> ## Documentation Index
> Fetch the complete documentation index at: https://voltaire.tevm.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Slot

> Consensus layer slot number (12 seconds per slot)

## 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.

```typescript theme={null}
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.

```typescript theme={null}
const slot = Slot.from(1000000n);
const num = Slot.toNumber(slot); // 1000000
```

### `Slot.toBigInt(slot)`

Convert Slot to bigint.

```typescript theme={null}
const slot = Slot.from(1000000);
const big = Slot.toBigInt(slot); // 1000000n
```

### `Slot.equals(a, b)`

Check if two slots are equal.

```typescript theme={null}
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).

```typescript theme={null}
const slot = Slot.from(96n);
const epoch = Slot.toEpoch(slot); // Epoch 3
```

## Usage Examples

### Calculate slot timing

```typescript theme={null}
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

```typescript theme={null}
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
```

## Related Types

* [Slot (Effect)](https://voltaire-effect.tevm.sh/primitives/slot) - Effect.ts integration with Schema validation
* [Epoch](/primitives/epoch) - 32 slots grouped into an epoch
* [ValidatorIndex](/primitives/validator-index) - Validator registry index
* [BeaconBlockRoot](/primitives/beacon-block-root) - Beacon block root hash

## References

* [Ethereum Consensus Specs](https://github.com/ethereum/consensus-specs)
* [EIP-4788](https://eips.ethereum.org/EIPS/eip-4788) - Beacon block root in EVM