News
Ion JS 3.0.0 Released
Ion Python 0.4.1 Released
Ion Hash Python 1.0.1 Released
Ion Schema Kotlin 1.0.0 Released
Ion Java 1.5.0 Released

Amazon Ion is a richly-typed, self-describing, hierarchical data serialization format offering interchangeable binary and text representations. The text format (a superset of JSON) is easy to read and author, supporting rapid prototyping. The binary representation is efficient to store, transmit, and skip-scan parse. The rich type system provides unambiguous semantics for long-term preservation of data which can survive multiple generations of software evolution.

Ion was built to address rapid development, decoupling, and efficiency challenges faced every day while engineering large-scale, service-oriented architectures. It has been addressing these challenges within Amazon for nearly a decade, and we believe others will benefit as well.

Available Libraries: Ion JavaIon CIon PythonIon JavaScript
Related Projects: Ion HashIon Schema
Tools: Hive SerDe


Getting Started

All JSON values are valid Ion values, and while any value can be encoded in JSON (e.g., a timestamp value can be converted to a string), such approaches require extra effort, obscure the actual type of the data, and tend to be error-prone.

In contrast, Ion’s rich type system enables unambiguous semantics for data (e.g., a timestamp value can be encoded using the timestamp type). The following illustrates some of the features of the Ion type system:

The Specification provides an overview of the full set of Ion types.

Binary Encoding

Ion provides two encodings: human-readable text (as shown above), and a space- and read-efficient binary encoding. When binary-encoded, every Ion value is prefixed with the value’s type and length. The following illustrates a few of the efficiences provided by Ion’s binary encoding:

Similar space efficiencies are found in other aspects of Ion’s binary encoding.

Give Ion a Try!

/* Ion supports comments. */ // Here is a struct, which is similar to a JSON object { // Field names don't always have to be quoted name: "fido", // This is an integer with a 'years' annotation age: years::4, // This is a timestamp with day precision birthday: 2012-03-01T, // Here is a list, which is like a JSON array toys: [ // These are symbol values, which are like strings, // but get encoded as integers in binary ball, rope, ], }

More Information

To learn more, check out the Docs page, or see Libs for the officially supported libraries as well as community supported tools. For information on how to contribute, how to contact the Ion Team, and answers to the frequently asked questions, see Help.