# Get Block Header

Request the header for a given block.


```
GET /header/:hash
```

## Parameters
* **hash** - `string` - The block hash
* **at** - `string` (optional) - Access Token (json web token). Required if authentication is activated. Alternatively, the access token can be passed through the `Authorization` HTTP header (with the `Bearer` scheme).

### Examples

```
GET /header/000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
```

#### Success
Status code 200 with JSON response:
```json
{
  "hash": "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f",
  "confirmations": 475000,
  "height": 0,
  "version": 1,
  "versionHex": "00000001",
  "merkleroot": "4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b",
  "time": 1231006505,
  "mediantime": 1231006505,
  "nonce": 2083236893,
  "bits": "1d00ffff",
  "difficulty": 1,
  "chainwork": "0000000000000000000000000000000000000000000000000000000100010001",
  "nextblockhash": "00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048"
}
```

#### Failure
Status code 400 with JSON response:
```json
{
  "status": "error",
  "error": "<error message>"
}
```