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Libraries

jpx is built on a stack of Rust crates that can be used independently in your own projects.

jpx-core

Self-contained JMESPath implementation with 490+ extension functions. Provides the parser, runtime, and function registry used by all other jpx crates. This is a from-scratch implementation with no upstream dependency on the unmaintained jmespath crate.

  • Uses serde_json::Value natively -- no type conversion overhead
  • 26 standard JMESPath built-in functions + 490+ extensions across 32 categories
  • functions.toml is the single source of truth for function metadata
  • Optional let-expr feature for JMESPath let expressions

crates.io | docs.rs

jpx-engine

Query engine with introspection, function discovery, configuration, and query store. Wraps jpx-core with higher-level features for building tools and services.

  • Single, batch, and streaming evaluation
  • Function introspection with BM25 search indexing
  • Session-scoped query store for named queries
  • JSON utilities: format, diff (RFC 6902), patch, merge (RFC 7396), stats, paths
  • Layered configuration via jpx.toml with discovery (cwd, home, XDG)

crates.io | docs.rs

jpx-mcp

Model Context Protocol server exposing 31 JMESPath tools to AI assistants, built on jpx-engine. Run it as a binary or embed the router in your own transport.

  • 31 tools across evaluation, introspection, JSON utilities, query store, and discovery
  • Install with cargo install jpx-mcp, or run the ghcr.io/joshrotenberg/jpx-mcp image
  • See the MCP Server section for setup and the full tool list

crates.io | docs.rs

Python Bindings

Use jpx functions in Python via the jpx package on PyPI.

  • Module-level functions: search(), compile(), validate(), list_functions()
  • CompiledExpression class for reusing compiled expressions
  • JpxEngine class wrapping the full engine

PyPI