@chainsafe/ssz

ssz

Simple Serialize (SSZ)

Install

npm install @chainsafe/ssz

Examples

Serialize

Deserialize

Hash Tree Root

Signing Root

Equals

Clone

Assert Valid Value

API

See our autogenerated API docs

Usage

In order to properly serialize/deserialize/hash values, we need both the value and the "type" of the value.

Types

The simple serialization spec operates over a few specific types. Types are either specified in a simplified form (eg: "uint32") or an extended form (eg: {type: Type.uint, byteLength: 4, offset: 0, useNumber: false}). In most cases, the simplified form suffices.

Uint

A uint serialization value may be either a js number or a BN from bn.js. A uint type is specified by either "uintN" or "numberN", where N is the number of bits to serialize. uintN > 48 bits is deserialized to a BN else deserialized to a number. Every numberN is deserialized to a number.

Boolean

A boolean serialization value must be either true or false. Anything other input will throw an Error. The boolean type is specified as "bool".

Vector

A "vector" according to the spec is a fixed-length list with every element of the same type. A vector serialization value may be either an Array or Buffer. Vector types are specified as either "bytesN" or [elementType, vectorlength] bytesN is deserialized to Buffer. [elementType, vectorLength] is deserialized to Array<elementType> unless elementType is byte, when the value is deserialized to Buffer.

List

A "list" according to the spec is a list of unspecified length with every element of the same type. A list serialization value may be either an Array or Buffer. Tuple types are specified as either "bytes" or [elementType] bytes is deserialized to Buffer. [elementType] is deserialized to Array<elementType> unless elementType is byte, when the value is deserialized to Buffer.

Container

A "container" according to the spec is a collection of values where the type of each element may differ. A container serialization value must be an Object. The container serialization type must be an Object, with a string name, and a fields value of `Array<[fieldName, fieldType]>.

Extended form

See FullSSZType in src/types.ts for more information.

License

Apache 2.0