MultiChain Developer Q&A - Recent questions

How can I retrieve blockchain data via MultiChain JSON-RPC API and efficiently handle large datasets?

Fri, 12 Dec 2025 12:44:12 +0000

I am trying to access blockchain data using MultiChain’s JSON‑RPC API for development purposes. I want to retrieve blocks, transactions, and associated metadata programmatically and handle large datasets efficiently. Any guidance on best practices, pagination, or API limitations would be helpful. Example use cases include exporting transaction histories and monitoring blockchain activity in real-time.

Get Asset Transaction Total Count

Thu, 06 Nov 2025 18:19:14 +0000

is it possible to get the total transaction of a specific asset? just the count just like what you did on explorerlistassetaddresses? you just add a parameter of '-' to get the count of all holders

File Handling Question

Wed, 05 Nov 2025 16:34:15 +0000

What is the best way to store files or should we really store file on the blockchain? if not, what are the best practices?

Get All Nodes

Mon, 03 Nov 2025 21:18:55 +0000

I am creating a blockchain as a service.. it is possible to get all nodes so that I can bill them or do you have any suggestions?

Send NFT

Sun, 02 Nov 2025 18:08:48 +0000

how to send NFT?
sendassetfrom "from-address" "to-address" "asset-identifier" asset-qty ( native-amount "comment" "comment-to" )

sendassetfrom doesn't have any way to send a specific token

Unable to connect second node to seed node – “Couldn’t connect to the seed node on port 4419”

Sun, 26 Oct 2025 06:59:49 +0000

Hi,

I’m currently setting up a MultiChain network (version 2.3.3 – protocol 20013) and facing an issue while connecting a secondary node to the seed node.

When I run the following command on the secondary node:

multichaind [chain-name]@[seed-node-ip]:[port-number] -datadir="E:\Multichain\nodes\SecondNode" -daemon

I receive this error:

Retrieving blockchain parameters from the seed node [seed-node-ip]:[port-number] ... Error: Couldn't connect to the seed node [seed-node-ip] on port [port-number] - please check multichaind is running at that address and that your firewall settings allow incoming connections.

Here are my setup details for context:

MultiChain version: 2.3.3 (Community Edition, protocol 20013)
Seed node IP: [seed-node-ip]
Port configuration: default-network-port = [port-number], default-rpc-port = [rpc-port]
OS: Windows Server on both nodes
Telnet test: Successful on port [port-number]
multichain.conf on seed node:
```
 
```
rpcbind=0.0.0.0 rpcallowip=0.0.0.0/0
Firewall: Port [port-number] opened for inbound/outbound TCP

Despite these settings, the secondary node still cannot connect.

Could you please help me identify what might be causing this connection failure?
Do I need to modify any additional parameters (such as bind, externalip, or interface configurations) for Windows environments?

Thank you in advance for your assistance.

No explorersupport in the docs

Wed, 22 Oct 2025 08:04:24 +0000

I checked the docs about the runtime parameters and it seems that there is no `explorersupport`..

New transaction

Wed, 22 Oct 2025 06:45:26 +0000

How do we know if we have a new transaction? i saw in the docs that we are going to use `blocknotify` but I checked the explorer, it doesn't use `blocknotify`.. can you guide me? not a python dev so im having a problem understanding the logic.. I dont want to run a scheduler just to check if there is a new transaction

Admin Permission Question

Mon, 20 Oct 2025 03:26:38 +0000

I have this genesis node, there is a node that is requesting a grant access so what I did was making the wallet of that node grant a permission as Admin. After making it an admin, i am wondering why that node can't create stream. I thought admin permission can do all, it is just returning error that the wallet cant create stream.

Multichain Suggested Servers

Mon, 13 Oct 2025 12:28:56 +0000

Hello! Can you suggest a server specs on digital ocean?
like entry, mid and enterprise level specs

Slow reindex probably due to high mempool

Tue, 16 Sep 2025 10:20:29 +0000

Hi,

My node has been reindexing for 3 weeks. Right now it has synchronized/checked 5kk out of 8kk blocks.

Mempool is very high, around 1.1k. My question is, what's the best way to handle this situation and what will happen if I restart multichain service during reindex process?

I'm not concerned about losing mempool since I can replicate the value(docs hash) of transactions. My primary goal is to get the node running correctly asap. Unfortunately, I do not have backup/snapshot of the node.

In advance, thank you for an assistance.

How to optimize MultiChain node performance for high transaction volume?

Tue, 29 Jul 2025 07:35:25 +0000

I’ve been working on optimizing MultiChain for high-throughput scenarios and noticed bottlenecks in block propagation.

At BitsBuffer, we recently shared a performance tuning checklist for MultiChain nodes, but I’m still seeing latency under certain load tests.

Has anyone found better ways to tweak the params.dat or manage memory allocation for faster confirmation times?

Would appreciate any tuning suggestions or real-world configs.

NFTs revisited

Mon, 16 Jun 2025 23:56:01 +0000

Hello MultiChain Team,

I've read an article about how a luxory watch manufacturer uses the blockchain to fight against counterfeit products. They make use of NFTs as well. I loved the idea and tried to reproduce the use case.

So issue an NFT:

multichain-cli chain1 issue 1UBXNq177rgPi8yperyAZgBhMNtr66hBAHxGCD 
'{"name": "12345klp111", "open": false, "fungible": false, 
"canopen": true}' 0 1 0 '{"Manufacturer" : "Swiss watch", 
"model" : "super time", "serial no" : "12345klp111"}'

e80aca96c38e7c239b5f186b461623c23e6bf70d1a0b0491208874912f2efd74

so far, so good. But actually, what are the parameters "open" and "canopen"? I understand that it allows some sort of later manipulation, like issuing a token that depends on the NFT? What use case would that be?

multichain-cli chain1 listassets "12345klp111"
{"method":"listassets","params":["12345klp111"],"id":"70189557-1750117422","chain_name":"chain1"}

[
    {
        "name" : "12345klp111",
        "issuetxid" : "e80aca96c38e7c239b5f186b461623c23e6bf70d1a0b0491208874912f2efd74",
        "assetref" : null,
        "multiple" : 1,
        "units" : 1,
        "open" : false,
        "restrict" : {
            "send" : false,
            "receive" : false,
            "issue" : true
        },
        "fungible" : false,
        "canopen" : true,
        "canclose" : false,
        "totallimit" : null,
        "issuelimit" : null,
        "details" : {
            "Manufacturer" : "Swiss watch",
            "model" : "super time",
            "serial no" : "12345klp111"
        },
        "issuecount" : 1,
        "issueqty" : 0,
        "issueraw" : 0,
        "subscribed" : true,
        "synchronized" : true,
        "transactions" : 1,
        "confirmed" : 0
    }
]

it looks good to me, NFT is created.

When I try to transfer it to another address (aka the watch is sold and the buyer shall get the digital representation of the watch into his wallet), I get an error:

multichain-cli chain1 sendasset 
1HrnzpVLvSu6Ecs26Q3ZRakTWd2NskzbgGCq64 "12345klp111" 1
{"method":"sendasset","params":
["1HrnzpVLvSu6Ecs26Q3ZRakTWd2NskzbgGCq64",
"12345klp111",1],"id":"22511383-1750117567",
"chain_name":"chain1"}

error code: -702
error message:
This API is not supported for nun-fungible assets

whats wrong here? Here is my getinfo:

multichain-cli chain1 getinfo
{"method":"getinfo","params":[],"id":"
49769585-1750117609","chain_name":"chain1"}

{
    "version" : "2.3.3",
    "nodeversion" : 20303901,
    "edition" : "Community",
    "protocolversion" : 20013,
    "chainname" : "chain1",
    "description" : "MultiChain chain1",
    "protocol" : "multichain",
    "port" : 5759,
    "setupblocks" : 60,
    "nodeaddress" : "chain1@192.168.10.114:5759",
    "burnaddress" : "1XXXXXXWpvXXXXXXZXXXXXXXk7XXXXXXV1FN3N",
    "incomingpaused" : false,
    "miningpaused" : false,
    "offchainpaused" : false,
    "walletversion" : 60000,
    "balance" : 0,
    "walletdbversion" : 3,
    "reindex" : false,
    "blocks" : 297171,
    "chainrewards" : 0,
    "assets" : 13,
    "streams" : 3,
    "addresses" : 12,
    "transactions" : 698134,
    "peers" : 0,
    "timeoffset" : 0,
    "connections" : 0,
    "proxy" : "",
    "difficulty" : 5.96046447753906e-8,
    "testnet" : false,
    "keypoololdest" : 1744062673,
    "keypoolsize" : 2,
    "paytxfee" : 0,
    "relayfee" : 0,
    "errors" : ""
}

ok, lets say sending works. Lets also assume, the watch was destroyed in a fire, so its time to destroy the belonging NFT as well. So I though I'll send it to the burn address:

multichain-cli chain1 sendasset 
1XXXXXXWpvXXXXXXZXXXXXXXk7XXXXXXV1FN3N  "12345klp111" 1
{"method":"sendasset","params":["1XXXXXXWpvXXXXXXZXXXXXXXk7XXXXXXV1FN3N",
"12345klp111",1],"id":"61043256-1750117758","chain_name":"chain1"}

error code: -704
error message:
Destination address doesn't have receive permission

This is also unexpected to me: I thought the burn address can receive every kind of tokens at all times.

I'd be very happy to get this straight - I also think this would help other interested folks get a deeper understanding for use cases for a blockchain.

Thanks for the great work anyway.

How to Perform a Backup of a Multichain Node and Restore on Another Server?

Fri, 02 May 2025 14:34:11 +0000

Hi,

I’m currently running a Multichain node and would like to back up all relevant data so I can restore it on a different server (e.g., for migration or redundancy purposes). I want to make sure I’m preserving the chain data, wallet, permissions, and configurations.

Could someone please clarify:

What is the correct process to back up a full Multichain node?
Which directories/files specifically need to be copied?
What are the steps to restore the node on a new server and ensure it reconnects to the same chain and retains all permissions?

Any best practices for this process would also be appreciated.

Thanks in advance!

Transaction ID hash

Tue, 25 Mar 2025 09:10:33 +0000

Which values, if any, are input into the transaction ID hash?

Performance Issues Running MultiChain Node on 14-inch AMD Laptop

Mon, 17 Mar 2025 12:41:25 +0000

Hello MultiChain Community,

I'm currently setting up a MultiChain node on my 14-inch AMD laptop for a private blockchain project. While the setup process went smoothly, I'm facing performance issues during peak data transactions. The system often shows high CPU usage, and at times, the node becomes unresponsive.

I've tried adjusting the blocknotify settings and limiting the maximum number of transactions per second, but the problem persists. I suspect my laptop's hardware may be a factor, but since it's a 14-inch AMD laptop with decent specs, I expected smoother performance.

Has anyone faced similar issues or successfully optimized MultiChain on similar hardware? I'd be grateful for any tips on improving performance, adjusting config settings, or managing resource limits effectively.

Looking forward to your suggestions!

Issuing assets is limited? Problem with new NFT in UI

Sun, 16 Mar 2025 16:39:51 +0000

Hi,

I was exploring the possibilities with assets and created a coin and an NFT. At least, I was hoping for doing it right, but I might have made an error. For the NFT I decleared the quantity to 3 and the units to 1:

Afterwards I've read in the API docs that the quantity for an NFT should be 0 and units should be 1. So I have a quantity of 3 at the moment, I was sending them back and forth between 2 nodes, now node 1 holds qty of 1 and node 2 holds also qty of 1. Where did the 3rd piece go?

I also issued a coin, transfers between nodes work fine. But now I am not able to issue anything new from the Web-UI. On the command line I can successfully run this command:

bbking@bc-debian:~$ multichain-cli chain1 issue 1UBXNq177rgPi8yperyAZgBhMNtr66hBAHxGCD '{"name": "realNFT", "open": true, "fungible": false, "canopen": true}' 0 1
{"method":"issue","params":["1UBXNq177rgPi8yperyAZgBhMNtr66hBAHxGCD",{"name":"realNFT","open":true,"fungible":false,"canopen":true},0,1],"id":"41253787-1742139590","chain_name":"chain1"}


c53c7736f22b05a3f4a12d5b6b7d4afe79887cc5cb8ebe8224e5cfd773c7f9e8

and I can see the NFT on the chain:

bbking@bc-debian:~$ multichain-cli chain1 listassets realNFT
{"method":"listassets","params":["realNFT"],"id":"11745015-1742142513","chain_name":"chain1"}

[
    {
        "name" : "realNFT",
        "issuetxid" : "c53c7736f22b05a3f4a12d5b6b7d4afe79887cc5cb8ebe8224e5cfd773c7f9e8",
        "assetref" : "197025-267-15557",
        "multiple" : 1,
        "units" : 1,
        "open" : true,
        "restrict" : {
            "send" : false,
            "receive" : false,
            "issue" : true
        },
        "fungible" : false,
        "canopen" : true,
        "canclose" : false,
        "totallimit" : null,
        "issuelimit" : null,
        "details" : {
        },
        "issuecount" : 1,
        "issueqty" : 0,
        "issueraw" : 0,
        "subscribed" : true,
        "synchronized" : true,
        "transactions" : 1,
        "confirmed" : 1
    }
]

When I go to the Web-UI "Issue Asset/Update" or "Send" menus, I don't see realNFT showing up there.

What do I do wrong?

Docker issue connecting to genesis node

Wed, 05 Mar 2025 23:08:00 +0000

I have "rpcallowip=0.0.0.0/0" in my multichain.conf

docker images are able to ping and netcat displays the necessary port on genesis image as open..

Any idea on why they wont talk?

https://imgur.com/a/kdDiDPG

Limits on attachment size

Mon, 24 Feb 2025 11:56:44 +0000

What are the limits on attachment size?

Smart filters: initiate transaction on certain condition in stream

Sun, 16 Feb 2025 21:31:00 +0000

Hi,

I was playing around with the smart filter function and was wondering about this scanario:
Node 1 pulishes to a stream certain values, like energy meter data:
{
    "energy": 1000
}

is it possible to craft a filter whoch checks if the energy value is over a certain value and create a transaction from Node1 to Node2? Would it be a transaction or a stream filter, anyway?

something like
function filtertransaction()
{
    var item=getfilterstreamitem();

    var json=item.data.json;

    if (json.energy > 1000)
        // check if there are enough funds
        // if yes, create transaction
        return "Transaction from address XX to YY was successful";
}

Or do I have a complete misunderstanding here? Based on this question I am not completly sure: https://www.multichain.com/qa/26462/add-balance-to-a-especific-address-using-smart-filters

Thanks a lot in advance.

edit: the smart filter is working. I tested it with values smaller and bigger than 1000 and if smaller than 1000 adding an entry to the stream is refused. Now the question is, if I can craft a transaction for when the condition gets true?

4 questions for better understanding

Tue, 07 Jan 2025 23:12:11 +0000

hi,

I am researching the possibilities with blockchain / Multichain and for better understanding I have these questions (at the moment):

when there are no transactions, what will be included in the blocks when block time is say, 60 seconds? just the reference to the previous block and the nonce?
I have an old Bitmain Antminer S9i with 13,5TH/s lying around. When I change Multichain to POW, could I simulate a 51% attack with that on Multichain?
When I implement the API in my application for accessing Multichain – would it also work 1:1 for the Bitcoin network, as Multichain is based on Bitcoin Core? If yes, for that to work I'd have to run the main bitcoind service and connect to it over the API?
How is mining working (even with proof-of-auth)? The node that has its turn in the round-robin scheduler just hashes the block with whatever nonce and thats the hash value the next block will reference?

Thanks in advance!

What is the strategy for attachments using the APIs

Mon, 23 Dec 2024 13:52:44 +0000

What is the best strategy for attachments using the APIs? Are the attachments inserted as a blob to the Multichain Blockchain, or is a path saved as a name value pair, while the attachment is saved on the file system?

Random crashes of multichain daemon

Thu, 05 Sep 2024 10:12:11 +0000

We have Multichain network consisting of over 30 nodes. We are using multichain in version 2.3.3.
Unfortunately sometimes we observe unexpected crashes of daemon. Below logs from syslog:

Sep 1 13:56:54 Blockchain kernel: [280185.244489] bitcoin-dmsghan[1299]: segfault at 7f4554cdc82c ip 00000000004b823a sp 00007f45b4e1d950 error 6 in multichaind[400000+16e
8000]
Sep 1 13:56:54 Blockchain kernel: [280185.244555] Code: 01 00 00 8b 44 24 1c 89 84 24 50 01 00 00 48 8b 05 a3 c2 3c 02 48 8b b8 98 01 00 00 e8 3f e1 3a 00 4d 85 ff 0f 84 a
f 00 00 00 <41> 89 5f 24 e9 86 fd ff ff 48 8d 9c 24 60 01 00 00 48 8d 35 39 f4

And some last lines from multichain debug.log:

024-09-01 11:56:14 progress=1.000000 cache=0
2024-09-01 11:56:50 Accepted header for block 0000ce1ea85c7a7ca867a2891520dcd1954046742159e344c8522764e6e7325b found on alternative chain at height 5159405
2024-09-01 11:56:50 UpdateTip: new best=0000cd0dd8140166c68bb856b4361916a1fc60a74afc18b4f1411792fb70f2da height=5159406 log2_work=42.406208 tx=5890340 date=2
024-09-01 11:56:11 progress=1.000000 cache=0
2024-09-01 11:56:52 UpdateTip: new best=00007ae05079b1cfd944dc04d5555d8a52993c4b6ddc2e785730337e8b4ea3b7 height=5159407 log2_work=42.406208 tx=5890341 date=2
024-09-01 11:56:16 progress=1.000000 cache=0
2024-09-01 11:56:52 Accepted header for block 0000cd83dc0a7d7c16389430e4987b1c3d8c828e479ffdb8ae67f6831434c541 found on alternative chain at height 5159407
2024-09-01 11:56:53 UpdateTip: new best=0000a31b7fed3a818ddb72ddff38fb1a92a573fe4f1842f5b8e549ebbd9e9e73 height=5159408 log2_work=42.406208 tx=5890342 date=2
024-09-01 11:56:12 progress=1.000000 cache=0
2024-09-01 11:56:53 Accepted header for block 0000d0c2cf49dbf8447df139496a1758953c5fba2fd518e6e5a19496b81bb3c1 found on alternative chain at height 5159408
Using RdSeed as additional entropy source
Using RdRand as an additional entropy source

Do you have any idea what can be a reason for it?

Regarding constructing the blockchain by directly using the source code library.

Sat, 24 Aug 2024 17:37:33 +0000

Currently, our embedded device uses JSON RPC to send API requests to the multichain-cli service. The issue arises when the number of requests becomes too large, causing the multichain-cli process to be repeatedly invoked, which leads to the creation of multiple processes. To address this, we're considering directly integrating the source code into our own project and modifying it to initiate the entire MultiChain service by calling the library directly. We're wondering if this approach is feasible. We would appreciate any advice you could provide. Thank you.

About custom Hash

Thu, 15 Aug 2024 17:39:15 +0000

Hi~

In a scenario where a blockchain is running on embedded devices with performance constraints, I would like to inquire if there is an API or any other method available to customize my own hash function for creating a txid when uploading data to a stream.

Thanks : )

Regarding the underlying mechanism of liststreamitems

Tue, 13 Aug 2024 17:24:56 +0000

Assuming there are now 10,000 items on this stream,

'multichain-cli mychain liststreamitems mystream false 100' will show 100 items.

My question is whether it reads out 10,000 pieces of data from disk and then displays 100 items, or if it only reads out 100 items exactly.

is 'publishmulti' command supported in multichain higher versions ?

Fri, 26 Jul 2024 04:24:27 +0000

is 'publishmulti' command supported in multichain newer versions other than 2.0.6 version?

any other alternative or similar command is available in higher versions ?

how to check total memory used to store chain data?

Wed, 24 Jul 2024 13:29:55 +0000

$ multichain-cli chain5xx getblockchainparams
{"method":"getblockchainparams","params":[],"id":"50148972-1721826859","chain_name":"chain5xx"}

{
    "chain-protocol" : "multichain",
    "chain-description" : "MultiChain chain5xx",
    "root-stream-name" : "root",
    "root-stream-open" : true,
    "chain-is-testnet" : false,
    "target-block-time" : 15,
    "maximum-block-size" : 8388608,
    "maximum-chunk-size" : 1048576,
    "maximum-chunk-count" : 1024,
    "default-network-port" : 4399,
    "default-rpc-port" : 4398,
    "anyone-can-connect" : false,
    "anyone-can-send" : false,
    "anyone-can-receive" : false,
    "anyone-can-receive-empty" : true,
    "anyone-can-create" : false,
    "anyone-can-issue" : false,
    "anyone-can-mine" : false,
    "anyone-can-activate" : false,
    "anyone-can-admin" : false,
    "support-miner-precheck" : true,
    "allow-arbitrary-outputs" : false,
    "allow-p2sh-outputs" : true,
    "allow-multisig-outputs" : true,
    "setup-first-blocks" : 60,
    "mining-diversity" : 0.3,
    "admin-consensus-upgrade" : 0.5,
    "admin-consensus-txfilter" : 0.5,
    "admin-consensus-admin" : 0.5,
    "admin-consensus-activate" : 0.5,
    "admin-consensus-mine" : 0.5,
    "admin-consensus-create" : 0,
    "admin-consensus-issue" : 0,
    "lock-admin-mine-rounds" : 10,
    "mining-requires-peers" : true,
    "mine-empty-rounds" : 10,
    "mining-turnover" : 0.5,
    "first-block-reward" : -1,
    "initial-block-reward" : 0,
    "reward-halving-interval" : 52560000,
    "reward-spendable-delay" : 1,
    "minimum-per-output" : 0,
    "maximum-per-output" : 100000000000000,
    "minimum-offchain-fee" : 0,
    "minimum-relay-fee" : 0,
    "native-currency-multiple" : 100000000,
    "skip-pow-check" : false,
    "pow-minimum-bits" : 8,
    "target-adjust-freq" : -1,
    "allow-min-difficulty-blocks" : false,
    "only-accept-std-txs" : true,
    "max-std-tx-size" : 4194304,
    "max-std-op-returns-count" : 32,
    "max-std-op-return-size" : 2097152,
    "max-std-op-drops-count" : 5,
    "max-std-element-size" : 40000,
    "chain-name" : "chain5xx",
    "protocol-version" : 20011,
    "network-message-start" : "f7c4cffc",
    "address-pubkeyhash-version" : "001e81a5",
    "address-scripthash-version" : "0568ec0b",
    "private-key-version" : "80794dd3",
    "address-checksum-value" : "06b82bc4",
    "genesis-pubkey" : "02c15c2f63d9af0fd8aa37ef6f3b2a3ec9ec2e1fa8cc6cb285e7587b6cf126a245",
    "genesis-version" : 1,
    "genesis-timestamp" : 1721760656,
    "genesis-nbits" : 536936447,
    "genesis-nonce" : 262,
    "genesis-pubkey-hash" : "8f87fe98e190bd1b3d8c6c3a8f1284b2fae41737",
    "genesis-hash" : "00facd7972ea2ef344e4be133926642bddb9dec3f17e7074747b64d21bacb02b",
    "chain-params-hash" : "fc24734afe979a2886a3fa2ca68b6728b9b0732c710f83c547593f210a6459f4"
}

Is MultiChain still being developed and supported?

Fri, 14 Jun 2024 18:09:03 +0000

Hi team,

Been a long-time user and proponent since late 2014. Was looking to use MultiChain for a private consortium use-case I have in mind, and it looks like the last release and Twitter post was over a year ago (May 2023) and the last blog post was November 2021; prior to these dates both releases and blog posts were fairly regular, so I'm wondering if the project is still alive.

Thanks,

Viv

error: Error parsing JSON:[{"keys": ..........while running publishmulti command

Fri, 14 Jun 2024 05:04:04 +0000

code:

import argparse
import subprocess
import time
import json
import os
import signal
import getpass
import psutil
import math
import pandas as pd

def test():
    publishitems=[]

    data1= {"a1":["2334","?452" ],
           "T1": ["tag1","tg"],
           "Q1": ["c1","c2"]
          }
    df1=pd.DataFrame(data1)
    #print(df1)
    data=df1.to_dict()
    #data=json.dumps(data)
    keyString='key'

    #item={"keys":[keyString],"data":data}
    item={"keys":[keyString],"data":{"json": data} }
    publishitems.append(item)
    data2= {"a1":["24","?42" ],
           "T1": ["tag1","tg" ],
           "Q1": ["cc1","mm"]
          }
    df2=pd.DataFrame(data2)
    data=df2.to_dict()
    #data=json.dumps(data)
    item={"keys":[keyString],"data":{"json": data}}
    publishitems.append(item)
    print(publishitems)
    import json
    class mylist(list):
        def __str__(self):
            return json.dumps(self)
    pairs = mylist(publishitems)
    #publishcmd= 'multichain-cli chaintxx publishmulti test \'{}\' '.format( (publishitems))
    publishcmd= 'multichain-cli chaintxx publishmulti test {} '.format( (pairs))
    print(publishcmd)
    daemonOut = subprocess.call(publishcmd.split())
    return 'finish'

def main():
    #createStreamCommand= 'multichain-cli chaintxx create stream test true'

    #procCreate = subprocess.Popen(createStreamCommand.split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    #procCreate.wait()

    subscribeStreamCommand= 'multichain-cli {} subscribe {}'.format('chaintxx', 'test')
    #subscribe to the stream
    procSubscribe = subprocess.Popen(subscribeStreamCommand.split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    procSubscribe.wait()
    print(test())


if __name__ == "__main__":
    main()

output:

$ python3 testdf.py
[{'keys': ['key'], 'data': {'json': {'a1': {0: '2334', 1: '?452'}, 'T1': {0: 'tag1', 1: 'tg'}, 'Q1': {0: 'c1', 1: 'c2'}}}}, {'keys': ['key'], 'data': {'json': {'a1': {0: '24', 1: '?42'}, 'T1': {0: 'tag1', 1: 'tg'}, 'Q1': {0: 'cc1', 1: 'mm'}}}}]
multichain-cli chaintxx publishmulti test '[{"keys": ["key"], "data": {"json": {"a1": {"0": "2334", "1": "?452"}, "T1": {"0": "tag1", "1": "tg"}, "Q1": {"0": "c1", "1": "c2"}}}}, {"keys": ["key"], "data": {"json": {"a1": {"0": "24", "1": "?42"}, "T1": {"0": "tag1", "1": "tg"}, "Q1": {"0": "cc1", "1": "mm"}}}}]'
error: Error parsing JSON:'[{"keys":

but when directly running publishmulti command on terminal directly, there is no error.

$ multichain-cli chaintxx publishmulti test '[{"keys": ["key"], "data": {"json": {"a1": {"0": "2334", "1": "?452"}, "T1": {"0": "tag1", "1": "tg"}, "Q1": {"0": "c1", "1": "c2"}}}}, {"keys": ["key"], "data": {"json": {"a1": {"0": "24", "1": "?42"}, "T1": {"0": "tag1", "1": "tg"}, "Q1": {"0": "cc1", "1": "mm"}}}}]'
{"method":"publishmulti","params":["test",[{"keys":["key"],"data":{"json":{"a1":{"0":"2334","1":"?452"},"T1":{"0":"tag1","1":"tg"},"Q1":{"0":"c1","1":"c2"}}}},{"keys":["key"],"data":{"json":{"a1":{"0":"24","1":"?42"},"T1":{"0":"tag1","1":"tg"},"Q1":{"0":"cc1","1":"mm"}}}}]],"id":"20274801-1718340965","chain_name":"chaintxx"}

9aab28705586beef188662d401a6cbcdbd20bb0170ec0d90c0d567a28bf1d867

can anyone help me out in finding the issue?

Interested reviewing MultiChain 2.0

Tue, 28 May 2024 13:27:02 +0000

The Developer of the Forum,

MultiChain

Greetings, I am honored to be a member of the forum. I am immensely interested for reviewing MultiChain 2.0 on my tech news site here. What do you say is it possible? If it is please let me know. I shall be highly thankful for your valuable feedback.

With reagrds,

Dalton

struggle with crafting an API request

Fri, 05 Apr 2024 17:22:29 +0000

hi everyone,

I am having difficulties with crafting my first API-request over postman.

I have set up a chain, I have the explorer and the web-demo running successfully - pretty much default values everywhere:

chain1/multichain.conf:
rpcallowip=192.168.10.0/24
rpcuser=multichainrpc
rpcpassword=XXXX

chain1/params.dat:
default-network-port = 5759
default-rpc-port = 5758
chain-name = chain1

when running a command from the console, everthing works:

bbking@bc-debian:~/.multichain/chain1$ multichain-cli chain1 getinfo
{"method":"getinfo","params":[],"id":"37999825-1712336614","chain_name":"chain1"}

{
    "version" : "2.3.3",
    "nodeversion" : 20303901,
    "edition" : "Community",
    "protocolversion" : 20013,
    "chainname" : "chain1",
    "description" : "MultiChain chain1",
    "protocol" : "multichain",
    "port" : 5759,

now my first question is, do I connect from an external host over port 5759 or 5758?

I wanted to replicate the "getinfo" command from postman:
http://192.168.10.114:5758?method=getinfo&params=[]&id=13054619-1712335590&chain_name=chain1

I have populated the "params" tab with the parameters as you can see.

I also activated "Basic Authorization" with the credentials from multichain.conf

On the "headers" tab, I've set these key-value pairs:
"Content-type" : "application/json"
"Accept" : "application/json"
"Content-length" : the length of the parameter string starting from "?" in the example above.

Now, when I send the request to port 5759, I get a "Could not get response"

when I send the request to port 5758 with "Content-length" activated, it times out.
without "Content-length" activated, I instantly get a "404 Not found"

Can someone help me with what am I doing wrong?

Thanks a lot in advance!

• Multithreading - executing codes sequentially

Wed, 20 Dec 2023 06:46:00 +0000

Please is there a way to prove that filters codes run sequentially? Please can I have a Transaction filter program that proves this?

Thanks in advance.

Importance of stream

Tue, 19 Dec 2023 23:36:27 +0000

Hi, Thank you for your numerous responses.

Please I need clarity on the relevance and importance of a stream. What can I relate stream to in another environent? How does it impact on the blockchain? I have read from your website that it can be used as data storage. Please can you give me a use case?

Thank you you in advance.

any document on double hash

Tue, 19 Dec 2023 20:23:24 +0000

Hi all

Please can I have resouces on this double -Sha 256. Something that speaks to how it works, Please.

Thank you

unable to publish long key item in multichain stream

Sun, 17 Dec 2023 19:50:28 +0000

str2 len: 137

error details:
8
b'{"method":"publish","params":["stream3","789c33343730b2303130b734d1b33436353334325788d650f77556d75150373435f055d7d45100f203817c330330db3118c8064a813911200e84e9eb02d503d1e2e70b97097207c978b81b18181a9ac43bba3b873803b1aebbb3a3bba3638873bc879b7778b84b704444bc0f5009447b00588f6f6251b64b69414e667262496ab1ba662c002ad42742","7b2730277d"],"id":"88675825-1702840795","chain_name":"tchain"}\n\nerror code: -8\nerror message:\nItem key is too long\n'

I am trying to publish a key (in byte form) having size 137 bytes, which is within the limit ( upto 256bytes). But still "long key error" is coming. Before this error, I was able to publish with long key in first try.

how key-value pairs having same key are stored in multichain stream?

Sun, 10 Dec 2023 08:00:02 +0000

when we publish data using same key value, separate transactions are created for every publish.

$ multichain-cli str liststreamitems s1
{"method":"liststreamitems","params":["s1"],"id":"54837938-1702194153","chain_name":"str"}

[
    {
        "publishers" : [
            "1UcZCK8r2SGfevz1xDWdFLe49FsCqHyrFtowzH"
        ],
        "key" : "k1",
        "data" : "11",
        "confirmations" : 13,
        "blocktime" : 1702188538,
        "txid" : "ec4042b12624b463bec52747b0de7ae88a4723cc8a602546f0ecf8e946133a78"
    },
    {
        "publishers" : [
            "1UcZCK8r2SGfevz1xDWdFLe49FsCqHyrFtowzH"
        ],
        "key" : "k1",
        "data" : "11",
        "confirmations" : 12,
        "blocktime" : 1702188543,
        "txid" : "0f7f0f414c43b323e7581d4037f60e0ceb294a2732c0bb04f58e26e9e5c38f90"
    },
    {
        "publishers" : [
            "1UcZCK8r2SGfevz1xDWdFLe49FsCqHyrFtowzH"
        ],
        "key" : "k1",
        "data" : "12",
        "confirmations" : 11,
        "blocktime" : 1702188563,
        "txid" : "1d84ed95425e4a84c938ab0d342f3fe87b20c835e3e758c02479071e8b819f7b"
    }
]
anju@DESKTOP-FFAFKFO:~$ multichain-cli str liststreamkeys s1
{"method":"liststreamkeys","params":["s1"],"id":"79880957-1702194238","chain_name":"str"}

[
    {
        "key" : "k1",
        "items" : 3,
        "confirmed" : 3
    }
]

does that mean- when we publish different copies of same key are created for every data item published , since blockchain is a append-only structure.

and when we list streamkeys, it only list unique keys with no. of items it is mapped. But in memory, multiple copies of same key value exist in different transactions. thus avoiding unnecessary repeated key valued being loaded since data items are not required now.

how to publish multiple items using- createrawsendfrom and publishmulti ?

Sun, 10 Dec 2023 07:50:55 +0000

$ multichain-cli str publishmulti s1 '[{"key":'k2', "data":'12'},{"key":'k2', "data":'13'},{"key":
'k3' ,"data":'uu'}]'
{"method":"publishmulti","params":["s1","[{\"key\":k2, \"data\":12},{\"key\":k2, \"data\":13},{\"key\":k3 ,\"data\":uu}]"],"id":"44294372-1702192055","chain_name":"str"}

error code: -32601
error message:
Method not found

Private/Public Key or no keys?

Tue, 05 Dec 2023 20:07:12 +0000

Hi

I have created a blockchain and done couple of transactions without outrightly transaction with public or private keys. I just stumble on this link that talks about creating the public/private keys and this has left me wondering, how have I been generating transactions and they have been impacting without me using a public/private key? Please could you explain?

Secondly, could you please clarify the difference between wallet address and public key? are they the same?

Navigating to the wallet.dat file, i can see the wallet address but i can't identify the provate key. Is it scramled?

Lastly. I created my block on a windows OS. I want to navigate to where the blockchain is located using windows and I went to the chain folder on the path \AppData\Roaming\MultiChain\demoChain. Could you please point me to the destination?

Many thanks

"prev block not found" error

Thu, 30 Nov 2023 12:17:29 +0000

In multichain debug.log I sometimes see logs like:
2023-11-29 20:29:37 ERROR: AcceptBlockHeader : prev block not found
2023-11-29 20:29:37 ERROR: ProcessNewBlock : AcceptBlock FAILED

What does it exactly mean?

I have already seen such errors in my multichain logs but since two days they happens much more often (even several times per hour). Such errors are treated as misbehaving and cause that banscore is increasing quickly and ends up in banning all (or nearly all) other multichain nodes and leads to network instability.
What can be a reason for it?

Thanks,
Damian

Current Hash Algorithm

Tue, 28 Nov 2023 06:20:07 +0000

Hi. Thanks for your usual support. I want to find out if Multichain is still using the SHA256 as at now. If not, what has it migrated to?.

Thanks.

issue "Stream with this name not found:" when stream already exist

Sun, 26 Nov 2023 13:33:51 +0000

anju@DESKTOP-FFAFKFO:/mnt/c/Users/RAM/mysam1$ multichain-cli chaint create stream "stream34" true
{"method":"create","params":["stream","stream34",true],"id":"35431233-1701004608","chain_name":"chaint"}

error code: -705
error message:
Stream or asset with this name already exists
anju@DESKTOP-FFAFKFO:/mnt/c/Users/RAM/mysam1$ multichain-cli chaint liststreamitems "stream34"
{"method":"liststreamitems","params":["stream34"],"id":"77217000-1701004620","chain_name":"chaint"}

error code: -708
error message:
Stream with this name not found: stream34
anju@DESKTOP-FFAFKFO:/mnt/c/Users/RAM/mysam1$ multichain-cli chaint liststreams
{"method":"liststreams","params":[],"id":"40556506-1701004667","chain_name":"chaint"}

[
    {
        "name" : "root",
        "createtxid" : "63dce96635857e601886fef54e3d92513de31fb9cf8d02d001782ea635786b0b",
        "streamref" : "0-0-0",
        "open" : true,
        "details" : {
        },
        "subscribed" : true,
        "synchronized" : false,
        "items" : 0,
        "confirmed" : 0,
        "keys" : 0,
        "publishers" : 0
    },
    {
        "name" : "stream33",
        "createtxid" : "c9fcfd1c206dbfef291b4e4d08ea6b2d5ce6d6b16b6ca0ab9a8dfcaac8f8852e",
        "streamref" : "60-265-64713",
        "open" : true,
        "details" : {
        },
        "subscribed" : true,
        "synchronized" : true,
        "items" : 74,
        "confirmed" : 74,
        "keys" : 19,
        "publishers" : 1
    },
    {
        "name" : "stream33",
        "createtxid" : "48d02ba3f270d3e6ed8259dfa55a5d9a63fe31998597696d3aed6f7660d629ae",
        "streamref" : "60-265-64713",
        "open" : true,
        "details" : {
        },
        "subscribed" : true,
        "synchronized" : true,
        "items" : 74,
        "confirmed" : 74,
        "keys" : 19,
        "publishers" : 1
    },
    {
        "name" : "stream34",
        "createtxid" : "a711284a75212700ea5a4806371dafac46ecc9162d45629ddd6a1f7b73f7cbc7",
        "streamref" : "60-492-4519",
        "open" : true,
        "details" : {
        },
        "subscribed" : true,
        "synchronized" : true,
        "items" : 12151,
        "confirmed" : 12151,
        "keys" : 5014,
        "publishers" : 1
    }
]

question:

In my chain, 2 stream exists with same name ie 'stream33'. is it possible?

and stream34 already exist, but i am not able to liststreamitems. and it is not allowing to create a stream also.

And when I tried to check key values again in 'stream33', the key values are set to " ".

  {
        "key" : "",
        "items" : 2,
        "confirmed" : 2
    }

whereas earlier the stream was having key values.

Can you tell me the possible reason for this unwanted and automatic changes in multichain streams?

Is there a formula to convert the value obtained from getdifficulty into a leading number of zeros?

Thu, 23 Nov 2023 17:04:16 +0000

Do you have a good link that I can use to learn how to convert :

getdifficulty
{"method":"getdifficulty","params":[],"id":"45126611-1700757630","chain_name":"base_blocks"}

1.35360941856863

to a leading number of zeros?

Is it possible to start a new chain with a specific difficulty?

Thu, 23 Nov 2023 02:25:02 +0000

We already have a chain running using permissionless PoW. We called that the "testnet". Soon we would like to migrate to a "mainnet". Essentially, it will be just cloning the existing "testnet". All of the miners will move over to that new chain. Since we have established a good difficulty value, we would like to start the new chain with that same value. getmininginfo returns:
{
    "blocks" : 3788,
    "currentblocksize" : 1000,
    "currentblocktx" : 0,
    "difficulty" : 1.52587890625e-5,
    "errors" : "",
    "genproclimit" : 1,
    "networkhashps" : 14351024,
    "pooledtx" : 0,
    "testnet" : false,
    "chain" : "main",
    "generate" : true,
    "hashespersec" : 1015190
}

How to store the json data of a stream which has multiple keys in a variable?

Mon, 20 Nov 2023 21:29:27 +0000

Gpu mining

Sun, 19 Nov 2023 17:22:45 +0000

Is it possible to mine multichain with gpu rather than cpu?

Can I deploy a multichain network where I can create chains later on?

Sat, 18 Nov 2023 20:48:49 +0000

For an Electronic health care system, I was thinking of creating chains for each user to store their data in streams. How do I do this?

how to use createrawsendfrom to publish items in multiple streams in a single transaction or API call

Wed, 15 Nov 2023 08:54:29 +0000

toPublish = []

toPublish.append({'for':streamName, 'key':key, 'data':hexData})

publishCommand = [multichainLoc+'multichain-cli', str('{}'.format(chainName)),'createrawsendfrom', addr, '{}' ,str('{}'.format(toPublish)), 'send']
            #supress output of the command

            try:
                dummy = subprocess.check_output(publishCommand, stderr=subprocess.STDOUT)
            except subprocess.CalledProcessError as e:
                print(e.returncode)
                print(e.output)

error:

b'[\n    "1D8TuBS6AkmsDx9fyJWm6A3LkHSCWYaisLt7q7"\n]\n'
address: 1D8TuBS6AkmsDx9fyJWm6A3LkHSCWYaisLt7q7
Traceback (most recent call last):
  File "storeFilex.py", line 187, in <module>
    storeFile(argv[1], filePath)
  File "storeFilex.py", line 67, in storeFile
    dummy = subprocess.check_output(publishCommand, stderr=subprocess.STDOUT)
  File "/usr/lib/python3.8/subprocess.py", line 415, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "/usr/lib/python3.8/subprocess.py", line 493, in run
    with Popen(*popenargs, **kwargs) as process:
  File "/usr/lib/python3.8/subprocess.py", line 858, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.8/subprocess.py", line 1704, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
PermissionError: [Errno 13] Permission denied: ' multichain-cli'

Additional features on multichain

Wed, 08 Nov 2023 16:45:45 +0000

Hi

I have created a blockchain with 2 additional nodes and created assets, streams etc as directed in the page Getting Started with MultiChain https://www.multichain.com/getting-started. I have also created web demo and implemented one of the smart contracts.

I am not sure what I need to do next. Could you please tell me what else to do? There are some questions I read on the Q and A page and I am so not able to understand the solution that is being discussed.

You could also give me links to your sites that capture additional implementations or configurations that I can do on my blockchain to make it more robust.

Thank you

multichain-util clone is ignoring -datadir option

Wed, 08 Nov 2023 14:05:35 +0000

After creating a chain like so:

multichain-util create test-test_3 -datadir=/mnt/disks/data/multichain_data/
MultiChain 2.3 Utilities (latest protocol 20013)
Blockchain parameter set was successfully generated.
You can edit it in /mnt/disks/data/multichain_data/test-test_3/params.dat before running multichaind for the first time.
To generate blockchain please run "multichaind test-test_3 -daemon".
Cannot create chain parameter set, file /home/test/.multichain/public_access_3/params.dat does not exist

I start the chain

multichaind test-test_3 -daemon
MultiChain 2.3 Daemon (Community Edition, latest protocol 20013)
Starting up node...
ERROR: Parameter set for blockchain test-test_3 is not complete.

If you want to create new blockchain please run one of the following:
multichain-util create test-test_3
multichain-util clone <old-blockchain-name> test-test_3
And rerun multichaind test-test_3

If you want to connect to existing blockchain please specify seed node:
multichaind test-test_3@<seed-node-ip>
multichaind test-test_3@<seed-node-ip>:<seed-node-port>

And when I try to clone an existing chain, -datadir is ignored and instead the multichain-util thinks I am pointing to elsewhere.

multichain-util clone public_access_3 test-test_3 -datadir=/mnt/disks/data/multichain_data/
MultiChain 2.3 Utilities (latest protocol 20013)
Cannot create chain parameter set, file /home/test/.multichain/public_access_3/params.dat does not exist
ERROR: Blockchain parameter set was not generated.