> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/Privacy-Cash/privacy-cash/llms.txt
> Use this file to discover all available pages before exploring further.

# Installation

> Set up your development environment for Privacy Cash

## Overview

This guide covers installing all dependencies needed to build and run Privacy Cash from source. If you're integrating Privacy Cash into an existing project, see the [Privacy Cash SDK](https://github.com/Privacy-Cash/privacy-cash-sdk) instead.

## System requirements

<CardGroup cols={2}>
  <Card title="Operating system" icon="computer">
    Linux, macOS, or Windows with WSL2
  </Card>

  <Card title="RAM" icon="memory">
    8GB minimum, 16GB recommended
  </Card>

  <Card title="Disk space" icon="hard-drive">
    At least 10GB free space
  </Card>

  <Card title="Internet" icon="wifi">
    Required for downloading dependencies
  </Card>
</CardGroup>

## Install Solana CLI

<Steps>
  <Step title="Download and install Solana CLI">
    Install version 2.1.18 or later:

    ```bash theme={null}
    sh -c "$(curl -sSfL https://release.solana.com/v2.1.18/install)"
    ```
  </Step>

  <Step title="Add Solana to your PATH">
    Add this to your shell profile (`~/.bashrc`, `~/.zshrc`, etc.):

    ```bash theme={null}
    export PATH="$HOME/.local/share/solana/install/active_release/bin:$PATH"
    ```

    Then reload your shell:

    ```bash theme={null}
    source ~/.bashrc  # or source ~/.zshrc
    ```
  </Step>

  <Step title="Verify installation">
    ```bash theme={null}
    solana --version
    ```

    You should see output like:

    ```
    solana-cli 2.1.18 (src:00000000; feat:1234567890)
    ```
  </Step>
</Steps>

<Note>
  Privacy Cash requires Solana CLI 2.1.18 or later for compatibility with the latest program features.
</Note>

## Install Rust

<Steps>
  <Step title="Install Rust using rustup">
    ```bash theme={null}
    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
    ```

    Follow the prompts to complete installation.
  </Step>

  <Step title="Install Rust 1.79.0">
    Privacy Cash requires Rust 1.79.0 or a compatible version:

    ```bash theme={null}
    rustup install 1.79.0
    rustup default 1.79.0
    ```
  </Step>

  <Step title="Verify Rust installation">
    ```bash theme={null}
    rustc --version
    cargo --version
    ```

    You should see:

    ```
    rustc 1.79.0 (129f3b996 2024-06-10)
    cargo 1.79.0 (ffa9cf99a 2024-06-03)
    ```
  </Step>
</Steps>

## Install Anchor

<Steps>
  <Step title="Install Anchor version manager (avm)">
    ```bash theme={null}
    cargo install --git https://github.com/coral-xyz/anchor avm --locked --force
    ```
  </Step>

  <Step title="Install Anchor 0.31.1">
    ```bash theme={null}
    avm install 0.31.1
    avm use 0.31.1
    ```
  </Step>

  <Step title="Verify Anchor installation">
    ```bash theme={null}
    anchor --version
    ```

    You should see:

    ```
    anchor-cli 0.31.1
    ```
  </Step>
</Steps>

<Warning>
  Privacy Cash is built with Anchor 0.31.1. Using a different version may cause compilation errors.
</Warning>

## Install Node.js and npm

<Steps>
  <Step title="Install Node.js 16 or later">
    Using nvm (recommended):

    ```bash theme={null}
    curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh | bash
    source ~/.bashrc  # or source ~/.zshrc
    nvm install 18
    nvm use 18
    ```

    Or download directly from [nodejs.org](https://nodejs.org/).
  </Step>

  <Step title="Verify Node.js and npm">
    ```bash theme={null}
    node --version
    npm --version
    ```

    You should see:

    ```
    v18.x.x
    9.x.x
    ```
  </Step>
</Steps>

## Install Circom

Circom is required to work with zero-knowledge circuits.

<Steps>
  <Step title="Install dependencies">
    <Tabs>
      <Tab title="Ubuntu/Debian">
        ```bash theme={null}
        sudo apt-get install build-essential libgmp-dev libsodium-dev nasm git
        ```
      </Tab>

      <Tab title="macOS">
        ```bash theme={null}
        brew install gmp libsodium nasm
        ```
      </Tab>
    </Tabs>
  </Step>

  <Step title="Download and install Circom v2.2.2">
    ```bash theme={null}
    git clone https://github.com/iden3/circom.git
    cd circom
    git checkout v2.2.2
    cargo build --release
    cargo install --path circom
    ```
  </Step>

  <Step title="Verify Circom installation">
    ```bash theme={null}
    circom --version
    ```

    You should see:

    ```
    circom compiler 2.2.2
    ```
  </Step>
</Steps>

<Info>
  Circom is used to compile the zero-knowledge circuits in the `circuits/` directory. The compiled artifacts are already included in `artifacts/circuits/`, so you only need Circom if you're modifying circuits.
</Info>

## Install project dependencies

Once all system tools are installed, set up the Privacy Cash project:

<Steps>
  <Step title="Clone the repository">
    ```bash theme={null}
    git clone https://github.com/Privacy-Cash/privacy-cash.git
    cd privacy-cash/anchor
    ```
  </Step>

  <Step title="Install npm dependencies">
    The project uses yarn as the package manager (configured in `Anchor.toml`):

    ```bash theme={null}
    yarn install
    ```

    Or if using npm:

    ```bash theme={null}
    npm install
    ```

    This installs all required packages including:

    * `@coral-xyz/anchor` - Anchor framework client
    * `@solana/spl-token` - SPL token utilities
    * `snarkjs` - Zero-knowledge proof library
    * `@lightprotocol/hasher.rs` - Poseidon hash implementation
    * `circomlib` - Circuit library
  </Step>

  <Step title="Build the program">
    ```bash theme={null}
    anchor build
    ```

    This compiles the Rust program and generates TypeScript types.
  </Step>
</Steps>

## Verify installation

Run the test suite to ensure everything is working:

```bash theme={null}
npm run test:sol
```

You should see output indicating tests are passing:

```
zkcash
  ✓ Double spend attack fails (15234ms)
  ✓ Can execute both deposit and withdraw instruction for correct input, with positive fee (18567ms)
  ✓ Can execute both deposit and withdraw instruction to PDA recipient, with positive fee (17891ms)

3 passing (52s)
```

<Note>
  The first test run may take longer as it compiles the circuits and generates proving keys.
</Note>

## Package versions

For reference, here are the exact package versions used by Privacy Cash:

<Accordion title="View package.json dependencies">
  ```json theme={null}
  {
    "dependencies": {
      "@coral-xyz/anchor": "^0.31.0",
      "@solana/spl-token": "^0.4.14",
      "circomlib": "^2.0.5",
      "ffjavascript": "^0.3.1"
    },
    "devDependencies": {
      "@ethersproject/sha2": "^5.8.0",
      "@lightprotocol/hasher.rs": "^0.2.1",
      "@types/bn.js": "^5.1.0",
      "@types/chai": "^4.3.0",
      "@types/mocha": "^9.0.0",
      "bn.js": "^5.2.2",
      "borsh": "^2.0.0",
      "chai": "^4.3.4",
      "ethers": "^6.13.7",
      "mocha": "^9.0.3",
      "prettier": "^2.6.2",
      "snarkjs": "^0.7.5",
      "tmp-promise": "^3.0.2",
      "ts-mocha": "^10.0.0",
      "typescript": "^5.7.3"
    }
  }
  ```
</Accordion>

## Troubleshooting

<AccordionGroup>
  <Accordion title="Anchor build fails with 'rustc version mismatch'">
    Ensure you're using Rust 1.79.0:

    ```bash theme={null}
    rustup default 1.79.0
    ```

    Clean and rebuild:

    ```bash theme={null}
    anchor clean
    anchor build
    ```
  </Accordion>

  <Accordion title="npm install fails on @lightprotocol/hasher.rs">
    This package requires Rust to build native modules. Ensure you have:

    1. Rust installed and in your PATH
    2. Build tools installed (gcc, make, etc.)

    On Ubuntu/Debian:

    ```bash theme={null}
    sudo apt-get install build-essential
    ```

    On macOS:

    ```bash theme={null}
    xcode-select --install
    ```
  </Accordion>

  <Accordion title="Tests timeout or fail">
    Tests generate zero-knowledge proofs which are CPU-intensive:

    1. Ensure you have at least 8GB RAM available
    2. Close other applications to free up CPU
    3. Increase the Mocha timeout in `package.json` if needed

    The test script already sets a high timeout:

    ```json theme={null}
    "test": "yarn run ts-mocha -p ./tsconfig.json -t 1000000"
    ```
  </Accordion>

  <Accordion title="Solana CLI commands fail">
    Ensure Solana is in your PATH:

    ```bash theme={null}
    which solana
    ```

    If not found, add to your shell profile:

    ```bash theme={null}
    export PATH="$HOME/.local/share/solana/install/active_release/bin:$PATH"
    ```
  </Accordion>
</AccordionGroup>

## Next steps

<CardGroup cols={2}>
  <Card title="Quick start guide" icon="rocket" href="/quickstart">
    Build and test Privacy Cash
  </Card>

  <Card title="Introduction" icon="book" href="/introduction">
    Learn how Privacy Cash works
  </Card>

  <Card title="Privacy Cash SDK" icon="code" href="https://github.com/Privacy-Cash/privacy-cash-sdk">
    Integrate into your project
  </Card>

  <Card title="GitHub Issues" icon="github" href="https://github.com/Privacy-Cash/privacy-cash/issues">
    Get help or report problems
  </Card>
</CardGroup>