@ethereumjs/evm/README.md

JavaScript Ethereum Virtual Machine (EVM) implementation

# @ethereumjs/evm `v10`

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| TypeScript implementation of the Ethereum EVM. |
| ---------------------------------------------- |

- 🦄 All hardforks up till **Pectra**
- 🌴 Tree-shakeable API
- 👷🏼 Controlled dependency set (7 external + `@Noble` crypto)
- 🧩 Flexible EIP on/off engine
- 🛠️ Custom precompiles
- 🚀 Build-in profiler
- 🪢 User-friendly colored debugging
- 🛵 422KB bundle size (110KB gzipped)
- 🏄🏾‍♂️ WASM-free default + Fully browser ready

## Table of Contents

- [Installation](#installation)
- [Getting Started](#getting-started)
- [Examples](#examples)
- [Browser](#browser)
- [API](#api)
- [Architecture](#architecture)
- [Supported Hardforks](#supported-hardforks)
- [Supported EIPs](#supported-eips)
- [Precompiles](#precompiles)
- [Events](#events)
- [Understanding the EVM](#understanding-the-evm)
- [Profiling the EVM](#profiling-the-evm)
- [Development](#development)
- [EthereumJS](#ethereumjs)
- [License](#license)


## Installation

To obtain the latest version, simply require the project using `npm`:

```shell
npm install @ethereumjs/evm
```

This package provides the core Ethereum Virtual Machine (EVM) implementation which is capable of executing EVM-compatible bytecode. The package has been extracted from the [@ethereumjs/vm](https://github.com/ethereumjs/ethereumjs-monorepo/tree/master/packages/vm) package along the VM `v6` release.

**Note:** Starting with the Dencun hardfork `EIP-4844` related functionality has become an integrated part of the EVM functionality with the activation of the point evaluation precompile. For this precompile to work a separate installation of the KZG library is necessary (we decided not to bundle due to large bundle sizes), see [KZG Setup](https://github.com/ethereumjs/ethereumjs-monorepo/tree/master/packages/tx/README.md#kzg-setup) for instructions.

## Getting Started

### Basic

The following is the simplest example for an EVM instantiation with reasonable defaults for state and blockchain information (like blockhashes):

```ts
// ./examples/simple.ts

import { createEVM } from '@ethereumjs/evm'
import { hexToBytes } from '@ethereumjs/util'

const main = async () => {
  const evm = await createEVM()
  const res = await evm.runCode({ code: hexToBytes('0x6001') }) // PUSH1 01 -- simple bytecode to push 1 onto the stack
  console.log(res.executionGasUsed) // 3n
}

void main()
```

### Blockchain, State and Events

If the EVM should run on a certain state an `@ethereumjs/statemanager` is needed. An `@ethereumjs/blockchain` instance can be passed in to provide access to external interface information like a blockhash:

```ts
// ./examples/withBlockchain.ts

import { createBlockchain } from '@ethereumjs/blockchain'
import { Common, Hardfork, Mainnet } from '@ethereumjs/common'
import { createEVM } from '@ethereumjs/evm'
import { MerkleStateManager } from '@ethereumjs/statemanager'
import { bytesToHex, hexToBytes } from '@ethereumjs/util'

import type { PrefixedHexString } from '@ethereumjs/util'

const main = async () => {
  const common = new Common({ chain: Mainnet, hardfork: Hardfork.Shanghai })
  const stateManager = new MerkleStateManager()
  const blockchain = await createBlockchain()

  const evm = await createEVM({
    common,
    stateManager,
    blockchain,
  })

  const STOP = '00'
  const ADD = '01'
  const PUSH1 = '60'

  // Note that numbers added are hex values, so '20' would be '32' as decimal e.g.
  const code = [PUSH1, '03', PUSH1, '05', ADD, STOP]

  evm.events.on('step', function (data) {
    // Note that data.stack is not immutable, i.e. it is a reference to the vm's internal stack object
    console.log(`Opcode: ${data.opcode.name}\tStack: ${data.stack}`)
  })

  const results = await evm.runCode({
    code: hexToBytes(('0x' + code.join('')) as PrefixedHexString),
    gasLimit: BigInt(0xffff),
  })

  console.log(`Returned: ${bytesToHex(results.returnValue)}`)
  console.log(`gasUsed: ${results.executionGasUsed.toString()}`)
}

void main()
```

Additionally this usage example shows the use of events to listen on the inner workings and procedural updates
(`step` event) of the EVM.

### WASM Crypto Support

This library by default uses JavaScript implementations for the basic standard crypto primitives like hashing or signature verification (for included txs). See `@ethereumjs/common` [README](https://github.com/ethereumjs/ethereumjs-monorepo/tree/master/packages/common) for instructions on how to replace with e.g. a more performant WASM implementation by using a shared `common` instance.

## Examples

See the [examples](./examples/) folder for different meaningful examples on how to use the EVM package and invoke certain aspects of it, e.g. running a bytecode snippet, listening to events or activate an EVM with a certain EIP for experimental purposes.

## Browser

We provide hybrid ESM/CJS builds for all our libraries. With the v10 breaking release round from Spring 2025, all libraries are "pure-JS" by default and we have eliminated all hard-wired WASM code. Additionally we have substantially lowered the bundle sizes, reduced the number of dependencies, and cut out all usages of Node.js-specific primitives (like the Node.js event emitter).

It is easily possible to run a browser build of one of the EthereumJS libraries within a modern browser using the provided ESM build. For a setup example see [./examples/browser.html](./examples/browser.html).

## API

### Docs

For documentation on `EVM` instantiation, exposed API and emitted `events` see generated [API docs](./docs/README.md).

### Hybrid CJS/ESM Builds

With the breaking releases from Summer 2023 we have started to ship our libraries with both CommonJS (`cjs` folder) and ESM builds (`esm` folder), see `package.json` for the detailed setup.

If you use an ES6-style `import` in your code files from the ESM build will be used:

```ts
import { EthereumJSClass } from '@ethereumjs/[PACKAGE_NAME]'
```

If you use Node.js specific `require`, the CJS build will be used:

```ts
const { EthereumJSClass } = require('@ethereumjs/[PACKAGE_NAME]')
```

Using ESM will give you additional advantages over CJS beyond browser usage like static code analysis / Tree Shaking which CJS can not provide.

## Architecture

### VM/EVM Relation

This package contains the inner Ethereum Virtual Machine core functionality which was included in the [@ethereumjs/vm](https://github.com/ethereumjs/ethereumjs-monorepo/tree/master/packages/vm) package up till v5 and has been extracted along the v6 release.

This will make it easier to customize the inner EVM, which can now be passed as an optional argument to the outer `VM` instance.

### State and Blockchain Information

For the EVM to properly work it needs access to a respective execution environment (to e.g. request on information like block hashes) as well as the connection to an outer account and contract state.

With the v2 release EVM, VM and StateManager have been substantially reworked in this regard, see PR [#2649](https://github.com/ethereumjs/ethereumjs-monorepo/pull/2649/) and PR [#2702](https://github.com/ethereumjs/ethereumjs-monorepo/pull/2702) for further deepening context.

The interfaces (in a non-TypeScript sense) between these packages have been simplified and the `EEI` package has been completely removed. Most of the EEI related logic is now either handled internally or more generic functionality being taken over by the `@ethereumjs/statemanager` package.

This allows for both a standalone EVM instantiation with reasonable defaults as well as for a simplified EVM -> VM passing if a customized EVM is needed.

## Supported Hardforks

The EthereumJS EVM implements all hardforks from `Frontier` (`chainstart`) up to the latest active mainnet hardfork.

Currently the following hardfork rules are supported:

- `chainstart` (a.k.a. Frontier)
- `homestead`
- `tangerineWhistle`
- `spuriousDragon`
- `byzantium`
- `constantinople`
- `petersburg`
- `istanbul`
- `muirGlacier` (only `mainnet`)
- `berlin` (`v5.2.0`+)
- `london` (`v5.4.0`+)
- `arrowGlacier` (only `mainnet`) (`v5.6.0`+)
- `merge`
- `shanghai` (`v2.0.0`+)
- `cancun` (`v2.0.0`+)
- `prague` (`v10`+)

Default: `prague` (taken from `Common.DEFAULT_HARDFORK`)

A specific hardfork EVM ruleset can be activated by passing in the hardfork
along the `Common` instance to the outer `@ethereumjs/vm` instance.

## Supported EIPs

If you want to activate an EIP not currently active on the hardfork your `common` instance is set to, it is possible to individually activate EIP support in the EVM by specifying the desired EIPs using the `eips` property in your `CommonOpts` setup, e.g.:

```ts
// ./examples/eips.ts

import { Common, Hardfork, Mainnet } from '@ethereumjs/common'
import { createEVM } from '@ethereumjs/evm'

const main = async () => {
  const common = new Common({ chain: Mainnet, hardfork: Hardfork.Cancun, eips: [7702] })
  const evm = await createEVM({ common })
  console.log(`EIP 7702 is active in isolation on top of the Cancun HF - ${evm.common.isActivatedEIP(7702)}`)
}

void main()
```

Currently supported EIPs:

- [EIP-1153](https://eips.ethereum.org/EIPS/eip-1153) - Transient storage opcodes (Cancun)
- [EIP-1559](https://eips.ethereum.org/EIPS/eip-1559) - Fee market change for ETH 1.0 chain
- [EIP-2537](https://eips.ethereum.org/EIPS/eip-2537) - Precompile for BLS12-381 curve operations (Prague)
- [EIP-2565](https://eips.ethereum.org/EIPS/eip-2565) - ModExp gas cost
- [EIP-2718](https://eips.ethereum.org/EIPS/eip-2718) - Transaction Types
- [EIP-2935](https://eips.ethereum.org/EIPS/eip-2935) - Serve historical block hashes in state (Prague)
- [EIP-2929](https://eips.ethereum.org/EIPS/eip-2929) - gas cost increases for state access opcodes
- [EIP-2930](https://eips.ethereum.org/EIPS/eip-2930) - Optional access list tx type
- [EIP-3074](https://eips.ethereum.org/EIPS/eip-3074) - AUTH and AUTHCALL opcodes
- [EIP-3198](https://eips.ethereum.org/EIPS/eip-3198) - Base fee Opcode
- [EIP-3529](https://eips.ethereum.org/EIPS/eip-3529) - Reduction in refunds
- [EIP-3541](https://eips.ethereum.org/EIPS/eip-3541) - Reject new contracts starting with the 0xEF byte
- [EIP-3554](https://eips.ethereum.org/EIPS/eip-3554) - Difficulty Bomb Delay to December 2021 (only PoW networks)
- [EIP-3607](https://eips.ethereum.org/EIPS/eip-3607) - Reject transactions from senders with deployed code
- [EIP-3651](https://eips.ethereum.org/EIPS/eip-3651) - Warm COINBASE (Shanghai)
- [EIP-3675](https://eips.ethereum.org/EIPS/eip-3675) - Upgrade consensus to Proof-of-Stake
- [EIP-3855](https://eips.ethereum.org/EIPS/eip-3855) - Push0 opcode (Shanghai)
- [EIP-3860](https://eips.ethereum.org/EIPS/eip-3860) - Limit and meter initcode (Shanghai)
- [EIP-4345](https://eips.ethereum.org/EIPS/eip-4345) - Difficulty Bomb Delay to June 2022
- [EIP-4399](https://eips.ethereum.org/EIPS/eip-4399) - Supplant DIFFICULTY opcode with PREVRANDAO (Merge)
- [EIP-4788](https://eips.ethereum.org/EIPS/eip-4788) - Beacon block root in the EVM (Cancun)
- [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844) - Shard Blob Transactions (Cancun)
- [EIP-4895](https://eips.ethereum.org/EIPS/eip-4895) - Beacon chain push withdrawals as operations (Shanghai)
- [EIP-5133](https://eips.ethereum.org/EIPS/eip-5133) - Delaying Difficulty Bomb to mid-September 2022 (Gray Glacier)
- [EIP-5656](https://eips.ethereum.org/EIPS/eip-5656) - MCOPY - Memory copying instruction (Cancun)
- [EIP-6110](https://eips.ethereum.org/EIPS/eip-6110) - Supply validator deposits on chain (Prague)
- [EIP-6780](https://eips.ethereum.org/EIPS/eip-6780) - SELFDESTRUCT only in same transaction (Cancun)
- [EIP-7002](https://eips.ethereum.org/EIPS/eip-7002) - Execution layer triggerable exits (Prague)
- [EIP-7251](https://eips.ethereum.org/EIPS/eip-7251) - Increase the MAX_EFFECTIVE_BALANCE (Prague)
- [EIP-7516](https://eips.ethereum.org/EIPS/eip-7516) - BLOBBASEFEE opcode (Cancun)
- [EIP-7623](https://eips.ethereum.org/EIPS/eip-7623) - Increase calldata cost (Prague)
- [EIP-7685](https://eips.ethereum.org/EIPS/eip-7685) - General purpose execution layer requests (Prague)
- [EIP-7691](https://eips.ethereum.org/EIPS/eip-7691) - Blob throughput increase (Prague)
- [EIP-7692](https://eips.ethereum.org/EIPS/eip-7692) - EVM Object Format (EOF) v1 (`experimental`)
- [EIP-7702](https://eips.ethereum.org/EIPS/eip-7702) - Set EOA account code (Prague)
- [EIP-7709](https://eips.ethereum.org/EIPS/eip-7709) - Read BLOCKHASH from storage and update cost (Verkle)

### EIP-4844 Shard Blob Transactions Support (Cancun)

This library supports the blob transaction type introduced with [EIP-4844](https://eips.ethereum.org/EIPS/eip-4844). EIP-4844 comes with a dedicated opcode `BLOBHASH` and has added a new point evaluation precompile at address `0x0a`.

**Note:** Usage of the point evaluation precompile needs a manual KZG library installation and global initialization, see [KZG Setup](https://github.com/ethereumjs/ethereumjs-monorepo/tree/master/packages/tx/README.md#kzg-setup) for instructions.

## Precompiles

This library support all EVM precompiles up to the `Prague` hardfork.

The following code allows to run precompiles in isolation, e.g. for testing purposes:

```ts
// ./examples/precompile.ts

import { Common, Hardfork, Mainnet } from '@ethereumjs/common'
import { createEVM, getActivePrecompiles } from '@ethereumjs/evm'
import { bytesToHex, hexToBytes } from '@ethereumjs/util'

const main = async () => {
  const common = new Common({ chain: Mainnet, hardfork: Hardfork.Prague })

  // Taken from test/eips/precompiles/bls/add_G1_bls.json
  const data = hexToBytes(
    '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',
  )
  const gasLimit = BigInt(5000000)

  const evm = await createEVM({ common })
  const precompile = getActivePrecompiles(common).get('000000000000000000000000000000000000000b')!

  const callData = {
    data,
    gasLimit,
    common,
    _EVM: evm,
  }
  const result = await precompile(callData)
  console.log(`Precompile result:${bytesToHex(result.returnValue)}`)
}

void main()
```

### EIP-2537 BLS Precompiles (Prague)

Starting with `v10` the EVM supports the BLS precompiles introduced with [EIP-2537](https://eips.ethereum.org/EIPS/eip-2537) in its final version introduced with the `Prague` hardfork. These precompiles run natively using the [@noble/curves](https://github.com/paulmillr/noble-curves) library (❤️ to `@paulmillr`!).

An alternative WASM implementation (using [bls-wasm](https://github.com/herumi/bls-wasm)) can be optionally used like this if needed for performance reasons:

```ts
import { EVM, MCLBLS } from '@ethereumjs/evm'

const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.Prague })
await mcl.init(mcl.BLS12_381)
const mclbls = new MCLBLS(mcl)
const evm = await createEVM({ common, bls })
```

## Events

### Tracing Events

The EVM emits events that support async listeners (using [EventEmitter3](https://github.com/primus/eventemitter3)).

You can subscribe to the following events:

- `beforeMessage`: Emits a `Message` right after running it.
- `afterMessage`: Emits an `EVMResult` right after running a message.
- `step`: Emits an `InterpreterStep` right before running an EVM step.
- `newContract`: Emits a `NewContractEvent` right before creating a contract. This event contains the deployment code, not the deployed code, as the creation message may not return such a code.

#### Event listeners

You can perform asynchronous operations from within an event handler
and prevent the EVM to keep running until they finish.

If subscribing to events with an async listener, specify the second
parameter of your listener as a `resolve` function that must be called once your listener code has finished.

See below for example usage:

```ts
// ./examples/eventListener.ts#L7-L14

evm.events.on('beforeMessage', (event) => {
  console.log('synchronous listener to beforeMessage', event)
})
evm.events.on('afterMessage', (event, resolve) => {
  console.log('asynchronous listener to beforeMessage', event)
  // we need to call resolve() to avoid the event listener hanging
  resolve?.()
})
```

If an exception is passed to that function, or thrown from within the
handler or a function called by it, the exception will bubble into the
EVM and interrupt it, possibly corrupting its state. It's strongly
recommended not to do that.

## Understanding the EVM

If you want to understand your EVM runs we have added a hierarchically structured list of debug loggers for your convenience which can be activated in arbitrary combinations. We also use these loggers internally for development and testing. These loggers use the [debug](https://github.com/visionmedia/debug) library and can be activated on the CL with `DEBUG=ethjs,[Logger Selection] node [Your Script to Run].js` and produce output like the following:

![EthereumJS EVM Debug Logger](./debug.png?raw=true)

The following loggers are currently available:

| Logger                             | Description                                         |
| ---------------------------------- | --------------------------------------------------- |
| `evm:evm`                          |  EVM control flow, CALL or CREATE message execution |
| `evm:gas`                          |  EVM gas logger                                     |
| `evm:precompiles`                  |  EVM precompiles logger                             |
| `evm:journal`                      |  EVM journal logger                                 |
| `evm:ops`                          |  Opcode traces                                      |
| `evm:ops:[Lower-case opcode name]` | Traces on a specific opcode                         |

Here are some examples for useful logger combinations.

Run one specific logger:

```shell
DEBUG=ethjs,evm tsx test.ts
```

Run all loggers currently available:

```shell
DEBUG=ethjs,evm:*,evm:*:* tsx test.ts
```

Run only the gas loggers:

```shell
DEBUG=ethjs,evm:*:gas tsx test.ts
```

Excluding the ops logger:

```shell
DEBUG=ethjs,evm:*,evm:*:*,-evm:ops tsx test.ts
```

Run some specific loggers including a logger specifically logging the `SSTORE` executions from the EVM (this is from the screenshot above):

```shell
DEBUG=ethjs,evm,evm:ops:sstore,evm:*:gas tsx test.ts
```

`ethjs` **must** be included in the `DEBUG` environment variables to enable **any** logs.
Additional log selections can be added with a comma separated list (no spaces). Logs with extensions can be enabled with a colon `:`, and `*` can be used to include all extensions.

`DEBUG=ethjs,evm:journal,evm:ops:* npx vitest test/runCall.spec.ts`

### Internal Structure

The EVM processes state changes at many levels.

- **runCall**
  - checkpoint state
  - transfer value
  - load code
  - runCode
  - materialize created contracts
  - revert or commit checkpoint
- **runCode**
  - iterate over code
  - run op codes
  - track gas usage
- **OpFns**
  - run individual op code
  - modify stack
  - modify memory
  - calculate fee

The opFns for `CREATE`, `CALL`, and `CALLCODE` call back up to `runCall`.

TODO: this section likely needs an update.

## Profiling the EVM

The EthereumJS EVM comes with build-in profiling capabilities to detect performance bottlenecks and to generally support the targeted evolution of the JavaScript EVM performance.

While the EVM has a dedicated `profiler` setting to activate, the profiler can best and most useful be run through the EthereumJS [client](https://github.com/ethereumjs/ethereumjs-monorepo/tree/master/packages/client) since this gives the most realistic conditions providing both real-world txs and a meaningful state size.

To repeatedly run the EVM profiler within the client sync the client on mainnet or a larger testnet to the desired block. Then the profiler should be run without sync (to not distort the results) by using the `--executeBlocks` and the `--vmProfileBlocks` (or `--vmProfileTxs`) flags in conjunction like:

```shell
npm run client:start -- --sync=none --vmProfileBlocks --executeBlocks=962720
```

This will give a profile output like the following:

![EthereumJS EVM Profiler](./profiler.png?raw=true)

The `total (ms)` column gives you a good overview what takes the most significant amount of time, to be put in relation with the number of calls.

The number to optimize for is the `Mgas/s` value. This value indicates how much gas (being a measure for the computational cost for an opcode) can be processed by the second.

A good measure to putting this relation with is by taking both the Ethereum gas limit (the max amount of "computation" per block) and the time/slot into account. With a gas limit of 30 Mio and a 12 sec slot time this leads to a following (very) minimum `Mgas/s` value:

```shell
30M / 12 sec = 2.5 Million gas per second
```

Note that this is nevertheless a very theoretical value but pretty valuable for some first rough orientation though.

Another note: profiler results for at least some opcodes are heavily distorted, first to mention the `SSTORE` opcode where the major "cost" occurs after block execution on checkpoint commit, which is not taken into account by the profiler.

Generally all results should rather encourage and need "self thinking" 😋 and are not suited to be blindly taken over without a deeper understanding/grasping of the underlying measurement conditions.

Happy EVM Profiling! 🎉 🤩

## Development

See [@ethereumjs/vm](https://github.com/ethereumjs/ethereumjs-monorepo/tree/master/packages/vm) README.

## EthereumJS

See our organizational [documentation](https://ethereumjs.readthedocs.io) for an introduction to `EthereumJS` as well as information on current standards and best practices. If you want to join for work or carry out improvements on the libraries, please review our [contribution guidelines](https://ethereumjs.readthedocs.io/en/latest/contributing.html) first.

## License

[MPL-2.0](<https://tldrlegal.com/license/mozilla-public-license-2.0-(mpl-2)>)

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