diff --git a/NAMESPACE b/NAMESPACE
index 67b120a1..7aaa82ea 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -64,6 +64,7 @@ export(construct_diff)
 export(construct_dump)
 export(construct_issues)
 export(construct_multi)
+export(construct_session)
 export(deparse_call)
 export(opts_Date)
 export(opts_POSIXct)
diff --git a/R/construct_reprex.R b/R/construct_reprex.R
new file mode 100644
index 00000000..333389c8
--- /dev/null
+++ b/R/construct_reprex.R
@@ -0,0 +1,129 @@
+# what to do with dots ?
+# they need to be evaled in different environments and might contain NSE too
+# we night try to eval what we can in the correct env
+# if env is not parent env we should store those in lists, maybe named ...1 etc
+# so we'll have foo(x = ...1$x + ...$y) or foo(x = with(...1, x + y))
+
+
+# FIXME: calling on a call or without arg in the call should be exactly the same and use more of the same code
+# FIXME: have a safe mode, arg name TBD so we construct only quosures, or list of quosures for dots,
+#  and then call inject, so we don't force any evaluation.
+# * If the expr is not a call or a symbol we can construct it as is without the quo
+# * If env is .GlobalEnv the object can also be defined as is and the expression directly fed to the call
+# * If env of all dots is .GlobalEnv we can define the object as
+construct_reprex <- function(x, quote = TRUE, ..., check = NULL, template = NULL) {
+  env <- parent.frame()
+  nse_msgs <- character()
+
+  if (missing(x)) {
+    call <- sys.call(-1)
+    call_matched <- match.call(sys.function(-1), call, envir = parent.frame(2))
+    call_expanded <- eval.parent(bquote(substitute(.(call))))
+    call_for_nms <- call_matched
+    dot_pos <- which(sapply(call_matched[-1], function(x) is.symbol(x) && grepl("^\\.\\.\\d+$", as.character(x))))
+    for(dot in dot_pos) {
+      val <- try(eval(call_matched[[dot + 1]], env), silent = TRUE)
+      if (inherits(val, "try-error")) {
+        call_matched[[dot + 1]] <- call_expanded[[dot + 1]]
+        call_for_nms[[dot + 1]] <- NULL
+      }
+    }
+    nms <- all.names(call_for_nms[-1], unique = TRUE)
+    call <- call_matched
+  } else {
+    call <- if (quote) substitute(x) else x
+    nms <- all.names(call, unique = TRUE)
+  }
+  objs <- sapply(nms, function(x) try(eval(as.symbol(x), env), silent = TRUE), simplify = FALSE)
+  errors_lgl <- sapply(objs, inherits, "try-error")
+  objs <- objs[!errors_lgl]
+  data <- preprocess_data(list("base", "methods", "datasets", "utils", "grDevices", "stats")) # FIXME: graphics doesn't work because plot's env is base
+  code <- lapply(objs, construct_raw, template = template, data = data, ...)
+  useful_code <- code[!mapply(code, names(code), FUN = identical)]
+  useful_code_with_assignments <- Map(
+    useful_code, names(useful_code),
+    f = function(x, y) {
+      x[[1]] <- paste(y, "<-", x[[1]])
+      c(x, "")
+    })
+  out <- c(unlist(useful_code_with_assignments), deparse_call(call))
+  if (any(errors_lgl)) {
+    msg <- "Some variable bindings couldn't be found so objects were not reproduced."
+    info <- sprintf("Non existent binding for %s", toString(shQuote(nms[errors_lgl])))
+    rlang::inform(c(msg, i = info))
+  }
+  out <- styler::style_text(out)
+  if (missing(x)) do.call("return", list(out), envir = sys.frame(1))
+  out
+}
+
+construct_reprex <- function(x, quote = TRUE, ..., check = NULL, template = NULL) {
+  ## was a call provided ?
+  if (missing(x)) {
+    ## fetch call and fun from stack, fetch env 2 frames above
+     call <- sys.call(-1)
+     env <- parent.frame(2)
+     fun <- sys.function(-2)
+  } else {
+    ## capture call, fetch env 1 frame above, eval fun
+    call <- substitute(x)
+    env <- parent.frame()
+    #fun <- sys.function(-1)
+    eval(call[[1]], env)
+  }
+  ## create matched call, will contain all named arg and ..n for dots, deduce args
+  call_matched <- match.call(fun, call, expand = FALSE, envir = env)
+  args <- as.list(call_matched[-1])
+  # all args are named since the call is matched and expand is FALSE
+  objs <- list()
+  #browser()
+  for (arg_nm in names(args)) {
+    if (arg_nm == "...") {
+      objs[["..."]] <- evalq(rlang::enquos(...), env)
+      args[["..."]] <- quote(!!!..args..$...)
+      names(args)[names(args) == "..."] <- ""
+      next
+    }
+    objs[[arg_nm]] <-  eval(substitute(enquo(ARG), list(ARG = .(sym(arg_nm)))), env)
+    args[[arg_nm]] <- substitute(!!..args..$ARG, list(ARG = .(sym(arg_nm))))
+  }
+
+  # update call
+  new_call <- as.call(c(call_matched[[1]], args))
+  new_call <- as.call(c(quote(rlang::inject), new_call))
+  new_call
+
+  # build code
+  multi_construct
+
+  code <- styler::style_text(code)
+  do.call("return", list(code), envir = sys.frame(1))
+}
+
+
+
+if (FALSE) {
+  f <- function(x, ...) {
+    construct_reprex()
+    c(x, ...)
+  }
+
+  # f <- function(x, y) {
+  #   construct_reprex()
+  #   x
+  # }
+
+  x <- 3
+  y <- 4
+  foo <- function(...) {
+    bar(...)
+  }
+
+  bar <- function(...) {
+    construct_reprex()
+    subset(...)
+  }
+
+  foo(cars, speed > 4)
+}
+
diff --git a/R/construct_session.R b/R/construct_session.R
new file mode 100644
index 00000000..49f8e78b
--- /dev/null
+++ b/R/construct_session.R
@@ -0,0 +1,205 @@
+#' Construct the session
+#'
+#' This builds code to reproduce the session. By default it prints comments describing
+#'   the setup, attaching all non base packages present in the search path,
+#'   and constructs all objects present in the global environment. Objects exported
+#'   by attached package are used as data to sinplify  object construction.
+#'
+#' More often than not it is not a perfectly faithful reproduction of the session,
+#' in particular it doesn't account (yet?) for:
+#' * Namespaces loaded by other means than `library()` calls
+#' * Modifications of namespaces
+#' * Other environments on the search opath
+#' * Options that have been set
+#' * And most likely anything weirder than the above
+#'
+#' @param ... Forwarded to `construct_multi()`. Should not include a `data` argument,
+#'   since `data` will be infered from attached packages.
+#' @param session_info Whether to describe the setup in comments
+#' @param library_calls Whether to include library calls
+#'
+#' @return An object of class 'constructive'.
+#' @export
+#' @examples
+#' construct_session()
+construct_session <- function(..., session_info = TRUE, library_calls = TRUE) {
+  # session info ---------------------------------------------------------------
+  if (session_info) {
+  si <- sessionInfo()
+  .rs.api.versionInfo <- NULL # to avoid note
+  si_code <- paste("#", c(
+    paste(si$R.version$version.string, if (Sys.getenv("RSTUDIO") == "1") paste("in RStudio", .rs.api.versionInfo()$version)),
+    paste("running", si$running, "on", si$platform),
+    paste("locale:", si$locale)
+  ))
+  }
+  libs <- search()
+
+  # library calls --------------------------------------------------------------
+  if (library_calls){
+
+  base_pkgs <- c("stats", "graphics", "grDevices", "utils", "datasets", "methods", "base")
+  ignore_libs <- c(paste0("package:", base_pkgs), "devtools_shims", "tools:rstudio", "Autoloads")
+  libs <- setdiff(libs, ignore_libs)
+  libs <- grep("^package:", libs, value = TRUE)
+  libs <- sub("package:", "", libs)
+  data_libs <- libs
+  # special case for tidyverse since it's quite common
+  if ("tidyverse" %in% libs) {
+    libs <- setdiff(libs, c("forcats", "stringr", "dplyr", "purrr", "readr", "tidyr", "tibble", "ggplot2"))
+  }
+  data_libs <- c(data_libs, base_pkgs)
+  lib_code <- if (length(libs)) sprintf("library(%s)", rev(libs))
+  } else {
+    data_libs <- base_pkgs
+  }
+
+  # namespaces -----------------------------------------------------------------
+  # TODO: attach namespaces that are not recursive deps of attached packages
+  # TODO: detach relevant namespaces
+
+  # options --------------------------------------------------------------------
+  # TODO
+
+  # objects --------------------------------------------------------------------
+  objs <- setdiff(ls(.GlobalEnv, all.names = TRUE), ".Random.seed")
+  objs <- mget(objs, .GlobalEnv, inherits = FALSE)
+  # FIXME: is there a max_size that makes sense ?
+  # total_size <- sum(sapply(objs, object.size))
+  # if (total_size > max_size) {
+  #   msg <- "The total size of objects must be less than `max_size`"
+  #   info1 <- sprintf(
+  #     "`max_size` is %s bytes, adjust the argument if necessary.",
+  #     format(max_size, scientific = FALSE, big.mark = " ")
+  #   )
+  #   info2 <- sprintf(
+  #     "The total size is %s bytes.",
+  #     format(total_size, scientific = FALSE, big.mark = " ")
+  #   )
+  #   abort(c(msg, i = info1, x = info2))
+  # }
+  res <- construct_multi(objs, data = as.list(data_libs), ...)
+  res$code <- c(si_code, lib_code, res$code)
+  class(res$code) <- "vertical"
+  res
+}
+
+get_set_options <- function() {
+  # get default and actual options
+  default_opts <- get_default_options()
+  opts <- options()
+  # ignore on both sides the options RStudio sets or changes
+  # note: based on RStudio 4.2.1 on R 4.2.1
+  rstudio_sets <- c(
+    "askpass", "asksecret", "buildtools.check", "buildtools.with",
+    "connectionObserver", "deparse.max.lines", "download.file.method",
+    "ggvis.renderer", "help_type", "page_viewer", "plumber.docs.callback",
+    "plumber.swagger.url", "profvis.keep_output", "profvis.print",
+    "profvis.prof_extension", "profvis.prof_output", "restart", "reticulate.initialized",
+    "reticulate.repl.busy", "reticulate.repl.hook", "reticulate.repl.initialize",
+    "reticulate.repl.teardown", "rstudio.notebook.executing", "RStudioGD.antialias",
+    "RStudioGD.backend", "shiny.launch.browser", "shinygadgets.showdialog",
+    "terminal.manager", "viewer"
+  )
+
+  rstudio_changes <- c(
+    "browser", "device", "echo", "HTTPUserAgent", "keep.source",
+    "max.print", "menu.graphics", "pager", "pdfviewer", "width"
+  )
+
+  default_opts[c(rstudio_sets, rstudio_changes)] <- NULL
+  opts[c(rstudio_sets, rstudio_changes)] <- NULL
+
+  for (opt in names(opts)) {
+    if (identical(opts[[opt]], default_opts[[opt]], ignore.environment = TRUE)) {
+      opts[[opt]] <- NULL
+      next
+    }
+    both_are_funs_with_same_body <-
+      is.function(opts[[opt]]) &&
+      is.function(default_opts[[opt]]) &&
+      identical(as.list(opts[[opt]]), as.list(default_opts[[opt]]))
+    if (both_are_funs_with_same_body) {
+      opts[[opt]] <- NULL
+    }
+  }
+  opts
+}
+
+# get_default_options <- function() {
+#   default_opts <- callr::r(function(libs) {
+#     lapply(libs, library, character.only = TRUE)
+#     options()
+#   }, list (libs = sub("^package:", "", grep("^package:", search(), value = TRUE))))
+#   # remove options set by {callr}
+#   callr_sets <- c("callr.rprofile_loaded", "error", "showErrorCalls")
+#   default_opts[callr_sets] <- NULL
+#   default_opts
+# }
+#
+#
+#
+# compare_to_default <- function() {
+#   opts <- options()
+#   # ignore on both sides the options RStudio sets or changes
+#   # note: based on RStudio 4.2.1 on R 4.2.1
+#   rstudio_sets <- c(
+#     "askpass", "asksecret", "buildtools.check", "buildtools.with",
+#     "connectionObserver", "deparse.max.lines", "download.file.method",
+#     "ggvis.renderer", "help_type", "page_viewer", "plumber.docs.callback",
+#     "plumber.swagger.url", "profvis.keep_output", "profvis.print",
+#     "profvis.prof_extension", "profvis.prof_output", "restart", "reticulate.initialized",
+#     "reticulate.repl.busy", "reticulate.repl.hook", "reticulate.repl.initialize",
+#     "reticulate.repl.teardown", "rstudio.notebook.executing", "RStudioGD.antialias",
+#     "RStudioGD.backend", "shiny.launch.browser", "shinygadgets.showdialog",
+#     "terminal.manager", "viewer"
+#   )
+#
+#   rstudio_changes <- c(
+#     "browser", "device", "echo", "HTTPUserAgent", "keep.source",
+#     "max.print", "menu.graphics", "pager", "pdfviewer", "width"
+#   )
+#
+#   rstudio_opts <- c(rstudio_sets, rstudio_changes)
+#   opts[rstudio_opts] <- NULL
+#   # we pass our system info to
+#   diffs <- callr::r(function(si, opts, rstudio_opts) {
+#     # libs in the correct attaching order
+#     libs <- rev(c(names(si$otherPkgs), si$basePkgs))
+#     lapply(libs, library, character.only = TRUE)
+#
+#     # namespaces
+#
+#     # callr loads several namespaces
+#     ## Imports:
+#     # processx (>= 3.6.1),  <- imports additionally ps
+#     # R6,                   <- also imported by RStudio
+#     # utils                 <- also imported by R
+#     default_ns <- loadedNamespaces()
+#     extra_ns <- setdiff(names(si$loadedOnly), default_ns)
+#     lapply(extra_ns, loadNamespace)
+#
+#     # options
+#
+#     default_opts <- options()
+#     callr_sets <- c("callr.rprofile_loaded", "error", "showErrorCalls")
+#     default_opts[c(callr_sets, rstudio_opts)] <- NULL
+#
+#     for (opt in names(opts)) {
+#       if (identical(opts[[opt]], default_opts[[opt]], ignore.environment = TRUE)) {
+#         opts[[opt]] <- NULL
+#         next
+#       }
+#       both_are_funs_with_same_body <-
+#         is.function(opts[[opt]]) &&
+#         is.function(default_opts[[opt]]) &&
+#         identical(as.list(opts[[opt]]), as.list(default_opts[[opt]]))
+#       if (both_are_funs_with_same_body) {
+#         opts[[opt]] <- NULL
+#       }
+#     }
+#
+#     list(opts = opts, extra_ns = extra_ns)
+#   }, list (si = sessionInfo(), opts = opts, rstudio_opts = rstudio_opts))
+#   diffs
+# }
diff --git a/man/construct_session.Rd b/man/construct_session.Rd
new file mode 100644
index 00000000..5c682f11
--- /dev/null
+++ b/man/construct_session.Rd
@@ -0,0 +1,39 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/construct_session.R
+\name{construct_session}
+\alias{construct_session}
+\title{Construct the session}
+\usage{
+construct_session(..., session_info = TRUE, library_calls = TRUE)
+}
+\arguments{
+\item{...}{Forwarded to \code{construct_multi()}. Should not include a \code{data} argument,
+since \code{data} will be infered from attached packages.}
+
+\item{session_info}{Whether to describe the setup in comments}
+
+\item{library_calls}{Whether to include library calls}
+}
+\value{
+An object of class 'constructive'.
+}
+\description{
+This builds code to reproduce the session. By default it prints comments describing
+the setup, attaching all non base packages present in the search path,
+and constructs all objects present in the global environment. Objects exported
+by attached package are used as data to sinplify  object construction.
+}
+\details{
+More often than not it is not a perfectly faithful reproduction of the session,
+in particular it doesn't account (yet?) for:
+\itemize{
+\item Namespaces loaded by other means than \code{library()} calls
+\item Modifications of namespaces
+\item Other environments on the search opath
+\item Options that have been set
+\item And most likely anything weirder than the above
+}
+}
+\examples{
+construct_session()
+}