fix(mcp): stub resources/list + prompts/list so MCP clients stop ERROR-logging (#107)

jphein · claude · web-flow · commit 6ca067061901 · 2026-05-21T20:13:25.000-07:00
opencode 1.15.x and other MCP clients probe `resources/list` and
`prompts/list` on connect to discover server capabilities. mempalace's
MCP server only exposes tools; these probes returned `-32601: Unknown
method`, which clients log as ERROR even though the result is benign
(no resources, no prompts). Two log-noise lines per session.

Both methods are optional per the MCP spec. Return empty lists instead
of the error, matching what other MCP servers without resources/prompts
do (e.g. server-everything, filesystem reference server).

Tests: tests/test_mcp_server.py — two new TestProtocol cases assert the
empty-list shape and absence of ERROR.

Co-authored-by: Claude Opus 4.7 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/mempalace/mcp_server.py b/mempalace/mcp_server.py
@@ -3029,6 +3029,17 @@ def handle_request(request):
                 ]
             },
         }
+    elif method == "resources/list":
+        # MCP spec optional method. We don't expose any resources — the
+        # palace surfaces drawers via the tools/call interface, not via
+        # the resource model. Return an empty list rather than -32601 so
+        # clients that probe on connect (e.g. OpenCode 1.15.x) don't log
+        # an ERROR every session. (#-32601-noise / fork follow-up.)
+        return {"jsonrpc": "2.0", "id": req_id, "result": {"resources": []}}
+    elif method == "prompts/list":
+        # MCP spec optional method. We don't expose any prompts. Same
+        # rationale as resources/list above — quiet client probes.
+        return {"jsonrpc": "2.0", "id": req_id, "result": {"prompts": []}}
     elif method == "tools/call":
         if not isinstance(params, dict) or "name" not in params:
             return {
diff --git a/tests/test_mcp_server.py b/tests/test_mcp_server.py
@@ -537,6 +537,27 @@ def test_tools_list(self):
         assert "mempalace_add_drawer" in names
         assert "mempalace_kg_add" in names
 
+    def test_resources_list_returns_empty_not_error(self):
+        """MCP clients (OpenCode 1.15.x, others) probe ``resources/list`` on
+        connect. We don't expose any resources — the palace surfaces drawers
+        via ``tools/call`` — but return ``{resources: []}`` rather than
+        ``-32601`` so the client doesn't log an ERROR every session."""
+        from mempalace.mcp_server import handle_request
+
+        resp = handle_request({"method": "resources/list", "id": 7, "params": {}})
+        assert "error" not in resp
+        assert resp["result"] == {"resources": []}
+
+    def test_prompts_list_returns_empty_not_error(self):
+        """Same rationale as ``test_resources_list_returns_empty_not_error``:
+        ``prompts/list`` is an optional MCP method some clients probe on
+        connect; returning an empty list quiets the noise."""
+        from mempalace.mcp_server import handle_request
+
+        resp = handle_request({"method": "prompts/list", "id": 8, "params": {}})
+        assert "error" not in resp
+        assert resp["result"] == {"prompts": []}
+
     def test_null_arguments_does_not_hang(self, monkeypatch, config, palace_path, seeded_kg):
         """Sending arguments: null should return a result, not hang (#394)."""
         _patch_mcp_server(monkeypatch, config, seeded_kg)
