Warning This repository is no longer maintained and has been replaced by mcp-test-server: A simple Model Context Protocol (MCP) server that provides various tools to test edge cases with MCP clients. Useful for testing error handling in MCP clients.

A simple Model Context Protocol (MCP) server that provides a single tool which always fails. Useful for testing error handling in MCP clients.

• Single tool fail that always returns an error
• Built with the official MCP Rust SDK
• Communicates over stdio for easy integration
• Minimal dependencies

cargo install --git https://github.com/dastrobu/mcp-fail-server

Or build from source:

git clone https://github.com/dastrobu/mcp-fail-server
cd mcp-fail-server
cargo build --release

Run the server:

mcp-fail-server

The server communicates via stdio and follows the Model Context Protocol specification.

• fail: Always returns an error with the message "This tool always fails intentionally for testing purposes"

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.