🏃‍♂️Quick Start


The Olac compiler is a single binary. It can be installed in different ways, listed below.

Option 1: Download from Brew

Olac is available on Brew via a private tap. This works only for MacOS systems, both Intel and Apple Silicon. To install Olac via Brew, run the following command:

brew install sin7y/ola/olac

Option 2: Download binaries

There are binaries available on github releases

Download the file and save it somewhere in your $PATH, for example the bin directory in your home directory. If the path you use is not already in $PATH, then you need to add it yourself.

On MacOS, remember to give execution permission to the file and remove it from quarantine by executing the following commands:

chmod +x olac-mac-arm
xattr -d com.apple.quarantine olac-mac-arm

If you are using an Intel based Mac, please, exchange olac-mac-arm by olac-mac-intel in both of the above commands.

On Linux, permission to execute the binary is also necessary, so, please, run chmod +x olac-linux-x86-64.

Option 3: Build Olac from source

In order to build Olac from source, you will need:

  • Rust nightly version 1.72.0 or higher

  • A pre-built LLVM Libraries, version 15.0.7

Step 1: Install Rust

If you do not have the correct version of rust installed, go to rustup.

Step 2: Install the LLVM Libraries

Ola needs a build of LLVM Libraries, You can download the pre-built libraries from github After that, you need to add the bin of your LLVM directory to your path, so that the build system of O la c can find the correct version of LLVM to use.


A pre-built version of LLVM, is available at https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.6/clang+llvm-15.0.6-x86_64-linux-gnu-ubuntu-18.04.tar.xz

wget https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.6/clang+llvm-15.0.6-x86_64-linux-gnu-ubuntu-18.04.tar.xz
tar Jxf clang+llvm-15.0.6-x86_64-linux-gnu-ubuntu-18.04.tar.xz
mv clang+llvm-15.0.6-x86_64-linux-gnu-ubuntu-18.04 llvm15.0

You need to replace your llvm download directory here.

echo 'export PATH=~/llvm15.0/bin:$PATH' >> ~/.bashrc
source ~/.bashrc


For Windows users, the official LLVM does not provide additional tools like llvm-config, which causes Olac to fail to build. Therefore, we provide pre-built versions for Windows. is available at https://github.com/Sin7Y/ola-llvm/releases/download/llvm15-0/llvm15.0-win.zip

After unzipping the file, add the bin directory to your path.

You need to replace your llvm download directory here.

set PATH=%PATH%;C:\llvm15.0\bin


For macOS users, you can download the llvm official build package. A pre-built version of LLVM for intel macs, is available at https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.7/clang+llvm-15.0.7-x86_64-apple-darwin21.0.tar.xz. After downloading, untar the file in a terminal and add it to your path like so:

wget https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.7/clang+llvm-15.0.7-x86_64-apple-darwin21.0.tar.xz
tar Jxf clang+llvm-15.0.7-x86_64-apple-darwin21.0.tar.xz
mv clang+llvm-15.0.7-x86_64-apple-darwin21.0 llvm15.0
xattr -rd com.apple.quarantine llvm15.0 

arm macs there is https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.7/clang+llvm-15.0.7-arm64-apple-darwin22.0.tar.xz After downloading, untar the file in a terminal and add it to your path like so:

wget  https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.7/clang+llvm-15.0.7-arm64-apple-darwin22.0.tar.xz
tar Jxf clang+llvm-15.0.7-arm64-apple-darwin22.0.tar.xz
mv clang+llvm-15.0.7-arm64-apple-darwin22.0 llvm15.0
xattr -rd com.apple.quarantine llvm15.0 

You need to replace your llvm download directory here.

echo 'export PATH=~/Downloads/llvm15.0/bin:$PATH' >> ~/.bash_profile
source ~/.bash_profile

After you finish installing LLVM, you should try the llvm-config command to check if the output version is correct.

llvm-config --version

Step 3: Build Olac

Once you have the correct LLVM version in your path, simply run:

git clone https://github.com/Sin7Y/ola-lang
cd ola-lang
cargo build --release

If you encounter the following error message, then you need to check if llvm is installed correctly and if the llvm-config command can be executed correctly.

error: No suitable version of LLVM was found system-wide or pointed to by LLVM_SYS_150_PREFIX.

          Consider using `llvmenv` to compile an appropriate copy of LLVM, and
          refer to the llvm-sys documentation for more information.
          llvm-sys: https://crates.io/crates/llvm-sys
          llvmenv: https://crates.io/crates/llvmenv

After you ensure that the LLVM environment variable is configured, you can clean the cargo build cache and re-build.

cargo clean
cargo build --release

The executable will be in target/release/olac

Alternative step 3: Build Olac from crates.io

The latest Ola release is on crates.io. Once you have the correct LLVM version in your path, ensure you have GNU make installed and simply run:

cargo install olac

Using olac on the command line

The olac compiler is run on the command line. The ola source file names are provided as command line arguments; the output is an optimized asm file and anabi file (also known as the abi).

Compiler Usage

olac compile [OLA SOURCE FILE] ... [OPTIONS]…

Assuming there is a Fibonacci sequence contract, the command to compile this contract is:

olac compile fib.ola

The above command will generate the files fib_abi.json and fib_asm.json.

Ola supports some debug mode options. This means that the command line is olac compile followed by any options described below, followed by one source file.


--gen phase

This option is can be used for debugging Olac itself. This is used to output early phases of compilation.

  • abi Ouput Ola contract's ABI information

  • ast Output Abstract Syntax Tree as a graphviz dot file. This can be viewed with xdot or any other tool that can visualize graphviz dot files.

  • llvm-ir Output llvm IR as text.

  • asm Output assembly text file.

Write Ola using an IDE

Ola supports writing on vscode, we have developed an extension to vscode to support ola syntax highlighting, and we will continue to improve the plugin in the future.

The extension can be found on the Visual Studio Marketplace.

Hello Ola

After configuring the above environment, we can happily write Ola smart contracts named fib.ola on vscode with ola extension. The following is an example of a Fibonacci sequence.

contract Fibonacci {

    fn fib_recursive(u32 n) -> (u32) {
        if (n <= 2) {
            return 1;
        return fib_recursive(n -1) + fib_recursive(n -2);

    fn fib_non_recursive(u32 n) -> (u32) {
        u32 first = 0;
        u32 second = 1;
        u32 third = 1;
        for (u32 i = 2; i <= n; i++) {
             third = first + second;
             first = second;
             second = third;
        return third;


Compile this contract next.

olac compile fib.ola

The above command will generate the files fib_abi.json and fib_asm.json. fib_abi.json is the ABI file of the contract, which will be used by ola-sdk to build contract request transactions. fib_asm.json is the assembly form of the contract source code, used for contract deployment and invocation.

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