JOLT: A Complete Guide to JSON Transformation (Basics to Advanced)

JOLT is a powerful tool for transforming JSON, but understanding how it works—especially wildcards and nested structures—can be challenging. This guide walks from basic concepts to advanced transformations with detailed examples. Introduction JOLT (JsOn Language for Transform) is a language used to transform JSON structures and is commonly found in integration layers where payloads need to be normalized, reshaped, enriched, or reduced before being consumed by downstream systems. This article was written as a detailed learning reference for developers with little or no prior experience with JOLT. The objective is to start from the basics and gradually move to more advanced behavior, preserving the details that are usually necessary to truly understand how JOLT works in practice. For testing all examples contained in this article: JOLT playground JOLT — JsOn Language for Transform JOLT is a language used for the transformation of JSON. It uses the following basic structure: [ { "operatio