JMESPath MCP Server Library

This library provides the MCP router and tools for JMESPath functionality. Use build_router() to create a configured router for use with any transport.

jpx

JMESPath CLI and tools with 400+ extended functions - a powerful jq alternative.

This repository contains the jpx ecosystem:

Quick Start

# Install
brew install joshrotenberg/brew/jpx
# or: cargo install jpx

# Use it
echo '{"name": "world"}' | jpx 'upper(name)'
# "WORLD"

curl -s https://api.github.com/users/octocat | jpx '{
  login: login,
  created: format_date(parse_date(created_at), `%B %Y`)
}'
# {"login": "octocat", "created": "January 2011"}

Docker

# CLI
echo '{"name": "world"}' | docker run -i ghcr.io/joshrotenberg/jpx 'upper(name)'

# MCP Server
docker run -i --rm ghcr.io/joshrotenberg/jpx-mcp

MCP Server

Give Claude (or any MCP client) the ability to query and transform JSON:

{
  "mcpServers": {
    "jpx": {
      "command": "jpx-mcp"
    }
  }
}

Tools: evaluate, batch_evaluate, validate, functions, describe, search, similar, format, diff, patch, merge, stats, paths, keys

Function Categories

The library provides 400+ functions across these categories:

See the documentation for the full function reference.

Acknowledgments

• JMESPath - The query language specification
• jmespath.rs - Rust implementation by @mtdowling
• jpx-core - JMESPath implementation with 400+ extension functions

License

MIT or Apache-2.0