Nebulous Pumpkin Moons

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    0.39.0 • Public • Published


    npm License Eth Consensus Spec v1.1.10 ES Version Node Version

    This package is part of ChainSafe's Lodestar project

    Lodestar defines all datatypes defined in the Ethereum Consensus spec. This tooling can be used for any Typescript project looking to operate on these types. Both Typescript interfaces and Simple Serialize (SSZ) methods are exported for consumers.


    npm install @chainsafe/lodestar-types


    The lodestar types library organizes datatypes on several dimensions:

    • Typescript interfaces vs SSZ objects
    • By fork

    Typescript interfaces

    Lodestar types are all defined as typescript interfaces. These interfaces can be used independently, and are used throughout downstream Lodestar packages (eg: in the beacon node).

    These interfaces are accessible via named exports.

    import {Epoch} from "@chainsafe/lodestar-types";
    const x: Epoch = 5;

    SSZ objects

    Lodestar types are also defined as SSZ objects. These "Type" objects provide convenient methods to perform SSZ operations (serialization / deserialization / merkleization/etc). The library exports a singleton object containing all SSZ objects.

    import {Type} from "@chainsafe/ssz";
    import {ssz, Epoch} from "@chainsafe/lodestar-types";
    const EpochType: Type<Epoch> = ssz.Epoch;
    const e = EpochType.defaultValue();

    By fork

    Lodestar types support multiple different consensus forks. In order to easily differentiate types that may change across forks, types are organized in namespaces according to the fork in which they're introduced. Types introduced in phase 0 are available under the phase0 namespace. Types introduced in altair are available under the altair namespace.

    import {altair, phase0, ssz} from "@chainsafe/lodestar-types";
    const phase0State: phase0.BeaconState = ssz.phase0.BeaconState.defaultValue();
    const altairState: altair.BeaconState = ssz.altair.BeaconState.defaultValue();

    Primitive types are directly available without a namespace.

    import {Epoch, ssz} from "@chainsafe/lodestar-types";
    const epoch: Epoch = ssz.Epoch.defaultValue();

    In some cases, we need interfaces that accept types across all forks, eg: when the fork is not known ahead of time. Typescript interfaces for this purpose are exported under the allForks namespace. SSZ Types typed to these interfaces are also provided under an allForks namespace, but keyed by ForkName.

    import {ForkName} from "@chainsafe/lodestar-params";
    import {allForks, ssz} from "@chainsafe/lodestar-types";
    const state: allForks.BeaconState = ssz.allForks[ForkName.phase0].BeaconState.defaultValue();


    Apache-2.0 ChainSafe Systems


    npm i @chainsafe/lodestar-types

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