This package contains all types and helpers for encoding and decoding anything to and from a Uint8Array
. It can be used standalone, but it is also exported as part of Kit @solana/kit
.
No matter which serialization strategy we use, Codecs abstract away its implementation and offers a simple encode
and decode
interface. Codecs are also highly composable, allowing us to build complex data structures from simple building blocks.
Here's a quick example that encodes and decodes a simple Person
object.
// Use composable codecs to build complex data structures.
type Person = { name: string; age: number };
const getPersonCodec = (): Codec<Person> =>
getStructCodec([
['name', addCodecSizePrefix(getUtf8Codec(), getU32Codec())],
['age', getU32Codec()],
]);
// Use your own codecs to encode and decode data.
const person = { name: 'John', age: 42 };
const personCodec = getPersonCodec();
const encodedPerson: Uint8Array = personCodec.encode(person);
const decodedPerson: Person = personCodec.decode(encodedPerson);
Whilst Codecs can both encode and decode, it is possible to only focus on encoding or decoding data, enabling the unused logic to be tree-shaken. For instance, here’s our previous example using Decoders only to decode a Person
type.
const getPersonDecoder = (): Decoder<Person> =>
getStructDecoder([
['name', addDecoderSizePrefix(getUtf8Decoder(), getU32Decoder())],
['age', getU32Decoder()],
]);
The @solana/codecs
package is composed of several smaller packages, each with its own set of responsibilities. You can learn more about codecs and how to create your own by reading their respective documentation.
@solana/codecs-core
This package lays the foundation of codecs by providing core type and helper functions to create and compose them.- Composing codecs.
- Composing encoders and decoders.
- Combining encoders and decoders.
- Different From and To types.
- Fixed-size and variable-size codecs.
- Creating custom codecs.
- Transforming codecs.
- Fixing the size of codecs.
- Prefixing codecs with their size.
- Adding sentinels to codecs.
- Adjusting the size of codecs.
- Offsetting codecs.
- Padding codecs.
- Reversing codecs.
- Byte helpers.
@solana/codecs-numbers
This package offers codecs for numbers of various sizes and characteristics.@solana/codecs-strings
This package provides codecs for strings of various encodings and size strategies.@solana/codecs-data-structures
This package offers a set of helpers for a variety of data structures such as objects, enums, arrays, maps, etc.@solana/options
This package adds Rust-likeOptions
to JavaScript and offers codecs and helpers to manage them.