From 64d76bf295ce1b1d69f63fe6d8609488eda068d6 Mon Sep 17 00:00:00 2001
From: KQAR <31615748+KQAR@users.noreply.github.com>
Date: Tue, 3 Mar 2026 14:29:43 +0800
Subject: [PATCH] fix(mcp): omit nextCursor when no more pages in tools/list

Previously, tools/list always returned `"nextCursor": ""` even when
all tools fit in a single page. Cursor-agent treats any present
nextCursor (including empty string) as "more pages available",
causing an infinite pagination loop (~170k requests in 55s) that
exhausts the V8 heap and crashes with OOM.

Only include nextCursor in the response when there are actually
more pages to fetch.

Made-with: Cursor
---
 src/cccc/ports/mcp/main.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/cccc/ports/mcp/main.py b/src/cccc/ports/mcp/main.py
index c1736c22..8a179a2b 100644
--- a/src/cccc/ports/mcp/main.py
+++ b/src/cccc/ports/mcp/main.py
@@ -141,10 +141,10 @@ def handle_request(req: Dict[str, Any]) -> Dict[str, Any]:
             limit = 100
         limit = max(1, min(limit, 200))
         page = tools[cursor : cursor + limit]
-        next_cursor = ""
+        result_payload: Dict[str, Any] = {"tools": page}
         if cursor + limit < len(tools):
-            next_cursor = _encode_cursor(cursor + limit)
-        return _make_response(req_id, {"tools": page, "nextCursor": next_cursor})
+            result_payload["nextCursor"] = _encode_cursor(cursor + limit)
+        return _make_response(req_id, result_payload)
 
     # Optional MCP surfaces (return empty to avoid noisy "Method not found" in some runtimes)
     if method == "resources/list":