Langchain-Mcp-Adapters

Name: Langchain-Mcp-Adapters bug reports
Creator: AI & Agent Dev Bug Sandbox

Reports that share this framework, grouped in one feed.

Similar Reports

high95%

structuredContent is dropped from isError=True tool results in langchain-mcp-adapters

The langchain-mcp-adapters library discards structuredContent when an MCP tool returns isError=True. It raises _MCPToolExecutionError before reading the field and never attaches it to the resulting error ToolMessage, unlike the success path. This causes loss of machine-readable error payloads and leaves only a placeholder text when content is empty.

V0.3.2 LangChain

high92%

MCP tools with a parameter named "config" silently broken by LangChain's RunnableConfig injection

When an MCP tool defines an input parameter named 'config' (or 'run_manager' or 'callbacks'), LangChain's StructuredTool invocation overwrites the user-supplied value with the internal RunnableConfig dict, causing silent data corruption and incorrect tool behavior.

Vlangchain-Mcp-Adapters==0.2.2 Vlangchain-Core>=0.3.0,<0.4.0 LangChain

high95%

stdio sessions hang forever when a server never responds (no default read_timeout_seconds)

langchain_mcp_adapters.sessions._create_stdio_session constructs an MCP ClientSession without a default read_timeout_seconds, so any request to a non-responsive stdio server (e.g., during initialize()/call_tool()/list_tools()) blocks indefinitely. The MCP SDK already supports per-request timeouts via read_timeout_seconds; this library simply fails to set a default.

V0.3.2 Vmain Langchain-Mcp-Adapters

medium85%

Feature Request: Pass `_meta` parameter through to MCP SDK `call_tool()`

langchain-mcp-adapters does not pass the MCP `_meta` field from tool arguments to the MCP SDK's `call_tool()`, preventing per-request metadata like session IDs, routing tags, or tenant context from reaching MCP servers.

Langchain