JSONPath Examples for Nested API Responses

Root, children and array indexes

The dollar sign represents the root value. Dot notation selects an object member with a simple name, while bracket notation handles spaces and punctuation. A numeric bracket selects one array position.

For a response shaped as store.books, $.store.books[0].title selects the title of the first book. The zero-based index is explicit and returns nothing when the array is empty, so production code should handle an absent match.

$.store.books[0].title
$['store']['books'][0]['title']

Wildcards and recursive descent

A wildcard selects every member or array item at one level. $.store.books[*].title returns each book title. Recursive descent searches through descendants and is convenient for discovery, but it can match fields from unrelated parts of a large document.

Prefer a specific path when the payload contract is known. Recursive expressions such as $..id may silently begin returning new IDs after an API adds another nested resource.

Slices and filters

Array slices select a positional range, while filters select items whose data meets a condition. A filter like $.store.books[?(@.price < 30)].title returns titles for books below a price threshold.

Filter capabilities and extension syntax historically differed among libraries. RFC 9535 standardized core JSONPath behavior, but implementations may still expose non-standard functions. Test expressions with the same library and version used by the destination system.

Treat zero, one and many as distinct outcomes

A JSONPath query naturally returns a sequence of matches. Even when you expect one value, decide what the application should do with zero or multiple matches. Taking the first result without checking can hide a contract change.

When debugging, display normalized paths alongside values. Two equal values from different locations look identical in a value-only list, while their paths reveal why the query returned more than expected.