diff --git a/.github/workflows/ci_cd.yml b/.github/workflows/ci_cd.yml
index 0536c7e5..39f7a2c9 100644
--- a/.github/workflows/ci_cd.yml
+++ b/.github/workflows/ci_cd.yml
@@ -44,6 +44,10 @@ jobs:
       run: |
         poetry run mypy landingai
     - name: Test with pytest
+      env:
+        # Not available to pull requests from forks; the integration tests that
+        # need it skip themselves when it is empty.
+        LANDINGAI_API_KEY: ${{ secrets.LANDINGAI_API_KEY }}
       run: |
         poetry run pytest -v tests
 
diff --git a/tests/integration/landingai/test_predict_e2e.py b/tests/integration/landingai/test_predict_e2e.py
index 0b320a94..aedaacf9 100644
--- a/tests/integration/landingai/test_predict_e2e.py
+++ b/tests/integration/landingai/test_predict_e2e.py
@@ -1,4 +1,5 @@
 import logging
+import os
 from pathlib import Path
 
 import numpy as np
@@ -9,7 +10,17 @@
 from landingai.predict import OcrPredictor, Predictor
 from landingai.visualize import overlay_predictions
 
-_API_KEY = "land_sk_aMemWbpd41yXnQ0tXvZMh59ISgRuKNRKjJEIUHnkiH32NBJAwf"
+# These tests call live LandingLens endpoints, so they need a real API key.
+# It is read from the LANDINGAI_API_KEY environment variable, which CI populates
+# from the repository secret of the same name. Secrets are not exposed to
+# workflow runs triggered by pull requests from forks, so skip instead of
+# failing when the key is absent.
+_API_KEY = os.environ.get("LANDINGAI_API_KEY", "")
+
+pytestmark = pytest.mark.skipif(
+    not _API_KEY,
+    reason="LANDINGAI_API_KEY is not set; skipping tests that call live endpoints.",
+)
 
 _EXPECTED_VP_PREDS = [
     {
diff --git a/tests/unit/conftest.py b/tests/unit/conftest.py
new file mode 100644
index 00000000..fafda79b
--- /dev/null
+++ b/tests/unit/conftest.py
@@ -0,0 +1,26 @@
+import pytest
+
+# Both cases are cleared because pydantic-settings matches env vars
+# case-insensitively, and the tests below set the lowercase spelling.
+_API_CREDENTIAL_ENV_VARS = (
+    "LANDINGAI_API_KEY",
+    "landingai_api_key",
+    "LANDINGAI_API_SECRET",
+    "landingai_api_secret",
+)
+
+
+@pytest.fixture(autouse=True)
+def unset_api_credential_env_vars(monkeypatch):
+    """Isolate unit tests from API credentials in the ambient environment.
+
+    CI exports LANDINGAI_API_KEY so the integration tests can call live
+    endpoints. Environment variables take precedence over .env files, so
+    without this the credential-loading tests would read the real key instead
+    of the one they set up, and the tests asserting that an invalid or missing
+    key raises would silently find a valid one.
+
+    Tests that need a credential set it themselves after this fixture runs.
+    """
+    for var in _API_CREDENTIAL_ENV_VARS:
+        monkeypatch.delenv(var, raising=False)