diff --git a/CHANGELOG.d/20260912-strix-optional-web-search-warning.md b/CHANGELOG.d/20260912-strix-optional-web-search-warning.md
new file mode 100644
index 0000000000..031003b570
--- /dev/null
+++ b/CHANGELOG.d/20260912-strix-optional-web-search-warning.md
@@ -0,0 +1,6 @@
+### Fixed
+
+- Keep completed Strix scans valid when their report contains only the exact
+  upstream warning for missing optional `EXA_API_KEY`, `PERPLEXITY_API_KEY`, or
+  combined web-search credentials. Unknown warnings remain fail-closed, and raw
+  report artifacts remain unchanged for audit evidence.
diff --git a/scripts/ci/strix_quick_gate.sh b/scripts/ci/strix_quick_gate.sh
index c08f2fa36c..886c13ec46 100755
--- a/scripts/ci/strix_quick_gate.sh
+++ b/scripts/ci/strix_quick_gate.sh
@@ -201,6 +201,13 @@ known_scanner_warning = re.compile(
     r"^(?:│  MODEL QUALITY WARNING\s+│|"
     r"Warning: You are sending unauthenticated requests to the HF Hub\.)"
 )
+known_optional_search_warning = re.compile(
+    r"^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d+ WARNING "
+    r"[^ ]+ - strix\.tools\.web_search\.tool: "
+    r"web_search invoked without "
+    r"(?:EXA_API_KEY|PERPLEXITY_API_KEY|EXA_API_KEY or PERPLEXITY_API_KEY) "
+    r"configured$"
+)
 
 
 def iter_report_logs(root: Path):
@@ -231,6 +238,7 @@ for log_path in iter_report_logs(root):
         for line in lines
         if not known_internal_warning.match(line)
         and not known_scanner_warning.match(line)
+        and not known_optional_search_warning.match(line)
     ]
     if filtered != lines:
         log_path.write_text("".join(filtered), encoding="utf-8")
diff --git a/tests/test_strix_optional_web_search_warning.py b/tests/test_strix_optional_web_search_warning.py
new file mode 100644
index 0000000000..9255fa66f2
--- /dev/null
+++ b/tests/test_strix_optional_web_search_warning.py
@@ -0,0 +1,108 @@
+"""Regression for Strix's optional web-search capability warning.
+
+Strix documents PERPLEXITY_API_KEY as optional and its web-search tool returns a
+sanitized ``success: false`` result instructing the agent to proceed when the
+key is absent. A completed scan must therefore not be reclassified as provider
+unavailability solely because that exact warning appears in ``strix.log``.
+Unknown warnings remain fail-closed.
+"""
+
+from __future__ import annotations
+
+import re
+import subprocess
+import tempfile
+import unittest
+from pathlib import Path
+
+
+REPOSITORY_ROOT = Path(__file__).resolve().parents[1]
+STRIX_GATE = REPOSITORY_ROOT / "scripts" / "ci" / "strix_quick_gate.sh"
+
+OPTIONAL_SEARCH_KEY_LABELS = (
+    "EXA_API_KEY",
+    "PERPLEXITY_API_KEY",
+    "EXA_API_KEY or PERPLEXITY_API_KEY",
+)
+UNKNOWN_SEARCH_WARNING = (
+    "2026-09-12 12:30:48.087 WARNING strix-pr-scope-vjsusm_b6ed - "
+    "strix.tools.web_search.tool: provider returned malformed search evidence\n"
+)
+COMPLETION_LINE = (
+    "2026-09-12 12:45:56.390 INFO    strix-pr-scope-vjsusm_b6ed - "
+    "strix.core.runner: Strix scan strix-pr-scope-vjsusm_b6ed done\n"
+)
+
+
+def _function_block(source: str, function_name: str) -> str:
+    match = re.search(
+        rf"(?ms)^{re.escape(function_name)}\(\) \{{\n.*?^\}}\n",
+        source,
+    )
+    if match is None:
+        raise AssertionError(f"missing Bash function: {function_name}")
+    return match.group(0)
+
+
+def _sanitize_then_signal(log_text: str) -> tuple[str, bool]:
+    gate_source = STRIX_GATE.read_text(encoding="utf-8")
+    blocks = [
+        _function_block(gate_source, name)
+        for name in (
+            "sanitize_known_strix_report_warnings",
+            "has_strix_report_failure_signal",
+        )
+    ]
+    with tempfile.TemporaryDirectory(prefix="strix-optional-search-") as temp_dir:
+        report_root = Path(temp_dir) / "run"
+        report_root.mkdir()
+        log_path = report_root / "strix.log"
+        log_path.write_text(log_text, encoding="utf-8")
+        script = "\n".join(
+            (
+                "set -uo pipefail",
+                'STRIX_REPORTS_DIR="/nonexistent/strix-reports"',
+                *blocks,
+                'sanitize_known_strix_report_warnings "$1"',
+                'if has_strix_report_failure_signal "$1"; then echo signal=1; else echo signal=0; fi',
+            )
+        )
+        completed = subprocess.run(
+            ["bash", "-c", script, "strix-optional-search", str(report_root)],
+            check=False,
+            capture_output=True,
+            text=True,
+        )
+        remaining = log_path.read_text(encoding="utf-8")
+    if completed.returncode != 0:
+        raise AssertionError(f"rc={completed.returncode}\n{completed.stderr}")
+    return remaining, "signal=1" in completed.stdout
+
+
+class StrixOptionalWebSearchWarningTests(unittest.TestCase):
+    def test_missing_optional_search_keys_do_not_fail_completed_scan(self) -> None:
+        for search_key_label in OPTIONAL_SEARCH_KEY_LABELS:
+            with self.subTest(search_key_label=search_key_label):
+                optional_search_warning = (
+                    "2026-09-12 12:30:48.087 WARNING strix-pr-scope-vjsusm_b6ed - "
+                    "strix.tools.web_search.tool: web_search invoked without "
+                    f"{search_key_label} configured\n"
+                )
+                remaining, signal = _sanitize_then_signal(
+                    optional_search_warning + COMPLETION_LINE
+                )
+                self.assertNotIn(
+                    f"web_search invoked without {search_key_label} configured",
+                    remaining,
+                )
+                self.assertIn("Strix scan strix-pr-scope-vjsusm_b6ed done", remaining)
+                self.assertFalse(signal)
+
+    def test_unknown_web_search_warning_remains_fail_closed(self) -> None:
+        remaining, signal = _sanitize_then_signal(UNKNOWN_SEARCH_WARNING + COMPLETION_LINE)
+        self.assertIn("provider returned malformed search evidence", remaining)
+        self.assertTrue(signal)
+
+
+if __name__ == "__main__":
+    unittest.main()