fastmcp.server.middleware.error_handling

Error handling middleware for consistent error responses and tracking.

Classes

ErrorHandlingMiddleware ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/middleware/error_handling.py#L18" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Middleware that provides consistent error handling and logging.

Catches exceptions, logs them appropriately, and converts them to proper MCP error responses. Also tracks error patterns for monitoring.

Methods:

on_message ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/middleware/error_handling.py#L120" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

on_message(self, context: MiddlewareContext, call_next: CallNext) -> Any

Handle errors for all messages.

get_error_stats ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/middleware/error_handling.py#L131" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

get_error_stats(self) -> dict[str, int]

Get error statistics for monitoring.

RetryMiddleware ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/middleware/error_handling.py#L136" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Middleware that implements automatic retry logic for failed requests.

Retries requests that fail with transient errors, using exponential backoff to avoid overwhelming the server or external dependencies.

Methods:

on_request ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/middleware/error_handling.py#L202" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

on_request(self, context: MiddlewareContext, call_next: CallNext) -> Any

Implement retry logic for requests.