What is JSONPath? The Complete RFC 9535 Guide

JSONPath Definition

JSONPath is a declarative query language for JSON, standardized by IETF RFC 9535 (2024). It enables XPath-like navigation of JSON trees without writing imperative traversal code.

Core JSONPath Syntax

• $ — Root of the document.
• .key or ["key"] — Access object property.
• [n] — Access array element at index n (0-based).
• [*] — Wildcard — all elements or properties.
• .. — Recursive descent — search all levels.
• [-1] — Last element in an array.
• [0,2] — Union — specific indices.
• [0:3] — Slice — elements from index 0 to 2.
• [?(@.price < 10)] — Filter expression — elements matching condition.

// Sample JSON:
{
  "store": {
    "books": [
      { "title": "Moby Dick", "price": 8.99, "category": "classic" },
      { "title": "Dune",      "price": 12.99, "category": "scifi" },
      { "title": "Hamlet",    "price": 6.99, "category": "classic" }
    ]
  }
}

// JSONPath Queries:
$.store.books[*].title       // All book titles
$.store.books[0].price       // Price of first book: 8.99
$.store.books[-1]            // Last book (Hamlet)
$..price                     // All prices anywhere: [8.99, 12.99, 6.99]
$.store.books[?(@.price < 10)] // Books under $10
$.store.books[?(@.category == "classic")].title // Classic book titles