function(x, ...) {
 
 #' @title Add an HTTP layer to a tower
 #' @description Add an HTTP layer to a tower. This layer
-#'   will be called before the Shiny app's httpHandler.
+#'   will be called before the 'shiny' app's httpHandler.
 #' @param tower A tower
 #' @param layer A function that takes a request and returns either
 #'   a response or NULL. NULL indicates that the layer did not
@@ -50,7 +50,7 @@ add_http_layer <- function(tower, layer) {
 
 #' @title Add a server layer to a tower
 #' @description Add a server layer to a tower. This layer
-#'   will run before the Shiny app's server function. This
+#'   will run before the 'shiny' app's server function. This
 #'   is useful for adding custom logic to the server function
 #'  without modifying the original server function.
 #' @param tower A tower
@@ -112,11 +112,11 @@ build_server <- function(tower) {
 
 }
 
-#' @title Build a Shiny app from a tower
-#' @description Build a Shiny app from a tower. This will create
-#'   a new Shiny app with the specified layers added.
+#' @title Build a 'shiny' app from a tower
+#' @description Build a 'shiny' app from a tower. This will create
+#'   a new 'shiny' app with the specified layers added.
 #' @param tower A tower
-#' @return A Shiny app object
+#' @return A 'shiny' app object that can be started
 #' @export
 build_tower <- function(tower) {
   app <- tower$app
diff --git a/README.md b/README.md
index 605dc38..b82aad0 100644
--- a/README.md
+++ b/README.md
@@ -37,34 +37,28 @@ library(shiny)
 library(tower)
 
 # Counter environment
-COUNTER <- new.env()
-COUNTER$counter <- 0
+global_counter <- new.env()
+global_counter$count <- 0
 
 # Middleware to increment the counter
 increment_counter <- function(req) {
-  if (req$PATH_INFO == "/increment") {
-    COUNTER$counter <- COUNTER$counter + 1
-    return(
-      httpResponse(
-        200,
-        "text/plain",
-        paste("Counter is now", COUNTER$counter)
-      )
-    )
-  }
+  global_counter$count <- global_counter$count + 1
+  response_builder() |>
+    add_body(paste("Counter is now", global_counter$count)) |>
+    build_response()
 }
 
-# A very empty Shiny app (not necessary for the demo)
+# A very empty Shiny app (not necesarry for the demo)
 ui <- fluidPage()
 server <- function(input, output, session) {}
 
 shinyApp(ui, server) |>
   create_tower() |>
-  add_http_layer(increment_counter) |>
+  add_get_route("/counter", increment_counter) |>
   build_tower()
 ```
 
-If you run the code above and visit the route `/increment` in your browser,
+If you run the code above and visit the route `/counter` in your browser,
 you will see the counter increment every time you visit the route.
 
 ## How it works
diff --git a/inst/examples/counter/app.R b/inst/examples/counter/app.R
index 8a801df..f088905 100644
--- a/inst/examples/counter/app.R
+++ b/inst/examples/counter/app.R
@@ -2,21 +2,15 @@ library(shiny)
 library(tower)
 
 # Counter environment
-COUNTER <- new.env()
-COUNTER$counter <- 0
+global_counter <- new.env()
+global_counter$count <- 0
 
 # Middleware to increment the counter
 increment_counter <- function(req) {
-  if (req$PATH_INFO == "/increment") {
-    COUNTER$counter <- COUNTER$counter + 1
-    return(
-      httpResponse(
-        200,
-        "text/plain",
-        paste("Counter is now", COUNTER$counter)
-      )
-    )
-  }
+  global_counter$count <- global_counter$count + 1
+  response_builder() |>
+    add_body(paste("Counter is now", global_counter$count)) |>
+    build_response()
 }
 
 # A very empty Shiny app (not necesarry for the demo)
@@ -25,5 +19,5 @@ server <- function(input, output, session) {}
 
 shinyApp(ui, server) |>
   create_tower() |>
-  add_http_layer(increment_counter) |>
+  add_get_route("/counter", increment_counter) |>
   build_tower()
diff --git a/inst/examples/json_api/app.R b/inst/examples/json_api/app.R
new file mode 100644
index 0000000..83e917a
--- /dev/null
+++ b/inst/examples/json_api/app.R
@@ -0,0 +1,45 @@
+library(tower)
+library(shiny)
+library(dplyr)
+
+filter_iris <- function(req) {
+  species <- req_query(req)$species
+  if (is.null(species)) {
+    return(
+      response_builder() |>
+        set_status(400) |>
+        add_body("species parameter is required") |>
+        build_response()
+    )
+  }
+  response_data <- iris |>
+    dplyr::filter(Species == species)
+  response_builder() |>
+    set_status(200) |>
+    add_body_json(response_data) |>
+    build_response()
+}
+
+ui <- fluidPage(
+  titlePanel("Iris data"),
+  sidebarLayout(
+    sidebarPanel(
+      selectInput("species", "Species", choices = unique(iris$Species))
+    ),
+    mainPanel(
+      tableOutput("table")
+    )
+  )
+)
+
+server <- function(input, output, session) {
+  output$table <- renderTable({
+    iris |>
+      dplyr::filter(Species == input$species)
+  })
+}
+
+shinyApp(ui, server) |>
+  create_tower() |>
+  add_get_route("/iris", filter_iris) |>
+  build_tower()
diff --git a/inst/examples/modify_req/app.R b/inst/examples/modify_req/app.R
new file mode 100644
index 0000000..f81134c
--- /dev/null
+++ b/inst/examples/modify_req/app.R
@@ -0,0 +1,22 @@
+library(shiny)
+library(tower)
+
+
+ui <- fluidPage()
+server <- function(input, output) { }
+
+shinyApp(ui, server) |>
+  create_tower() |>
+  add_http_layer(function(req) {
+    req$NEW_DATA <- "new data"
+    return(NULL)
+  }) |>
+  add_http_layer(function(req) {
+    req$NEW_DATA <- paste0(req$NEW_DATA, " and more data")
+    return(NULL)
+  }) |>
+  add_http_layer(function(req) {
+    print(req$NEW_DATA)
+    return(NULL)
+  }) |>
+  build_tower()
diff --git a/man/add_body.Rd b/man/add_body.Rd
new file mode 100644
index 0000000..7cc4bf5
--- /dev/null
+++ b/man/add_body.Rd
@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{add_body}
+\alias{add_body}
+\title{Add a body to a response}
+\usage{
+add_body(res, body)
+}
+\arguments{
+\item{res}{A response builder object}
+
+\item{body}{The body to add}
+}
+\value{
+The response builder object
+}
+\description{
+Adds a body to a response, if no content type is set, it will be detected
+}
diff --git a/man/add_body_json.Rd b/man/add_body_json.Rd
new file mode 100644
index 0000000..0c85a84
--- /dev/null
+++ b/man/add_body_json.Rd
@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{add_body_json}
+\alias{add_body_json}
+\title{Add a body to a response as JSON}
+\usage{
+add_body_json(res, body)
+}
+\arguments{
+\item{res}{A response builder object}
+
+\item{body}{The body to add}
+}
+\value{
+The response builder object
+}
+\description{
+Adds a body to a response as JSON
+}
diff --git a/man/add_cookie.Rd b/man/add_cookie.Rd
new file mode 100644
index 0000000..8d73f25
--- /dev/null
+++ b/man/add_cookie.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{add_cookie}
+\alias{add_cookie}
+\title{Add a cookie to a response}
+\usage{
+add_cookie(res, name, value)
+}
+\arguments{
+\item{res}{A response builder object}
+
+\item{name}{The name of the cookie}
+
+\item{value}{The value of the cookie}
+}
+\value{
+The response builder object
+}
+\description{
+Adds a cookie to a response
+}
diff --git a/man/add_delete_route.Rd b/man/add_delete_route.Rd
new file mode 100644
index 0000000..ae71fec
--- /dev/null
+++ b/man/add_delete_route.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{add_delete_route}
+\alias{add_delete_route}
+\title{Add a DELETE route}
+\usage{
+add_delete_route(tower, path, handler)
+}
+\arguments{
+\item{tower}{A tower object}
+
+\item{path}{A string containing the path to match}
+
+\item{handler}{A function to call when the route is matched}
+}
+\value{
+A tower object with the route added
+}
+\description{
+Adds a DELETE route to a tower
+}
diff --git a/man/add_get_route.Rd b/man/add_get_route.Rd
new file mode 100644
index 0000000..591cf30
--- /dev/null
+++ b/man/add_get_route.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{add_get_route}
+\alias{add_get_route}
+\title{Add a GET route}
+\usage{
+add_get_route(tower, path, handler)
+}
+\arguments{
+\item{tower}{A tower object}
+
+\item{path}{A string containing the path to match}
+
+\item{handler}{A function to call when the route is matched}
+}
+\value{
+A tower object with the route added
+}
+\description{
+Adds a GET route to a tower
+}
diff --git a/man/add_http_layer.Rd b/man/add_http_layer.Rd
index 8ac786f..6b67491 100644
--- a/man/add_http_layer.Rd
+++ b/man/add_http_layer.Rd
@@ -20,5 +20,5 @@ The tower with the layer added
 }
 \description{
 Add an HTTP layer to a tower. This layer
-will be called before the Shiny app's httpHandler.
+will be called before the 'shiny' app's httpHandler.
 }
diff --git a/man/add_patch_route.Rd b/man/add_patch_route.Rd
new file mode 100644
index 0000000..02ab140
--- /dev/null
+++ b/man/add_patch_route.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{add_patch_route}
+\alias{add_patch_route}
+\title{Add a PATCH route}
+\usage{
+add_patch_route(tower, path, handler)
+}
+\arguments{
+\item{tower}{A tower object}
+
+\item{path}{A string containing the path to match}
+
+\item{handler}{A function to call when the route is matched}
+}
+\value{
+A tower object with the route added
+}
+\description{
+Adds a PATCH route to a tower
+}
diff --git a/man/add_post_route.Rd b/man/add_post_route.Rd
new file mode 100644
index 0000000..7ef6354
--- /dev/null
+++ b/man/add_post_route.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{add_post_route}
+\alias{add_post_route}
+\title{Add a POST route}
+\usage{
+add_post_route(tower, path, handler)
+}
+\arguments{
+\item{tower}{A tower object}
+
+\item{path}{A string containing the path to match}
+
+\item{handler}{A function to call when the route is matched}
+}
+\value{
+A tower object with the route added
+}
+\description{
+Adds a POST route to a tower
+}
diff --git a/man/add_put_route.Rd b/man/add_put_route.Rd
new file mode 100644
index 0000000..e9115ce
--- /dev/null
+++ b/man/add_put_route.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{add_put_route}
+\alias{add_put_route}
+\title{Add a PUT route}
+\usage{
+add_put_route(tower, path, handler)
+}
+\arguments{
+\item{tower}{A tower object}
+
+\item{path}{A string containing the path to match}
+
+\item{handler}{A function to call when the route is matched}
+}
+\value{
+A tower object with the route added
+}
+\description{
+Adds a PUT route to a tower
+}
diff --git a/man/add_route.Rd b/man/add_route.Rd
new file mode 100644
index 0000000..c4e493f
--- /dev/null
+++ b/man/add_route.Rd
@@ -0,0 +1,23 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{add_route}
+\alias{add_route}
+\title{Add an HTTP layer to a tower}
+\usage{
+add_route(tower, method = "GET", path, handler)
+}
+\arguments{
+\item{tower}{A tower object}
+
+\item{method}{A string containing the HTTP method to match}
+
+\item{path}{A string containing the path to match}
+
+\item{handler}{A function to call when the layer is matched}
+}
+\value{
+A tower object with the layer added
+}
+\description{
+Adds an HTTP layer to a tower
+}
diff --git a/man/add_server_layer.Rd b/man/add_server_layer.Rd
index 9551845..0d1a056 100644
--- a/man/add_server_layer.Rd
+++ b/man/add_server_layer.Rd
@@ -19,7 +19,7 @@ The tower with the layer added
 }
 \description{
 Add a server layer to a tower. This layer
-will run before the Shiny app's server function. This
+will run before the 'shiny' app's server function. This
 is useful for adding custom logic to the server function
 without modifying the original server function.
 }
diff --git a/man/build_http_cookie.Rd b/man/build_http_cookie.Rd
new file mode 100644
index 0000000..fc31a06
--- /dev/null
+++ b/man/build_http_cookie.Rd
@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{build_http_cookie}
+\alias{build_http_cookie}
+\title{Build a cookie}
+\usage{
+build_http_cookie(key, value)
+}
+\arguments{
+\item{key}{A string containing the cookie key}
+
+\item{value}{A string containing the cookie value}
+}
+\value{
+A string containing the cookie
+}
+\description{
+Builds an HttpOnly cookie from a key and value
+}
diff --git a/man/build_response.Rd b/man/build_response.Rd
new file mode 100644
index 0000000..5a61f31
--- /dev/null
+++ b/man/build_response.Rd
@@ -0,0 +1,17 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{build_response}
+\alias{build_response}
+\title{Build a response}
+\usage{
+build_response(res)
+}
+\arguments{
+\item{res}{A response builder object}
+}
+\value{
+A response object
+}
+\description{
+Builds a response
+}
diff --git a/man/build_tower.Rd b/man/build_tower.Rd
index 493a4c8..10c0c9d 100644
--- a/man/build_tower.Rd
+++ b/man/build_tower.Rd
@@ -2,7 +2,7 @@
 % Please edit documentation in R/service.R
 \name{build_tower}
 \alias{build_tower}
-\title{Build a Shiny app from a tower}
+\title{Build a 'shiny' app from a tower}
 \usage{
 build_tower(tower)
 }
@@ -10,9 +10,9 @@ build_tower(tower)
 \item{tower}{A tower}
 }
 \value{
-A Shiny app object
+A 'shiny' app object that can be started
 }
 \description{
-Build a Shiny app from a tower. This will create
-a new Shiny app with the specified layers added.
+Build a 'shiny' app from a tower. This will create
+a new 'shiny' app with the specified layers added.
 }
diff --git a/man/create_tower.Rd b/man/create_tower.Rd
index 2e0acc0..a680bb9 100644
--- a/man/create_tower.Rd
+++ b/man/create_tower.Rd
@@ -7,7 +7,7 @@
 create_tower(app)
 }
 \arguments{
-\item{app}{A shiny app object}
+\item{app}{A 'shiny' app object}
 }
 \value{
 A new tower
diff --git a/man/parse_cookies.Rd b/man/parse_cookies.Rd
new file mode 100644
index 0000000..ea6df0f
--- /dev/null
+++ b/man/parse_cookies.Rd
@@ -0,0 +1,18 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{parse_cookies}
+\alias{parse_cookies}
+\title{Parse cookies}
+\usage{
+parse_cookies(x)
+}
+\arguments{
+\item{x}{A string containing the cookies}
+}
+\value{
+A list containing the cookies
+}
+\description{
+Parses cookies from a string
+}
+\keyword{internal}
diff --git a/man/req_body_form.Rd b/man/req_body_form.Rd
new file mode 100644
index 0000000..4046c92
--- /dev/null
+++ b/man/req_body_form.Rd
@@ -0,0 +1,17 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{req_body_form}
+\alias{req_body_form}
+\title{Extract form data from a request}
+\usage{
+req_body_form(req)
+}
+\arguments{
+\item{req}{A request object}
+}
+\value{
+A list containing the form data
+}
+\description{
+Extracts form data from a request
+}
diff --git a/man/req_body_json.Rd b/man/req_body_json.Rd
new file mode 100644
index 0000000..4986fd0
--- /dev/null
+++ b/man/req_body_json.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{req_body_json}
+\alias{req_body_json}
+\title{Extract the request body from a JSON request}
+\usage{
+req_body_json(req, ...)
+}
+\arguments{
+\item{req}{A request object}
+
+\item{...}{Additional arguments to pass to \code{\link[jsonlite]{fromJSON}}
+when parsing the request body. This will only be used the first time the
+request body is parsed. Subsequent calls will return the cached result.}
+}
+\value{
+A list containing the request body
+}
+\description{
+Extracts the request body from a JSON request
+}
diff --git a/man/req_cookies.Rd b/man/req_cookies.Rd
new file mode 100644
index 0000000..a95af05
--- /dev/null
+++ b/man/req_cookies.Rd
@@ -0,0 +1,17 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{req_cookies}
+\alias{req_cookies}
+\title{Extract cookies from a request}
+\usage{
+req_cookies(req)
+}
+\arguments{
+\item{req}{A request object}
+}
+\value{
+A list containing the cookies
+}
+\description{
+Extracts cookies from a request
+}
diff --git a/man/req_query.Rd b/man/req_query.Rd
new file mode 100644
index 0000000..03157bd
--- /dev/null
+++ b/man/req_query.Rd
@@ -0,0 +1,17 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/http_helpers.R
+\name{req_query}
+\alias{req_query}
+\title{Extract query parameters from a request}
+\usage{
+req_query(req)
+}
+\arguments{
+\item{req}{A request object}
+}
+\value{
+A list containing the query parameters
+}
+\description{
+Extracts query parameters from a request
+}
diff --git a/man/response_builder.Rd b/man/response_builder.Rd
new file mode 100644
index 0000000..193f78a
--- /dev/null
+++ b/man/response_builder.Rd
@@ -0,0 +1,14 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{response_builder}
+\alias{response_builder}
+\title{Create a response builder}
+\usage{
+response_builder()
+}
+\value{
+A response builder object
+}
+\description{
+Creates a response builder
+}
diff --git a/man/set_content_type.Rd b/man/set_content_type.Rd
new file mode 100644
index 0000000..66b0f71
--- /dev/null
+++ b/man/set_content_type.Rd
@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{set_content_type}
+\alias{set_content_type}
+\title{Set the content type of a response}
+\usage{
+set_content_type(res, content_type)
+}
+\arguments{
+\item{res}{A response builder object}
+
+\item{content_type}{The content type to set}
+}
+\value{
+The response builder object
+}
+\description{
+Sets the content type of a response
+}
diff --git a/man/set_header.Rd b/man/set_header.Rd
new file mode 100644
index 0000000..a088d54
--- /dev/null
+++ b/man/set_header.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{set_header}
+\alias{set_header}
+\title{Set a header on a response}
+\usage{
+set_header(res, name, value)
+}
+\arguments{
+\item{res}{A response builder object}
+
+\item{name}{The name of the header}
+
+\item{value}{The value of the header}
+}
+\value{
+The response builder object
+}
+\description{
+Sets or adds a header to a response
+}
diff --git a/man/set_status.Rd b/man/set_status.Rd
new file mode 100644
index 0000000..58955d7
--- /dev/null
+++ b/man/set_status.Rd
@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/response_builder.R
+\name{set_status}
+\alias{set_status}
+\title{Set the status of a response}
+\usage{
+set_status(res, status)
+}
+\arguments{
+\item{res}{A response builder object}
+
+\item{status}{The status to set}
+}
+\value{
+The response builder object
+}
+\description{
+Sets the status of a response
+}
diff --git a/tests/testthat/test-http_helpers.R b/tests/testthat/test-http_helpers.R
new file mode 100644
index 0000000..e9e971d
--- /dev/null
+++ b/tests/testthat/test-http_helpers.R
@@ -0,0 +1,430 @@
+test_that("can add an arbitraty route", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_route("GET", "/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "text/plain",
+        content = "Hello, world!"
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- list(
+    PATH_INFO = "/hello",
+    REQUEST_METHOD = "GET"
+  )
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can add a get route", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_get_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "text/plain",
+        content = "Hello, world!"
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- list(
+    PATH_INFO = "/hello",
+    REQUEST_METHOD = "GET"
+  )
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can add a post route", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_post_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "text/plain",
+        content = "Hello, world!"
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- list(
+    PATH_INFO = "/hello",
+    REQUEST_METHOD = "POST"
+  )
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can add a put route", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_put_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "text/plain",
+        content = "Hello, world!"
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- list(
+    PATH_INFO = "/hello",
+    REQUEST_METHOD = "PUT"
+  )
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can add a delete route", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_delete_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "text/plain",
+        content = "Hello, world!"
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- list(
+    PATH_INFO = "/hello",
+    REQUEST_METHOD = "DELETE"
+  )
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can add a patch route", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_patch_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "text/plain",
+        content = "Hello, world!"
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- list(
+    PATH_INFO = "/hello",
+    REQUEST_METHOD = "PATCH"
+  )
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+create_dummy_rook_input <- function(content) {
+  list(
+    read_lines = function() {
+      return(content)
+    }
+  )
+}
+
+test_that("can extract req body as a json", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_post_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "application/json",
+        content = tower::req_body_json(req)$secret
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- new.env()
+  request$PATH_INFO <- "/hello"
+  request$REQUEST_METHOD <- "POST"
+  request$CONTENT_TYPE <- "application/json"
+  request$rook.input <- create_dummy_rook_input('{"secret": "Hello, world!"}')
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can extract req body as a json on multiple layers", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_http_layer(function(req) {
+      body <- tower::req_body_json(req)
+      testthat::expect_equal(body$secret, "Hello, world!")
+      return(NULL)
+    }) |>
+    tower::add_post_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "application/json",
+        content = tower::req_body_json(req)$secret
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- new.env()
+  request$PATH_INFO <- "/hello"
+  request$REQUEST_METHOD <- "POST"
+  request$CONTENT_TYPE <- "application/json"
+  request$rook.input <- create_dummy_rook_input('{"secret": "Hello, world!"}')
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can extract req body form", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_post_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "application/json",
+        content = tower::req_body_form(req)$secret
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- new.env()
+  request$PATH_INFO <- "/hello"
+  request$REQUEST_METHOD <- "POST"
+  request$CONTENT_TYPE <- "application/x-www-form-urlencoded"
+  request$rook.input <- create_dummy_rook_input("say=Hello&to=World&secret=Hello%2C%20world%21")
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can extract req body form on many layers", {
+
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_http_layer(function(req) {
+      body <- tower::req_body_form(req)
+      testthat::expect_equal(body$secret, "Hello, world!")
+      return(NULL)
+    }) |>
+    tower::add_post_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "application/json",
+        content = tower::req_body_form(req)$secret
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- new.env()
+  request$PATH_INFO <- "/hello"
+  request$REQUEST_METHOD <- "POST"
+  request$CONTENT_TYPE <- "application/x-www-form-urlencoded"
+  request$rook.input <- create_dummy_rook_input("say=Hello&to=World&secret=Hello%2C%20world%21")
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "Hello, world!")
+
+})
+
+test_that("can extract req query", {
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_get_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "application/json",
+        content = tower::req_query(req)$secret
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- new.env()
+  request$PATH_INFO <- "/hello"
+  request$REQUEST_METHOD <- "GET"
+  request$CONTENT_TYPE <- "application/x-www-form-urlencoded"
+  request$QUERY_STRING <- "say=Hello&to=World&secret=Hello%2C%20world%21"
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "Hello, world!")
+
+
+})
+
+test_that("can extract req http cookies", {
+  app <- shiny::shinyApp(
+    ui = shiny::fluidPage(),
+    server = function(input, output, session) {}
+  )
+
+  app <- app |>
+    tower::create_tower() |>
+    tower::add_get_route("/hello", function(req) {
+      shiny::httpResponse(
+        status = 200,
+        content_type = "application/json",
+        content = tower::req_cookies(req)$secret
+      )
+    }) |>
+    tower::build_tower()
+
+  request <- new.env()
+  request$PATH_INFO <- "/hello"
+  request$REQUEST_METHOD <- "GET"
+  request$CONTENT_TYPE <- "application/x-www-form-urlencoded"
+  request$HTTP_COOKIE <- "say=Hello; to=World; secret=Hello%2C%20world%21"
+
+  parts <- app |>
+    tower::app_into_parts()
+
+  response <- parts$ui(request)
+
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "Hello, world!")
+
+})
diff --git a/tests/testthat/test-response-builder.R b/tests/testthat/test-response-builder.R
new file mode 100644
index 0000000..e6a1936
--- /dev/null
+++ b/tests/testthat/test-response-builder.R
@@ -0,0 +1,137 @@
+test_that("can build an empty response", {
+  response <- tower::response_builder() |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, character(0))
+})
+
+test_that("can build a response with a status", {
+  response <- tower::response_builder() |>
+    tower::set_status(404) |>
+    tower::build_response()
+  expect_equal(response$status, 404)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, character(0))
+})
+
+test_that("can build a response with a content type", {
+  response <- tower::response_builder() |>
+    tower::set_content_type("application/json") |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "{}")
+})
+
+test_that("can build a response with a body", {
+  response <- tower::response_builder() |>
+    tower::add_body("Hello, world!") |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+})
+
+test_that("can build a response with a body and content type", {
+  response <- tower::response_builder() |>
+    tower::set_content_type("text/html") |>
+    tower::add_body("<h1>Hello, world!</h1>") |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/html")
+  expect_equal(response$content, "<h1>Hello, world!</h1>")
+})
+
+test_that("shiny::tags get converted to html", {
+  response <- tower::response_builder() |>
+    tower::set_content_type("text/html") |>
+    tower::add_body(shiny::tags$h1("Hello, world!")) |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/html")
+  expect_equal(response$content, "<h1>Hello, world!</h1>")
+})
+
+test_that("can build a response with a body as JSON", {
+  response <- tower::response_builder() |>
+    tower::add_body_json(list(a = 1, b = 2)) |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "{\"a\":[1],\"b\":[2]}")
+})
+
+test_that("can build a response with a body as JSON and content type", {
+  response <- tower::response_builder() |>
+    tower::set_content_type("application/json") |>
+    tower::add_body_json(list(a = 1, b = 2)) |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/json")
+  expect_equal(response$content, "{\"a\":[1],\"b\":[2]}")
+})
+
+test_that("can build a response with a raw body", {
+  response <- tower::response_builder() |>
+    tower::add_body(as.raw(0:255)) |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/octet-stream")
+  expect_equal(response$content, as.raw(0:255))
+})
+
+test_that("can build a response with a raw body and content type", {
+  response <- tower::response_builder() |>
+    tower::set_content_type("application/octet-stream") |>
+    tower::add_body(as.raw(0:255)) |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "application/octet-stream")
+  expect_equal(response$content, as.raw(0:255))
+})
+
+test_that("can build a response with cookies", {
+  response <- tower::response_builder() |>
+    tower::add_cookie("name", "value") |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, character(0))
+  expect_equal(response$headers$`Set-Cookie`, "name=value; path=/; SameSite=Lax; HttpOnly")
+})
+
+test_that("can build a response with many cookies", {
+  response <- tower::response_builder() |>
+    tower::add_cookie("name", "value") |>
+    tower::add_cookie("name2", "value2") |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, character(0))
+  # Get all headers with name "Set-Cookie"
+  cookies <- response$headers[names(response$headers) == "Set-Cookie"]
+  expect_equal(cookies[[1]], "name=value; path=/; SameSite=Lax; HttpOnly")
+  expect_equal(cookies[[2]], "name2=value2; path=/; SameSite=Lax; HttpOnly")
+})
+
+test_that("can build a response with a cookie and a body", {
+  response <- tower::response_builder() |>
+    tower::add_cookie("name", "value") |>
+    tower::add_body("Hello, world!") |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, "Hello, world!")
+  expect_equal(response$headers$`Set-Cookie`, "name=value; path=/; SameSite=Lax; HttpOnly")
+})
+
+test_that("can add headers to a response", {
+  response <- tower::response_builder() |>
+    tower::set_header("X-Test", "test") |>
+    tower::build_response()
+  expect_equal(response$status, 200)
+  expect_equal(response$content_type, "text/plain")
+  expect_equal(response$content, character(0))
+  expect_equal(response$headers$`X-Test`, "test")
+})