MultiChain Developer Q&A - Recent questions tagged sendwithmetadatafrom

Is it possible to send an image and text and video in one datastream transaction?

Tue, 31 Jan 2017 05:34:41 +0000

Hi,

I have a datastream transaction that I would like to add to my blockchain. It consists of an image, audio, and video file all of which describe a certain data set. Is it possible to list all in one transaction instead of adding 3 separate transactions for it? Thanks.

Address with permission gets doesn't have permission error

Tue, 06 Dec 2016 16:25:59 +0000

After granting 'send' permission to an address, this address is unable to be used as a 'from' address in the 'sendwithmetadatafrom' command. Below I have pasted relevant outputs from multichain:

Command:

multichain-cli accomplishments sendwithmetadatafrom 1PoxkF6j6CD65dcrRkhNJn6NKgmReNw2Tc4okY 1PoxkF6j6CD65dcrRkhNJn6NKgmReNw2Tc4okY 0 536F6D652044617461

Output:

{"method":"sendwithmetadatafrom","params":["1PoxkF6j6CD65dcrRkhNJn6NKgmReNw2Tc4okY","1PoxkF6j6CD65dcrRkhNJn6NKgmReNw2Tc4okY",0,"536F6D652044617461"],"id":1,"chain_name":"accomplishments"}

error code: -5
error message:
from-address doesn't have send permission

Permission output for relevant address:

{
"address" : "1PoxkF6j6CD65dcrRkhNJn6NKgmReNw2Tc4okY",
"for" : null,
"type" : "send",
"startblock" : 0,
"endblock" : 4294967295,
"admins" : [
"1YSGrLsv8AS2qr9kwcyh3Jcz7KnfB9tZ5SpTAd"
],
"pending" : [
]
},
{
"address" : "1PoxkF6j6CD65dcrRkhNJn6NKgmReNw2Tc4okY",
"for" : null,
"type" : "receive",
"startblock" : 0,
"endblock" : 4294967295,
"admins" : [
"1YSGrLsv8AS2qr9kwcyh3Jcz7KnfB9tZ5SpTAd"
],
"pending" : [
]
}

If I run the `sendwithmetadata` command, omitting the from address, this call works fine. Any insight as to why an address with the send permission would be getting an error saying it does not have the send permission?

I am running this as a single original node and one worker node. I have run the above commands on the worker node.

Unsufficient funds

Mon, 08 Aug 2016 18:58:45 +0000

Hi,

I want use MultiChain as a private database, without the asset/currency aspect. I would like to store "Hello World" as hex to myself for now, with the amount of 0.

icsv-chain: sendwithmetadatafrom 1AD9yHodgUQJ85uNwTd9Ucmq4T5NXa7Le6fci2 1AD9yHodgUQJ85uNwTd9Ucmq4T5NXa7Le6fci2 0 48656c6c6f20576f726c64
{"method":"sendwithmetadatafrom","params":["1AD9yHodgUQJ85uNwTd9Ucmq4T5NXa7Le6fci2","1AD9yHodgUQJ85uNwTd9Ucmq4T5NXa7Le6fci2",0,"48656c6c6f20576f726c64"],"id":1,"chain_name":"icsv-chain"}

error code: -4
error message:
Insufficient funds

Any advice?

High volume of transactions

Thu, 09 Jun 2016 10:52:33 +0000

Hello,

What are the current limitations of multichain, when trying to put through a high volume of send transactions?

Stores of data not financial transactions?

Tue, 03 May 2016 14:05:56 +0000

Hey all,

I have experience using and developing on multichain with making my own explorer before the official one was live.

My new project wants to implement a blockchain to store messages/data/files, then attribute meta-data to the record for easy searching on a front-end. I assume I can do this by just converting the raw strings to hexadecimal. What about perhaps a .pdf or .docx? Can this be attached/encoded then sent as a transaction to the network?

This chain will have free transactions.

To achieve meta information on transactions, is it possible to attach the data in a JSON object with the actual file/text in a sub-object?

Storage of data

Tue, 23 Feb 2016 19:09:15 +0000

I've seen mention of 8MB transactions being stored, how is this effected? Is the OP_RETURN the only way to store data in the chain?

Thanks again,

Rua

MultiChain data storage limitations/questions.

Mon, 22 Feb 2016 20:23:47 +0000

Hello,

I am currently starting a project and am hoping that MultiChain will be fit for our uses. I want to be able to store a file in the chain (ranging in size from approx 3MB to 7MB) so as a locally stored copy of the file can be compared to the data that is stored within the blockchain to ensure that this indeed is the file in question and that it has been in no way altered since it was created.

I have done quite a bit of reading through this website and have seen how metadata can be stored as part of the OP_RETURN part of the transaction however the limit on this is approx 125KB. Elsewhere on this forum it has been stated that the maximum size one can encode is 8MB. Am I missing something here? Is there a way to encode more data than 1048576 in a transaction? If the transaction size can be set to 10000000 what happens to all this other available space and is there an api call to manipulate this? My current chain has the following params configured:

only-accept-std-txs = true              # Only standard transactions are accepted to mempool and relayed.
max-std-tx-size = 3000000               # Maximal size of standard transaction. (1024 - 10000000)
max-std-op-return-size = 1048576        # Maximal size of the data after OP_RETURN. (0 - 1048576)
max-std-op-drops-count = 5              # Maximal amount of OP_DROPs in the script. (0 - 100)
max-std-op-drop-size = 64               # Maximal size of the script element followed by OP_DROPs. (0 - 32768)

I have been currently using the sendwithmetadatafrom api, along with listtransactions and getwallettransaction to query the transactions from the other node. Could you elaborate a bit more on these limits of file size etc, and point me in the right direction as to how to best proceed.

On another related issue, I wrote a simple shell script which was basically a for loop to do 10000 of these transactions (sendwithmetadatafrom with the addresses and approx 100KB of metadata) however it appears to have broken the chain somewhat. 490 of these transactions completed and the rest I am not quite sure what has happened to them. I was thinking that perhaps with the 15secondconsensus time that some transactions got bottlenecked and were parsed wrong, however while I can see the send transactions from the first node they are not available for query on the second node? Am I on the right track here or do you have any information on what would be the best way to effectively "load" a chain full of transactions.

I am new to MultiChain and any help you can give me here will be greatly appreciated.

Thanks in advance,

Rua