Willem Jiang 1b88c38d80 fix(mcp): persist MCP sessions across tool calls for stateful servers ...

MCP tools loaded via langchain-mcp-adapters created a new session on
  every call, causing stateful servers like Playwright to lose browser
  state (pages, forms) between consecutive tool invocations within the
  same thread.

  Add MCPSessionPool that maintains persistent sessions scoped by
  (server_name, thread_id). Tool calls within the same thread now reuse
  the same MCP session, preserving server-side state. Sessions are evicted
  in LRU order (max 256) and cleaned up on cache invalidation.

  Fixes #3054

2026-05-20 11:17:58 +08:00

..

harness

fix(mcp): persist MCP sessions across tool calls for stateful servers

2026-05-20 11:17:58 +08:00