Using Truffle Develop and the Console¶

Sometimes it's nice to work with your contracts interactively for testing and debugging purposes, or for executing transactions by hand. Truffle provides you two easy ways to do this via an interactive console, with your contracts available and ready to use.

Truffle Console: A basic interactive console connecting to any Ethereum client
Truffle Develop: An interactive console that also spawns a development blockchain

Note: Your contract names get loaded as variables into the console context. For this reason it is recommended to avoid names that might conflict with Node's native objects like Buffer or String. For updates see the related issue on GitHub.

Why two different consoles?¶

Having two different consoles allows you to choose the best tool for your needs.

Reasons to use Truffle Console:

You have a client you're already using, such as Ganache or geth
You want to migrate to a testnet (or the main Ethereum network)
You want to use a specific mnemonic or account list

Reasons to use Truffle Develop:

You are testing your project with no intention of immediately deploying
You don't need to work with specific accounts (and you're fine with using default development accounts)
You don't want to install and manage a separate blockchain client

Commands¶

All commands require that you be in your project folder. You do not need to be at the root.

Console¶

To launch the console:

truffle console

This will look for a network definition called development in the configuration, and connect to it, if available. You can override this using the --network <name> option or customize the development network settings. See more details in the Networks section as well as the command reference.

When you load the console, you'll immediately see the following prompt:

truffle(development)>

This tells you you're running within a Truffle console using the development network.

Truffle Develop¶

To launch Truffle Develop:

truffle develop

This will spawn a development blockchain locally on port 9545 by default. If you already have a truffle develop session running, it will instead connect to that development blockchain.

When you load Truffle Develop, you will see the following:

Truffle Develop started at http://localhost:9545/

Accounts:
(0) 0x627306090abab3a6e1400e9345bc60c78a8bef57
(1) 0xf17f52151ebef6c7334fad080c5704d77216b732
(2) 0xc5fdf4076b8f3a5357c5e395ab970b5b54098fef
(3) 0x821aea9a577a9b44299b9c15c88cf3087f3b5544
(4) 0x0d1d4e623d10f9fba5db95830f7d3839406c6af2
(5) 0x2932b7a2355d6fecc4b5c0b6bd44cc31df247a2e
(6) 0x2191ef87e392377ec08e7c08eb105ef5448eced5
(7) 0x0f4f2ac550a1b4e2280d04c21cea7ebd822934b5
(8) 0x6330a553fc93768f612722bb8c2ec78ac90b3bbc
(9) 0x5aeda56215b167893e80b4fe645ba6d5bab767de

Private Keys:
(0) c87509a1c067bbde78beb793e6fa76530b6382a4c0241e5e4a9ec0a0f44dc0d3
(1) ae6ae8e5ccbfb04590405997ee2d52d2b330726137b875053c36d94e974d162f
(2) 0dbbe8e4ae425a6d2687f1a7e3ba17bc98c673636790f1b8ad91193c05875ef1
(3) c88b703fb08cbea894b6aeff5a544fb92e78a18e19814cd85da83b71f772aa6c
(4) 388c684f0ba1ef5017716adb5d21a053ea8e90277d0868337519f97bede61418
(5) 659cbb0e2411a44db63778987b1e22153c086a95eb6b18bdf89de078917abc63
(6) 82d052c865f5763aad42add438569276c00d3d88a2d062d36b2bae914d58b8c8
(7) aa3680d5d48a8283413f7a108367c7299ca73f553735860a87b08f39395618b7
(8) 0f62d96d6675f32685bbdb8ac13cda7c23436f63efbb9d07700d8669ff12b7c4
(9) 8d5366123cb560bb606379f90a0bfd4769eecc0557f1b362dcae9012b548b1e5

Mnemonic: candy maple cake sugar pudding cream honey rich smooth crumble sweet treat

This shows you the addresses, private keys, and mnemonic for this particular blockchain.

Note: When you run truffle develop for the first time, Truffle will generate a random mnemonic that will persist for you and you alone. If you want to use a different mnemonic or set of addresses, we recommend using Ganache.

Warning: Remember to never use any of these addresses or the mnemonic on the mainnet. This is for development only.

Log RPC Activity¶

If you wish to see information regarding RPC activity during your Truffle develop session, you can use the --log option.

When you run truffle develop --log, Truffle will start up a new develop session and output the addresses and keys as described in the previous section. However, in this terminal window you will not be able to interact with the console like you would in a normal Truffle develop session. Instead it will only output the RPC activity occurring on the network. If you want to interact with the console, you will have to open a new terminal window and connect to the current session by running truffle develop.

If you already have a Truffle develop session running and want to log all RPC activity occurring on it, you can run truffle develop --log in a separate terminal window. It will then connect to that session and act the same way as described above.

Configuring Truffle Develop¶

You can configure truffle develop to use any of the available ganache-core options and configurable network settings.

For example:

module.exports = {
  /* ... rest of config */

  networks: {
    /* ... other networks */

    develop: {
      port: 8545,
      network_id: 20,
      accounts: 5,
      defaultEtherBalance: 500,
      blockTime: 3
    }
  }
};

Features¶

Both Truffle Develop and the console provide most of the features available in the Truffle command line tool. For instance, you can type migrate --reset within the console, and it will be interpreted the same as if you ran truffle migrate --reset on the command line.

Additionally, both Truffle Develop and the console have the following features:

All of your compiled contracts are available and ready for use.
After each command (such as migrate --reset) your contracts are reprovisioned so you can start using the newly assigned addresses and binaries immediately.
The web3 library is made available and is set to connect to your Ethereum client.

Commands available¶

build
compile
create
debug
deploy
exec
help
install
migrate
networks
opcode
publish
run
test
version

If a Truffle command is not available, it is because it is not relevant for an existing project (for example, init) wouldn't make sense (for example, develop or console).

See full command reference for more information.