Overview

The Echo MCP Server is a minimal yet fully‑compliant implementation of the Model Context Protocol (MCP) that demonstrates how to expose a simple, yet useful, tool to AI assistants. It allows any MCP‑compatible client—such as Claude Desktop or custom applications—to send a message and receive that same message back, optionally formatted according to user‑defined templates. This server is built on .NET Core with the official C# MCP SDK, ensuring that developers familiar with .NET can quickly understand and extend its behavior.

Solving a Common Integration Need

When building AI workflows, developers often need a lightweight way to test tool invocation, validate client‑server communication, or provide an echo service for debugging. The Echo MCP Server fills this gap by offering a ready‑to‑run, zero‑dependency tool that can be deployed locally or as a Docker container. It eliminates the need to write custom echo logic from scratch, allowing teams to focus on higher‑level application logic while still having a reliable MCP endpoint for round‑trip message verification.

What the Server Provides

At its core, the server exposes a single tool named . Clients invoke this tool by passing a parameter; the server responds with the message wrapped in a configurable format. The formatting is controlled via a template that can be set either in an file or through environment variables, making it adaptable to both local development and containerized deployments. The default format is , but developers can customize it to match branding or context requirements, such as or .

Key Features in Plain Language

• Simplicity – Only one tool, minimal code path, easy to understand.
• Configurability – Message formatting is adjustable without recompilation.
• Cross‑platform deployment – Works on any host that can run .NET Core or Docker.
• MCP compliance – Uses the official C# SDK, ensuring full compatibility with existing MCP clients.
• Extensibility – The lightweight architecture makes it trivial to add more tools or logic in the future.

Real‑World Use Cases

• Debugging Tool Chains – Verify that a client can reach the MCP server and that parameters are correctly serialized.
• Prototype Development – Quickly spin up an echo service to test conversational flows before adding complex logic.
• Learning MCP – New developers can experiment with tool invocation, request/response handling, and configuration management.
• Integration Testing – Automated tests can call the echo tool to assert that request payloads are transmitted unchanged.

Integration with AI Workflows

To use the Echo MCP Server, a developer configures the server in the AI assistant’s settings (e.g., Claude Desktop’s section). The client then sends a request like:

The server returns the formatted string, allowing the assistant to display or log the response. Because the server follows MCP’s standard message format and error handling, it can be dropped into any existing MCP‑enabled pipeline without additional adapters.

Unique Advantages

Unlike generic echo utilities, this server is MCP‑native, meaning it adheres to the same protocol standards used by advanced AI assistants. Its configuration flexibility via environment variables makes it ideal for containerized environments where secrets and context must be injected at runtime. Moreover, its minimal footprint ensures that it can run on resource‑constrained devices, enabling edge deployments or quick prototyping without the overhead of a full application stack.

In summary, the Echo MCP Server is a lightweight, configurable, and fully‑compliant tool that empowers developers to test, prototype, and validate MCP integrations with ease, all while providing a clear example of how to build more complex tools on top of the same foundation.