diff --git a/cli/bash/commands/basectl/basectl.sh b/cli/bash/commands/basectl/basectl.sh
index b5f361ec..51b97b1f 100644
--- a/cli/bash/commands/basectl/basectl.sh
+++ b/cli/bash/commands/basectl/basectl.sh
@@ -121,6 +121,7 @@ Wrapper options:
   --debug-wrapper    Enable DEBUG logging before the Base runtime is loaded.
   --verbose-wrapper  Enable verbose runtime argument handling before dispatch.
   --utc-wrapper      Print wrapper/runtime log timestamps in UTC.
+  --keep-temp        Preserve temporary run files after the command completes.
   --color            Preserve color-aware wrapper argument handling.
 
 Notes:
@@ -131,12 +132,14 @@ Notes:
     Base rejects `--option=value` syntax before command delegation. Arguments
     after `--` belong to the delegated project command.
   - Use `-v` for command-level debug logs. Python package standard options such
-    as `--debug`, `--quiet`, `--log-file`, `--config`, `--environment`, and
-    `--keep-temp` are not public `basectl` options.
+    as `--debug`, `--quiet`, `--log-file`, `--config`, and `--environment` are
+    not public `basectl` options.
   - Invoking `basectl` with no command starts a Base runtime shell for the
     nearest project manifest above the current directory, preserving that
     directory. If no manifest is found, it falls back to project `base`. In
     non-interactive shells it prints this help text.
+  - Use `--keep-temp` before the command name to preserve the complete run
+    temporary tree; temporary files are removed by default.
   - Use `--debug-wrapper` when debugging startup before command dispatch or
     Base runtime initialization.
 EOF
@@ -643,6 +646,9 @@ basectl_finalize_run_bundle() {
         "${BASE_CLI_HISTORY_STARTED_AT:-}" \
         "$(date -u +%Y-%m-%dT%H:%M:%SZ 2>/dev/null || true)" >"$tmp_file" && mv -f "$tmp_file" "$run_root/run.json"
     chmod 600 "$run_root/run.json" "${BASE_CLI_PRIMARY_LOG:-$run_root/logs/primary.log}" || return 1
+    if [[ "${BASE_CLI_KEEP_TEMP:-}" != true ]]; then
+        rm -rf -- "$run_root/tmp"
+    fi
 }
 
 basectl_history_record() {
@@ -682,7 +688,12 @@ basectl_history_record() {
 
 
 basectl_main() {
-    local base_debug=0 command="" command_status run_bundle_enabled=1
+    local base_debug=0 keep_temp=0 command="" command_status run_bundle_enabled=1
+
+    while [[ "${1:-}" == --keep-temp ]]; do
+        keep_temp=1
+        shift
+    done
     local history_args=() history_scope="${BASE_CLI_HISTORY_SCOPE:-primary}"
     local opt
 
@@ -752,6 +763,11 @@ basectl_main() {
     done
     shift $((OPTIND - 1))
 
+    while [[ "${1:-}" == --keep-temp ]]; do
+        keep_temp=1
+        shift
+    done
+
     command="${1:-}"
     [[ -n "$command" ]] && shift
     history_args=("$@")
@@ -762,6 +778,9 @@ basectl_main() {
     basectl_history_recordable_command "$command" || run_bundle_enabled=0
 
     basectl_get_base_home || return 1
+    if ((keep_temp)); then
+        export BASE_CLI_KEEP_TEMP=true
+    fi
     if ((run_bundle_enabled)); then
         basectl_initialize_run_bundle "$command" "$@" || return 1
     fi
diff --git a/cli/bash/commands/basectl/tests/help.bats b/cli/bash/commands/basectl/tests/help.bats
index 62aacfb6..6bfd4e70 100644
--- a/cli/bash/commands/basectl/tests/help.bats
+++ b/cli/bash/commands/basectl/tests/help.bats
@@ -41,6 +41,7 @@ load ./basectl_helpers.bash
     [[ "$output" == *"--debug-wrapper"* ]]
     [[ "$output" == *"--verbose-wrapper"* ]]
     [[ "$output" == *"--utc-wrapper"* ]]
+    [[ "$output" == *"--keep-temp"* ]]
     [[ "$output" == *"--color"* ]]
 }
 
diff --git a/cli/bash/commands/basectl/tests/runtime-dispatch.bats b/cli/bash/commands/basectl/tests/runtime-dispatch.bats
index 489ac38e..9c526962 100644
--- a/cli/bash/commands/basectl/tests/runtime-dispatch.bats
+++ b/cli/bash/commands/basectl/tests/runtime-dispatch.bats
@@ -46,6 +46,60 @@ load ./basectl_helpers.bash
 }
 
 
+@test "basectl removes the complete temp tree by default" {
+    run env \
+        BASE_HOME="$BASE_REPO_ROOT" \
+        BASE_TEST_TMPDIR="$TEST_TMPDIR" \
+        bash -c '
+            source "$BASE_HOME/cli/bash/commands/basectl/basectl.sh"
+            BASE_CACHE_DIR="$BASE_TEST_TMPDIR/cache" basectl_initialize_run_bundle setup base-demo || exit $?
+            mkdir -p "$BASE_CLI_RUN_ROOT/tmp/base_setup"
+            printf "temporary\n" >"$BASE_CLI_RUN_ROOT/tmp/base_setup/file.txt"
+            run_root="$BASE_CLI_RUN_ROOT"
+            basectl_finalize_run_bundle 0 || exit $?
+            printf "run_root=%s\n" "$run_root"
+            [[ ! -e "$run_root/tmp" ]]
+        '
+
+    [ "$status" -eq 0 ]
+}
+
+
+@test "basectl preserves the complete temp tree when explicitly requested" {
+    run env \
+        BASE_HOME="$BASE_REPO_ROOT" \
+        BASE_TEST_TMPDIR="$TEST_TMPDIR" \
+        BASE_CLI_KEEP_TEMP=true \
+        bash -c '
+            source "$BASE_HOME/cli/bash/commands/basectl/basectl.sh"
+            BASE_CACHE_DIR="$BASE_TEST_TMPDIR/cache" basectl_initialize_run_bundle setup base-demo || exit $?
+            mkdir -p "$BASE_CLI_RUN_ROOT/tmp/base_setup"
+            printf "temporary\n" >"$BASE_CLI_RUN_ROOT/tmp/base_setup/file.txt"
+            run_root="$BASE_CLI_RUN_ROOT"
+            basectl_finalize_run_bundle 0 || exit $?
+            [[ -f "$run_root/tmp/base_setup/file.txt" ]]
+        '
+
+    [ "$status" -eq 0 ]
+}
+
+
+@test "basectl exposes keep-temp as a wrapper option" {
+    run env \
+        BASE_HOME="$BASE_REPO_ROOT" \
+        bash -c '
+            source "$BASE_HOME/cli/bash/commands/basectl/basectl.sh"
+            log_debug() { :; }
+            basectl_get_base_home() { return 0; }
+            basectl_do_version() { printf "keep=%s\n" "${BASE_CLI_KEEP_TEMP:-}"; }
+            basectl_main --keep-temp version
+        '
+
+    [ "$status" -eq 0 ]
+    [ "$output" = "keep=true" ]
+}
+
+
 @test "basectl prints help when no command is given in a non-interactive shell" {
     run_basectl
 
diff --git a/docs/base-cli.md b/docs/base-cli.md
index 937485cf..c7a884d3 100644
--- a/docs/base-cli.md
+++ b/docs/base-cli.md
@@ -191,7 +191,7 @@ Directory lifecycle:
 
 | Directory | Created | Removed |
 |---|---|---|
-| `run.json`, `logs/`, `tmp/` | before command execution | run-bundle cleanup |
+| `run.json`, `logs/`, `tmp/` | before command execution | run-bundle cleanup; `tmp/` is removed unless `--keep-temp` is requested |
 | `cache/components/` | when a component needs it | explicit CLI cleanup |
 
 Commands running with `ctx.dry_run` skip default `logs/`, `cache/`, and
@@ -352,8 +352,9 @@ arguments.
 These are direct Python package options. Public `basectl` launchers expose
 `-v` for command-level debug logs and command-specific flags from
 `basectl <command> --help`; they do not expose `--debug`, `--quiet`,
-`--log-file`, `--config`, `--environment`, or `--keep-temp` as public
-`basectl` options.
+`--log-file`, `--config`, or `--environment` as public `basectl` options.
+The wrapper-level `basectl --keep-temp <command>` option explicitly preserves
+the complete temporary tree for that run.
 
 ## Interrupt And Cleanup
 
@@ -362,7 +363,7 @@ register them on import. Cleanup should:
 
 1. call user cleanup hooks
 2. flush and close log handlers
-3. remove `ctx.temp_dir` unless `keep_temp` is true
+3. remove `ctx.temp_dir` and empty temporary parents unless `keep_temp` is true
 
 CLI authors can register hooks:
 
diff --git a/docs/cache-ownership-and-layout.md b/docs/cache-ownership-and-layout.md
index b86db3e5..6726201e 100644
--- a/docs/cache-ownership-and-layout.md
+++ b/docs/cache-ownership-and-layout.md
@@ -140,9 +140,11 @@ project run through the history index and `run.json` metadata.
 
 ### `tmp/`
 
-Temporary files scoped to one run and component. Successful runs remove these
-directories automatically unless retention is requested. Failed or interrupted
-runs retain them for diagnosis until cleanup removes the completed bundle.
+Temporary files scoped to one run and component. Base removes the complete
+`tmp/` tree, including empty component parents, after every run by default.
+Pass the explicit `--keep-temp` wrapper option to preserve the complete tree
+for diagnosis. Run metadata, history, and `primary.log` are retained
+independently of this choice.
 
 ## Timestamps and permissions
 
diff --git a/docs/command-reference.md b/docs/command-reference.md
index df75ea36..54312ced 100644
--- a/docs/command-reference.md
+++ b/docs/command-reference.md
@@ -11,8 +11,9 @@ syntax.
 
 `basectl` exposes `-v` as the public command-level debug switch. Direct
 `base_cli` package standard options such as `--debug`, `--quiet`, `--log-file`,
-`--config`, `--environment`, and `--keep-temp` are private to Python package
-execution and are rejected by `basectl`.
+`--config` and `--environment` are private to Python package execution and are
+rejected by `basectl`. Use `basectl --keep-temp <command>` when temporary run
+files must be preserved for diagnosis; they are removed by default.
 
 ## Stability Tiers
 
diff --git a/lib/python/base_cli/README.md b/lib/python/base_cli/README.md
index f242edc9..fc347ec2 100644
--- a/lib/python/base_cli/README.md
+++ b/lib/python/base_cli/README.md
@@ -75,8 +75,9 @@ equals-form values such as `--name=Ada` before Click parses arguments.
 These are direct package options. Public `basectl` launchers expose `-v` for
 command-level debug logs and command-specific flags from
 `basectl <command> --help`; they do not expose `--debug`, `--quiet`,
-`--log-file`, `--config`, `--environment`, or `--keep-temp` as public
-`basectl` options.
+`--log-file`, `--config`, or `--environment` as public `basectl` options.
+The wrapper-level `basectl --keep-temp <command>` option preserves the
+complete temporary tree for that run.
 
 ## Command Registration
 
diff --git a/lib/python/base_cli/context.py b/lib/python/base_cli/context.py
index 314d8f45..0b564588 100644
--- a/lib/python/base_cli/context.py
+++ b/lib/python/base_cli/context.py
@@ -67,6 +67,11 @@ def cleanup(self) -> None:
         if not self.keep_temp and self.temp_dir.exists():
             try:
                 shutil.rmtree(self.temp_dir)
+                for parent in (self.temp_dir.parent, self.temp_dir.parent.parent):
+                    try:
+                        parent.rmdir()
+                    except OSError:
+                        break
             except OSError as exc:
                 self.log.warning("Temp directory cleanup failed for '%s': %s", self.temp_dir, exc)
         for handler in list(self.log.handlers):
diff --git a/lib/python/base_cli/tests/test_base_cli.py b/lib/python/base_cli/tests/test_base_cli.py
index dede6c83..65986dab 100644
--- a/lib/python/base_cli/tests/test_base_cli.py
+++ b/lib/python/base_cli/tests/test_base_cli.py
@@ -598,6 +598,8 @@ def main(ctx: base_cli.Context, name: str) -> None:
             self.assertEqual(result.exit_code, 0, result.output)
             self.assertEqual(seen["name"], "Ada")
             self.assertFalse(seen["temp_dir"].exists())
+            self.assertFalse(seen["temp_dir"].parent.exists())
+            self.assertFalse(seen["temp_dir"].parent.parent.exists())
             self.assertTrue(seen["cache_dir"].is_dir())
             log_dir = home / ".cache" / "base" / "base" / "runs" / next(
                 path.name for path in (home / ".cache" / "base" / "base" / "runs").iterdir()
@@ -945,6 +947,7 @@ def main(ctx: base_cli.Context, token: str) -> None:
                 self.assertEqual(seen["token"], "super-secret")
                 self.assertTrue(seen["debug"])
                 self.assertTrue(seen["temp_dir"].exists())
+                self.assertTrue(seen["temp_dir"].parent.exists())
                 self.assertEqual(seen["log_file"], log_file)
                 self.assertTrue(
                     seen["temp_dir"].is_relative_to(home / ".cache" / "base" / "base" / "runs")