Skip to main content

​
Overview

Slot represents a consensus layer slot number in Ethereum’s proof-of-stake system. Each slot is 12 seconds and represents an opportunity for a validator to propose a block. Type: bigint & { readonly [brand]: "Slot" }

​
Key Concepts

  • Duration: Each slot is exactly 12 seconds
  • Epochs: 32 slots = 1 epoch (6.4 minutes)
  • Validator duties: Validators are assigned to propose/attest in specific slots
  • Post-merge: Slots are the fundamental unit of time in PoS Ethereum

​
Methods

​
Slot.from(value)

Create Slot from number, bigint, or string. 
import { Slot } from '@tevm/primitives';

const slot1 = Slot.from(1000000n);
const slot2 = Slot.from(1000000);
const slot3 = Slot.from("0xf4240");

​
Slot.toNumber(slot)

Convert Slot to number. Throws if exceeds MAX_SAFE_INTEGER. 
const slot = Slot.from(1000000n);
const num = Slot.toNumber(slot); // 1000000

​
Slot.toBigInt(slot)

Convert Slot to bigint. 
const slot = Slot.from(1000000);
const big = Slot.toBigInt(slot); // 1000000n

​
Slot.equals(a, b)

Check if two slots are equal. 
const a = Slot.from(1000000n);
const b = Slot.from(1000000n);
Slot.equals(a, b); // true

​
Slot.toEpoch(slot)

Convert slot to its corresponding epoch (slot / 32). 
const slot = Slot.from(96n);
const epoch = Slot.toEpoch(slot); // Epoch 3

​
Usage Examples

​
Calculate slot timing

import { Slot } from '@tevm/primitives';

const genesisTime = 1606824023; // Beacon chain genesis
const slot = Slot.from(1000000n);

// Calculate timestamp for this slot
const slotTime = genesisTime + Number(slot) * 12;
console.log(`Slot ${slot} occurred at: ${new Date(slotTime * 1000)}`);

​
Work with epochs

import { Slot, Epoch } from '@tevm/primitives';

const slot = Slot.from(100n);
const epoch = Slot.toEpoch(slot); // Epoch 3

// Get first slot of next epoch
const nextEpoch = Epoch.from(epoch + 1n);
const nextEpochSlot = Epoch.toSlot(nextEpoch); // Slot 128

​
References