> ## 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.

# Block

> Complete Ethereum block representation

## Overview

Block represents a complete Ethereum block with header, body, hash, and metadata. Used for block validation, storage, and propagation.

```typescript theme={null}
import * as Block from '@voltaire/primitives/Block'

const block = Block.from({
  header: blockHeader,
  body: blockBody,
  hash: "0x1234567890abcdef...",
  size: 1024n,
  totalDifficulty: 12345678n, // Optional, pre-merge only
})
```

## Type Definition

```typescript theme={null}
type BlockType = {
  readonly header: BlockHeaderType
  readonly body: BlockBodyType
  readonly hash: BlockHashType
  readonly size: Uint256Type
  readonly totalDifficulty?: Uint256Type
}
```

**Fields:**

* `header` - Block metadata and Merkle roots
* `body` - Transactions, uncles/ommers, withdrawals
* `hash` - Keccak256(RLP(header))
* `size` - Block size in bytes (RLP-encoded)
* `totalDifficulty` - Cumulative difficulty (pre-merge only)

## Creating Blocks

### from

Universal constructor from block components.

```typescript theme={null}
import * as Block from '@voltaire/primitives/Block'
import * as BlockHeader from '@voltaire/primitives/BlockHeader'
import * as BlockBody from '@voltaire/primitives/BlockBody'

const header = BlockHeader.from({
  parentHash: "0x...",
  // ... other header fields
})

const body = BlockBody.from({
  transactions: [tx1, tx2],
  ommers: [],
  withdrawals: [w1, w2],
})

const block = Block.from({
  header,
  body,
  hash: "0xabc123...",
  size: 2048n,
})
```

## Block Components

A complete block consists of:

1. **Header** - Metadata and Merkle roots for verification
2. **Body** - Actual content (transactions, uncles, withdrawals)
3. **Hash** - Unique block identifier computed from header
4. **Size** - Total RLP-encoded size in bytes

## Post-Merge Changes

After The Merge (September 2022):

* `totalDifficulty` is no longer relevant
* Proof-of-Work fields in header are zeroed
* Beacon chain handles consensus

```typescript theme={null}
// Pre-merge block
const premerge = Block.from({
  header,
  body,
  hash: "0x...",
  size: 1024n,
  totalDifficulty: 58750003716598352816469n,
})

// Post-merge block (no totalDifficulty)
const postmerge = Block.from({
  header,
  body,
  hash: "0x...",
  size: 1024n,
})
```

## See Also

* [Block (Effect)](https://voltaire-effect.tevm.sh/primitives/block) - Effect.ts integration with Schema validation
* [BlockHeader](/primitives/block-header) - Block header details
* [BlockBody](/primitives/block-body) - Block body details
* [BlockHash](/primitives/block-hash) - Block identifier
* [BlockNumber](/primitives/block-number) - Block height