diff --git a/.gitignore b/.gitignore
index 5387b99..626665b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -97,3 +97,4 @@ rsconnect/
 /attic/
 .Rprofile
 kaggle/
+deepcave
\ No newline at end of file
diff --git a/DESCRIPTION b/DESCRIPTION
index 4ab70c0..b3e3839 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -27,7 +27,8 @@ Imports:
     mlr3tuningspaces,
     paradox (>= 1.0.1),
     R6,
-    utils
+    utils,
+    jsonlite
 Suggests:
     catboost,
     e1071,
@@ -62,4 +63,5 @@ Collate:
     'LearnerClassifAutoXgboost.R'
     'LearnerRegrAuto.R'
     'helper.R'
+    'save_deepcave_run.R'
     'zzz.R'
diff --git a/NAMESPACE b/NAMESPACE
index 6fc0f11..14bb580 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -4,6 +4,7 @@ export(LearnerClassifAuto)
 export(LearnerClassifAutoSVM)
 export(LearnerClassifAutoXgboost)
 export(LearnerRegrAuto)
+export(save_deepcave_run)
 import(R6)
 import(checkmate)
 import(data.table)
diff --git a/R/save_deepcave_run.R b/R/save_deepcave_run.R
new file mode 100644
index 0000000..c71745e
--- /dev/null
+++ b/R/save_deepcave_run.R
@@ -0,0 +1,317 @@
+#' @title Save Tuning History as a DeepCAVE Run
+#' 
+#' @description
+#' Exports information stored in a `TuningInstance` in a format recognized by [DeepCAVE](https://automl.github.io/DeepCAVE/main/index.html) as a run. Each run is stored as a folder containing five files `configs.json`, `configspace.json`, `history.jsonl`, `meta.json`, and `origins.json`.
+#' 
+#' @param instance ([TuningInstanceAsyncSingleCrit])
+#' Tuning instance to save.
+#' 
+#' @param path (`character(1)`)
+#' Path to save the run. Defaults to `"logs/mlr3automl`.
+#' 
+#' @param prefix (`character(1)`)
+#' Prefix for the name of a new subfolder under `path` for storing the current run.
+#' 
+#' @param overwrite (`character(1)`)
+#' If `FALSE` (default), creates a new subfolder to save the current run. If `TRUE`, all existing runs will be deleted.
+#' 
+#' @export
+#' @examples
+#' \dontrun{
+#' rush_plan(n_workers = 2)
+#' task = tsk("penguins")
+#' 
+#' learner1 = lrn("classif.auto",
+#'   learner_ids = c("svm", "ranger"),
+#'   small_data_size = 1,
+#'   resampling = rsmp("holdout"),
+#'   measure = msr("classif.ce"),
+#'   terminator = trm("evals", n_evals = 6)
+#' )
+#' learner1$train(task)
+#' # save to `logs/mlr3automl/run_1`
+#' save_deepcave_run(learner1$instance)
+#' 
+#' # save to `logs/mlr3automl/run`
+#' # if this folder already exists, it will be overwritten
+#' save_deepcave_run(learner1$instance, overwrite = TRUE)
+#' 
+#' learner2 = lrn("classif.auto",
+#'   learner_ids = c("catboost", "xgboost"),
+#'   small_data_size = 1,
+#'   resampling = rsmp("holdout"),
+#'   measure = msr("classif.ce"),
+#'   terminator = trm("evals", n_evals = 6)
+#' )
+#' learner2$train(task)
+#' # save to `logs/mlr3automl/run_2`
+#' save_deepcave_run(learner2$instance)
+#' }
+save_deepcave_run = function(instance, path = "logs/mlr3automl", prefix = "run", overwrite = FALSE) {
+  # don't save untuned instance
+  if (is.null(instance$result_learner_param_vals)) {
+    warning("No run is saved, because no tuning has been completed.")
+    return()
+  }
+
+  # create a subfolder for saving the current run
+  # original Python implementation see `Recorder._set_path()`
+  # (https://github.com/automl/DeepCAVE/blob/main/deepcave/runs/recorder.py)
+  if (!overwrite) {
+    new_idx = 0
+    for (fn in list.files(path)) {
+      if (!startsWith(fn, prefix)) next
+
+      splitted = strsplit(fn, "_")[[1]]
+      if (length(splitted) == 1) next # no run index attached
+
+      idx = suppressWarnings(last(splitted))
+      if (is.na(idx)) next # idx cannot be coerced to a number
+
+      idx_int = as.integer(idx)
+      if (idx_int > new_idx) {
+        new_idx = idx_int
+      }
+    }
+
+    new_idx = new_idx + 1
+    run_path = file.path(path, paste0(prefix, "_", new_idx))
+
+    dir.create(run_path, recursive = TRUE)
+  } else {
+    run_path = file.path(path, prefix)
+    if (file.exists(run_path)) {
+      lapply(list.files(run_path, full.names = TRUE), file.remove)
+    } else{
+      dir.create(run_path, recursive = TRUE)
+    }
+  }
+
+
+  # `configspace.json`
+  jsonlite::write_json(
+    get_configspace(instance),
+    file.path(run_path, "configspace.json"),
+    auto_unbox = TRUE, pretty = TRUE, null = "null"
+  )
+
+  # `configs.json` 
+  jsonlite::write_json(
+    get_configs(instance),
+    file.path(run_path, "configs.json"),
+    auto_unbox = TRUE, pretty = TRUE, null = "null"
+  )
+
+  # `meta.json`
+  jsonlite::write_json(
+    get_meta(instance),
+    file.path(run_path, "meta.json"),
+    auto_unbox = TRUE, pretty = TRUE, null = "null"
+  )
+
+  # `history.jsonl` 
+  con = file(file.path(run_path, "history.jsonl"), open = "w")
+  jsonlite::stream_out(
+    get_history(instance),
+    con,
+    # objectives must be a list, so do not auto unbox if a list has only one entry
+    auto_unbox = FALSE,
+    pretty = TRUE, null = "list", na = "null",
+    dataframe = "values",
+    verbose = FALSE
+  )
+  close(con)
+  
+  # `origins.json` (a list of `null`s)
+  origins = rep(list(NULL), nrow(instance$archive$data))
+  names(origins) = seq(nrow(instance$archive$data)) - 1
+  jsonlite::write_json(
+    origins,
+    file.path(run_path, "origins.json"),
+    pretty = TRUE, null = "null"
+  )
+}
+
+
+# Prepare the list for converting to `configs.json`
+get_configs = function(instance){
+  param_ids = instance$search_space$data$id
+
+  # skip branch.selection if there is only one level
+  id = NULL # resolve global variable note in R CDM check
+  nbranches = instance$search_space$data[id == "branch.selection", "nlevels", with = FALSE]
+  if (nbranches == 1) {
+    param_ids = setdiff(param_ids, "branch.selection")
+  }
+
+  config_table = instance$archive$data[, param_ids, with = FALSE]
+  # param values in deepcave are on the original scale, not the log scale
+  logscale_params = param_ids[instance$search_space$is_logscale[param_ids]]
+  config_table[, (logscale_params) := lapply(.SD, exp), .SDcols = logscale_params]
+
+  configs_list = map(seq_len(nrow(config_table)), function(i) {
+    discard(as.list(config_table[i, ]), is.na)
+  })
+  names(configs_list) = seq_along(configs_list) - 1
+
+  return(configs_list)
+}
+
+
+# Prepare the list for converting to `configspace.json`
+get_configspace = function(instance) {
+  param_ids = instance$search_space$data$id
+
+  hyperparameters_list = map(param_ids, function(param_id) {
+    id = NULL # resolve global variable note in R CDM check
+    row = instance$search_space$data[id == param_id, ]
+
+    # skip branch.selection if there is only one branch
+    if (param_id == "branch.selection" && row[["nlevels"]] == 1) return()
+
+    type = switch(row[["class"]],
+      ParamFct = "categorical",
+      ParamLgl = "categorical",
+      ParamDbl = "uniform_float",
+      ParamInt = "uniform_int")
+    
+    # categorical params
+    if (type == "categorical") {
+      choices = unlist(row[["levels"]])
+      return(list(
+        name = param_id,
+        type = type,
+        choices = choices,
+        # FIXME: `default` is wrong
+        default = choices[[1]],
+        probabilities = NULL
+      ))
+    }
+
+    # int / float params
+    is_logscale = instance$search_space$is_logscale[[param_id]]
+    lower = row[["lower"]]
+    upper = row[["upper"]]
+    # FIXME: default is wrong
+    default = lower
+    if (is_logscale) {
+      lower = exp(lower)
+      upper = exp(upper)
+      default = exp(default)
+    }
+    return(list(
+      name = param_id,
+      type = type,
+      log = is_logscale,
+      lower = lower,
+      upper = upper,
+      default = default,
+      q = NULL
+    ))
+  })
+  # skipping branch.selection results in null entries => discard them
+  hyperparameters_list = discard(hyperparameters_list, is.null)
+
+
+  conditions_list = map(setdiff(param_ids, "branch.selection"), function(param_id) {
+    id = NULL # resolve global variable note in R CDM check
+    dependency = instance$search_space$deps[id == param_id, ]
+    # `svm.degree` and `svm.gamma` depends on `svm.kernel` as well as `branch.selection`.
+    # DeepCAVE does not allow one parameter to be conditioned on multiple others.
+    # So remove their dependency on `branch.selection`.
+    if (nrow(dependency) > 1) {
+      on = NULL # resolve global variable note in R CDM check
+      dependency = dependency[on != "branch.selection", ]
+    }
+    child = param_id
+    parent = dependency[["on"]]
+
+    # remove dependency on branch.selection if there is only one branch
+    nbranches = instance$search_space$data[id == "branch.selection", "nlevels", with = FALSE]
+    if (parent == "branch.selection" && nbranches == 1) return()
+    
+    # `cond` below is a list of `Condition`s.
+    # Currently, there are only 'CondEqual' and 'CondAnyOf', which should not be used simultaneously.
+    # So this list should always contain only one entry.
+    cond = dependency[["cond"]][[1]]
+    if (class(cond)[[1]] == "CondEqual") {
+        return(list(child = child, parent = parent, type = "EQ", value = cond$rhs))
+    }
+    return(list(child = child, parent = parent, type = "IN", values = cond$rhs))
+  })
+  # skipping branch.selection results in null entries => discard them
+  conditions_list = discard(conditions_list, is.null)
+
+  return(list(
+    hyperparameters = hyperparameters_list,
+    conditions = conditions_list,
+    forbiddens = list()
+  ))
+}
+
+# Prepare the data.table for converting to `history.jsonl`
+get_history = function(instance) {
+  costs = instance$objective$codomain$data$id
+
+  selected_cols = c(costs, "timestamp_xs", "timestamp_ys", "state")
+  timestamp_xs = timestamp_ys = state = NULL # resolve global variable note in R CDM check
+  history_table = instance$archive$data[, selected_cols, with = FALSE][, list(
+    config_id = seq_len(nrow(instance$archive$data)) - 1,
+    budget = 0,
+    seed = -1,
+    # combine costs into a list column
+    costs = lapply(transpose(.SD), c),
+    # handle start and end time (time elapsed since first timestamp)
+    # see https://github.com/automl/DeepCAVE/blob/main/deepcave/runs/recorder.py
+    # start and end time here might having different meanings than the original implementation
+    start_time = as.numeric(timestamp_xs - timestamp_xs[1]),
+    end_time = as.numeric(timestamp_ys - timestamp_ys[1]),
+    # state is either "finished" <=> SUCESS = 1 or ABORTED = 5
+    # see https://github.com/automl/DeepCAVE/blob/main/deepcave/runs/status.py
+    state = ifelse(state == "finished", 1, 5),
+    additionals = list()
+  ), .SDcols = costs]
+
+  return(history_table)
+}
+
+
+# Prepare the list for converting to 'meta.json'
+get_meta = function(instance){
+  costs = instance$objective$codomain$data$id
+
+  objectives_list = map(costs, function(cost) {
+    measure = msr(cost)
+
+    lower = measure$range[[1]]
+    if (is.finite(lower)) {
+      lock_lower = TRUE
+    } else {
+      lower = min(instance$archive$data[, cost, with = FALSE])
+      lock_lower = FALSE
+    }
+
+    upper = measure$range[[2]]
+    if (is.finite(upper)) {
+      lock_upper = TRUE
+    } else {
+      upper = max(instance$archive$data[, cost, with = FALSE])
+      lock_upper = FALSE
+    }
+
+    optimize = if (measure$minimize) {
+      "lower"
+    } else {
+      "upper"
+    }
+
+    return(list(name = cost, lower = lower, upper = upper,
+      lock_lower = lock_lower, lock_upper = lock_upper, optimize = optimize))
+  })
+  
+  return(list(
+    objectives = objectives_list,
+    budgets = list(0),
+    seeds = list(-1)
+  ))
+}
diff --git a/man/save_deepcave_run.Rd b/man/save_deepcave_run.Rd
new file mode 100644
index 0000000..61ca04d
--- /dev/null
+++ b/man/save_deepcave_run.Rd
@@ -0,0 +1,61 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/save_deepcave_run.R
+\name{save_deepcave_run}
+\alias{save_deepcave_run}
+\title{Save Tuning History as a DeepCAVE Run}
+\usage{
+save_deepcave_run(
+  instance,
+  path = "logs/mlr3automl",
+  prefix = "run",
+  overwrite = FALSE
+)
+}
+\arguments{
+\item{instance}{(\link{TuningInstanceAsyncSingleCrit})
+Tuning instance to save.}
+
+\item{path}{(\code{character(1)})
+Path to save the run. Defaults to \verb{"logs/mlr3automl}.}
+
+\item{prefix}{(\code{character(1)})
+Prefix for the name of a new subfolder under \code{path} for storing the current run.}
+
+\item{overwrite}{(\code{character(1)})
+If \code{FALSE} (default), creates a new subfolder to save the current run. If \code{TRUE}, all existing runs will be deleted.}
+}
+\description{
+Exports information stored in a \code{TuningInstance} in a format recognized by \href{https://automl.github.io/DeepCAVE/main/index.html}{DeepCAVE} as a run. Each run is stored as a folder containing five files \code{configs.json}, \code{configspace.json}, \code{history.jsonl}, \code{meta.json}, and \code{origins.json}.
+}
+\examples{
+\dontrun{
+rush_plan(n_workers = 2)
+task = tsk("penguins")
+
+learner1 = lrn("classif.auto",
+  learner_ids = c("svm", "ranger"),
+  small_data_size = 1,
+  resampling = rsmp("holdout"),
+  measure = msr("classif.ce"),
+  terminator = trm("evals", n_evals = 6)
+)
+learner1$train(task)
+# save to `logs/mlr3automl/run_1`
+save_deepcave_run(learner1$instance)
+
+# save to `logs/mlr3automl/run`
+# if this folder already exists, it will be overwritten
+save_deepcave_run(learner1$instance, overwrite = TRUE)
+
+learner2 = lrn("classif.auto",
+  learner_ids = c("catboost", "xgboost"),
+  small_data_size = 1,
+  resampling = rsmp("holdout"),
+  measure = msr("classif.ce"),
+  terminator = trm("evals", n_evals = 6)
+)
+learner2$train(task)
+# save to `logs/mlr3automl/run_2`
+save_deepcave_run(learner2$instance)
+}
+}
diff --git a/tests/testthat/test_save_deepcave_run.R b/tests/testthat/test_save_deepcave_run.R
new file mode 100644
index 0000000..4a3f85b
--- /dev/null
+++ b/tests/testthat/test_save_deepcave_run.R
@@ -0,0 +1,64 @@
+test_that("run is saved without overwriting", {
+  dir = tempdir()
+
+  previous_run = file.path(dir, "test-1-run_1")
+  dir.create(previous_run, showWarnings = FALSE)
+  
+  rush_plan(n_workers = 2)
+  skip_if_not_installed("e1071")
+
+  task = tsk("penguins")
+  learner = lrn("classif.auto",
+    learner_ids = "svm",
+    small_data_size = 1,
+    resampling = rsmp("holdout"),
+    measure = msr("classif.ce"),
+    terminator = trm("evals", n_evals = 6)
+  )
+  learner$train(task)
+  
+  expected_path = file.path(dir, "test-1-run_2")
+  if (file.exists(expected_path)) {
+    lapply(list.files(expected_path, full.names = TRUE), file.remove)
+    file.remove(expected_path)
+  }
+
+  save_deepcave_run(learner$instance, path = dir, prefix = "test-1-run", overwrite = FALSE)
+
+  expect_file_exists(file.path(expected_path, "configspace.json"))
+  expect_file_exists(file.path(expected_path, "configs.json"))
+  expect_file_exists(file.path(expected_path, "history.jsonl"))
+  expect_file_exists(file.path(expected_path, "meta.json"))
+  expect_file_exists(file.path(expected_path, "origins.json"))
+})
+
+test_that("overwriting works", {
+  dir = tempdir()
+  expected_path = file.path(dir, "test-run-overwrite")
+  file.create(file.path(expected_path, "configs.json"), showWarnings = FALSE)
+  file.create(file.path(expected_path, "configspace.json"), showWarnings = FALSE)
+  file.create(file.path(expected_path, "history.jsonl"), showWarnings = FALSE)
+  file.create(file.path(expected_path, "meta.json"), showWarnings = FALSE)
+  file.create(file.path(expected_path, "origins.json"), showWarnings = FALSE)
+
+  rush_plan(n_workers = 2)
+  skip_if_not_installed("e1071")
+
+  task = tsk("penguins")
+  learner = lrn("classif.auto",
+    learner_ids = "svm",
+    small_data_size = 1,
+    resampling = rsmp("holdout"),
+    measure = msr("classif.ce"),
+    terminator = trm("evals", n_evals = 6)
+  )
+  learner$train(task)
+
+  save_deepcave_run(learner$instance, path = dir, prefix = "test-run-overwrite", overwrite = TRUE)
+
+  expect_file_exists(file.path(expected_path, "configspace.json"))
+  expect_file_exists(file.path(expected_path, "configs.json"))
+  expect_file_exists(file.path(expected_path, "history.jsonl"))
+  expect_file_exists(file.path(expected_path, "meta.json"))
+  expect_file_exists(file.path(expected_path, "origins.json"))
+})