diff --git a/strix/runtime/session_manager.py b/strix/runtime/session_manager.py
index cdc6d9558..3e7d57154 100644
--- a/strix/runtime/session_manager.py
+++ b/strix/runtime/session_manager.py
@@ -21,6 +21,11 @@
 
 # In-container Caido sidecar port (matches the image's caido-cli bind).
 _CONTAINER_CAIDO_PORT = 48080
+_CONTAINER_CAIDO_SCHEME = "http"
+_CONTAINER_CAIDO_HOST = "127.0.0.1"
+_HOST_GATEWAY_NAME = "host.docker.internal"
+_NO_PROXY_VALUE = "localhost,127.0.0.1"
+_CA_BUNDLE_PATH = "/etc/ssl/certs/ca-certificates.crt"
 
 
 _SESSION_CACHE: dict[str, dict[str, Any]] = {}
@@ -29,6 +34,29 @@
 _WORKSPACE_ROOT = "/workspace"
 
 
+def _container_caido_url() -> str:
+    return f"{_CONTAINER_CAIDO_SCHEME}://{_CONTAINER_CAIDO_HOST}:{_CONTAINER_CAIDO_PORT}"
+
+
+def build_sandbox_environment() -> dict[str, Any]:
+    """Return environment variables inherited by sandbox subprocesses."""
+    container_caido_url = _container_caido_url()
+    return {
+        "PYTHONUNBUFFERED": "1",
+        "HOST_GATEWAY": _HOST_GATEWAY_NAME,
+        "http_proxy": container_caido_url,
+        "https_proxy": container_caido_url,
+        "HTTP_PROXY": container_caido_url,
+        "HTTPS_PROXY": container_caido_url,
+        "ALL_PROXY": container_caido_url,
+        "all_proxy": container_caido_url,
+        "NO_PROXY": _NO_PROXY_VALUE,
+        "no_proxy": _NO_PROXY_VALUE,
+        "REQUESTS_CA_BUNDLE": _CA_BUNDLE_PATH,
+        "SSL_CERT_FILE": _CA_BUNDLE_PATH,
+    }
+
+
 def build_session_entries(
     local_sources: list[dict[str, Any]],
 ) -> tuple[dict[str | Path, BaseEntry], list[dict[str, Any]], list[Path]]:
@@ -91,19 +119,10 @@ async def create_or_reuse(
     # picks up these env vars automatically. ``NO_PROXY`` keeps the
     # agent-browser CDP daemon's localhost traffic from looping back
     # through Caido.
-    container_caido_url = f"http://127.0.0.1:{_CONTAINER_CAIDO_PORT}"
+    container_caido_url = _container_caido_url()
     manifest = Manifest(
         entries=entries,
-        environment=Environment(
-            value={
-                "PYTHONUNBUFFERED": "1",
-                "HOST_GATEWAY": "host.docker.internal",
-                "http_proxy": container_caido_url,
-                "https_proxy": container_caido_url,
-                "ALL_PROXY": container_caido_url,
-                "NO_PROXY": "localhost,127.0.0.1",
-            },
-        ),
+        environment=Environment(value=build_sandbox_environment()),
     )
 
     backend_name = load_settings().runtime.backend
diff --git a/tests/test_session_entries.py b/tests/test_session_entries.py
index e08c59aa1..830c49175 100644
--- a/tests/test_session_entries.py
+++ b/tests/test_session_entries.py
@@ -6,13 +6,18 @@
 
 from agents.sandbox.entries import LocalDir
 
-from strix.runtime.session_manager import build_session_entries
+from strix.runtime.session_manager import build_sandbox_environment, build_session_entries
 
 
 if TYPE_CHECKING:
     from pathlib import Path
 
 
+EXPECTED_CAIDO_URL = "http://127.0.0.1:48080"
+EXPECTED_CA_BUNDLE = "/etc/ssl/certs/ca-certificates.crt"
+EXPECTED_NO_PROXY = "localhost,127.0.0.1"
+
+
 def _source(subdir: str, path: str, *, mount: bool = False) -> dict[str, Any]:
     return {"source_path": path, "workspace_subdir": subdir, "mount": mount}
 
@@ -85,3 +90,18 @@ def test_symlink_tree_is_staged(tmp_path: Path) -> None:
     assert entry.src == staged_dirs[0]
     assert not (staged_dirs[0] / "link.txt").is_symlink()
     assert (staged_dirs[0] / "link.txt").read_text() == "content"
+
+
+def test_sandbox_environment_exports_proxy_and_ca_aliases() -> None:
+    env = build_sandbox_environment()
+
+    assert env["http_proxy"] == EXPECTED_CAIDO_URL
+    assert env["https_proxy"] == EXPECTED_CAIDO_URL
+    assert env["HTTP_PROXY"] == EXPECTED_CAIDO_URL
+    assert env["HTTPS_PROXY"] == EXPECTED_CAIDO_URL
+    assert env["ALL_PROXY"] == EXPECTED_CAIDO_URL
+    assert env["all_proxy"] == EXPECTED_CAIDO_URL
+    assert env["NO_PROXY"] == EXPECTED_NO_PROXY
+    assert env["no_proxy"] == EXPECTED_NO_PROXY
+    assert env["REQUESTS_CA_BUNDLE"] == EXPECTED_CA_BUNDLE
+    assert env["SSL_CERT_FILE"] == EXPECTED_CA_BUNDLE