io.github.MukundaKatta/jmespath-mcp MCP Server

The io.github.MukundaKatta/jmespath-mcp server runs JMESPath queries against JSON. It is a pure JavaScript implementation, designed to work without a native binary, and provides the same behavior on macOS / Linux / Windows. It exposes one tool: json_query(expression, data).

🛠️ Key Features

Executes JMESPath expressions over JSON input
Tool: json_query(expression, data) (one tool total)
Pure JS implementation; no jq binary required
Intended to behave consistently across macOS, Linux, and Windows

🚀 Use Cases

Query JSON when array projections like people[*].name are needed
Apply JMESPath filters such as locations[?state == 'WA']
Use JMESPath pipes and built-in functions (e.g., length, sort_by, contains, keys)
Handle transformations involving to_entries / from_entries round-trips

⚡ Developer Benefits

Avoids platform-specific native dependencies
Uses JMESPath, described as the AWS-standardized query language for JSON

⚠️ Limitations

The provided documentation excerpt specifies only a single tool (json_query); no additional tools or capabilities are listed.

Why this exists

LLMs handle shallow JSON paths well (foo.bar.baz) but reliably mess up:

Array projections (people[*].name)

Filters (locations[?state == 'WA'])

Pipes and built-in functions (length, sort_by, contains, keys)

Round-trips through to_entries / from_entries

JMESPath is the AWS-standardized query language for JSON. This server runs your expression through the real JMESPath engine and returns the result.

io.github.MukundaKatta/jmespath-mcp