Fix: apm marketplace add silently fails for private repos

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fix `apm marketplace add` silently failing for private repos by using credentials when probing `marketplace.json` (#701)
 - Pin codex setup to `rust-v0.118.0` for security and reproducibility; update config to `wire_api = "responses"` (#663)
 - Propagate headers and environment variables through OpenCode MCP adapter with defensive copies to prevent mutation (#622)
 - Fix `apm install` hanging indefinitely when corporate firewalls silently drop SSH packets by setting `GIT_SSH_COMMAND` with `ConnectTimeout=30` (#652)

src/apm_cli/marketplace/client.py

@@ -1,7 +1,7 @@
 """Fetch, parse, and cache marketplace.json from GitHub repositories.
 
-Uses ``AuthResolver.try_with_fallback(unauth_first=True)`` for public-first
-access with automatic credential fallback for private marketplace repos.
+Uses ``AuthResolver.try_with_fallback(unauth_first=False)`` for auth-first
+access so private marketplace repos are fetched with credentials when available.
 When ``PROXY_REGISTRY_URL`` is set, fetches are routed through the registry
 proxy (Artifactory Archive Entry Download) before falling back to the
 GitHub Contents API.  When ``PROXY_REGISTRY_ONLY=1``, the GitHub fallback
@@ -243,7 +243,7 @@ def _do_fetch(token, _git_env):
             source.host,
             _do_fetch,
             org=source.owner,
-            unauth_first=True,
+            unauth_first=False,
         )
     except Exception as exc:
         raise MarketplaceFetchError(source.name, str(exc)) from exc

tests/unit/marketplace/test_marketplace_client.py

@@ -315,6 +315,85 @@ def test_fetch_marketplace_via_proxy_end_to_end(self):
         assert manifest.plugins[0].name == "p1"
 
 
+@patch("apm_cli.marketplace.client._try_proxy_fetch", return_value=None)
+class TestPrivateRepoAuth:
+    """Verify unauth_first=False so private repos get credentials before unauthenticated fallback.
+
+    GitHub returns 404 (not 403) for unauthenticated requests to private repos.
+    With unauth_first=True the old code would try unauthenticated first, receive a 404, and
+    silently treat the repo as non-existent.  The fix sets unauth_first=False so the token
+    is used on the first attempt.
+    """
+
+    _MARKETPLACE_JSON = {"name": "Private Plugins", "plugins": []}
+
+    def test_fetch_file_private_repo_auth_first(self, _proxy):
+        """_fetch_file passes unauth_first=False so private repos are reached via auth first."""
+        source = _make_source()
+        with patch("apm_cli.deps.registry_proxy.RegistryConfig.from_env", return_value=None):
+            mock_resolver = MagicMock()
+            mock_resolver.try_with_fallback.return_value = self._MARKETPLACE_JSON
+            mock_resolver.classify_host.return_value = MagicMock(api_base="https://api.github.com")
+
+            result = client_mod._fetch_file(source, "marketplace.json", auth_resolver=mock_resolver)
+
+        assert result == self._MARKETPLACE_JSON
+        mock_resolver.try_with_fallback.assert_called_once()
+        _, call_kwargs = mock_resolver.try_with_fallback.call_args
+        assert call_kwargs.get("unauth_first") is False, (
+            "unauth_first must be False -- private repos respond 404 to unauthenticated requests"
+        )
+
+    def test_fetch_file_no_proxy_passes_unauth_first_false(self, _proxy):
+        """With no proxy, try_with_fallback is explicitly called with unauth_first=False (not True)."""
+        source = _make_source()
+        with patch("apm_cli.deps.registry_proxy.RegistryConfig.from_env", return_value=None):
+            mock_resolver = MagicMock()
+            # Simulate private repo returning None (404) for unauthenticated; would succeed with auth
+            mock_resolver.try_with_fallback.return_value = None
+            mock_resolver.classify_host.return_value = MagicMock(api_base="https://api.github.com")
+
+            client_mod._fetch_file(source, "marketplace.json", auth_resolver=mock_resolver)
+
+        mock_resolver.try_with_fallback.assert_called_once()
+        call_kwargs = mock_resolver.try_with_fallback.call_args.kwargs
+        assert "unauth_first" in call_kwargs, (
+            "unauth_first kwarg must be passed explicitly to try_with_fallback"
+        )
+        assert call_kwargs["unauth_first"] is False, (
+            f"Expected unauth_first=False, got {call_kwargs['unauth_first']!r}"
+        )
+
+    def test_auto_detect_private_repo_succeeds_with_auth(self, _proxy):
+        """_auto_detect_path finds a private repo's manifest via auth on the third candidate path."""
+        source = _make_source()
+        call_count = [0]
+
+        def mock_try_with_fallback(host, op, org=None, unauth_first=False):
+            call_count[0] += 1
+            if call_count[0] < 3:
+                # marketplace.json and .github/plugin/marketplace.json: 404 on private repo
+                return None
+            # .claude-plugin/marketplace.json: found with auth
+            return self._MARKETPLACE_JSON
+
+        mock_resolver = MagicMock()
+        mock_resolver.try_with_fallback.side_effect = mock_try_with_fallback
+        mock_resolver.classify_host.return_value = MagicMock(api_base="https://api.github.com")
+
+        with patch("apm_cli.deps.registry_proxy.RegistryConfig.from_env", return_value=None):
+            path = client_mod._auto_detect_path(source, auth_resolver=mock_resolver)
+
+        assert path == ".claude-plugin/marketplace.json"
+        # All three candidates were probed before finding it on the third
+        assert mock_resolver.try_with_fallback.call_count == 3
+        # Every probe used unauth_first=False (auth credentials always tried first)
+        for call in mock_resolver.try_with_fallback.call_args_list:
+            assert call.kwargs.get("unauth_first") is False, (
+                f"Expected unauth_first=False for all probes, got {call.kwargs!r}"
+            )
+
+
 class TestCacheKey:
     """Cache key includes host for non-github.com sources."""