diff --git a/craft_store/__init__.py b/craft_store/__init__.py
index 4239e4c..ee222b8 100644
--- a/craft_store/__init__.py
+++ b/craft_store/__init__.py
@@ -20,8 +20,9 @@
 __version__ = "3.0.0"
 
 
-from . import creds, endpoints, errors, models, publishergateway
+from . import creds, endpoints, errors, models
 from ._httpx_auth import CandidAuth, DeveloperTokenAuth
+from .publisher import PublisherGateway
 from .auth import Auth
 from .base_client import BaseClient
 from .http_client import HTTPClient
@@ -33,7 +34,7 @@
     "endpoints",
     "errors",
     "models",
-    "publishergateway",
+    "PublisherGateway",
     "Auth",
     "BaseClient",
     "CandidAuth",
diff --git a/craft_store/_httpx_auth.py b/craft_store/_httpx_auth.py
index 9e63b95..3c8e15e 100644
--- a/craft_store/_httpx_auth.py
+++ b/craft_store/_httpx_auth.py
@@ -59,9 +59,7 @@ def _update_headers(self, request: httpx.Request) -> None:
         """Add token to the request."""
         logger.debug("Adding ephemeral token to request headers")
         if self._token is None:
-            raise errors.DeveloperTokenUnavailableError(
-                message="Token is not available"
-            )
+            raise errors.AuthTokenUnavailableError(message="Token is not available")
         request.headers["Authorization"] = self._format_auth_header()
 
     def _format_auth_header(self) -> str:
@@ -73,6 +71,11 @@ def _format_auth_header(self) -> str:
 class CandidAuth(_TokenAuth):
     """Candid based authentication class for httpx store clients."""
 
+    def __init__(
+        self, *, auth: auth.Auth, auth_type: Literal["bearer", "macaroon"] = "macaroon"
+    ) -> None:
+        super().__init__(auth=auth, auth_type=auth_type)
+
     def get_token_from_keyring(self) -> str:
         """Get token stored in the credentials storage."""
         logger.debug("Getting candid from credential storage")
diff --git a/craft_store/errors.py b/craft_store/errors.py
index 7121810..722e144 100644
--- a/craft_store/errors.py
+++ b/craft_store/errors.py
@@ -41,13 +41,25 @@ def __init__(
         store_errors: StoreErrorList | None = None,
     ) -> None:
         super().__init__(message)
-        if not details:
+        if store_errors and not details:
             details = str(store_errors)
         self.details = details
         self.resolution = resolution
         self.store_errors = store_errors
 
 
+class InvalidRequestError(CraftStoreError, ValueError):
+    """Error when the request is invalid in a known way."""
+
+    def __init__(
+        self,
+        message: str,
+        details: str | None = None,
+        resolution: str | None = None,
+    ) -> None:
+        super().__init__(message, details, resolution)
+
+
 class NetworkError(CraftStoreError):
     """Error to raise on network or infrastructure issues.
 
@@ -209,5 +221,5 @@ def __init__(self, url: str) -> None:
         super().__init__(f"Empty token value returned from {url!r}.")
 
 
-class DeveloperTokenUnavailableError(CraftStoreError):
-    """Raised when developer token is not set."""
+class AuthTokenUnavailableError(CraftStoreError):
+    """Raised when an authorization token is not available."""
diff --git a/craft_store/publishergateway/__init__.py b/craft_store/publisher/__init__.py
similarity index 100%
rename from craft_store/publishergateway/__init__.py
rename to craft_store/publisher/__init__.py
diff --git a/craft_store/publishergateway/_publishergw.py b/craft_store/publisher/_publishergw.py
similarity index 88%
rename from craft_store/publishergateway/_publishergw.py
rename to craft_store/publisher/_publishergw.py
index c401302..781419a 100644
--- a/craft_store/publishergateway/_publishergw.py
+++ b/craft_store/publisher/_publishergw.py
@@ -14,7 +14,9 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Client for the publisher gateway."""
+from __future__ import annotations
 
+from json import JSONDecodeError
 from typing import cast
 
 import httpx
@@ -48,7 +50,7 @@ def _check_error(response: httpx.Response) -> None:
             return
         try:
             error_response = response.json()
-        except Exception as exc:
+        except JSONDecodeError as exc:
             raise errors.CraftStoreError(
                 f"Invalid response from server ({response.status_code})",
                 details=response.text,
@@ -61,7 +63,8 @@ def _check_error(response: httpx.Response) -> None:
         if len(error_list) == 1:
             brief = f"{brief}: {error_list[0].get('message')}"
         else:
-            brief = f"{brief}. See log for details"
+            fancy_error_list = errors.StoreErrorList(error_list)
+            brief = f"{brief}.\n{fancy_error_list}"
         raise errors.CraftStoreError(
             brief, store_errors=errors.StoreErrorList(error_list)
         )
@@ -87,7 +90,7 @@ def create_tracks(self, name: str, *tracks: _request.CreateTrackRequest) -> int:
             to which this track will be attached.
         :param tracks: Each track is a dictionary mapping query values.
         :returns: The number of tracks created by the store.
-        :raises: ValueError if a track name is invalid.
+        :returns: InvalidRequestError if the name field of any passed track is invalid.
 
         API docs: https://api.charmhub.io/docs/default.html#create_tracks
         """
@@ -99,7 +102,10 @@ def create_tracks(self, name: str, *tracks: _request.CreateTrackRequest) -> int:
         }
         if bad_track_names:
             bad_tracks = ", ".join(sorted(bad_track_names))
-            raise ValueError(f"The following track names are invalid: {bad_tracks}")
+            raise errors.InvalidRequestError(
+                f"The following track names are invalid: {bad_tracks}",
+                resolution="Ensure all tracks have valid names.",
+            )
 
         response = self._client.post(
             f"/v1/{self._namespace}/{name}/tracks", json=tracks
diff --git a/craft_store/publishergateway/_request.py b/craft_store/publisher/_request.py
similarity index 100%
rename from craft_store/publishergateway/_request.py
rename to craft_store/publisher/_request.py
diff --git a/craft_store/publishergateway/_response.py b/craft_store/publisher/_response.py
similarity index 100%
rename from craft_store/publishergateway/_response.py
rename to craft_store/publisher/_response.py
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index 98c1118..6a4eea7 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -21,7 +21,7 @@
 
 import pytest
 import yaml
-from craft_store import StoreClient, auth, endpoints, publishergateway
+from craft_store import StoreClient, auth, endpoints, publisher
 
 
 @pytest.fixture(scope="session")
@@ -63,7 +63,7 @@ def charmhub_auth(charmhub_base_url):
 
 @pytest.fixture
 def publisher_gateway(charmhub_base_url, charmhub_auth):
-    return publishergateway.PublisherGateway(
+    return publisher.PublisherGateway(
         base_url=charmhub_base_url, namespace="charm", auth=charmhub_auth
     )
 
diff --git a/tests/integration/publishergateway/__init__.py b/tests/integration/publisher/__init__.py
similarity index 100%
rename from tests/integration/publishergateway/__init__.py
rename to tests/integration/publisher/__init__.py
diff --git a/tests/integration/publishergateway/test_read.py b/tests/integration/publisher/test_read.py
similarity index 90%
rename from tests/integration/publishergateway/test_read.py
rename to tests/integration/publisher/test_read.py
index 1df570d..3d97ae3 100644
--- a/tests/integration/publishergateway/test_read.py
+++ b/tests/integration/publisher/test_read.py
@@ -16,14 +16,14 @@
 """Tests that only involve reading from the store."""
 
 
-from craft_store import publishergateway
+from craft_store import publisher
 
 from tests.integration.conftest import needs_charmhub_credentials
 
 
 @needs_charmhub_credentials()
 def test_get_package_metadata(
-    publisher_gateway: publishergateway.PublisherGateway, charmhub_charm_name: str
+    publisher_gateway: publisher.PublisherGateway, charmhub_charm_name: str
 ):
     metadata = publisher_gateway.get_package_metadata(charmhub_charm_name)
     assert metadata.get("name") == charmhub_charm_name
diff --git a/tests/integration/publishergateway/test_write.py b/tests/integration/publisher/test_write.py
similarity index 91%
rename from tests/integration/publishergateway/test_write.py
rename to tests/integration/publisher/test_write.py
index ed3ae81..4378f81 100644
--- a/tests/integration/publishergateway/test_write.py
+++ b/tests/integration/publisher/test_write.py
@@ -20,7 +20,7 @@
 import time
 
 import pytest
-from craft_store import errors, publishergateway
+from craft_store import errors, publisher
 
 from tests.integration.conftest import needs_charmhub_credentials
 
@@ -30,7 +30,7 @@
 @pytest.mark.parametrize("version_pattern", [None, r"\d+"])
 @pytest.mark.parametrize("percentages", [None, 50])
 def test_create_tracks(
-    publisher_gateway: publishergateway.PublisherGateway,
+    publisher_gateway: publisher.PublisherGateway,
     charmhub_charm_name: str,
     version_pattern,
     percentages,
@@ -64,7 +64,7 @@ def test_create_tracks(
 @pytest.mark.slow
 @needs_charmhub_credentials()
 def test_create_disallowed_track(
-    publisher_gateway: publishergateway.PublisherGateway, charmhub_charm_name: str
+    publisher_gateway: publisher.PublisherGateway, charmhub_charm_name: str
 ):
     track_name = "disallowed"
 
@@ -78,7 +78,7 @@ def test_create_disallowed_track(
 @pytest.mark.slow
 @needs_charmhub_credentials()
 def test_create_existing_track(
-    publisher_gateway: publishergateway.PublisherGateway, charmhub_charm_name: str
+    publisher_gateway: publisher.PublisherGateway, charmhub_charm_name: str
 ):
     track_name = "1"
 
diff --git a/tests/unit/publisher/__init__.py b/tests/unit/publisher/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/unit/test_publishergateway.py b/tests/unit/publisher/test_publishergateway.py
similarity index 81%
rename from tests/unit/test_publishergateway.py
rename to tests/unit/publisher/test_publishergateway.py
index 261e8d5..b57d9bb 100644
--- a/tests/unit/test_publishergateway.py
+++ b/tests/unit/publisher/test_publishergateway.py
@@ -15,11 +15,12 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Unit tests for the publisher gateway."""
 
+import textwrap
 from unittest import mock
 
 import httpx
 import pytest
-from craft_store import errors, publishergateway
+from craft_store import errors, publisher
 
 
 @pytest.fixture
@@ -29,14 +30,14 @@ def mock_httpx_client():
 
 @pytest.fixture
 def publisher_gateway(mock_httpx_client):
-    gw = publishergateway.PublisherGateway("http://localhost", "charm", mock.Mock())
+    gw = publisher.PublisherGateway("http://localhost", "charm", mock.Mock())
     gw._client = mock_httpx_client
     return gw
 
 
 @pytest.mark.parametrize("response", [httpx.Response(status_code=204)])
 def test_check_error_on_success(response: httpx.Response):
-    assert publishergateway.PublisherGateway._check_error(response) is None
+    assert publisher.PublisherGateway._check_error(response) is None
 
 
 @pytest.mark.parametrize(
@@ -68,26 +69,31 @@ def test_check_error_on_success(response: httpx.Response):
                 418,
                 json={
                     "error-list": [
-                        {"code": "whelp", "message": "I am a teapot"},
+                        {"code": "good", "message": "I am a teapot"},
                         {
                             "code": "bad",
-                            "message": "Why would you ask me for a coffee?",
+                            "message": "Why would you ask me for coffee?",
                         },
                     ]
                 },
             ),
-            r"Error 418 returned from store. See log for details",
+            textwrap.dedent(
+                """\
+                Error 418 returned from store.
+                - good: I am a teapot
+                - bad: Why would you ask me for coffee?"""
+            ),
             id="multiple-client-errors",
         ),
     ],
 )
 def test_check_error(response: httpx.Response, match):
     with pytest.raises(errors.CraftStoreError, match=match):
-        publishergateway.PublisherGateway._check_error(response)
+        publisher.PublisherGateway._check_error(response)
 
 
 def test_get_package_metadata(
-    mock_httpx_client: mock.Mock, publisher_gateway: publishergateway.PublisherGateway
+    mock_httpx_client: mock.Mock, publisher_gateway: publisher.PublisherGateway
 ):
     mock_httpx_client.get.return_value = httpx.Response(
         200, json={"metadata": {"meta": "data"}}
@@ -110,7 +116,7 @@ def test_get_package_metadata(
     ],
 )
 def test_create_tracks_validation(
-    publisher_gateway: publishergateway.PublisherGateway,
+    publisher_gateway: publisher.PublisherGateway,
     tracks,
     match,
 ):
@@ -119,7 +125,7 @@ def test_create_tracks_validation(
 
 
 def test_create_tracks_success(
-    mock_httpx_client: mock.Mock, publisher_gateway: publishergateway.PublisherGateway
+    mock_httpx_client: mock.Mock, publisher_gateway: publisher.PublisherGateway
 ):
     mock_httpx_client.post.return_value = httpx.Response(
         200, json={"num-tracks-created": 0}
diff --git a/tests/unit/test_httpx_auth.py b/tests/unit/test_httpx_auth.py
index 4bad55e..e90aab7 100644
--- a/tests/unit/test_httpx_auth.py
+++ b/tests/unit/test_httpx_auth.py
@@ -44,7 +44,7 @@ def test_candid_auth_flow(mock_auth, candid_auth):
 
     next(candid_auth.auth_flow(request))
 
-    assert request.headers["Authorization"] == "Bearer {}"
+    assert request.headers["Authorization"] == "Macaroon {}"
 
 
 @pytest.fixture
@@ -122,10 +122,9 @@ def test_auth_if_token_unset(
     mocker.patch.object(
         developer_token_auth, "get_token_from_keyring", return_value=None
     )
-    httpx_client = httpx.Client(auth=developer_token_auth)
-
+    client = httpx.Client(auth=developer_token_auth)
     with pytest.raises(
-        errors.DeveloperTokenUnavailableError,
+        errors.AuthTokenUnavailableError,
         match="Token is not available",
     ):
-        httpx_client.request("GET", "https://fake-testcraft-url.localhost")
+        client.request("GET", "https://fake-testcraft-url.localhost")