Custom MCP Server

A Model Context Protocol (MCP) server built with Next.js, providing useful tools and utilities through both HTTP and Server-Sent Events (SSE)

Local serverstdioTypeScript

What is the Custom MCP server?

A Model Context Protocol (MCP) server built with Next.js, providing useful tools and utilities through both HTTP and Server-Sent Events (SSE) transports. Exposed over MCP by the custom mcp server, that capability becomes something an assistant can invoke while it works, not something you go and do afterwards.

Adding it to your client

Setup follows the usual MCP pattern — install or clone the server, register it in your client's configuration file, restart the client. The configuration blocks on this page cover the common clients.

Its toolset

Everything the assistant can do here goes through one of these:

  • echo — Echo any message back (perfect for testing)
  • get-current-time — Get the current timestamp and ISO date
  • calculate — Perform basic mathematical calculations safely
  • Prerequisites — The Prerequisites tool exposed by this server
  • Setup — 1. Clone and install dependencies: bash npm install

Configuration

You will need 3 environment variables: REDIS_URL, UPSTASH_REDIS_REST_URL, UPSTASH_REDIS_REST_TOKEN. The server will not start without them, which is usually why the tools fail to appear on a first run. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

  • Node.js 18+ - npm or yarn - Docker (optional, for local Redis)

Caveats

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the custom mcp server does with a few real requests.

When to reach for it

Plenty of developer tooling servers cover similar ground. The differences that matter in practice are scope of access and how much setup stands between you and a working tool call. Custom's toolset — echo, get-current-time, calculate and 2 more — is a fair guide to whether it matches your workflow. It is maintained by Meerisha; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

Available tools

ToolWhat it does
echoEcho any message back (perfect for testing)
get-current-timeGet the current timestamp and ISO date
calculatePerform basic mathematical calculations safely
PrerequisitesThe Prerequisites tool exposed by this server.
Setup1. **Clone and install dependencies:** bash npm install

How to install the Custom MCP server

For older Cursor versions:

```json
{
  "mcpServers": {
    "custom-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "http://localhost:3000/mcp"
      ]
    }
  }
}

Configuration as documented by the project. Restart the client after saving.

Configuration

  • Node.js 18+ - npm or yarn - Docker (optional, for local Redis)
VariableDescriptionRequired
REDIS_URLEndpoint or connection string the server talks to.Yes
UPSTASH_REDIS_REST_URLEndpoint or connection string the server talks to.Yes
UPSTASH_REDIS_REST_TOKENCredential the server authenticates with.Yes

Example prompts to try

  • Use Custom to echo.
  • Use Custom to get-current-time.
  • Use Custom to calculate.

Frequently asked questions

It connects Custom to MCP-compatible AI assistants such as Claude and Cursor, exposing 5 tools (echo, get-current-time, calculate, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Custom directly.