diff --git a/pyEX/__init__.py b/pyEX/__init__.py
index 9ac76c2..1435fba 100644
--- a/pyEX/__init__.py
+++ b/pyEX/__init__.py
@@ -22,6 +22,7 @@
 from .files import *
 from .fx import *
 from .markets import *
+from .metadata import *
 from .options import *
 from .points import *
 from .premium import *
diff --git a/pyEX/client.py b/pyEX/client.py
index 6414c03..b33a0d8 100644
--- a/pyEX/client.py
+++ b/pyEX/client.py
@@ -8,6 +8,7 @@
 import os
 import types
 from functools import partial, wraps
+import warnings
 
 from .account import messageBudget, metadata, metadataDF, usage, usageDF
 from .alternative import ceoCompensation, ceoCompensationDF, sentiment, sentimentDF
@@ -32,6 +33,7 @@
     latestFXDF,
 )
 from .markets import markets, marketsDF
+from .metadata import queryMetadata, queryMetadataDF
 from .options import optionExpirations, options, optionsDF
 from .points import points, pointsDF
 from .premium import (
@@ -863,6 +865,10 @@
     ("searchDF", searchDF),
     ("tags", tags),
     ("tagsDF", tagsDF),
+    # Metadata
+    # TODO move?
+    ("queryMetadata", queryMetadata),
+    ("queryMetadataDF", queryMetadataDF),
 ]
 
 _INCLUDE_FUNCTIONS_MARKET = [
@@ -1624,9 +1630,10 @@ def __init__(self, api_token=None, version="v1", api_limit=DEFAULT_API_LIMIT):
             raise PyEXception("Unrecognized api version: {}".format(version))
 
         if self._token.startswith("T") and version != "sandbox":
-            raise PyEXception(
-                "Using test key but attempting to connect to non-sandbox environment"
+            warnings.warn(
+                "Using test key but attempting to connect to non-sandbox environment. Switching to sandbox"
             )
+            version = "sandbox"
 
         self._version = version
         self._api_limit = api_limit
diff --git a/pyEX/metadata/__init__.py b/pyEX/metadata/__init__.py
new file mode 100644
index 0000000..d8208da
--- /dev/null
+++ b/pyEX/metadata/__init__.py
@@ -0,0 +1,39 @@
+# *****************************************************************************
+#
+# Copyright (c) 2022, the pyEX authors.
+#
+# This file is part of the pyEX library, distributed under the terms of
+# the Apache License 2.0.  The full license can be found in the LICENSE file.
+#
+from functools import wraps
+import pandas as pd
+from ..common import _get
+
+
+def queryMetadata(
+    id="", key="", subkey="", token="", version="stable", filter="", format="json"
+):
+    """Get inventory of available time series endpoints
+
+    Args:
+        id (str): Timeseries ID
+        key (str): Timeseries Key
+        subkey (str): Timeseries Subkey
+        token (str): Access token
+        version (str): API version
+        filter (str): https://iexcloud.io/docs/api/#filter-results
+        format (str): output format
+    """
+    url = "metadata/time-series"
+    if id:
+        url += "/{}".format(id)
+        if key:
+            url += "/{}".format(key)
+            if subkey:
+                url += "/{}".format(subkey)
+    return _get(url, token=token, version=version, filter=filter, format=format)
+
+
+@wraps(queryMetadata)
+def queryMetadataDF(*args, **kwargs):
+    return pd.DataFrame(queryMetadata(*args, **kwargs))
diff --git a/pyEX/tests/test_api.py b/pyEX/tests/test_api.py
index 67ec740..f3a8459 100644
--- a/pyEX/tests/test_api.py
+++ b/pyEX/tests/test_api.py
@@ -527,6 +527,8 @@ def test_all(self):
             "productEventsWallStreetHorizon",
             "productEventsWallStreetHorizonDF",
             "propane",
+            "queryMetadata",
+            "queryMetadataDF",
             "quote",
             "quoteDF",
             "recent",
diff --git a/pyEX/tests/test_api_client.py b/pyEX/tests/test_api_client.py
index f2385de..3a3985b 100644
--- a/pyEX/tests/test_api_client.py
+++ b/pyEX/tests/test_api_client.py
@@ -107,6 +107,13 @@ def test_all_markets(self):
             assert hasattr(self.c, meth)
             assert hasattr(self.c.market, meth)
 
+    def test_all_metadata(self):
+        for meth in (
+            "queryMetadata",
+            "queryMetadataDF",
+        ):
+            assert hasattr(self.c, meth)
+
     def test_all_stats(self):
         for meth in (
             "systemStats",