Skip to content
develop
Switch branches/tags
Code

Files

Permalink
Failed to load latest commit information.

Ganache

A tool for creating a local blockchain for fast Ethereum development.

FeaturesGetting StartedDocumentationCommunityDockerContributingRelated


Features

Ganache is an Ethereum simulator that makes developing Ethereum applications faster, easier, and safer. It includes all popular RPC functions and features (like events) and can be run deterministically to make development a breeze.

  • Zero-config Mainnet Forking
  • Fork any Ethereum network without waiting to sync
  • Ethereum JSON-RPC support
  • Snapshot/revert state
  • Mine blocks instantly, on demand, or at an interval
  • Fast-forward time
  • Impersonate any account (no private keys required!)
  • Listens for JSON-RPC 2.0 requests over HTTP/WebSockets
  • Programmatic use in Node.js
  • Pending Transactions

Getting Started

Ganache can be used from the command line, programmatically via Node.js, or in the browser.

Command line use

You must first install Node.js >= v10.13.0 and npm >= 6.4.1.

To install Ganache globally, run:

$ npm install ganache --global

In case youe're upgrading from a previous version of Ganache, we've also written up this handy guide on how to upgrade/install Ganache and to document all breaking changes to look out for.

Once installed globally, you can start ganache right from your command line:

$ ganache
Ganache CLI v6.12.1 (ganache-core: 2.13.1)

Available Accounts
==================
(0) 0xe261e26aECcE52b3788Fac9625896FFbc6bb4424 (100 ETH)
(1) 0xcE16e8eb8F4BF2E65BA9536C07E305b912BAFaCF (100 ETH)
(2) 0x02f1c4C93AFEd946Cce5Ad7D34354A150bEfCFcF (100 ETH)
(3) 0x0B75F0b70076Fab3F18F94700Ecaf3B00fE528E7 (100 ETH)
(4) 0x7194d1F1d43c2c58302BB61a224D41B649e65C93 (100 ETH)
(5) 0xC9A2d92c5913eDEAd9a7C936C96631F0F2241063 (100 ETH)
(6) 0xD79BcDE5Cb11cECD1dfC6685B65690bE5b6a611e (100 ETH)
(7) 0xb6D080353f40dEcA2E67108087c356d3A1AfcD64 (100 ETH)
(8) 0x31A064DeeaD74DE7B9453beB4F780416D8859d3b (100 ETH)
(9) 0x37524a360a40C682F201Fb011DB7bbC8c8A247c6 (100 ETH)

Private Keys
==================
(0) 0x7f109a9e3b0d8ecfba9cc23a3614433ce0fa7ddcc80f2a8f10b222179a5a80d6
(1) 0x6ec1f2e7d126a74a1d2ff9e1c5d90b92378c725e506651ff8bb8616a5c724628
(2) 0xb4d7f7e82f61d81c95985771b8abf518f9328d019c36849d4214b5f995d13814
(3) 0x941536648ac10d5734973e94df413c17809d6cc5e24cd11e947e685acfbd12ae
(4) 0x5829cf333ef66b6bdd34950f096cb24e06ef041c5f63e577b4f3362309125863
(5) 0x8fc4bffe2b40b2b7db7fd937736c4575a0925511d7a0a2dfc3274e8c17b41d20
(6) 0xb6c10e2baaeba1fa4a8b73644db4f28f4bf0912cceb6e8959f73bb423c33bd84
(7) 0xfe8875acb38f684b2025d5472445b8e4745705a9e7adc9b0485a05df790df700
(8) 0xbdc6e0a69f2921a78e9af930111334a41d3fab44653c8de0775572c526feea2d
(9) 0x3e215c3d2a59626a669ed04ec1700f36c05c9b216e592f58bbfd3d8aa6ea25f9

HD Wallet
==================
Mnemonic:      candy maple velvet cake sugar cream honey rich smooth crumble sweet treat
Base HD Path:  m/44'/60'/0'/0/{account_index}

Default Gas Price
==================
20000000000

Gas Limit
==================
6721975

Call Gas Limit
==================
9007199254740991

Listening on 127.0.0.1:8545

To install Ganache into an npm project, run:

$ npm install ganache

You can then add Ganache to your package.json scripts:

"scripts": {
  "ganache": "ganache --wallet.seed myCustomSeed"
}

See Documentation for additional command line options.

Then start it:

$ npm run ganache

Programmatic use

You can use Ganache programmatically from Node.js. Install Ganache into your npm package:

$ npm install ganache

Then you can use ganache as an EIP-1193 provider only, an EIP-1193 provider and JSON-RPC web server, as a Web3 provider, or an ethers provider.

As an EIP-1193 provider only:

const ganache = require("ganache");

const options = {};
const provider = ganache.provider(options);
const accounts = await provider.request({ method: "eth_accounts", params: [] });

As an EIP-1193 provider and JSON-RPC web server:

const ganache = require("ganache");

const options = {};
const server = ganache.server(options);
const PORT = 8545;
server.listen(PORT, err => {
  if (err) throw err;

  console.log(`ganache listening on port ${PORT}...`);
  const provider = server.provider;
  const accounts = await provider.request({
    method: "eth_accounts",
    params: []
  });
});

As a web3.js provider:

To use ganache as a Web3 provider:

const Web3 = require("web3");
const ganache = require("ganache");

const web3 = new Web3(ganache.provider());

NOTE: depending on your web3 version, you may need to set a number of confirmation blocks

const web3 = new Web3(ganache.provider(), null, { transactionConfirmationBlocks: 1 });

As an ethers.js provider:

const ganache = require("ganache");

const provider = new ethers.providers.Web3Provider(ganache.provider());

Browser Use

You can also use Ganache in the browser by adding the following script to your HTML:

<script src="https://cdn.jsdelivr.net/npm/ganache@{VERSION}/dist/web/ganache.min.js"></script>

NOTE: the {VERSION} in the above path needs to be replaced with a version number or tag that is listed in npm.

From there, Ganache is available in your browser for use:

const options = {};
const provider = Ganache.provider(options);

NOTE: currently forking does not work in the browser, but we plan to add support in the future.

Documentation

New interactive RPC documentation coming soon! In the meantime, check out our Ethereum JSON-RPC documentation.

Startup Options

The startup options are grouped in the chain, database, fork, logging, miner, and wallet namespaces, and should be used as such on startup, i.e.

ganache --namespace.option="value"

for CLI use, and

const options = { namespace: { option: "value"}};
const provider = ganache.provider(options);

for programmatic use.

The following options are listed for command line use, but can also be used when running Ganache programatically in your project.

Chain:
  --chain.allowUnlimitedContractSize    Allows unlimited contract sizes while debugging. Setting this to true
                                        will cause ganache to behave differently than production environments.
                                                                                    [boolean] [default: false]

  --chain.asyncRequestProcessing        When set to false only one request will be processed at a time.
                                                                                     [boolean] [default: true]

  --chain.chainId                       The currently configured chain id.            [number] [default: 1337]

  -i, --chain.networkId                 The id of the network returned by the RPC method net_version.
                                        deprecated aliases: --networkId
                                                            [number] [default: System time at process start or
                                                               Network ID of forked blockchain if configured.]

  -t, --chain.time                      Date that the first block should start.
                                        deprecated aliases: --time                                    [number]

  -k, --chain.hardfork                  Set the hardfork rules for the EVM.
                                        deprecated aliases: --hardfork
                                               [string] [choices: "constantinople", "byzantium", "petersburg",
                                                 "istanbul", "muirGlacier", "berlin", "london","arrowGlacier"]
                                                                                             [default: london]

  --chain.vmErrorsOnRPCResponse         Whether to report runtime errors from EVM code as RPC errors.
                                                                                    [boolean] [default: false]


Database:
  --database.dbPath                     Specify a path to a directory to save the chain database.
                                        deprecated aliases: --db, --db_path                           [string]

Logging:
  --logging.debug                       Set to true to log EVM opcodes.             [boolean] [default: false]

  -q, --logging.quiet                   Set to true to disable logging.
                                        deprecated aliases: --quiet                 [boolean] [default: false]

  -v, --logging.verbose                 Set to true to log all RPC requests and responses.
                                        deprecated aliases: --verbose               [boolean] [default: false]


Miner:
  -b, --miner.blockTime                 Sets the blockTime in seconds for automatic mining. A blockTime of 0
                                        enables "instamine mode", where new executable transactions will be
                                        mined instantly.
                                        deprecated aliases: --blockTime                  [number] [default: 0]

  -g, --miner.defaultGasPrice           Sets the default gas price in WEI for transactions if not otherwise
                                        specified.
                                        deprecated aliases: --gasPrice          [string] [default: 0x77359400]

  -l, --miner.blockGasLimit             Sets the block gas limit in WEI.
                                        deprecated aliases: --gasLimit            [string] [default: 0xb71b00]

  --miner.defaultTransactionGasLimit    Sets the default transaction gas limit in WEI. Set to "estimate" to
                                        use an estimate (slows down transaction execution by 40%+).
                                                                                   [string] [default: 0x15f90]

  --miner.difficulty                    Sets the block difficulty.                     [string] [default: 0x1]

  --miner.callGasLimit                  Sets the transaction gas limit in WEI for eth_call and eth_estimateGas
                                        calls.
                                                                          [string] [default: 0x1fffffffffffff]
  --miner.instamine                     Set the instamine mode to either "eager" (default) or "strict". In
                                        "eager" mode a transaction will be included in a block before its hash
                                        is returned to the caller. In "strict" mode a transaction's hash is
                                        returned to the caller before the transaction is included in a block.
                                        This value has no effect if `blockTime` is *not* `0` (the default).`
                                                      [string] [choices: "eager", "strict"] [default: "eager"]

  --miner.coinbase                      Sets the address where mining rewards will go.
                                                         [default: 0x0000000000000000000000000000000000000000]

  --miner.extraData                     Set the extraData block header field a miner can include.
                                                                                        [string] [default: 0x]

  --miner.priceBump                     Minimum price bump percentage needed to replace a transaction that
                                        already exists in the transaction pool.         [string] [default: 10]


Wallet:
  --wallet.accounts                     Account data in the form <private_key>,<initial_balance>, can be
                                        specified multiple times. Note that private keys are 64 characters
                                        long and must be entered as an 0x-prefixed hex string. Balance can
                                        either be input as an integer, or as a 0x-prefixed hex string with
                                        either form specifying the initial balance in wei.
                                        deprecated aliases: --account                                  [array]

  -a, --wallet.totalAccounts            Number of accounts to generate at startup.
                                        deprecated aliases: --accounts                  [number] [default: 10]

  -d, --wallet.deterministic            Use pre-defined, deterministic seed.
                                        deprecated aliases: --deterministic         [boolean] [default: false]

  -s, --wallet.seed                     Seed to use to generate a mnemonic.
                                        deprecated aliases: --seed
                                                                                                      [string]
                                             [default: Random value, unless wallet.deterministic is specified]

  -m, --wallet.mnemonic                 Use a specific HD wallet mnemonic to generate initial addresses.
                                        deprecated aliases: --mnemonic                                [string]
                                                                         [default: Generated from wallet.seed]

  -u, --wallet.unlockedAccounts         Array of addresses or address indexes specifying which accounts should
                                        be unlocked.
                                        deprecated aliases: --unlock                                   [array]

  -n, --wallet.lock                     Lock available accounts by default (good for third party transaction
                                        signing).
                                        deprecated aliases: --secure, --lock        [boolean] [default: false]

  --wallet.passphrase                   Passphrase to use when locking accounts.
                                        deprecated aliases: --passphrase                              [string]

  --wallet.accountKeysPath              Specifies a file to save accounts and private keys to, for testing.
                                        deprecated aliases: --account_keys_path, --acctKeys           [string]

  -e, --wallet.defaultBalance           The default account balance, specified in ether.
                                        deprecated aliases: --defaultBalanceEther     [number] [default: 1000]

  --wallet.hdPath                       The hierarchical deterministic path to use when generating accounts.
                                                                            [string] [default: m,44',60',0',0]


Fork:
  -f, --fork.url                        Fork from another currently running Ethereum client at a given block.
                                        Input should be the URL of the node, e.g. "http://localhost:1337". You
                                        can optionally specify the block to fork from using an @ sign:
                                        "http://localhost:1337@8675309".

                                        You can specify Basic Authentication credentials in the URL as well.
                                        e.g., "wss://user:password@example.com/". If you need to use an Infura
                                        Project Secret, you would use it like this:
                                        "wss://:{YOUR-PROJECT-SECRET}@mainnet.infura.com/..."

                                        Alternatively, you can use the fork.username and fork.password
                                        options.
                                        deprecated aliases: --fork

  --fork.network                        A network name to fork from; uses Infura's archive nodes.

                                        Use the shorthand command ganache --fork to automatically fork from
                                        Mainnet at the latest block.
                                        [choices: "mainnet", "ropsten", "kovan", "rinkeby", "goerli", "görli"]

  --fork.blockNumber                    Block number the provider should fork from.
                                                                                [default: Latest block number]

  --fork.preLatestConfirmations         When the fork.blockNumber is set to "latest" (default), the number of
                                        blocks before the remote node's "latest" block to fork from.
                                                                                         [number] [default: 5]

  --fork.username                       Username to use for Basic Authentication. Does not require setting
                                        fork.password.

                                        When combined with fork.password, is shorthand for fork: { headers: {
                                        "Authorization": "Basic {ENCODED-BASIC-HEADER}" } }

                                        If the fork.headers option specifies an "Authorization" header, it
                                        will be be inserted after this Basic token.

  --fork.password                       Password to use for Basic Authentication. Does not require setting
                                        fork.username.

                                        When combined with fork.username, is shorthand for fork: { headers: {
                                        "Authorization": "Basic {ENCODED-BASIC-HEADER}" } }

                                        If the fork.headers option specifies an "Authorization" header, it
                                        will be be inserted after this Basic token.

  --fork.jwt                            Encoded JSON Web Token (JWT) used for authenticating to some servers.

                                        Shorthand for fork:
                                          { headers: { "Authorization": "Bearer {YOUR-ENCODED-JWT}" } }

                                        If the fork.headers option specifies an "Authorization" header, it
                                        will be be inserted after the JWT Bearer token.

  --fork.userAgent                      The User-Agent header sent to the fork on each request.

                                        Sent as Api-User-Agent when used in the browser.

                                        Will be overridden by a "User-Agent" defined in the fork.headers
                                        option, if provided.

                                                                                [default: Ganache/7.0.0-beta.0
                                          (https://www.trufflesuite.com/ganache; ganache<at>trufflesuite.com)]

  --fork.origin                         The Origin header sent to the fork on each request.

                                        Ignored in the browser.

                                        Will be overridden by an "Origin" value defined in the fork.headers
                                        option, if provided.

  --fork.headers                        Headers to supply on each request to the forked provider.

                                        Headers set here override headers set by other options, unless
                                        otherwise specified.

                                                                    Defaults to: ["User-Agent: Ganache/VERSION
                                         (https://www.trufflesuite.com/ganache; ganache<at>trufflesuite.com)"]
                                                                                                       [array]

  --fork.requestsPerSecond              Restrict the number of requests per second sent to the fork provider.
                                        0 means no limit is applied.                     [number] [default: 0]

  --fork.disableCache                   Disables caching of all forking requests.   [boolean] [default: false]

  --fork.deleteCache                    Deletes the persistent cache before starting.
                                                                                    [boolean] [default: false]


Server:
  --server.ws                           Enable a websocket server.                   [boolean] [default: true]

  --server.wsBinary                     Whether or not websockets should response with binary data
                                        (ArrayBuffers) or strings.
                                                                            [choices: "true", "false", "auto"]
                                                                                               [default: auto]

  --server.rpcEndpoint                  Defines the endpoint route the HTTP and WebSocket servers will listen
                                        on.
                                                               [default: "/" (Ethereum), "/rpc/v0" (Filecoin)]

  -h, --server.host                     Hostname to listen on.
                                        deprecated aliases: --host, --hostname
                                                                               [string] [default: "127.0.0.1"]

  -p, --server.port, --port             Port to listen on.
                                        deprecated aliases: --port
                                                                                      [number] [default: 8545]

Ganache Provider Events

In addition to EIP-1193's "message" event and the legacy "data" event, Ganache emits 3 additional events: "ganache:vm:tx:before", "ganache:vm:tx:step", and "ganache:vm:tx:after".

These events can be used to observe the lifecycle of any transaction executed via *sendTransaction, eth_call, debug_traceTransaction, or debug_storageRangeAt.

These share the event paradigm that Truffle uses, but without any of the wildcard handling, i.e., no "vm:*" support (for now).

Each of these events will emit a context object which is a unique object that can be used to identify a transaction over the course of its lifecycle. For example:

interface StepEvent {
  account: {
    nonce: bigint;
    balance: bigint;
    stateRoot: Buffer;
    codeHash: Buffer;
  };
  address: Buffer;
  codeAddress: Buffer;
  depth: number;
  gasLeft: bigint;
  gasRefund: bigint;
  memory: Buffer;
  memoryWordCount: bigint;
  opcode: {
    name: string;
    fee: number;
  };
  pc: number;
  returnStack: Buffer[];
  stack: Buffer[];
}

const contexts = new Map();
provider.on("ganache:vm:tx:before", (event: { context: {} }) => {
  contexts.set(event.context, []);
});
provider.on("ganache:vm:tx:step", (event: StepEvent) => {
  contexts.get(event.context).push(event.data);
});
provider.on("ganache:vm:tx:after", (event: { context: {} }) => {
  doAThingWithThisTransactionsSteps(contexts.get(event.context));
  contexts.delete(event.context);
});

The reason this context is necessary is that Ganache may run multiple transactions simultaneously, so "ganache:vm:tx:step" events from different transactions could be intermingled.

The above events will be emitted for eth_call, *sendTransaction, debug_traceTransaction, and debug_storageRangeAt.

Currently, we do not await the event listener's return value, however, we'll likely enable this in the future.

Community

Docker

The simplest way to get started with the Docker image:

$ docker run --detach --publish 8545:8545 trufflesuite/ganache:rc

To pass options to Ganache through Docker simply add the arguments to the end of the run command, e.g.,

$ docker run --detach --publish 8545:8545 trufflesuite/ganache:latest --accounts 10 --debug
                                                                    ^^^^^^^^^^^^^^^^^^^^^

The Docker container adds an environment variable DOCKER=true; when this variable is set to true (case insensitive), Ganache uses a default hostname IP of 0.0.0.0 instead of the normal default 127.0.0.1. You can still specify a custom hostname however:

$ docker run --detach --publish 8545:8545 trufflesuite/ganache:latest --host XXX.XXX.XXX.XXX
                                                                    ^^^^^^^^^^^^^^^^^^^^^^

To build and run the Docker container from source:

$ git clone https://github.com/trufflesuite/ganache.git && cd ganache

then:

$ docker build --tag trufflesuite/ganache --file ./src/packages/ganache/Dockerfile .
$ docker run --publish 8545:8545 trufflesuite/ganache

Contributing

See CONTRIBUTING.md for our guide to contributing to Ganache.

Related



Truffle