MCP

In 2025, I introduced MCP (Model Context Protocol) at the iThome Taiwan Cloud Summit. At that time, I mentioned that the official team has been continuously revising the authentication protocol to address complex authentication flows. The previous design involved DCR (Dynamic Client Registration), so as expected, on 2025/11/25, a new Authorization mechanism was released. This authentication mechanism is called “Client ID Metadata Documents, abbreviated as CIMD”.

When installing a Model Context Protocol (MCP) server, the most challenging part is often not the protocol itself, but how to establish trust between the client and server. If you’ve ever tried to connect an MCP client to an MCP server it has never encountered before, you’ve probably run into what’s known as the “registration wall”.

Pre-registering with every possible authorization server is simply not scalable, and while Dynamic Client Registration (DCR) helps, it lacks reliable mechanisms to verify client identity, making it vulnerable to phishing attacks. Beyond security concerns, DCR also creates operational overhead by generating an ever-growing number of duplicate client identities that need to be managed.

2025 年在 iThome 臺灣雲端大會介紹過 MCP (Model Context Protocol)，那時候就有提到在認證協議部分，官方其實一直都在改版解決複雜的認證流程，之前設計的 DCR (Dynamic Client Registration)，所以沒意外去年 2025/11/25 又推出一版 Authorization 機制，此認證機制取名叫『Client ID Metadata Documents 簡稱 CIMD』。

安裝 Model Context Protocol（MCP）伺服器時，最棘手的部分往往不是協議本身，而是如何讓客戶端與伺服器彼此建立信任。如果你曾嘗試讓一個 MCP 客戶端連線到一個從未接觸過的 MCP 伺服器，你大概遇過所謂的「註冊高牆（registration wall）」。

要預先在每一個可能的授權伺服器完成註冊根本無法擴展，而 Dynamic Client Registration（DCR）雖然有所幫助，但因為缺乏可靠的機制來驗證客戶端身份，所以容易遭受網路釣魚攻擊。除了安全性問題之外，DCR 還會造成營運負擔，因為它會產生越來越多需要管理的重複客戶端身份。

In 2025, I delivered a workshop at the iThome Taiwan Cloud Summit in Taipei, titled “Step-by-Step Guide to Building MCP Server and Client with Golang (Model Context Protocol)”. The goal of this workshop was to help developers understand how to implement the MCP protocol using Golang, providing practical code examples and hands-on guidance. I have organized all workshop materials into a GitHub repository, which you can find at go-training/mcp-workshop. For detailed workshop content, please refer to this link.

2025 年在台北 iThome 臺灣雲端大會 (CloudSummit) 給一場 Workshop，主題是「一步步學會用 Golang 開發 MCP 伺服器與客戶端 (Model Context Protocol)」。這次的工作坊旨在幫助開發者了解如何使用 Golang 實現 MCP 協議，並提供實際的程式碼範例和操作指南。我已經先將 Workshop 的內容整理成一個 GitHub Repo，您可以在 go-training/mcp-workshop 找到相關資源。詳細 Workshop 內容，請參考此連結。