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K Semantics of the Ethereum Virtual Machine (EVM)

KEVM: Semantics of EVM in K

In this repository we provide a model of the EVM in K.


These may be useful for learning KEVM and K (newest to oldest):

To get support for KEVM, please join our Riot Room.

Repository Structure

The following files constitute the KEVM semantics:

These additional files extend the semantics to make the repository more useful:


K Backends

There are three backends of K available: LLVM (default) for concrete execution and Java (default) and Haskell for symbolic execution. This repository generates the build-products for each backend in .build/defn/.

System Dependencies

The following are needed for building/running KEVM:

For the exact dependencies check the Dockerfile, but they should look something like this. On Ubuntu >= 18.04 (for example):

sudo apt-get install --yes                                                       \
            autoconf bison clang-8 cmake curl flex gcc jq libboost-test-dev      \
            libcrypto++-dev libffi-dev libgflags-dev libjemalloc-dev libmpfr-dev \
            libprocps-dev libsecp256k1-dev libssl-dev libtool libyaml-dev        \
            lld-8 llvm-8-tools make maven netcat-openbsd openjdk-11-jdk          \
            pkg-config python3 python-pygments python-recommonmark               \
            python-sphinx rapidjson-dev time z3 zlib1g-dev

On Ubuntu < 18.04, you’ll need to skip libsecp256k1-dev and instead build it from source (via our Makefile):

make libsecp256k1

On ArchLinux:

sudo pacman -S                                               \
    base base-devel boost clang cmake crypto++ curl git gmp  \
    gflags jdk-openjdk jemalloc libsecp256k1 lld llvm maven  \
    mpfr python stack yaml-cpp z3 zlib

In addition, you’ll need the glog-git AUR package:

On OSX, using Homebrew, after installing the command line tools package:

brew tap caskroom/cask
brew cask install adoptopenjdk12
brew install automake libtool gmp mpfr pkg-config maven z3 libffi
make libsecp256k1

NOTE: a previous version of these instructions required the user to run brew link flex --force. After fetching this revision, you should first run brew unlink flex, as it is no longer necessary and will cause an error if you have the homebrew version of flex installed instead of the xcode command line tools version.

To upgrade stack (if needed):

stack upgrade
export PATH=$HOME/.local/bin:$PATH

Build Dependencies

K Framework

The Makefile and kevm will work with either a (i) globally installed K, or (ii) a K submodule included in this repository. If you want to use the K submodule, follow these instructions get the submodule and build K:

git submodule update --init --recursive -- deps/k
make k-deps

If you don’t need either the LLVM or Haskell backend, there are flags to skip them:

make k-deps SKIP_LLVM=true SKIP_HASKELL=true

Blockchain Plugin

You also need to get the blockchain plugin submodule and install it.

git submodule update --init --recursive -- deps/plugin
make plugin-deps


Finally, you can build the semantics.

make build

Example Usage

After building the definition, you can run the definition using ./kevm. Read the ./kevm script for examples of the actual invocations of krun that ./kevm makes.

Run the file tests/ethereum-tests/VMTests/vmArithmeticTest/add0.json:

./kevm run tests/ethereum-tests/VMTests/vmArithmeticTest/add0.json

To run proofs, you can similarly use ./kevm. For example, to prove one of the specifications:

./kevm prove tests/specs/erc20/ds/transfer-failure-1-a-spec.k VERIFICATION

Running Tests

The tests are run using the supplied Makefile. First, run make split-tests to generate some of the tests from the markdown files.

The following subsume all other tests:

These are the individual test-suites (all of these can be suffixed with -all to also run slow tests):

When running tests with the Makefile, you can specify the TEST_CONCRETE_BACKEND (for concrete tests), or TEST_SYMBOLIC_BACKEND (for proofs).


This repository can build two pieces of documentation for you, the Jello Paper and the 2017 Devcon3 presentation.

System Dependencies

For the presentations in the media directory, you’ll need pdflatex, commonly provided with texlive-full, and pandoc.

sudo apt install texlive-full pandoc


To build all the PDFs (presentations and reports) available in the media/ directory, use:

make media


For more information about The K Framework, refer to these sources: