diff --git a/hermes_cli/model_catalog.py b/hermes_cli/model_catalog.py
index 703d958402ca4..2f9979ac085b7 100644
--- a/hermes_cli/model_catalog.py
+++ b/hermes_cli/model_catalog.py
@@ -46,6 +46,7 @@
 
 import json
 import logging
+import math
 import time
 import urllib.error
 import urllib.request
@@ -53,7 +54,7 @@
 from typing import Any
 
 from hermes_cli import __version__ as _HERMES_VERSION
-from utils import atomic_replace
+from utils import atomic_replace, is_truthy_value
 
 logger = logging.getLogger(__name__)
 
@@ -104,13 +105,26 @@ def _load_catalog_config() -> dict[str, Any]:
         raw = {}
 
     return {
-        "enabled": bool(raw.get("enabled", True)),
+        "enabled": is_truthy_value(raw.get("enabled"), default=True),
         "url": str(raw.get("url") or DEFAULT_CATALOG_URL),
-        "ttl_hours": float(raw.get("ttl_hours") or DEFAULT_TTL_HOURS),
+        "ttl_hours": _parse_ttl_hours(raw.get("ttl_hours")),
         "providers": raw.get("providers") if isinstance(raw.get("providers"), dict) else {},
     }
 
 
+def _parse_ttl_hours(value: Any) -> float:
+    """Parse ``model_catalog.ttl_hours`` while preserving explicit zero."""
+    if value is None or value == "":
+        return float(DEFAULT_TTL_HOURS)
+    try:
+        ttl = float(value)
+    except (TypeError, ValueError):
+        return float(DEFAULT_TTL_HOURS)
+    if not math.isfinite(ttl):
+        return float(DEFAULT_TTL_HOURS)
+    return max(0.0, ttl)
+
+
 def _cache_path() -> Path:
     """Return the disk cache path. Import lazily so tests can monkeypatch home."""
     from hermes_constants import get_hermes_home
diff --git a/tests/hermes_cli/test_model_catalog.py b/tests/hermes_cli/test_model_catalog.py
index 43ad6e42cadb8..6ca26bf0bedce 100644
--- a/tests/hermes_cli/test_model_catalog.py
+++ b/tests/hermes_cli/test_model_catalog.py
@@ -94,6 +94,52 @@ def test_rejects_non_string_model_id(self, isolated_home):
         assert _validate_manifest(m) is False
 
 
+class TestConfig:
+    def test_boolish_disabled_string_is_respected(self, isolated_home):
+        from hermes_cli import model_catalog
+
+        with patch(
+            "hermes_cli.config.load_config",
+            return_value={"model_catalog": {"enabled": "false"}},
+        ):
+            cfg = model_catalog._load_catalog_config()
+
+        assert cfg["enabled"] is False
+
+    def test_ttl_hours_string_and_zero_are_preserved(self, isolated_home):
+        from hermes_cli import model_catalog
+
+        with patch(
+            "hermes_cli.config.load_config",
+            return_value={"model_catalog": {"ttl_hours": "0"}},
+        ):
+            cfg = model_catalog._load_catalog_config()
+
+        assert cfg["ttl_hours"] == 0.0
+
+    def test_invalid_ttl_hours_falls_back_to_default(self, isolated_home):
+        from hermes_cli import model_catalog
+
+        with patch(
+            "hermes_cli.config.load_config",
+            return_value={"model_catalog": {"ttl_hours": "not-a-number"}},
+        ):
+            cfg = model_catalog._load_catalog_config()
+
+        assert cfg["ttl_hours"] == float(model_catalog.DEFAULT_TTL_HOURS)
+
+    def test_negative_ttl_hours_clamps_to_zero(self, isolated_home):
+        from hermes_cli import model_catalog
+
+        with patch(
+            "hermes_cli.config.load_config",
+            return_value={"model_catalog": {"ttl_hours": "-5"}},
+        ):
+            cfg = model_catalog._load_catalog_config()
+
+        assert cfg["ttl_hours"] == 0.0
+
+
 class TestFetchSuccess:
     def test_fetch_and_cache_writes_disk(self, isolated_home):
         from hermes_cli import model_catalog