diff --git a/adapters/python/claude/README.md b/adapters/python/claude/README.md
index 31c06290..efb10342 100644
--- a/adapters/python/claude/README.md
+++ b/adapters/python/claude/README.md
@@ -118,8 +118,10 @@ Schema defaults are documentation only; planning preserves the supplied settings
 without adding `setting_sources`.
 
 The adapter filters the inherited environment before launching Claude Code.
-It retains portable OS/config variables, the selected model's `api_key_env`,
-and explicitly configured `environment.env` values. Raw Claude stderr is consumed
+It retains portable OS/config variables, NeMo Relay logging variables
+(`NEMO_RELAY_LOG`, `NEMO_RELAY_LOG_CONFIG_PATH`, `NEMO_RELAY_LOG_STDERR`, and
+`NEMO_RELAY_LOG_STDERR_FORMAT`), the selected model's `api_key_env`, and
+explicitly configured `environment.env` values. Raw Claude stderr is consumed
 by the SDK and is not persisted as a NeMo Fabric artifact.
 
 ## Relay Observability
diff --git a/adapters/python/claude/src/nemo_fabric_adapters/claude/adapter.py b/adapters/python/claude/src/nemo_fabric_adapters/claude/adapter.py
index 804553c4..c7880fa9 100644
--- a/adapters/python/claude/src/nemo_fabric_adapters/claude/adapter.py
+++ b/adapters/python/claude/src/nemo_fabric_adapters/claude/adapter.py
@@ -79,6 +79,12 @@
     "LC_ALL",
     "LC_CTYPE",
     "LOCALAPPDATA",
+    # Relay hook commands reject these when set to an empty string, and the
+    # SDK can only override inherited variables, so keep the parent's values.
+    "NEMO_RELAY_LOG",
+    "NEMO_RELAY_LOG_CONFIG_PATH",
+    "NEMO_RELAY_LOG_STDERR",
+    "NEMO_RELAY_LOG_STDERR_FORMAT",
     "NO_PROXY",
     "PATH",
     "PATHEXT",
diff --git a/tests/adapters/test_claude_adapter.py b/tests/adapters/test_claude_adapter.py
index dd71f7c9..0a4650e6 100644
--- a/tests/adapters/test_claude_adapter.py
+++ b/tests/adapters/test_claude_adapter.py
@@ -700,6 +700,36 @@ def test_build_options_adds_relay_plugin_and_gateway_environment(
     ).exists()
 
 
+@pytest.mark.parametrize(
+    "logging_environment",
+    [
+        {
+            "NEMO_RELAY_LOG": "debug",
+            "NEMO_RELAY_LOG_STDERR": "true",
+            "NEMO_RELAY_LOG_STDERR_FORMAT": "jsonl",
+        },
+        {"NEMO_RELAY_LOG_CONFIG_PATH": "/etc/relay/logging.toml"},
+    ],
+)
+def test_build_options_relay_logging_environment_set_forwards_parent_values(
+    relay_payload, tmp_path, logging_environment
+):
+    # Relay rejects an empty logging variable, so a blanked value makes every
+    # Claude hook fail before it reaches the gateway.
+    os.environ.update(logging_environment)
+    os.environ["NEMO_RELAY_CLIENT_TOKEN"] = "parent-route-token"
+    os.environ["FABRIC_UNRELATED_SECRET"] = "do-not-forward"
+
+    options = build_options(relay_payload, relay=relay_settings(tmp_path, {}))
+
+    forwarded_logging_environment = {
+        name: options.env[name] for name in logging_environment
+    }
+    assert forwarded_logging_environment == logging_environment
+    assert options.env["NEMO_RELAY_CLIENT_TOKEN"] == ""
+    assert options.env["FABRIC_UNRELATED_SECRET"] == ""
+
+
 def test_build_options_does_not_enable_skills_for_relay_plugin_alone(
     relay_payload, tmp_path
 ):