<p>Currently, AssumeUTXO uses hardcoded block and snapshot hashes so you can only load specific snapshots. It does not work generically with any snapshot. If you want to use different snapshot blocks, then you will need to modify the source code and recompile.</p>
<p>There is no snapshot data set for mainnet yet, so you cannot use AssumeUTXO on mainnet without modifying the code.</p>
<p>The snapshot info for testnet can be found at <a href="https://github.com/bitcoin/bitcoin/blob/3695ecbf680a66b718f97d504308578d001eec49/src/kernel/chainparams.cpp#L269" rel="nofollow noreferrer">https://github.com/bitcoin/bitcoin/blob/3695ecbf680a66b718f97d504308578d001eec49/src/kernel/chainparams.cpp#L269</a> and for signet at <a href="https://github.com/bitcoin/bitcoin/blob/3695ecbf680a66b718f97d504308578d001eec49/src/kernel/chainparams.cpp#L378" rel="nofollow noreferrer">https://github.com/bitcoin/bitcoin/blob/3695ecbf680a66b718f97d504308578d001eec49/src/kernel/chainparams.cpp#L378</a></p>

CC BY-SA 4.0
2024-04-27T13:40:36.507Z
I'm working on adding support for this in bitcoin-s via RPC, would be a huge lift to allow a carve out on regtest? Otherwise this ends up being untestable. AFAICT results in this not being tested in the python test framework either. https://github.com/bitcoin-s/bitcoin-s/pull/5550/commits/585701568d616dfa1b1058ad5172399df0ade977

If it wouldn't be a huge lift, happy to file an issue on the bitcoin/bitcoin issue tracker at minimum and potentially implement myself. If its a complicated change... well maybe its an exercise best left to more experience hands :-)
Chris Stewart
CC BY-SA 4.0
2023-12-16T20:56:45.450Z
2023-12-16T22:10:35.043Z
2023-12-16T22:10:35.043Z
Ava Chow
<p>I am attempting to use assumeutxo, but I may be overlooking something. I attempted to use my own snapshots from another node, but I consistently encountered the following error, where <code>&lt;BLOCKHASH&gt;</code> is present on the current blockheaders:</p>
<pre><code>Unable to load utxo snapshot, assumeutxo block hash in snapshot not recognized &lt;BLOCKHASH&gt;
</code></pre>
<p><a href="https://i.sstatic.net/zsRmU.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/zsRmU.png" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2023-12-19T17:48:51.187Z
FYI I just updated this project and now i'm hosting the assumeutxo files as well: 

https://bitcoin-snapshots.jaonoct.us

* mainnet one, as Ava said, needs a [patch](https://github.com/jaonoctus/docker-bitcoind/blob/165e073036ea7bd1bef0098fa3d1db1b29ac0b12/26.0/patches/assumeutxo.patch)
jaonoctus
<full-node><assume-utxo>
Anyone tried assumeutxo yet?
jaonoctus
# Anyone tried assumeutxo yet?

(Asked by: username_0 on 2023-12-16)

I am attempting to use assumeutxo, but I may be overlooking something. I attempted to use my own snapshots from another node, but I consistently encountered the following error, where `<BLOCKHASH>` is present on the current blockheaders:

```
Unable to load utxo snapshot, assumeutxo block hash in snapshot not recognized <BLOCKHASH>

```

[![enter image description here](https://i.sstatic.net/zsRmU.png)](https://i.sstatic.net/zsRmU.png)

**Tags:** full-node, assume-utxo

> **Comments:**
> **username_0**: FYI I just updated this project and now i'm hosting the assumeutxo files as well:   https://bitcoin-snapshots.jaonoct.us  * mainnet one, as Ava said, needs a [patch](https://github.com/username_0/docker-bitcoind/blob/165e073036ea7bd1bef0098fa3d1db1b29ac0b12/26.0/patches/assumeutxo.patch)  

---

## 1 answers

### Answer by username_1 on 2023-12-16. Score: 2 | Accepted answer

Currently, AssumeUTXO uses hardcoded block and snapshot hashes so you can only load specific snapshots. It does not work generically with any snapshot. If you want to use different snapshot blocks, then you will need to modify the source code and recompile.

There is no snapshot data set for mainnet yet, so you cannot use AssumeUTXO on mainnet without modifying the code.

The snapshot info for testnet can be found at <https://github.com/bitcoin/bitcoin/blob/3695ecbf680a66b718f97d504308578d001eec49/src/kernel/chainparams.cpp#L269> and for signet at <https://github.com/bitcoin/bitcoin/blob/3695ecbf680a66b718f97d504308578d001eec49/src/kernel/chainparams.cpp#L378>

> **Comments:**
> **username_2**: I'm working on adding support for this in bitcoin-s via RPC, would be a huge lift to allow a carve out on regtest? Otherwise this ends up being untestable. AFAICT results in this not being tested in the python test framework either. https://github.com/bitcoin-s/bitcoin-s/pull/5550/commits/585701568d616dfa1b1058ad5172399df0ade977  If it wouldn't be a huge lift, happy to file an issue on the bitcoin/bitcoin issue tracker at minimum and potentially implement myself. If its a complicated change... well maybe its an exercise best left to more experience hands :-)  

---

