response_limiting

fastmcp.server.middleware.response_limiting

Response limiting middleware for controlling tool response sizes.

Classes

ResponseLimitingMiddleware

Middleware that limits the response size of tool calls.

Intercepts tool call responses and enforces size limits. If a response exceeds the limit, it extracts text content, truncates it, and returns a single TextContent block.

Methods:

on_call_tool

on_call_tool(self, context: MiddlewareContext[mt.CallToolRequestParams], call_next: CallNext[mt.CallToolRequestParams, ToolResult]) -> ToolResult

Intercept tool calls and limit response size.