diff --git a/backend/druks/setup_env.py b/backend/druks/setup_env.py
index 0454e98b..21c41d38 100644
--- a/backend/druks/setup_env.py
+++ b/backend/druks/setup_env.py
@@ -42,6 +42,10 @@
         "REDIS_URL",
         "DRUKS_AUTH_HEADER",
         "DEFAULT_HOST_PROVIDER",
+        "REGISTRY_HOST",
+        "REGISTRY_USERNAME",
+        "REGISTRY_PASSWORD",
+        "TEMPLATE_REPOSITORY",
         "SERVICE_TOKENS",
         "DRUKS_AUTH_MODE",
         "DRUKS_AUTH_JWKS_URL",
@@ -84,6 +88,10 @@
         "service_url",
         "service_token",
         "image",
+        "registry_host",
+        "registry_username",
+        "registry_password",
+        "template_repository",
         "proxy_url",
         "issuer_url",
         "browser_login_proxy",
@@ -200,6 +208,13 @@ def run_setup(
 service_url = ""
 service_token = ""
 image = ""
+# Access to private sandbox images on one registry host, for example ghcr.io.
+registry_host = ""
+registry_username = ""
+registry_password = ""
+# The repository path on that host where drukbox publishes sandbox templates.
+# The exe provider requires it.
+template_repository = ""
 # The secrets proxy, at the address a sandbox dials. A sandbox sends its HTTPS
 # through it. The docker shape uses the Docker bridge gateway. A remote shape
 # names the address of this host that its sandboxes reach, for example the
@@ -250,9 +265,6 @@ def _fresh_values(*, provider: str, home: str) -> tuple[tuple[tuple[str, ...], s
             (("sandbox", "service_url"), "http://127.0.0.1:8780"),
             (("sandbox", "service_token"), _hex_secret()),
             (("sandbox", "exe", "EXE_API_TOKEN"), ""),
-            (("sandbox", "exe", "EXE_IMAGE_REGISTRY"), ""),
-            (("sandbox", "exe", "EXE_REGISTRY_USERNAME"), ""),
-            (("sandbox", "exe", "EXE_REGISTRY_PASSWORD"), ""),
             (("sandbox", "exe", "TAILSCALE_TAILNET"), ""),
             (("sandbox", "exe", "TAILSCALE_OAUTH_CLIENT_ID"), ""),
             (("sandbox", "exe", "TAILSCALE_OAUTH_CLIENT_SECRET"), ""),
@@ -424,6 +436,10 @@ def _render_env(
             (
                 ("DEFAULT_HOST_PROVIDER", provider),
                 ("SERVICE_TOKENS", service_tokens),
+                ("REGISTRY_HOST", _get_string(config, ("sandbox", "registry_host"))),
+                ("REGISTRY_USERNAME", _get_string(config, ("sandbox", "registry_username"))),
+                ("REGISTRY_PASSWORD", _get_string(config, ("sandbox", "registry_password"))),
+                ("TEMPLATE_REPOSITORY", _get_string(config, ("sandbox", "template_repository"))),
                 ("SECRETS_KEY", _get_string(config, ("secrets", "drukbox_secrets_key"))),
                 ("SECRETS_PROXY_URL", proxy_url),
                 # The proxy binds the address sandboxes dial and nothing else.
diff --git a/backend/tests/test_setup_env.py b/backend/tests/test_setup_env.py
index 7f3410b1..ab6a2fe0 100644
--- a/backend/tests/test_setup_env.py
+++ b/backend/tests/test_setup_env.py
@@ -61,9 +61,6 @@ def test_fresh_exe_render_matches_the_deployment_contract(tmp_path):
     assert config["paths"]["harness_config_root"] == values["DRUKS_HARNESS_CONFIG_ROOT"]
     assert "EXE_API_TOKEN" not in values
     assert "TAILSCALE_TAILNET" not in values
-    for key in ("EXE_IMAGE_REGISTRY", "EXE_REGISTRY_USERNAME", "EXE_REGISTRY_PASSWORD"):
-        assert config["sandbox"]["exe"][key] == ""
-        assert key not in values
     assert len(config["secrets"]["postgres_password"]) == 64
     assert len(config["secrets"]["drukbox_secrets_key"]) == 44
     assert len(config["sandbox"]["service_token"]) == 64
@@ -581,36 +578,31 @@ def test_a_copy_of_a_secrets_setting_is_a_named_gap(tmp_path, assignment, gap):
     assert "SECRETS_PROXY_URL" not in values
 
 
-@pytest.mark.parametrize("repository", ["ghcr.io/acme/templates", "docker.io/acme/templates"])
-def test_exe_template_registry_uses_existing_provider_contract(tmp_path, repository):
+@pytest.mark.parametrize("provider", ["docker", "exe"])
+def test_registry_settings_render_for_drukbox_on_every_provider(tmp_path, provider):
     env_path = tmp_path / ".env"
     printed = []
-    assert (
-        _run(
-            env_path,
-            print_fn=printed.append,
-            set_values=(
-                "sandbox.proxy_url=http://100.64.0.10:8880",
-                "sandbox.exe.EXE_API_TOKEN=exe-token",
-                "sandbox.exe.TAILSCALE_TAILNET=tail.ts.net",
-                f"sandbox.exe.EXE_IMAGE_REGISTRY={repository}",
-                "sandbox.exe.EXE_REGISTRY_USERNAME=builder",
-                "sandbox.exe.EXE_REGISTRY_PASSWORD=registry-token",
-            ),
-        )
-        == 0
+    _run(
+        env_path,
+        provider=provider,
+        print_fn=printed.append,
+        set_values=(
+            "sandbox.registry_host=ghcr.io",
+            "sandbox.registry_username=builder",
+            "sandbox.registry_password=registry-token",
+            "sandbox.template_repository=acme/templates",
+        ),
     )
     values = read_env(env_path)
     expected = {
-        "EXE_IMAGE_REGISTRY": repository,
-        "EXE_REGISTRY_USERNAME": "builder",
-        "EXE_REGISTRY_PASSWORD": "registry-token",
+        "REGISTRY_HOST": "ghcr.io",
+        "REGISTRY_USERNAME": "builder",
+        "REGISTRY_PASSWORD": "registry-token",
+        "TEMPLATE_REPOSITORY": "acme/templates",
     }
     for key, value in expected.items():
         assert values[key] == value
         assert env_path.read_text().count(f"{key}=") == 1
-    assert "REGISTRY_HOST" not in values
-    assert "TEMPLATE_REPOSITORY" not in values
     assert "registry-token" not in "\n".join(printed)
     assert stat.S_IMODE(env_path.stat().st_mode) == 0o600
     assert stat.S_IMODE((tmp_path / "druks.toml").stat().st_mode) == 0o600
diff --git a/docs/configuration.md b/docs/configuration.md
index b817fdba..a41cf572 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -40,7 +40,7 @@ host-run development template for that environment plane.
 | `[urls]` | Dashboard callback base URL and public webhook hostname |
 | `[secrets]` | Generated deployment secrets |
 | `[paths]` | Host data and harness configuration paths |
-| `[sandbox]` | Drukbox provider, service URL and token, image override, and the proxy and issuer addresses |
+| `[sandbox]` | Drukbox provider, service URL and token, image override, registry access, and the proxy and issuer addresses |
 | `[sandbox.<provider>]` | Provider environment passed through to the remote stack |
 | `[env]` | Additional deployment environment settings rendered verbatim |
 
@@ -606,6 +606,8 @@ before provisioning a VM if its selected credential is missing.
 | `sandbox.service_token` | Drukbox API token |
 | `sandbox.timeout` | Control-plane request timeout. The default is 180 seconds |
 | `sandbox.image` | Optional provider image override |
+| `sandbox.registry_host`, `sandbox.registry_username`, `sandbox.registry_password` | Access to private sandbox images on one registry host, for example `ghcr.io`. Set the three together. See [Drukbox](https://github.com/czpython/drukbox/blob/main/docs/deploy.md#private-image-registry) |
+| `sandbox.template_repository` | The repository path on that host where Drukbox publishes sandbox templates. The exe provider requires it |
 | `sandbox.proxy_url` | The secrets proxy, at the address a sandbox dials. The docker shape sets `http://172.17.0.1:8880`. docker-sbx leaves it empty |
 | `sandbox.issuer_url` | The issuer base URL the secrets exchange dials. The default is `http://127.0.0.1:8001`. For a Drukbox on another server, set the address of the Druks host that Drukbox reaches. The installer then serves the issuer route there ([the issuer listener](deployment.md#the-issuer-listener)) |
 | `sandbox.browser_login_proxy` | Login-window egress proxy. An empty value keeps the box IP |