<p>You should not interact with bitcoind, because it (current versions at least) filteres double-spend transactions</p>

<p>You should have your own network-sniffer solutution - the program which connects to the network nodes (as many as possible) and listens for <strong>all</strong> transactions, checking do they have conflicts with particular ones.</p>

<p>(How much would you pay for such program? Just interesting :) )</p>

<p>This is also not 100% safe solution - a miner can place double-spending transaction in block and mine it himself. Look here: <a href="https://bitcointalk.org/index.php?topic=327767.0" rel="nofollow">https://bitcointalk.org/index.php?topic=327767.0</a></p>

CC BY-SA 3.0
2014-10-01T09:54:59.487Z
You can send a question to an owner of http://respends.thinlink.com/ Hope it helps
amaclin
CC BY-SA 3.0
2014-11-20T18:52:41.787Z
Isn't this: http://bitcoin.stackexchange.com/a/32636/14319 a way to detect double-spending through bitcoind?
Doug Peters
CC BY-SA 3.0
2014-10-01T08:53:46.563Z
2014-10-01T08:53:46.563Z
amaclin
<p>Check out <a href="https://github.com/bitcoinxt/bitcoinxt/releases" rel="nofollow">Bitcoin XT</a> which is an early release version of functions that are proposed for Bitcoin Core.  It relays double spends, and notifies the wallet of double-spend attempts that affect it.</p>

<p>You can hook up your own code to be run immediately when a double-spend is detected, using the -respendnotify option.</p>

CC BY-SA 3.0
2015-02-28T19:33:42.310Z
2015-02-28T19:33:42.310Z
Tom Harding
<p>Yes bitcoind filters double-spends. I am not aware of anything that can listen and detect double-spends. I too would be interested in this. I would imagine that a simple tool would be needed which just detects double-spends. You could then do as you wish with the tx ID and notify an existing payment application.</p>

CC BY-SA 3.0
2014-10-01T23:53:07.770Z
2014-10-01T23:53:07.770Z
banker_delight
<p>I would like to accept 0-confirmation bitcoin for very small amounts. I am happy to accept zero-confirmation spends and am aware of the risks. However, the tool needs the ability to "flag" the accepted transaction/s if a double-spend is detected. I can then decide what action to take.</p>

<p>I do not want to use a centralized third-party tool. I would like to use something locally on the server. It would simply display pre-generated public addresses. No need for private keys and/or seeds to be on the server.</p>

<p>Does such a tool exist?</p>

<p>Thank you.</p>

CC BY-SA 3.0
2014-10-01T08:45:37.223Z
I tried to clarify a title bit. Hopefully it is ok.
Mikko Ohtamaa
CC BY-SA 3.0
2014-10-01T08:46:02.613Z
I would imagine you need to interact directly with bitcoind, but there are some wrappers.
Mikko Ohtamaa
CC BY-SA 3.0
2014-10-01T08:52:35.813Z
Here is one: https://github.com/snitko/straight-server - you can try to fish out Bitcond wrappers for your favorite programming language on Github search. EDIT: Straight uses blockchain.info instead of Bitcoin network, so it is out of the question
Mikko Ohtamaa
<transactions>
Accepting 0-confirmation transactions and detecting double-spends with open source solution
itshappening1
# Accepting 0-confirmation transactions and detecting double-spends with open source solution

(Asked by: username_0 on 2014-10-01)

I would like to accept 0-confirmation bitcoin for very small amounts. I am happy to accept zero-confirmation spends and am aware of the risks. However, the tool needs the ability to "flag" the accepted transaction/s if a double-spend is detected. I can then decide what action to take.

I do not want to use a centralized third-party tool. I would like to use something locally on the server. It would simply display pre-generated public addresses. No need for private keys and/or seeds to be on the server.

Does such a tool exist?

Thank you.

**Tags:** transactions

> **Comments:**
> **username_1**: I tried to clarify a title bit. Hopefully it is ok.  
> **username_1**: I would imagine you need to interact directly with bitcoind, but there are some wrappers.  
> **username_1**: Here is one: https://github.com/snitko/straight-server - you can try to fish out Bitcond wrappers for your favorite programming language on Github search. EDIT: Straight uses blockchain.info instead of Bitcoin network, so it is out of the question  

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## 3 answers

### Answer by username_2 on 2014-10-01. Score: 1

You should not interact with bitcoind, because it (current versions at least) filteres double-spend transactions

You should have your own network-sniffer solutution - the program which connects to the network nodes (as many as possible) and listens for **all** transactions, checking do they have conflicts with particular ones.

(How much would you pay for such program? Just interesting :) )

This is also not 100% safe solution - a miner can place double-spending transaction in block and mine it himself. Look here: <https://bitcointalk.org/index.php?topic=327767.0>

> **Comments:**
> **username_2**: You can send a question to an owner of http://respends.thinlink.com/ Hope it helps  
> **username_3**: Isn't this: http://bitcoin.stackexchange.com/a/32636/14319 a way to detect double-spending through bitcoind?  

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### Answer by username_4 on 2015-02-28. Score: 0

Check out [Bitcoin XT](https://github.com/bitcoinxt/bitcoinxt/releases) which is an early release version of functions that are proposed for Bitcoin Core. It relays double spends, and notifies the wallet of double-spend attempts that affect it.

You can hook up your own code to be run immediately when a double-spend is detected, using the -respendnotify option.


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### Answer by username_5 on 2014-10-01. Score: 0

Yes bitcoind filters double-spends. I am not aware of anything that can listen and detect double-spends. I too would be interested in this. I would imagine that a simple tool would be needed which just detects double-spends. You could then do as you wish with the tx ID and notify an existing payment application.


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