# @chainsafe/lodestar-config > Chain configuration required for lodestar Latest version **0.39.0** (published 2022-06-28) · Apache-2.0 license · 0 weekly downloads ## Install ```sh npm install @chainsafe/lodestar-config pnpm add @chainsafe/lodestar-config yarn add @chainsafe/lodestar-config bun add @chainsafe/lodestar-config ``` ## Health **Score 40/100 (D)** — status: abandoned. Positive: has types; esm support; no vulnerabilities; high maintenance score. Warnings: low downloads; pre 1.0. Negative: abandoned. ## Facts | | | |---|---| | Version | 0.39.0 | | Published | 2022-06-28 | | First published | 2020-02-25 | | Weekly downloads | 0 | | License | Apache-2.0 | | TypeScript types | bundled | | Module format | ESM | | Dependencies | 3 | | Unpacked size | 69.3 KB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 1421 | | Author | ChainSafe Systems | | Maintainers | gregthegreek, priom, dapplion, wemeetagain, mpetrunic | | Keywords | ethereum, eth-consensus, beacon, blockchain | ## Links - npm: https://www.npmjs.com/package/@chainsafe/lodestar-config - Repository: https://github.com/ChainSafe/lodestar - Homepage: https://github.com/ChainSafe/lodestar#readme - Issues: https://github.com/ChainSafe/lodestar/issues - npm.io page: https://npm.io/package/@chainsafe/lodestar-config ## Dependencies (3) - [@chainsafe/ssz](https://npm.io/package/@chainsafe/ssz.md) ^0.9.2 - [@chainsafe/lodestar-types](https://npm.io/package/@chainsafe/lodestar-types.md) ^0.39.0 - [@chainsafe/lodestar-params](https://npm.io/package/@chainsafe/lodestar-params.md) ^0.39.0 ## Recent versions - 0.39.0 (latest) — 2022-06-28 - 0.40.0-dev.3682e4cd3e (next) — 2022-07-06 - 0.39.0-rc.2 (rc) — 2022-06-28 - 0.40.0-dev.4faff3a7b9 — 2022-07-06 - 0.40.0-dev.a627e72d80 — 2022-07-06 - 0.40.0-dev.1b03e81198 — 2022-07-06 - 0.40.0-dev.0b4c4bf39a — 2022-07-05 - 0.40.0-dev.22963ebba9 — 2022-07-05 - 0.40.0-dev.ccdf688e6e — 2022-07-05 - 0.40.0-dev.138225fed4 — 2022-07-05 - 0.39.0-dev.77c0ce6d0f — 2022-07-04 - 0.39.0-dev.5e9288b64c — 2022-07-04 - 0.39.0-dev.7decce4fec — 2022-07-01 - 0.39.0-dev.3f9f5cbfdd — 2022-07-01 - 0.39.0-dev.4d7852e106 — 2022-06-30 - … 825 more at https://npm.io/package/@chainsafe/lodestar-config/versions ## README # lodestar-config [![npm](https://img.shields.io/npm/v/@chainsafe/lodestar-config)](https://www.npmjs.com/package/@chainsafe/lodestar-config) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![Eth Consensus Spec v1.1.10](https://img.shields.io/badge/ETH%20consensus--spec-1.1.10-blue)](https://github.com/ethereum/consensus-specs/releases/tag/v1.1.10) ![ES Version](https://img.shields.io/badge/ES-2020-yellow) ![Node Version](https://img.shields.io/badge/node-12.x-green) > This package is part of [ChainSafe's Lodestar](https://lodestar.chainsafe.io) project Lodestar defines all [network configuration variables](https://github.com/ethereum/consensus-specs/tree/v1.1.10/configs) defined in the [Ethereum Consensus spec](https://github.com/ethereum/consensus-specs). This tooling may be used to configure testnets, ingest mainnet/testnet config variables, or be used in downstream Lodestar libraries. ## Installation ```sh npm install @chainsafe/lodestar-config ``` ## Usage The Lodestar config package contains several interfaces used in downstream Lodestar libraries: - `IChainConfig` - Typescript interface, Default (mainnet) values, and matching SSZ helper type object - `IForkConfig` - A fork helper object that's structured around the fork schedule - `IChainForkConfig` A wrapper object that implements `IChainConfig` and `IForkConfig` - `ICachedGenesis` - A helper object for caching domains (which relies on the genesis validators root) - `IBeaconConfig` - A wrapper object that implements all above interfaces ### Chain config The Ethereum consensus spec defines a bunch of variables that may be easily configured per testnet. These include the `GENESIS_TIME`, `SECONDS_PER_SLOT`, and various `*_FORK_EPOCH`s, `*_FORK_VERSION`s, etc. The Lodestar config package exports the `IChainConfig` interface and matching `ChainConfig` SSZ type, which include all of these variables, named verbatim from the spec. ```typescript import {IChainConfig} from "@chainsafe/lodestar-config"; import {chainConfig} from "@chainsafe/lodestar-config/default"; let config: IChainConfig = chainConfig; const x: number = config.SECONDS_PER_SLOT; ``` Mainnet default values are available as a singleton `IChainConfig` under the `default` import path. ```typescript import {chainConfig} from "@chainsafe/lodestar-config/default"; chainConfig.SECONDS_PER_SLOT === 12; ``` There are also utility functions to help create a `IChainConfig` from unknown input and partial configs. ```typescript import {createIChainConfig, IChainConfig, chainConfigFromJson} from "@chainsafe/lodestar-config"; // example config let chainConfigObj: Record = { // phase0 MIN_PER_EPOCH_CHURN_LIMIT: 4, CHURN_LIMIT_QUOTIENT: 65536, MIN_GENESIS_ACTIVE_VALIDATOR_COUNT: 128, MIN_GENESIS_TIME: 1621504614, ETH1_FOLLOW_DISTANCE: 2048, SECONDS_PER_ETH1_BLOCK: 14, DEPOSIT_CHAIN_ID: 5, DEPOSIT_NETWORK_ID: 5, DEPOSIT_CONTRACT_ADDRESS: "0x2cc88381fe23027743c1f85512bffb383acca7c7", EJECTION_BALANCE: 16000000000, GENESIS_FORK_VERSION: "0x00004811", GENESIS_DELAY: 1100642, SECONDS_PER_SLOT: 12, MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256, SHARD_COMMITTEE_PERIOD: 256, // altair INACTIVITY_SCORE_BIAS: 4, INACTIVITY_SCORE_RECOVERY_RATE: 16, ALTAIR_FORK_VERSION: "0x01004811", ALTAIR_FORK_EPOCH: 10, }; const partialChainConfig: Partial = chainConfigFromJson(chainConfigObj); // Fill in the missing values with mainnet default values const chainConfig: IChainConfig = createIChainConfig(partialChainConfig); ``` ### Fork config The variables described in the spec can be used to assemble a more structured 'fork schedule'. This info is organized as `IForkConfig` in the Lodestar config package. In practice, the `IChainConfig` and `IForkConfig` are usually combined as a `IChainForkConfig`. A `IForkConfig` provides methods to select the fork info, fork name, fork version, or fork ssz types given a slot. ```typescript import {GENESIS_SLOT} from "@chainsafe/lodestar-params"; import {createIChainForkConfig, IChainForkConfig} from "@chainsafe/lodestar-config"; import {config as chainConfig} from "@chainsafe/lodestar-config/default"; const config: IChainForkConfig = createIChainForkConfig(chainConfig); const version = config.getForkVersion(GENESIS_SLOT); ``` ### Cached genesis For signing Ethereum consensus objects, a cryptographic "domain" is computed and mixed into the signed message. This domain separates signatures made for the Ethereum mainnet from testnets or other instances of the chain. The `ICachedGenesis` interface is used to provide a cache for this purpose. Practically, the domain rarely changes, only per-fork, and so the value can be easily cached. Since the genesis validators root is part of the domain, it is required input to instantiate an `ICachedGenesis`. In practice, the `IChainForkConfig` and `ICachedGenesis` are usually combined as a `IBeaconConfig`. This is the 'highest level' object exported by the Lodestar config library. ```typescript import {DOMAIN_DEPOSIT, GENESIS_SLOT} from "@chainsafe/lodestar-params"; import {createIBeaconConfig, IBeaconConfig} from "@chainsafe/lodestar-config"; import {config as chainConfig} from "@chainsafe/lodestar-config/default"; // dummy test root let genesisValidatorsRoot: Uint8Array = new Uint8Array(); const config: IBeaconConfig = createIBeaconConfig(chainConfig, genesisValidatorsRoot); const domain = config.getDomain(DOMAIN_DEPOSIT, GENESIS_SLOT); ``` ## License Apache-2.0 [ChainSafe Systems](https://chainsafe.io) --- _Source: https://npm.io/package/@chainsafe/lodestar-config · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._