diff --git a/tests/tools/test_terminal_tool.py b/tests/tools/test_terminal_tool.py
index b17fc332c49..fe2f5e3f514 100644
--- a/tests/tools/test_terminal_tool.py
+++ b/tests/tools/test_terminal_tool.py
@@ -168,3 +168,46 @@ def test_validate_workdir_blocks_shell_metacharacters_in_windows_paths():
     assert terminal_tool._validate_workdir(r"C:\Users\Alice\project; rm -rf /")
     assert terminal_tool._validate_workdir(r"C:\Users\Alice\project$(whoami)")
     assert terminal_tool._validate_workdir("C:\\Users\\Alice\\project\nwhoami")
+
+
+def test_get_env_config_ignores_bad_docker_json_for_local_backend(monkeypatch):
+    """Docker-only JSON env vars must not break the default local backend."""
+    monkeypatch.setenv("TERMINAL_ENV", "local")
+    monkeypatch.setenv("TERMINAL_DOCKER_VOLUMES", "None")
+    monkeypatch.setenv("TERMINAL_DOCKER_ENV", "not-json")
+    monkeypatch.setenv("TERMINAL_DOCKER_FORWARD_ENV", "not-json")
+    monkeypatch.setenv("TERMINAL_DOCKER_EXTRA_ARGS", "not-json")
+
+    config = terminal_tool._get_env_config()
+
+    assert config["env_type"] == "local"
+    assert config["docker_volumes"] == []
+    assert config["docker_env"] == {}
+    assert config["docker_forward_env"] == []
+    assert config["docker_extra_args"] == []
+
+
+def test_get_env_config_ignores_bad_docker_json_for_ssh_backend(monkeypatch):
+    """Non-container remote backends should also ignore Docker-only JSON."""
+    monkeypatch.setenv("TERMINAL_ENV", "ssh")
+    monkeypatch.setenv("TERMINAL_DOCKER_VOLUMES", "None")
+    monkeypatch.setenv("TERMINAL_DOCKER_ENV", "not-json")
+
+    config = terminal_tool._get_env_config()
+
+    assert config["env_type"] == "ssh"
+    assert config["docker_volumes"] == []
+    assert config["docker_env"] == {}
+
+
+def test_get_env_config_still_rejects_bad_docker_json_for_docker_backend(monkeypatch):
+    """Selecting Docker should keep the existing actionable config error."""
+    monkeypatch.setenv("TERMINAL_ENV", "docker")
+    monkeypatch.setenv("TERMINAL_DOCKER_VOLUMES", "None")
+
+    try:
+        terminal_tool._get_env_config()
+    except ValueError as exc:
+        assert "TERMINAL_DOCKER_VOLUMES" in str(exc)
+    else:
+        raise AssertionError("Docker backend must validate TERMINAL_DOCKER_VOLUMES")
diff --git a/tools/terminal_tool.py b/tools/terminal_tool.py
index e859cf10cad..d9edd7a5d5d 100644
--- a/tools/terminal_tool.py
+++ b/tools/terminal_tool.py
@@ -1030,7 +1030,7 @@ def _resolve_container_task_id(task_id: Optional[str]) -> str:
 
 # Configuration from environment variables
 
-def _parse_env_var(name: str, default: str, converter=int, type_label: str = "integer"):
+def _parse_env_var(name: str, default: str, converter: Any = int, type_label: str = "integer"):
     """Parse an environment variable with *converter*, raising a clear error on bad values.
 
     Without this wrapper, a single malformed env var (e.g. TERMINAL_TIMEOUT=5m)
@@ -1067,6 +1067,32 @@ def _get_env_config() -> Dict[str, Any]:
     env_type = os.getenv("TERMINAL_ENV", "local")
     
     mount_docker_cwd = os.getenv("TERMINAL_DOCKER_MOUNT_CWD_TO_WORKSPACE", "false").lower() in {"true", "1", "yes"}
+    container_backend = env_type in {"docker", "singularity", "modal", "daytona"}
+    docker_backend = env_type == "docker"
+
+    # Docker/container-only env vars may be bridged from config.yaml even when
+    # the active backend is local/ssh.  Do not parse their JSON/numeric payloads
+    # until a backend that can consume them is selected; a stale or invalid
+    # Docker value should not make local terminal/execute_code unusable.
+    if container_backend:
+        container_cpu = _parse_env_var("TERMINAL_CONTAINER_CPU", "1", float, "number")
+        container_memory = _parse_env_var("TERMINAL_CONTAINER_MEMORY", "5120")
+        container_disk = _parse_env_var("TERMINAL_CONTAINER_DISK", "51200")
+    else:
+        container_cpu = 1.0
+        container_memory = 5120
+        container_disk = 51200
+
+    if docker_backend:
+        docker_forward_env = _parse_env_var("TERMINAL_DOCKER_FORWARD_ENV", "[]", json.loads, "valid JSON")
+        docker_volumes = _parse_env_var("TERMINAL_DOCKER_VOLUMES", "[]", json.loads, "valid JSON")
+        docker_env = _parse_env_var("TERMINAL_DOCKER_ENV", "{}", json.loads, "valid JSON")
+        docker_extra_args = _parse_env_var("TERMINAL_DOCKER_EXTRA_ARGS", "[]", json.loads, "valid JSON")
+    else:
+        docker_forward_env = []
+        docker_volumes = []
+        docker_env = {}
+        docker_extra_args = []
 
     # Default cwd: local uses the host's current directory, ssh uses the
     # remote home, and everything else starts in the backend's default
@@ -1110,7 +1136,7 @@ def _get_env_config() -> Dict[str, Any]:
         "env_type": env_type,
         "modal_mode": coerce_modal_mode(os.getenv("TERMINAL_MODAL_MODE", "auto")),
         "docker_image": os.getenv("TERMINAL_DOCKER_IMAGE", default_image),
-        "docker_forward_env": _parse_env_var("TERMINAL_DOCKER_FORWARD_ENV", "[]", json.loads, "valid JSON"),
+        "docker_forward_env": docker_forward_env,
         "singularity_image": os.getenv("TERMINAL_SINGULARITY_IMAGE", f"docker://{default_image}"),
         "modal_image": os.getenv("TERMINAL_MODAL_IMAGE", default_image),
         "daytona_image": os.getenv("TERMINAL_DAYTONA_IMAGE", default_image),
@@ -1134,14 +1160,14 @@ def _get_env_config() -> Dict[str, Any]:
         "local_persistent": os.getenv("TERMINAL_LOCAL_PERSISTENT", "false").lower() in {"true", "1", "yes"},
         # Container resource config (applies to docker, singularity, modal,
         # daytona -- ignored for local/ssh)
-        "container_cpu": _parse_env_var("TERMINAL_CONTAINER_CPU", "1", float, "number"),
-        "container_memory": _parse_env_var("TERMINAL_CONTAINER_MEMORY", "5120"),     # MB (default 5GB)
-        "container_disk": _parse_env_var("TERMINAL_CONTAINER_DISK", "51200"),        # MB (default 50GB)
+        "container_cpu": container_cpu,
+        "container_memory": container_memory,     # MB (default 5GB)
+        "container_disk": container_disk,        # MB (default 50GB)
         "container_persistent": os.getenv("TERMINAL_CONTAINER_PERSISTENT", "true").lower() in {"true", "1", "yes"},
-        "docker_volumes": _parse_env_var("TERMINAL_DOCKER_VOLUMES", "[]", json.loads, "valid JSON"),
-        "docker_env": _parse_env_var("TERMINAL_DOCKER_ENV", "{}", json.loads, "valid JSON"),
+        "docker_volumes": docker_volumes,
+        "docker_env": docker_env,
         "docker_run_as_host_user": os.getenv("TERMINAL_DOCKER_RUN_AS_HOST_USER", "false").lower() in {"true", "1", "yes"},
-        "docker_extra_args": _parse_env_var("TERMINAL_DOCKER_EXTRA_ARGS", "[]", json.loads, "valid JSON"),
+        "docker_extra_args": docker_extra_args,
         # Cross-process container reuse (issue #20561).  The docs claim
         # "ONE long-lived container shared across sessions" — this toggle
         # makes that real by probing for a labeled container at startup and