Questions tagged [op-return]

An opcode that allows you to create an unspendable transaction output that stores up to 80 bytes of data.

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Is the Bitcoin whitepaper embedded in the Bitcoin blockchain? [duplicate]

The Bitcoin blockchain can store arbitrary data. Especially recently, with the ordinals inscriptions, I've seen claims that images up to 390 kB are stored on the chain. In light of this, I was ...
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How can I store a file hash in a Schnorr signature? Or something other than an OP_RETURN?

I have this python script that puts file hashes on the bitcoin blockchain: from bitcoinutils.utils import to_satoshis from bitcoinutils.setup import setup from bitcoinutils.transactions import ...
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How can I optimize my python script that creates a btc native segwit tx with an OP_RETURN message?

I have the following code that successfully created a bitcoin transaction with an OP_RETURN message: from bitcoinutils.utils import to_satoshis from bitcoinutils.setup import setup from bitcoinutils....
ChristianOConnor's user avatar
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How do I use python-bitcoin-utils to add an OP_RETURN message into a bitcoin transaction?

I have the following code that successfully created a bitcoin transaction with python-bitcoin-utils: from bitcoinutils.utils import to_satoshis from bitcoinutils.setup import setup from bitcoinutils....
ChristianOConnor's user avatar
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3 answers
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Can someone break down what is returned by pybtc?

I am feeding network data to pybtc.Transactions. What I do is I take tx messages (which I understand to only contain a single transaction) and I feed them into pybtc.Transaction but only after ...
bitcoinluvr6969's user avatar
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Why weren’t Inscriptions possible before taproot by just using OP_RETURN to store the data?

With the recent rise of Inscriptions using the script in the taproot input, why wasn't this possible previously just using OP_RETURN? What is special about the taproot upgrade that made this feasible ...
Patoshi パトシ's user avatar
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Can any Script opcode be used in the witness program, or only specific ones?

I was wondering, can one use an OP_RETURN in the witness script? If not, why not? Also, how could I figure this out from reading Bitcoin Core source? I looked at this file, and it wasn't quite clear ...
Hunter Beast's user avatar
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Understanding how ordinals work with the Bitcoin blockchain. What is exactly stored on the blockchain?

Supposedly someone uploaded a Doom clone to the bitcoin blockchain: https://ordinals.com/content/521f8eccffa4c41a3a7728dd012ea5a4a02feed81f41159231251ecf1e5c79dai0 But I'm a bit confused on exactly ...
Patoshi パトシ's user avatar
2 votes
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161 views

Raw data vs information encoded in OP_RETURNs

Imagine I want to fill the 80 bytes of OP_RETURN data with zeroes, so that the resulting data is 640 bits set to 0, or 160 hex digits set to 0. The data is 640 bits but the information encoded is much ...
Son Kaos999's user avatar
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Was the lifting of the Taproot transaction size limit "accidental"? Why would ordinals want to fill a block with OP_RETURNs?

I was reading this Twitter thread from pourteaux. I'm pretty sure there are some inaccuracies in it but I have a couple of questions. He states: Taproot accidentally blew up the old transaction size ...
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How can I recognize an OP_RETURN transaction looking only at the hex?

Looking at these two transactions for example: tx1 and tx2. tx1 is an OP_RETURN trasaction, tx2 is a normal transaction. raw hex from tx1 (OP_RETURN): ...
luisschwab's user avatar
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Can BIP351 notification transactions be discovered via compact client-side block filters?

I have been reading a bit about BIP351 Private Payments. BIP351 uses nulldata outputs (OP_RETURN) to create shared secrets on the blockchain. Could these notification outputs be monitored client-side ...
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How can I prevent a transaction from being spent

For an academic article I want to know if I can prevent a transaction from being spent at all? I tried to send a transaction with only one output that contains only data (no output address provided) ...
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What are the mean, median, range, limits and trends in the size of coinbase transactions?

I'm attempting to estimate how much "spare capacity" there is for merged mining protocols. As I understand it the scriptSig in the coinbase transaction must be less than 100B. However, the ...
Lee's user avatar
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Tx with OP_RETURN with 77 bytes of data refused by node

A transaction with a 77 bytes OP_RETURN is refused, but with shorter data (e.g. 74 bytes) is accepted, although up to 80 bytes should work. What is the safe limit to be used? Per these references the ...
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Why isn't it possible to add an OP_RETURN (or some arbitrary script) inside a taproot script path with a descriptor?

I'm reading the Bitcoin Core's descriptor documentation and I noticed that the raw() SCRIPT expression can only be used at descriptor top-level. Indeed when called with this descriptor ...
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What is OP_RETURN b9e11b6d?

While investigating some Bitcoin coinbase transactions, I notice that a lot of them have an output of the form OP_RETURN OP_PUSHBYTES_36 b9e11b6d… where ‘…’ is 32 bytes, probably a hash of something. ...
George Lowther's user avatar
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How can I query for all OP_RETURN data starting at a specific block height (or hash)

I'm working on a "light client" for ION (Identity Overlay Network), and I'd like to see if there is a better method to grab the OP_RETURN data that it needs in order to build state. ...
user1943442's user avatar
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Different ways in which bitcoin can be burnt

I'm interested in the different ways in which bitcoin can be burnt. I can see three ways: Send coins to a 'made-up' address. There's no way to distinguish it from a real address (so the transaction ...
andrewr's user avatar
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Are OP_RETURN transactions not stored in chainstate database?

I'm running a bitcoin node on regtest. I'm writing scripts to interact with the chain-state database. For my purpose, I'm creating, signing and sending a transaction to my node (pretty much following ...
Nirmal Khedkar's user avatar
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Was Bitcoin 0.3.7 actually hard-forking?

Reading through the wiki (bitcoin.it consensus versions) I noticed that release 0.3.7 ("scriptSig + scriptPubKey evaluations separated") is listed as a hard-forking change. In BitMEX's ...
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What is encoded in the first taproot enabled block?

There are a bunch of encoded messages in the first taproot enabled block in op_return outputs. What is encoded there?
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Creating an OP_Return TX with Python bitcoinlib

How can I create an op_return TX with python bitcoinlib? The transaction should include the OP_RETURN HEX-Data and an address where I send my change money
Captain Evening's user avatar
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How much information can a single taproot output hold?

Does taproot make OP_RETURN obsolete? How much information can I stuff into an output? A tapscript leaf? Is there a max depth to the tapscript tree?
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How does OP_RETURN burn coins?

What exactly causes the output containing OP_RETURN to be unspendable? And why do I have to use the byes after OP_RETURN for keeping data in the blockchain and I can't use bytes before OP_RETURN?
Rony Tesler's user avatar
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Why are OP_RETURN transactions discouraged? Does using version or locktime make any difference?

Why are OP_RETURN transactions discouraged? Are they paying less fees compared to other transactions? Will it make any difference if same thing is done using version or locktime when data is either 1 ...
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Accessing bitcoind from python module hits error

I am experimenting with the blockchain a bit, specifically trying to use the python-OP_RETURN module to put a few bytes into the blockchain op_return field. To use this module I blv I need a running ...
jeremy_rutman's user avatar
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What has OP_RETURN been used for over Bitcoin's history?

What has OP_RETURN been used for over Bitcoin's history? How were these use cases enabled?
Michael Folkson's user avatar
2 votes
1 answer
302 views

Can Taproot be used to commit arbitrary data to chain without any additional footprint?

A common way of committing some data to the chain is through an OP_RETURN with some hash. Doing this marks an output unspendable, but the output still requires some footprint (and cost) on the chain ...
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"At first, anyone could spend anyone's coins"?

I've been watching this Bitcoin video: https://youtu.be/ZIugzFygviw?t=294 At the linked-to timestamp, he claims that: Due to bugs, at first, anyone could spend anyone's coins! I'm not saying that I ...
Infinity's user avatar
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Why is the source code fee calculated higher than the current bitcoin fee amount?

In python bit (https://github.com/ofek/bit/), when sending a message, it is properly 80 bytes or less (https://developer.bitcoin.org/devguide/transactions.html) fee is If it is a 4-byte character ...
ground clown's user avatar
4 votes
4 answers
838 views

What is the currently most efficient and reliable method to store the Bitcoin blockchain in a local database?

I have seen several posts on this before, and have tried all the suggested solutions, but I can't get any of them to work. I am interested in analysing transactions with the OP_RETURN opcode for a ...
Johannes Mols's user avatar
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1 answer
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How to send a 100KB OP_RETURN? [closed]

I'm trying to send an OP_RETURN transaction, and the program says that I can't do it because it is over 80 bytes. I would like to send a transaction using OP_RETURN that stores data. There is a site ...
Flash Uploader's user avatar
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How to add money to my Bitcoin Wallet and send my first Raw Transaction with OP_RETURN using bitcoin-cli

Background So after reading these two articles (Learning Bitcoin from the Command Line and Mastering Bitcoin), I am trying to piece together how I can get my first transaction with OP_RETURN data ...
Lance's user avatar
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Send payment and message at the same time

I am using NBitcoin to write some code. I want to send some bitcoin to an address AND include a message with it. The message could say who the payment came from or why it was sent. According to the ...
ThirdPrize's user avatar
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Is OP_RETURN dangerous for Bitcoin?

Please explain something about OP_RETURN to me? https://bitcointalk.org/index.php?topic=1166928.0 I saw a discussion that the contents of OP_RETURN can open the value of access to the private key. I ...
Izi Tors's user avatar
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1 answer
802 views

Why does this coinbase transaction have two op_return outputs?

I've been looking at coinbase transactions for fun and I came across one with two op_return outputs.. Does anyone know what the second one is? Also, I understand the first op_return is used to ...
Andrew's user avatar
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What is service or entity broadcasts transactions with OP_RETURN data starting with "LP..."?

There have been quite a few OP_RETURN transactions recently where OP_RETURN data in the scriptPubKey starts with 4c 50 which is LP as ASCII. For example these transactions: - ...
0xb10c's user avatar
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How do I broadcast an OP_RETURN transaction using bitcoin cli

I am using Bitcoin Testnet's command line (and GUI). I am curious how, using my own computer and equipment (I already used a faucet) I could send a transaction easily. I tried https://github.com/...
Number File's user avatar
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Retrieve number of OP-RETURN transaction

Is there a possible way to extract the bitcoin transaction protocoll with Python and extract specifically OP RETURN transaction? I want to plot the number of those over the course of time to derive ...
Nils2's user avatar
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In the bitcoin scripting language, how can I access other outputs of the transaction? Or how else can I limit how the coins may be spent?

Is there any way to add an opcode to a UTXO that prevents how the coins are spent? For example, in order to to spend the output, a person must send X number of bitcoin to Y address within the ...
nick carraway's user avatar
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2 answers
425 views

Is there anything preventing Lightning Network from passing embedded data in OP_RETURN?

As long as you pay a BTC fee for all the routing node incentives and the last layer in the onion routing includes a transaction with OP_RETURN, wouldn't that allow using OP_RETURN for various ...
Cloud Strife's user avatar
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214 views

What Opcodes are used to store a file within Bitcoin? [closed]

At a block-to-block level, what is actually encoded at a byte[] level to encode a file stream?
TLDR's user avatar
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Can PUSHDATA/OP_RETURN be used to break a trail of transactions permanently?

I was reading the Bitcoin wiki on how the Bitcoin protocol has no "From" address and the closest thing to a from address is a "previously receiving address". The article then proceeds to show a ...
Dimitris Sfounis's user avatar
3 votes
1 answer
735 views

What's the deal with OP_RETURN and length?

It seems like most OP_RETURN transactions include length as the first byte after the OP_RETURN code. Is this specified anywhere? Also, the length is sometimes the entire length of the rest of the ...
Curyous's user avatar
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Consensus roles for op_return

What is the validation rule, not policy, for op_return? What is the maximum length of the data that can be attached? Is it 514 bytes? As if the maximum script size was 520 bytes -1 byte for the ...
Wapac's user avatar
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OP_RETURN max bytes clarification

I've read that an OP_RETURN opcode allows up to 80 arbitrary bytes to be used in an unspendable transaction. My question is, how is it possible that in this famous transaction (...
robermann's user avatar
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2 answers
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Why would a miner put an OP_RETURN in a coinbase transaction?

I’m looking at this coinbase transaction. I'm confused why there are two outputs and why one of them is labelled with OP_RETURN.
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How is "additional information" stored in the ledger and which blockchain projects don't allow it?

So there have been these rumours going around about child abuse information being stored in the bitcoin ledger, that might make bitcoin illegal to possess. How is this infirmation stored and are ...
Валентин Антонов's user avatar
3 votes
2 answers
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What's with this address 1111111111111111111114oLvT2?

It was the burn address with the most BTC received in 2017 according to http://bitcoinwhoswho.com/blog/2017/12/30/8-97-bitcoins-burned-in-2017/. It's Hash160 is ...
Bitcoin WhosWho's user avatar