xcashd

Use X-Cash Daemon (xcashd) to create a node, sync the blockchain and relay transactions

Overview

Syncing the blockchain

The X-Cash daemon xcashd keeps your computer synced up with the X-Cash network.

It downloads and validates the blockchain from the other nodes.

Overview of the daemon syncing and checking the blockchain by 100 blocks chunks

About privacy and best practices

xcashd is entirely decoupled from your wallet.

xcashd does not access your private keys and therefore doesn't know your transactions and balance.

This means that you can run xcashdon a separate computer or in the cloud and access it remotely to retrieve/provide the data needed for wallet operations.

In practice, you can connect to a remotexcashdinstance provided by a semi-trusted 3rd party. Such 3rd party will not be able to steal your funds as all transactions are signed locally.

However, there are privacy and reliability implications when using a remote, untrusted node. For any real business we recommend running your own full node.

To provide a better reliability and trust, the team has setup a several public remote nodes across different locations:

Name

Location

usseed1.x-cash.org:18281

US - Oregon

usseed2.x-cash.org:18281

US - Virginia

euseed1.x-cash.org:18281

Europe - Germany

euseed3.x-cash.org:18281

Europe - France

asiaseed2.x-cash.org:18281

Asia - Singapore

Syntax

./xcashd [options] [command]

Options define how the daemon should be working and are optional. Their names follow the --option-name convention.

Commands give access to specific services provided by the daemon. Commands are executed against the running daemon. Their names follow the command_name convention.

Running

Go to directory where you unpacked X-Cash.

For learning and experimentation, you should stick to the testnet to avoid any wrong manipulation.

./xcashd --stagenet --detach # run as a daemon in background
./xcashd --stagenet exit # ask daemon to exit gracefully

By default, the daemon connects to the mainnet. If you want to use real XCASH there is no need to add a specific argument.

./xcashd --detach # run as a daemon in background
./xcashd exit # ask daemon to exit gracefully

Options

Options define how the daemon should be working. Their names follow the --option-nameconvention.

The following groups are only to make reference easier to follow. The daemon itself does not group options in any way.

Help and version

Option

Description

--help

Enlist available options.

--version

Show xcashd version to stdout. Example: X-CASH '' (v1.5.0-unknown)

--os-version

Show build timestamp and target operating system. Example output: OS: Microsoft (build 17763), 64-bit

Pick network

Option

Description

(missing)

By default xcashd assumes mainnet.

--stagenet

Run on stagenet. Remember to run your wallet with --stagenet as well.

--testnet

Run on testnet. Remember to run your wallet with --testnet as well.

Logging

Option

Description

--log-file

Full path to the log file. Example (make sure your file permissions are correctly setup): ./xcashd --log-file=/var/log/xcash/mainnet/xcash.log

--log-level

0-4 with 0 being minimal logging and 4 being full tracing. Defaults to 0. These are general presets and do not directly map to severity levels. For example, even with minimal 0, you may see some most important INFO entries. Temporarily changing to 1 allows for much better understanding of how the full node operates. Example: ./xcashd --log-level=1

--max-log-file-size

Soft limit in bytes for the log file (=104850000 by default, which is just under 100MB). Once log file grows past that limit, xcashd creates the next log file with a UTC timestamp postfix -YYYY-MM-DD-HH-MM-SS. In production deployments, you would probably prefer to use established solutions like logrotate instead. In that case, set --max-log-file-size=0 to prevent xcashd from managing the log files.

--max-log-files

Limit on the number of log files (=50 by default). The oldest log files are removed. In production deployments, you would probably prefer to use established solutions like logrotate instead.

Server

xcashd defaults are adjusted for running it occasionally on the same computer as your X-Cash wallet.

The following options will be helpful if you intend to have an always running node — most likely on a remote server or your own separate PC.

Option

Description

--config-file

Full path to the configuration file. By default xcashd looks for bitxcash.conf in X-Cash data directory.

--data-dir

Full path to data directory. This is where the blockchain, log files, and p2p network memory are stored. For defaults and details see data directory.

--pidfile

Full path to the PID file. Works only with --detach. Example: ./xcashd --detach --pidfile=/run/xcash/xcashd.pid

--detach

Go to background (decouple from the terminal). This is useful for long-running / server scenarios. Typically, you will also want to manage xcashddaemon with systemd or similar. By default xcashd runs in a foreground.

--non-interactive

Do not require tty in a foreground mode. Helpful when running in a container. By default xcashd runs in a foreground and opens stdin for reading. This breaks containerization because no tty gets assigned and xcashd process crashes. You can make it run in a background with --detach but this is inconvenient in a containerized environment because the canonical usage is that the container waits on the main process to exist (forking makes things more complicated).

--no-igd

Disable UPnP port mapping on the router ("Internet Gateway Device"). Add this option to improve security if you are not behind a NAT (you can bind directly to public IP or you run through Tor).

--max-txpool-weight

Set maximum transactions pool size in bytes. By default 648000000 (~618MB). These are transactions pending for confirmations (not included in any block).

--enforce-dns-checkpointing

The emergency checkpoints set by X-CashPulse operators will be enforced. It is probably a good idea to set enforcing for unattended nodes.

If encountered block hash does not match corresponding checkpoint, the local blockchain will be rolled back a few blocks, effectively blocking following what X-CashPulse operators consider invalid fork. The log entry will be produced: ERROR Local blockchain failed to pass a checkpoint, rolling back! Eventually, the alternative ("fixed") fork will get heavier and the node will follow it, leaving the "invalid" fork behind.

By default checkpointing only notifies about discrepancy by producing the following log entry: ERRORWARNING: local blockchain failed to pass a xcashPulse checkpoint, and you could be on a fork. You should either sync up from scratch, OR download a fresh blockchain bootstrap, OR enable checkpoint enforcing with the --enforce-dns-checkpointing command-line option.

As of 04/09/2019, X-Cash has not implemented X-CashPulse operators.

--disable-dns-checkpoints

The X-CashPulse checkpoints set by core developers will be discarded. As of 04/09/2019, X-Cash has not implemented the X-CashPulse operators feature.

P2P network

The following options define how your node participates in X-Cash peer-to-peer network. This is for node-to-node communication. The following options do not affect wallet-to-node interface.

The node and peer words are used interchangeably.

Option

Description

--p2p-bind-ip

Network interface to bind to for p2p network protocol. Default value 0.0.0.0 binds to all network interfaces and should be used in general working conditions. You must change this if you want to constrain binding, for example to configure connection through Tor via torsocks: DNS_PUBLIC=tcp://1.1.1.1 TORSOCKS_ALLOW_INBOUND=1 torsocks ./xcashd --p2p-bind-ip 127.0.0.1 --no-igd --hide-my-port

--p2p-bind-port

TCP port to listen for p2p network connections. Defaults to 18281 for mainnet, 28281 for testnet, and 38281 for stagenet. You normally wouldn't change that. This is helpful to run several nodes on your machine to simulate private a X-Cash p2p network (likely using private testnet). Example: ./xcashd --p2p-bind-port=48080

--p2p-external-port

TCP port to listen for p2p network connections on your router. Relevant if you are behind a NAT and still want to accept incoming connections. You must then set this to relevant port on your router. This is to let xcashd know what to advertise on the network. By default this value is 0.

--hide-my-port

xcashd will still open and listen on the p2p port. However, it will not announce itself as a peer list candidate. Technically, it will return port 0 in a response to p2p handshake (node_data.my_port = 0 in get_local_node_data function). In effect nodes you connect to won't spread your IP to other nodes. To sum up, it is not really hiding, it is more like "do not advertise".

--seed-node

Connect to a node to retrieve other nodes' addresses, and disconnect. If not specified, xcashd will use hardcoded seed nodes on the first run, and peers cached on disk on subsequent runs.

--add-peer

Manually add node to local peer list.

--add-priority-node

Specify list of nodes to connect to and then attempt to keep the connection open. To add multiple nodes use the option several times. Example: ./xcashd --add-priority-node=178.128.192.138:18081 --add-priority-node=144.76.202.167:18081

--add-exclusive-node

Specify list of nodes to connect to only. If this option is given the options --add-priority-node and --seed-node are ignored. To add multiple nodes use the option several times. Example: ./xcashd --add-exclusive-node=178.128.192.138:18081 --add-exclusive-node=144.76.202.167:18081

--out-peers

Set max number of outgoing connections to other nodes. By default 8. Value -1represents the code default.

--in-peers

Set max number of incoming connections (nodes actively connecting to you). By default unlimited. Value -1 represents the code default.

--limit-rate-up

Set outgoing data transfer limit [kB/s]. By default 2048 kB/s. Value -1 represents the code default.

--limit-rate-down

Set incoming data transfer limit [kB/s]. By default 8192 kB/s. Value -1 represents the code default.

--limit-rate

Set the same limit value for incoming and outgoing data transfer. By default (-1) the individual up/down default limits will be used. It is better to use --limit-rate-upand --limit-rate-down instead to avoid confusion.

--offline

Do not listen for peers, nor connect to any. Useful for working with a local, archival blockchain.

--allow-local-ip

Allow adding local IP to peer list. Useful mostly for debug purposes when you may want to have multiple nodes on a single machine.

Node RPC API

xcashd node offers a powerful API. It serves 3 purposes:

  • provides network data (stats, blocks, transactions, ...)

  • provides local node information (peer list, hash rate if mining, ...)

  • provides interface for wallets (send transactions, ...)

This API is typically referred to as "RPC" because it is mostly based on JSON/RPC standard.

The following options define how the API behaves.

Option

Description

--rpc-bind-ip

IP to listen on. By default 127.0.0.1 because API gives full administrative capabilities over the node. Set it to 0.0.0.0 to listen on all interfaces - but only in connection with one of *-restricted-* options and --confirm-external-bind.

--rpc-bind-port

TCP port to listen on. By default 18281 (mainnet), 28281 (testnet), 38281(stagenet).

--rpc-restricted-bind-port

TCP port to listen on with the limited version of API. The limited API can be made public to create an Open Node. At the same time, you may firewall the full API port to still enjoy local querying and administration.

--confirm-external-bind

Confirm you consciously set --rpc-bind-ip to non-localhost IP and you understand the consequences.

--restricted-rpc

Restrict API to view only commands and do not return privacy sensitive data. Note this does not make sense with --rpc-restricted-bind-portbecause you would end up with two restricted APIs.

--rpc-login

Specify username[:password] required to connect to API. Practical usage is limited because API communication is in plain text over HTTP.

--rpc-access-control-origins

Specify a comma separated list of origins to allow cross origin resource sharing. This is useful if you want to use xcashd API directly from a web browser via JavaScript (say in a pure-fronted web appp scenario). With this option xcashd will put proper HTTP CORS headers to its responses. You will also need to set --rpc-login if you use this option. Normally though, the API is used by backend app and this option isn't necessary.

Accepting X-Cash

These are network notifications offered by xcashd. There are also wallet notifications like --tx-notify offered by xcashd-wallet-rpc here.

Option

Description

--block-notify

Run a program for each new block. The <arg> must be a full path. If the <arg>contains %s it will be replaced by the block hash. Example: ./xcashd --block-notify="/usr/bin/echo %s" Block notifications are good for immediate reaction. However, you should always assume you will miss some block notifications and you should independently poll the API to cover this up. Mind blockchain reorganizations. Block notifications can revert to same and past heights. Small reorganizations are natural and happen every day.

--block-rate-notify

Run a program when the number of blocks received in the recent past deviates significantly from the expectation. The <arg> must be a full path. The <arg> can contain any of %t, %b, %e symbols to interpolate: %t: the number of minutes in the observation window %b: the number of blocks observed in that window %e: the ideal number of blocks expected in that window The option will let you know if the network hash rate drops by a lot. This may be indicative of a large section of the network miners moving off to mine a private chain, to be later released to the network. Note that if this event triggers, it is not incontrovertible proof that this is happening. It might just be chance. The longer the window (the %t parameter), and the larger the distance between actual and expected number of blocks, the more indicative it is of a possible chain reorg double-spend attack being prepared. Recommendation: unless you run economically significant X-Cash exchange or operation, do not act on this data. It is hard to calibrate and easy to misinterpret. If this is a real attack, it will target high-liquidity entities and not small merchants.

--reorg-notify

Run a program when reorganization happens (ie, at least one block is removed from the top of the blockchain). The <arg> must be a full path. The <arg> can contain any of %s, %h, %n symbols to interpolate: %s: the height at which the split occurs %h: the height of the new blockchain %d: the number of blocks discarded from the old chain %n: the number of blocks being added The option will let you know when a block is removed from the chain to be replaced by other blocks. This happens when a 51% attack occurs, but small reorgs also happen in the normal course of things. The %d parameter will be set to the number of blocks discarded from the old chain (so if this is higher than the number of confirmations you wait to act upon an incoming payment, that payment might have been cancelled). The %n parameter wil be set to the number of blocks in the new chain (so if this is higher than the number of confirmations you wait to act upon an incoming payment, any incoming payment in the first block will be automatically acted upon by your platform). Recommendation: unless you run economically significant X-Cash exchange or operation, you do not need to bother with this option. Simply account for reorganizations by requiring at least 10 confirmations to consider payments no reversible.

Performance

These are advanced options that allow you to optimize performance of your xcashd node, sometimes at the expense of reliability.

Option

Description

--db-sync-mode

Specify sync option, using format: [safe|fast|fastest]:[sync|async]:[<nblocks_per_sync>[blocks]|<nbytes_per_sync>[bytes]] The default is fast:async:250000000bytes. The fast:async:* can corrupt blockchain database in case of a system crash. It should not corrupt if just xcashd crashes. If you are concerned with system crashes use safe:sync.

--max-concurrency

Max number of threads to use for parallel jobs. The default value 0 uses the number of CPU threads.

--prep-blocks-threads

Sync up most of the way by using embedded, "known" block hashes. Pass 1to turn on and 0 to turn off. This is on (1) by default. Normally, for every block the full node must calculate the block hash to verify miner's proof of work. Because the CryptoNight PoW used in X-Cash is very expensive (even for verification), xcashd offers skipping these calculations for old blocks. In other words, it's a mechanism to trust xcashd binary regarding old blocks' PoW validity, to sync up faster.

--block-sync-size

How many blocks are processed in a single batch during chain synchronization. By default this is 20 blocks for newer history and 100 blocks for older history ("pre v4"). Default behavior is represented by value 0. Intuitively, the more resources you have, the bigger batch size you may want to try out. Example: ./xcashd --block-sync-size=500

--bootstrap-daemon-address

The host:port of a "bootstrap" remote open node that the connected wallets can use while this node is still not fully synced. Example: ./xcashd --bootstrap-daemon-address=opennode.xmr-tw.org:18089. The node will forward selected RPC calls to the bootstrap node. The wallet will handle this automatically and transparently. Obviously, such bootstraping phase has privacy implications similar to directly using a remote node.

--bootstrap-daemon-login

Specify username:password for the bootstrap daemon login (if required). This considers the RPC interface used by the wallet. Normally, open nodes do not require any credentials.

Mining

The following options configure solo mining using CPU with the standard software stack xcashd. This is mostly useful for:

  • generating your stagenet or testnet coins

  • experimentation and learning

  • if you have super cheap access to vast CPU resources

Be advised though that real mining happens in pools and with high-end GPU-s instead of CPU-s. Note: On block 281000, X-Cash switched to Cryptonight HeavyX algorithm which is ASIC and NiceHash resistant.

Option

Description

--start-mining

Specify wallet address to mining for. This must be a standard address! It can be neither a subaddres nor integrated address.

--mining-threads

Specify mining threads count. By default ony one thread will be used. For best results, set it to number of your physical cores.

--extra-messages-file

Specify file for extra messages to include into coinbase transactions.

--bg-mining-enable

Enable unobtrusive mining. In this mode mining will use a small percentage of your system resources to never noticeably slow down your computer. This is intended to encourage people to mine to improve decentralization. That being said chances of finding a block are diminishingly small with solo CPU mining, and even lesser with its unobtrusive version. You can tweak the unobtrusivness / power trade-offs with the further --bg-*options below.

--bg-mining-ignore-battery

If true, assumes plugged in when unable to query system power status.

--bg-mining-min-idle-interval

Specify min lookback interval in seconds for determining idle state.

--bg-mining-idle-threshold

Specify minimum avg idle percentage over lookback interval.

--bg-mining-miner-target

Specify maximum percentage cpu use by miner(s).

Testing X-Cash itself

These options are useful for X-Cash project developers and testers. Normal users shouldn't be concerned with these.

Option

Description

--test-drop-download

For net tests: in download, discard ALL blocks instead checking/saving them (very fast).

--test-drop-download-height

Like test-drop-download but discards only after around certain height. By default 0.

--regtest

Run in a regression testing mode.

--fixed-difficulty

Fixed difficulty used for testing. By default 0.

--test-dbg-lock-sleep

Sleep time in ms, defaults to 0 (off), used to debug before/after locking mutex. Values 100 to 1000 are good for tests.

--save-graph

Save data for dr X-Cash.

Legacy

These options should no longer be necessary but are still present in xcashd for backwards compatibility.

Option

Description

--fluffy-blocks

Relay compact blocks. Default. Compact block is just a header and a list of transaction IDs.

--no-fluffy-blocks

Relay classic full blocks. Classic block contains all transactions

--show-time-stats

Official docs say "Show time-stats when processing blocks/txs and disk synchronization" but it does not seem to produce any output during usual blockchain synchronization.

--zmq-rpc-bind-ip

IP for ZMQ RPC server to listen on. By default 127.0.0.1. This is not yet widely used as ZMQ interface currently does not provide meaningful advantage over classic JSON-RPC interface. Unfortunately, currently there is no way to disable the ZMQ server.

--zmq-rpc-bind-port

Port for ZMQ RPC server to listen on. By default 18082 for mainnet, 38082 for stagenet, and 28082 for testnet.

--db-type

Specify database type. The default and only available: lmdb.

Commands

Commands give access to specific services provided by the daemon. Commands are executed against the running daemon. Their names follow the command_name convention.

The following groups are only to make reference easier to follow. The daemon itself does not group commands in any way.

See running for example usage. You can also type commands directly in the console of the running xcashd (if not detached).

Help, version, status

Option

Description

help [<command>]

Show help for <command>.

version

Show version information. Example output: X-CASH '' (v1.5.0-unknown)

status

Show status. Example output: Height: 424951/424951 (100.0%) on mainnet, not mining, net hash 2.38 MH/s, v12, update needed, 8(out)+0(in) connections, uptime 0d 1h 18m 25s

P2P network

Option

Description

print_pl

Show the full peer list.

print_pl_stats

Show the full peer list statistics (white vs gray peers). White peers are online and reachable. Grey peers are offline but your xcashd remembers them from past sessions.

print_cn

Show connected peers with connection initiative (incoming/outgoing) and other stats.

ban <IP> [<seconds>]

Ban a given <IP> for a given amount of <seconds>. By default the ban is for 24h. Example: ./xcashd ban 187.63.135.161

unban <IP>

Unban a given <IP>.

bans

Show the currently banned IPs. Example output: 187.63.135.161 banned for 86397 seconds.

in_peers <max_number>

Set the of incoming connections from other peers.

out_peers <max_uber>

Set the of outgoing connections to other peers.

limit [<kB/s>]

Get or set the download and upload limit.

limit_down [<kB/s>]

Get or set the download limit.

limit_up [<kB/s>]

Get or set the upload limit.

Transaction pool

Option

Description

flush_txpool [<txid>]

Flush specified transaction from transactions pool, or flush the whole transactions pool if was not provided.

print_pool

Print the transaction pool using a verbose format.

print_pool_sh

Print the transaction pool using a short format.

print_pool_stats

Print the transaction pool's statistics (number of transactions, memory size, fees, double spend attempts etc).

Transactions

Option

Description

print_coinbase_tx_sum <start_height> [<block_count>]

Show a sum of all emitted coins and paid fees within specified range. Example: ./xcashd print_coinbase_tx_sum 0 1000000000000

print_tx <transaction_hash> [+hex] [+json]

Show specified transaction as JSON and/or HEX.

relay_tx <txid>

Force relaying the transaction. Useful if you want to rebroadcast the transaction for any reason or if transaction was previously created with "do_not_relay":true.

Blockchain

Option

Description

print_height

Show local blockchain height.

sync_info

Show blockchain sync progress and connected peers along with download / upload stats.

print_bc <begin_height> [<end_height>]

Show detailed data of specified block.

hard_fork_info

Show current consensus version and future hard fork block height, if any.

is_key_image_spent <key_image>

Check if specified key image is spent. Key image is a hash.

Manage daemon

Option

Description

exit, stop_daemon

Ask daemon to exit gracefully. The exit and stop_daemon are identical (one is alias of the other).

set_log <level>|<{+,-,}categories>

Set the current log level/categories where <level> is a number 0-4

print_status

Show if daemon is running.

update (check|download)

Check if update is available and optionally download it. The hash is SHA-256. On linux use sha256sum to verify. Example output: Update available: v0.13.0.4: https://downloads.getxcash.org/cli/xcash-linux-x64-v0.13.0.4.tar.bz2, hash 693e1a0210201f65138ace679d1ab1928aca06bb6e679c20d8b4d2d8717e50d6 Update downloaded to: /opt/xcash-v0.13.0.2/xcash-linux-x64-v0.13.0.4.tar.bz2

Mining

Option

Description

show_hr

Ask xcashd daemon to stop printing current hash rate. Relevant only if xcashd is mining.

hide_hr

Ask xcashd daemon to print current hash rate. Relevant only if xcashdis mining.

start_mining <adr> [<threads>] [do_background_mining] [ignore_battery]

Ask xcashddaemon to start mining. Block reward will go to <addr>.

stop_mining

Ask xcashd daemon to stop mining.

Testing X-Cash itself

Option

Description

start_save_graph

Start saving data for dr X-Cash.

stop_save_graph

Stop saving data for dr X-Cash.

Legacy

Option

Description

save

Flush blockchain data to disk. This is normally no longer necessary as xcashd saves the blockchain automatically on exit.

output_histogram [@<amount>] <min_count> [<max_count>]

Show number of outputs for each amount denomination. This was only relevant in the pre-RingCT era. The old wallet used this to determine which outputs can be used for the requested mixin. With RingCT denominations are irrelevant as amounts are hidden. More info in these SA answers.