Testing Applications

Dash Core provides several network options designed to let developers test their applications with reduced risks and limitations.

Testnet

When run with no arguments, all Dash Core programs default to Dash's main network (mainnet). However, for development, it's safer and cheaper to use Dash's test network (testnet) where the duffs spent have no real-world value. Testnet also relaxes some restrictions (such as standard transaction checks) so you can test functions which might currently be disabled by default on mainnet.

To use testnet, use the argument -testnet with dash-cli, dashd or dash-qt or add testnet=1 to your dash.conf file as described earlier. To get free duffs for testing, check the faucets listed below. Some are community supported and due to potentially frequent Testnet changes, one or more of them may be unavailable at a given time:

• Testnet Faucet - Dash Core Group
• Testnet Faucet - Crowdnode.io

Testnet is a public resource provided for free by Dash Core Group and members of the community, so please don't abuse it.

Regtest mode

For situations where interaction with random peers and blocks is unnecessary or unwanted, Dash Core's regression test mode (regtest mode) lets you instantly create a brand-new private block chain with the same basic rules as testnet---but one major difference: you choose when to create new blocks, so you have complete control over the environment.

Many developers consider regtest mode the preferred way to develop new applications. The following example will let you create a regtest environment after you first configure dashd.

Bash

> dashd -regtest -daemon
Dash Core server starting

Start dashd in regtest mode to create a private block chain.

Text

## Dash Core
dash-cli -regtest generate 101

Generate 101 blocks using a special RPC which is only available in regtest mode. This takes less than a second on a generic PC. Because this is a new block chain using Dash's default rules, the first blocks pay a block reward of 500 dash. Unlike mainnet, in regtest mode only the first 150 blocks pay a reward of 500 dash. However, a block must have 100 confirmations before that reward can be spent, so we generate 101 blocks to get access to the coinbase transaction from block #1.

Bash

dash-cli -regtest getbalance
500.00000000

Verify that we now have 500 dash available to spend.

You can now use Dash Core RPCs prefixed with dash-cli -regtest.

Regtest wallets and block chain state (chainstate) are saved in the regtest subdirectory of the Dash Core configuration directory. You can safely delete the regtest subdirectory and restart Dash Core to start a new regtest. (See the Developer Examples Introduction for default configuration directory locations on various operating systems. Always back up mainnet wallets before performing dangerous operations such as deleting.)

The complete set of regtest-specific arguments can be found on the dashd Arguments and Commands page.

Devnet mode

Overview

Developer networks (devnets) have some aspects of testnet and some aspects of regtest. Unlike testnet, multiple independent devnets can be created and coexist without interference. Devnets can consist of nodes running on the same computer, on a small private network, or distributed across the internet.

Each devnet is identified by a name which is hardened into a "devnet genesis" block that is automatically positioned at height 1. Validation rules ensure that a node from devnet=test1 will not accept blocks from devnet=test2. This is done by checking the expected devnet genesis block. Also, the devnet name is put into the sub-version field of the version message. If a node connects to the wrong network, it will immediately be disconnected.

The genesis block of the devnet is the same as the one from regtest. This starts the devnet with a very low difficulty, allowing quick generation of a sufficient balance to create a masternode.

Configuration

To use devnet, use the argument -devnet=<name> with dash-cli, dashdor dash-qt or add devnet=<name> to your dash.conf file as described earlier.

Devnets must be assigned both -port and -rpcport unless they are not listening (-listen=0). It is possible to run a devnet on a private (RFC1918) network by using the -allowprivatenet=1 argument.

Example devnet start command:

Bash

> dashd -devnet=mydevnet -rpcport=18998 -port=18999 -daemon
Dash Core server starting

Devnet-specific options

Devnets can use 3 devnet-specific options to enable quickly mining large amounts of Dash. This enables quick establishment of test masternodes, etc. The following dash.conf excerpt shows these configuration options in use:

# First 1000 blocks mined with the lowest difficulty (like regtest)
# and first 500 blocks mined with a block subsidity multiplied by 10
# This allows immediate MN registration (DIP3 activates on block 2)
minimumdifficultyblocks=1000
highsubsidyblocks=500
highsubsidyfactor=10

The complete set of devnet-specific arguments can be found on the dashd Arguments and Commands page.

Management

Devnet wallets and block chain state (chainstate) are saved in the devnet-<name> subdirectory of the Dash Core configuration directory. You can safely delete the devnet-<name> subdirectory and restart Dash Core to start a new devnet. (See the Developer Examples Introduction for default configuration directory locations on various operating systems. Always back up mainnet wallets before performing dangerous operations such as deleting.)

An old devnet can be easily dropped and a new one started just by destroying all nodes and recreating them with a new devnet name. This works best in combination with an automated deployment using something like Ansible and Terraform. The Dash Network Deploy tool provides a way to do this.

Network type comparison

Each network type has some unique characteristics to support development and testing. The tables below summarize some of the significant differences between the 4 network types.

Network characteristics

	Mainnet	Testnet	Regtest	Devnet
Public network	Yes	Yes	No	Optional
Private network	No	No	Yes	Optional
Number of networks	1	1	Unlimited	Unlimited / Unique (named)

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Using sporks

To enable or disable sporks on a regtest or devnet, set sporkaddr and sporkkey in the dash.conf config file. Any valid Dash address / private key can be used. You can get an address using the getnewaddress RPC and retrieve its private key using the dumpprivkey RPC.

Mining characteristics

Network Type	Difficulty adjustment algorithm
Testnet	Mainnet algorithm, but allows minimum difficulty blocks if no blocks are created for 5 minutes
Regtest	Mines blocks at the minimum difficulty level
Devnet	Mainnet algorithm after 4001 blocks unless overridden by devnet-specific options

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See chainparams.cpp for details on other differences