This package is part of ChainSafe's Lodestar project
Lodestar defines all constants and presets defined in the Ethereum Consensus spec. This can be used in conjunction with other Lodestar libraries to interact with the Ethereum consensus.
npm install @lodestar/params
The Lodestar params package contains several items used in all downstream Lodestar libraries:
- Fork names
- Constants
- Presets
Many downstream components are namespaced on fork names, or otherwise rely on knowing the fork names ahead of time. The Lodestar params package exports an enum ForkName
the enumerates all known fork names.
import {ForkName} from "@lodestar/params";
// dummy data
let forkName = "phase0";
switch (forkName) {
case ForkName.phase0:
case ForkName.altair:
case ForkName.bellatrix:
default:
}
All constants defined in the spec are exported verbatim.
import {GENESIS_SLOT} from "@lodestar/params";
Presets are defined in the spec as "constantish" and can only be configured at build-time. These are meant to be treated as constants, and indeed are treated as constants by all downstream Lodestar libraries. The default preset is mainnet
. The only other preset defined is minimal
, used only in testing environments.
The active preset is exported under the ACTIVE_PRESET
named export.
import {ACTIVE_PRESET, SLOTS_PER_EPOCH} from "@lodestar/params";
The preset may be set in one of two ways:
- by setting the
LODESTAR_PRESET
environment variable - by executing the
setActivePreset(preset: Preset)
function
Important Notes:
- Interacting with and understanding the active preset is only necessary in very limited testing environments, like for ephemeral testnets
- The
minimal
preset is NOT compatible with themainnet
preset. - using
setActivePreset
may be dangerous, and only should be run once before loading any other libraries. All downstream Lodestar libraries expect the active preset to never change. - Preset values can be overridden by executing
setActivePreset(presetName: PresetName, overrides?: Partial<BeaconPreset>)
and supplying values to override. - The Lodestar CLI exposes
setActivePreset
through--presetFile
flag which allows to override the active preset with custom values from file.
Apache-2.0 ChainSafe Systems