Building an MCP server with Express so Claude can call your own API

On October 30, 2026, a backend developer published a walkthrough on Juejin describing how to build an MCP Server with Express so that Claude can call an existing API directly. The author, who describes themselves as an Express veteran with years of experience, said they had been seeing talk about AI agents and MCP everywhere and initially worried that a completely new framework would be required. After building it, they found that was not the case: the MCP Server can be implemented using the familiar Express approach, reusing existing Express patterns rather than learning a separate stack. The article does not present benchmarks or performance comparisons, nor does it discuss latency or cost trade-offs; it focuses on the practical observation that Express conventions carry over to this use case. As of now, only this single piece of coverage has surfaced, and no follow-up reports have appeared, so there is nothing further to add about subsequent developments.