Mori MCP Server

Persistent Data Structures for JavaScript

Local serverstdio

What is the Mori MCP server?

Mori MCP server exists for a simple reason — assistants are far more useful when they can act on Mori directly instead of describing what you should do. Persistent Data Structures for JavaScript.

What you get

A simple bridge to ClojureScript's persistent data structures and supporting APIs for vanilla JavaScript. Pull requests welcome.

Setting it up

The server ships on npm as mori, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

What the assistant can call

Once Mori is connected, these are the calls the assistant has available:

  • Faster — Mori is considerably faster across the board thanks to recent enhancements to the ClojureScript compiler. For users who would like to benchmark their
  • Documentation — You can find extensive documentation and examples here
  • Transducers — Mori includes Transducers. Zero allocation collection operations FTW:
  • Prerequisites — You will first need to install the Java SDK, if it's not already installed on

Configuration and credentials

You will first need to install the Java SDK, if it's not already installed on your system. On Windows, you will need to manually install Leiningen. On UNIX-like systems, Leiningen will be installed within the project automatically if the lein executable is not found on your path or

Before you rely on it

  • 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.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the mori mcp server does with a few real requests.

Choosing this one

This sits in the developer tooling group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Mori's toolset — Faster, Documentation, Transducers and 1 more — is a fair guide to whether it matches your workflow. It is maintained by dnolen; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against Mori's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Available tools

ToolWhat it does
FasterMori is considerably faster across the board thanks to recent enhancements to the ClojureScript compiler. For users who would like to benchmark their immutable data structure implementations against Mori, Mori now expose
DocumentationYou can find extensive [documentation and examples](http://swannodette.github.io/mori/) here.
TransducersMori includes Transducers. Zero allocation collection operations FTW:
PrerequisitesYou will first need to install the [Java](http://www.oracle.com/technetwork/java/javase/downloads/index.html) SDK, if it's not already installed on your system.

How to install the Mori MCP server

{
  "mcpServers": {
    "mori": {
      "command": "npx",
      "args": ["-y", "mori"]
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

You will first need to install the Java SDK, if it's not already installed on your system. On Windows, you will need to manually install Leiningen. On UNIX-like systems, Leiningen will be installed within the project automatically if the lein executable is not found on your path or

Example prompts to try

  • Use Mori to Faster.
  • Use Mori to Documentation.
  • Use Mori to Transducers.

Frequently asked questions

It connects Mori to MCP-compatible AI assistants such as Claude and Cursor, exposing 4 tools (Faster, Documentation, Transducers, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Mori directly.