Jmespath Extensions MCP Server

This work has moved to https://github.com/joshrotenberg/jpx which includes a full [JMESPath Specification](https://jmespath.org/specification.html)

Local serverstdioPython

What is the Jmespath Extensions MCP server?

Jmespath Extensions MCP server is a locally run integration for AI assistants that speak the Model Context Protocol. This work has moved to https://github.com/joshrotenberg/jpx which includes a full JMESPath Specification implementation with some performance improvements over the official crate, the full.

What the assistant can call

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

  • Rust — The Rust tool exposed by this server

Setting it up

jmespath-extensions on PyPI is all you need. Most clients run it directly, so configuration is a few lines and a restart.

Choosing this one

Among the developer tooling options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Jmespath Extensions's toolset — Rust — is a fair guide to whether it matches your workflow. It is maintained by joshrotenberg; 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.

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 jmespath extensions mcp server does with a few real requests.

Available tools

ToolWhat it does
RustThe Rust tool exposed by this server.

How to install the Jmespath Extensions MCP server

{
  "mcpServers": {
    "jmespath-extensions": {
      "command": "uvx",
      "args": ["jmespath-extensions"]
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Example prompts to try

  • Use Jmespath Extensions to Rust.

Frequently asked questions

It connects Jmespath Extensions to MCP-compatible AI assistants such as Claude and Cursor, exposing 1 tool (Rust) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Jmespath Extensions directly.