diff --git a/src/codex.bash b/src/codex.bash
index 43b14b1..c9e5e68 100644
--- a/src/codex.bash
+++ b/src/codex.bash
@@ -117,9 +117,14 @@ cdx_launch_node() {
   cdx_ensure_ready "$@"
 }
 
+cdx_pid() {
+  local node_index="$1"
+  echo "${_cdx_pids[$node_index]}"
+}
+
 cdx_destroy_node() {
   local node_index="$1" wipe_data="${2:-false}" pid
-  pid="${_cdx_pids[$node_index]}"
+  pid="$(cdx_pid "$node_index")"
   if [ -z "$pid" ]; then
     echoerr "Error: no process ID for node $node_index"
     return 1
@@ -197,6 +202,15 @@ cdx_download_file() {
     -o "${_cdx_downloads}/codex-${node_index}/$cid" || return 1
 }
 
+cdx_download_file_async() {
+  (
+    cdx_download_file "$@"
+    pm_job_exit $?
+  ) &
+  pm_track_last_job
+  echo $!
+}
+
 cdx_upload_sha1() {
   local node_index="$1" cid="$2"
   cat "${_cdx_uploads}/codex-${node_index}/${cid}.sha1" || return 1
diff --git a/src/procmon.bash b/src/procmon.bash
index 7893f88..298473f 100644
--- a/src/procmon.bash
+++ b/src/procmon.bash
@@ -191,6 +191,11 @@ pm_kill_rec() {
     kill -s TERM "$descendant" 2> /dev/null || true
   done
 
+  # Tries to wait so processes are not left lingering.
+  for descendant in "${result[@]}"; do
+    await "$descendant" || echo "[procmon] failed to wait for process $descendant"
+  done
+
   return 0
 }
 
diff --git a/src/utils.bash b/src/utils.bash
index 94fd659..3405f02 100644
--- a/src/utils.bash
+++ b/src/utils.bash
@@ -18,6 +18,10 @@ clh_output_folder() {
   echo "${OUTPUTS}/$1"
 }
 
+clh_clear_outputs() {
+  rm -rf "${OUTPUTS}" || true
+}
+
 echoerr() {
   echo "$@" >&2
 }
diff --git a/test/test_codex.bats b/test/test_codex.bats
index 8aa5563..03bfb44 100755
--- a/test/test_codex.bats
+++ b/test/test_codex.bats
@@ -74,7 +74,7 @@ setup() {
   pm_stop
 }
 
-@test "should upload and synchronously download file to Codex node" {
+@test "should upload and synchronously download file from Codex node" {
   pm_start
 
   assert cdx_launch_node 0
@@ -83,8 +83,29 @@ setup() {
   filename=$(cdx_generate_file 10)
   cid=$(cdx_upload_file 0 "$filename")
 
-  cdx_download_file 0 "$cid"
+  assert cdx_download_file 0 "$cid"
   assert_equal $(sha1 "${filename}") $(cdx_download_sha1 0 "$cid")
 
   pm_stop
+}
+
+@test "should upload and asynchronously download file from Codex node" {
+  pm_start
+
+  assert cdx_launch_node 0
+  assert cdx_ensure_ready 0 3
+
+  filename=$(cdx_generate_file 10)
+  cid=$(cdx_upload_file 0 "$filename")
+
+  handle=$(cdx_download_file_async 0 "$cid")
+  await $handle 3
+
+  assert_equal $(sha1 "${filename}") $(cdx_download_sha1 0 "$cid")
+
+  pm_stop
+}
+
+teardown() {
+  clh_clear_outputs
 }
\ No newline at end of file