diff --git a/docs/agents/action/iteration/roundtrip.md b/docs/agents/action/iteration/roundtrip.md
index aad94d9b78..f88464b74a 100644
--- a/docs/agents/action/iteration/roundtrip.md
+++ b/docs/agents/action/iteration/roundtrip.md
@@ -14,7 +14,7 @@ For debugging the compose deploy of one role, see [Compose Loop](compose.md); fo
 - With no `apps=`, the loop defaults to **every application, most-complex first** (the `complexity` CLI: `infinito meta roles applications complexity --sort "desc weight" --format string`). That is a large run (one compose plus one swarm deploy per app), so narrow it with `apps=` while iterating.
 - The mode sequence defaults to `compose swarm` and is overridable with `modes="compose swarm"`. The order is always compose first, so the cheaper mode fails fast before the expensive swarm rebuild. Append `k8s` here once that mode exists.
 - Per step the output is streamed to `${TMPDIR:-/tmp}/roundtrip-<app>-<mode>.log`. Tell the operator the exact `tail -f` path for the running step.
-- The compose step runs `compose-deploy mode=reinstall apps=<app> full_cycle=true variant=0`; the swarm step runs `swarm-zombie app=<app>`, pinned to `variant:0` and, whenever the role can take it, to the `multi` network mode, so a multi-variant app validates one cluster (parity with the compose step, not the full per-variant CI matrix that runs one isolated runner per variant). The cluster is named `<app>-swarm-mgr-01` etc. via the mandatory `SWARM_NAME` (the app id is the default cluster id). Each validated swarm cluster is released afterwards unless you pass `keep=true`.
+- The compose step runs `compose-deploy mode=reinstall apps=<app> full_cycle=true variant=0`; the swarm step runs `swarm-zombie app=<app>`, pinned to `variant:0` and to a network mode: `clearnet` when `disable=` holds the `tor` key, else `multi` whenever the role can take it, so a multi-variant app validates one cluster (parity with the compose step, not the full per-variant CI matrix that runs one isolated runner per variant). The cluster is named `<app>-swarm-mgr-01` etc. via the mandatory `SWARM_NAME` (the app id is the default cluster id). Each validated swarm cluster is released afterwards unless you pass `keep=true`.
 - `make autoformat` and `make test` MUST be green before a roundtrip; the loop does not re-run them per app.
 - **A blocked mode is NEVER a reason to silently switch to another.** If a mode cannot run (the swarm NFS wedge below, a wedged daemon, a missing host capability), STOP the whole sweep, report the blocker together with the exact recovery command, and wait for it to be cleared. You MUST NOT fall back to a `modes=compose`-only (or any reduced) sweep to look productive: it hides the unmet swarm parity and never satisfies the compose-AND-swarm gate. Resume the full sweep only once the blocker is gone.
 
diff --git a/scripts/tests/deploy/roundtrip.sh b/scripts/tests/deploy/roundtrip.sh
index b969b88212..99f281d247 100755
--- a/scripts/tests/deploy/roundtrip.sh
+++ b/scripts/tests/deploy/roundtrip.sh
@@ -7,7 +7,8 @@ set -euo pipefail
 #           (complexity clone == false), most complex first, when unset
 #   modes - mode sequence (default "compose swarm"; append "k8s" here once it exists)
 #   keep  - true keeps each validated swarm cluster instead of releasing it
-#   disable - comma-separated provider keys removed from the test inventory
+#   disable - comma-separated provider keys removed from the test inventory;
+#             the Tor key pins the swarm step to clearnet
 _repo_root="$(cd "$(dirname "$0")/../../.." && pwd)"
 
 # shellcheck source=scripts/meta/env/load.sh
@@ -28,6 +29,10 @@ _log_dir="${TMPDIR:-/tmp}" # nocheck: posix TMPDIR convention
 read -ra _apps <<<"${apps//$'\n'/ }"
 read -ra _modes <<<"$modes"
 
+_tor_key="$("${PYTHON}" -c "import sys; sys.path.insert(0, '${_repo_root}'); from utils.github.variant.network import TOR_SERVICE; print(TOR_SERVICE)")"
+_disabled=",${disable:-},"
+_disabled="${_disabled//[[:space:]]/,}"
+
 for app in "${_apps[@]}"; do
 	app_skip="$("${PYTHON}" -c "import sys; sys.path.insert(0, '${_repo_root}'); from utils.roles.meta_lookup import get_role_skip; print(' '.join(get_role_skip('${app}')))")"
 	for mode in "${_modes[@]}"; do
@@ -45,7 +50,9 @@ for app in "${_apps[@]}"; do
 			;;
 		swarm)
 			network=""
-			if "${PYTHON}" -m cli.meta.ci.validate --modes swarm --whitelist "${app}#0@swarm+multi" >/dev/null 2>&1; then
+			if [[ "${_disabled}" == *",${_tor_key},"* ]]; then
+				network="clearnet"
+			elif "${PYTHON}" -m cli.meta.ci.validate --modes swarm --whitelist "${app}#0@swarm+multi" >/dev/null 2>&1; then
 				network="multi"
 			fi
 			echo "==> roundtrip: ${app} [swarm] network=${network:-rotation}"
diff --git a/scripts/tests/workspace/swarm/02_zombie.sh b/scripts/tests/workspace/swarm/02_zombie.sh
index 5f81f90936..a49399be39 100755
--- a/scripts/tests/workspace/swarm/02_zombie.sh
+++ b/scripts/tests/workspace/swarm/02_zombie.sh
@@ -15,7 +15,7 @@ docker image inspect "${node_image}" >/dev/null 2>&1 || {
 }
 
 echo "Deploying the MariaDB database role ${MARIADB_APP} on a throwaway swarm cluster."
-make swarm-zombie app="${MARIADB_APP}" disable="$(variable_services mariadb node nfs-server)"
+make swarm-zombie app="${MARIADB_APP}" disable="$(variable_services mariadb node nfs-server)" network=clearnet
 
 echo "Releasing the swarm cluster."
 make swarm-down name="${MARIADB_APP}"
diff --git a/tests/unit/python/scripts/tests/deploy/test_roundtrip.py b/tests/unit/python/scripts/tests/deploy/test_roundtrip.py
index 9e1ae703c5..5012055a33 100644
--- a/tests/unit/python/scripts/tests/deploy/test_roundtrip.py
+++ b/tests/unit/python/scripts/tests/deploy/test_roundtrip.py
@@ -1,9 +1,14 @@
-"""Contract between the swarm drill's completion marker and the roundtrip gate."""
+"""The roundtrip gate: its drill-completion contract and the network its swarm step pins."""
 
 from __future__ import annotations
 
+import os
 import re
+import subprocess
+import sys
+import tempfile
 import unittest
+from pathlib import Path
 
 from utils.cache.files import PROJECT_ROOT, read_text
 
@@ -12,6 +17,73 @@ DRILL = (
 )
 GATE = PROJECT_ROOT / "scripts" / "tests" / "deploy" / "roundtrip.sh"
 MARKER = "==> swarm drill complete: app="
+APP = "svc-db-postgres"
+PYTHON_STUB = (
+    "#!/usr/bin/env bash\n"
+    'if [ "$1" = -m ]; then exit "${STUB_MULTI_RC}"; fi\n'
+    'exec "${REAL_PYTHON}" "$@"\n'
+)
+MAKE_STUB = (
+    "#!/usr/bin/env bash\n"
+    'printf "%s\\n" "$*" >>"${STUB_LOG}"\n'
+    'echo "==> swarm drill complete: app=${STUB_APP}"\n'
+)
+
+
+def swarm_network(disable: str, *, multi_accepted: bool) -> str:
+    """Run the roundtrip's swarm step against stubs and return the network it pins.
+
+    Args:
+        disable: the ``disable`` env the roundtrip runs with.
+        multi_accepted: whether the stubbed validator accepts the role's
+            ``multi`` row.
+
+    Returns:
+        The ``network=`` value the roundtrip hands to ``swarm-zombie``.
+    """
+    with tempfile.TemporaryDirectory() as tmp:
+        root = Path(tmp) / "repo"
+        script = root / "scripts" / "tests" / "deploy" / "roundtrip.sh"
+        script.parent.mkdir(parents=True)
+        script.symlink_to(GATE)
+        loader = root / "scripts" / "meta" / "env" / "load.sh"
+        loader.parent.mkdir(parents=True)
+        loader.write_text("")
+        bin_dir = Path(tmp) / "bin"
+        bin_dir.mkdir()
+        for name, body in (("python", PYTHON_STUB), ("make", MAKE_STUB)):
+            stub = bin_dir / name
+            stub.write_text(body)
+            stub.chmod(0o755)
+        log = Path(tmp) / "make.log"
+        log.touch()
+        env = {k: v for k, v in os.environ.items() if k != "BASH_ENV"}
+        env.update(
+            PATH=f"{bin_dir}{os.pathsep}{os.environ['PATH']}",
+            PYTHON=str(bin_dir / "python"),
+            REAL_PYTHON=sys.executable,
+            PYTHONPATH=str(PROJECT_ROOT),
+            TMPDIR=tmp,
+            STUB_LOG=str(log),
+            STUB_APP=APP,
+            STUB_MULTI_RC="0" if multi_accepted else "1",
+            apps=APP,
+            modes="swarm",
+            keep="true",
+            disable=disable,
+        )
+        done = subprocess.run(
+            ["bash", str(script)],
+            env=env,
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        if done.returncode != 0:
+            raise AssertionError(f"roundtrip failed: {done.stderr}")
+        calls = log.read_text().splitlines()  # nocheck: cache-read  stub call log
+    zombie = next(call for call in calls if " swarm-zombie " in call)
+    return re.search(r"(?:^| )network=(\S*)", zombie).group(1)
 
 
 class TestRoundtripMarker(unittest.TestCase):
@@ -44,5 +116,29 @@ class TestRoundtripMarker(unittest.TestCase):
         self.assertNotIn("provision/deploy/e2e/verify per round", self.gate)
 
 
+class TestRoundtripSwarmNetwork(unittest.TestCase):
+    def test_a_role_that_takes_multi_is_pinned_to_multi(self) -> None:
+        self.assertEqual(
+            swarm_network("matomo,dashboard", multi_accepted=True), "multi"
+        )
+
+    def test_a_role_refused_multi_keeps_the_rotation(self) -> None:
+        self.assertEqual(swarm_network("", multi_accepted=False), "")
+
+    def test_a_disabled_tor_provider_pins_clearnet(self) -> None:
+        self.assertEqual(
+            swarm_network("matomo,tor,zammad", multi_accepted=True), "clearnet"
+        )
+
+    def test_a_disabled_tor_provider_pins_clearnet_over_the_rotation(self) -> None:
+        self.assertEqual(swarm_network("tor", multi_accepted=False), "clearnet")
+
+    def test_a_space_separated_tor_key_pins_clearnet(self) -> None:
+        self.assertEqual(swarm_network("matomo tor", multi_accepted=True), "clearnet")
+
+    def test_a_key_that_only_starts_with_tor_keeps_multi(self) -> None:
+        self.assertEqual(swarm_network("tor-smtp", multi_accepted=True), "multi")
+
+
 if __name__ == "__main__":
     unittest.main()