<p>BIP 34 requires the script to start with a push of block height.</p>
<p>The script length cannot exceed a limit ( ~100 bytes IIRC)</p>

CC BY-SA 4.0
2024-08-18T16:15:50.830Z
2024-08-18T16:15:50.830Z
RedGrittyBrick
<p>In the coinbase transaction, the arbitrary data in the coinbase script can indeed be customized, but it’s not just a free-for-all. Miners typically use this space for things like including the mining pool name, extra nonce, or even creative messages. However, it’s essential to ensure that the data inserted doesn't interfere with the transaction’s proper function, as it’s still part of the validated script. Keep it fun, but keep it functional! </p>

CC BY-SA 4.0
2024-08-19T11:30:42.720Z
2024-08-19T11:30:42.720Z
CoinChampion24
<pre><code>01000000 .............................. Version    

01 .................................... Number of inputs     
| 00000000000000000000000000000000    
| 00000000000000000000000000000000 ...  Previous outpoint TXID     
| ffffffff ............................ Previous outpoint index     
|    
| 29 .................................. Bytes in coinbase    
| |     
| | 03 ................................ Bytes in height    
| | | 4e0105 .......................... Height: 328014    
| |    
| | 062f503253482f0472d35454085fffed    
| | f2400000f90f54696d65202620486561    
| | 6c74682021 ........................ Arbitrary data      
| 00000000 ............................ Sequence     

01 .................................... Output count   
| 2c37449500000000 .................... Satoshis (25.04275756 BTC)   
| 1976a914a09be8040cbf399926aeb1f4    
| 70c37d1341f3b46588ac ................ P2PKH script   
| 00000000 ............................ Locktime    
</code></pre>
<p>when building the coinbase transaction Arbitrary data is the coinbase script? can you make it whatever you want? :$</p>

<transactions><coinbase-transaction>
coinbase script arbitrary data in coinbase input
meanthatmuchtoyou
# coinbase script arbitrary data in coinbase input

(Asked by: username_0 on 2024-08-18)

```
01000000 .............................. Version    

01 .................................... Number of inputs     
| 00000000000000000000000000000000    
| 00000000000000000000000000000000 ...  Previous outpoint TXID     
| ffffffff ............................ Previous outpoint index     
|    
| 29 .................................. Bytes in coinbase    
| |     
| | 03 ................................ Bytes in height    
| | | 4e0105 .......................... Height: 328014    
| |    
| | 062f503253482f0472d35454085fffed    
| | f2400000f90f54696d65202620486561    
| | 6c74682021 ........................ Arbitrary data      
| 00000000 ............................ Sequence     

01 .................................... Output count   
| 2c37449500000000 .................... Satoshis (25.04275756 BTC)   
| 1976a914a09be8040cbf399926aeb1f4    
| 70c37d1341f3b46588ac ................ P2PKH script   
| 00000000 ............................ Locktime    

```

when building the coinbase transaction Arbitrary data is the coinbase script? can you make it whatever you want? :$

**Tags:** transactions, coinbase-transaction


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## 2 answers

### Answer by username_1 on 2024-08-18. Score: 2 | Accepted answer

BIP 34 requires the script to start with a push of block height.

The script length cannot exceed a limit ( ~100 bytes IIRC)


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### Answer by username_2 on 2024-08-19. Score: -1

In the coinbase transaction, the arbitrary data in the coinbase script can indeed be customized, but it’s not just a free-for-all. Miners typically use this space for things like including the mining pool name, extra nonce, or even creative messages. However, it’s essential to ensure that the data inserted doesn't interfere with the transaction’s proper function, as it’s still part of the validated script. Keep it fun, but keep it functional!


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