# Block Response

Raw response from `getBlockByHash` / `getLatestBlock` on a Casper 2.x node.

## Raw JSON

```json
{
  "api_version": "2.0.0",
  "block_with_signatures": {
    "block": {
      "Version2": {
        "hash": "b51e5d16944c63eab276e6c5494fd39a454418e3a3f6aa519797882b6c3c0d4b",
        "header": {
          "parent_hash": "11040b60955bc9921dfbeff3abf4ee3e1c702865b0183638cd5eba922cd34fe3",
          "state_root_hash": "cf1d7c8d33ce0fbc6c5211000ade4cc88ab671cb51e8be6e458c774dd82f8ab0",
          "body_hash": "ab363e6bf68b4190176b53196caa16954d2eb97f3f0dbe004b16f0e6951893cc",
          "timestamp": "2025-01-27T10:51:36.846Z",
          "era_id": 14828,
          "height": 3444515,
          "protocol_version": "2.0.1",
          "proposer": "0140afe8f752e5ff100e0189c080bc207e8805b3e5e82f792ec608de2f11f39f6c",
          "current_gas_price": 1,
          "last_switch_block_hash": "a265470a3663bbf88ab37d276cd1786c5e0f53f3da5a8fc268dfddedaf890b93",
          "era_end": null,
          "random_bit": true,
          "accumulated_seed": "22cfe5e17ebb2f79af99556e2f134051d8a64e6ff6cb96eac5378f24b8b8a486"
        },
        "body": {
          "transactions": {
            "3": [
              { "Deploy": "c102a6fed7f4b9a435ca8584b4d2f704f419d523a1c3f7199799b534df264c9a" }
            ]
          },
          "rewarded_signatures": [[240], [0], [0]]
        }
      }
    },
    "proofs": [
      {
        "public_key": "01032146b0b9de01e26aaec7b0d1769920de94681dbd432c3530bfe591752ded6c",
        "signature": "0120730fd151cfd40d8b86abfc679c66dd50f49d0c76fe6d68a75d7f18efd05b..."
      }
    ]
  }
}
```

## Field reference

### Top level

| Field | Description |
|---|---|
| `api_version` | Node API version - `"2.0.0"` for Casper 2.x |
| `block_with_signatures` | The block and its finality proofs |

### `block.Version2.header`

| Field | Type | Description |
|---|---|---|
| `hash` | hex string | Block hash |
| `parent_hash` | hex string | Previous block hash |
| `state_root_hash` | hex string | Merkle root after this block's execution |
| `era_id` | number | Era this block belongs to |
| `height` | number | Block height (0-indexed) |
| `protocol_version` | string | e.g. `"2.0.1"` |
| `timestamp` | ISO 8601 | When this block was proposed |
| `proposer` | public key hex | Validator that proposed the block |
| `current_gas_price` | number | Gas price multiplier for this block |
| `era_end` | object \| null | Non-null only on the **switch block** (the last block of an era); contains equivocators, rewards, and next-era validator weights |

### `block.Version2.body.transactions`

The transactions map uses lane IDs as keys:

| Lane | Meaning |
|---|---|
| `"0"` | Mint (native CSPR transfers) |
| `"1"` | Auction (delegate/undelegate) |
| `"2"` | Install/upgrade contracts |
| `"3"` | Legacy Deploy wrapper |

Each entry is either `{ "Deploy": "<hash>" }` or `{ "Version1": "<hash>" }`.

### `proofs`

Array of finality signatures from validators. Each has:
- `public_key` - validator's public key
- `signature` - their signature over the block hash

## SDK usage

```ts
const result = await rpcClient.getBlockByHash(
  'b51e5d16944c63eab276e6c5494fd39a454418e3a3f6aa519797882b6c3c0d4b'
);

const block = result.block!;

console.log(block.hash.toHex());           // block hash
console.log(block.header.height);          // 3444515
console.log(block.header.eraId);           // 14828
console.log(block.header.timestamp.toJSON()); // "2025-01-27T10:51:36.846Z"
console.log(block.header.stateRootHash.toHex()); // state root

// Proposer public key
console.log(block.header.proposer?.toHex());

// Finality signatures
result.blockWithSignatures?.proofs.forEach(proof => {
  console.log(proof.publicKey.toHex());
});
```

## 1.x vs 2.x differences

On a Casper 1.x node (`api_version: "1.x.x"`), the response uses a `Version1` block format:

```json
{
  "block": {
    "Version1": {
      "hash": "...",
      "header": {
        "parent_hash": "...",
        "state_root_hash": "...",
        "era_id": 1234,
        "height": 500000,
        "protocol_version": "1.5.6"
      },
      "body": {
        "deploy_hashes": ["abc123..."],
        "transfer_hashes": ["def456..."]
      }
    }
  }
}
```

Notable differences:
- Body uses `deploy_hashes` / `transfer_hashes` arrays instead of a lane map
- No `current_gas_price` field
- No `last_switch_block_hash`

The SDK's `ChainGetBlockResult` handles both formats transparently.

## Related

- [`getLatestBlock`](/actions/block/getLatestBlock)
- [`getBlockByHash`](/actions/block/getBlockByHash)
- [`getBlockByHeight`](/actions/block/getBlockByHeight)
- [Block type](/types/block)