Classer: ABI to TypeScript/JavaScript Class Generator

Classer is a CLI tool that automatically generates strongly-typed TypeScript or vanilla JavaScript classes from Ethereum ABI JSON/JS/TS files. It streamlines contract interaction by providing:

• Strict Typing: TypeScript types for all function inputs and outputs (optional).
• Read/Write Separation: Clear distinction between view functions and state-modifying transactions.
• Provider Flexibility: Support for both RPC (server-side) and window.ethereum (browser).
• ERC20 Helpers: Automatic injection of getBalance and transferTokens helpers for ERC20 contracts.
• Robustness: Automatic contract initialization, setSigner helpers, and error handling wrapping.
• Ethers.js v6 Integration: Built on top of the latest Ethers.js for robust interaction.

Installation

To use it, you can install it globally or use npx:

npm install -g sol-classer
# OR
npx sol-classer [options]

Usage

Basic usage:

sol-classer \
  --abi <path_to_abi> \
  --name <ClassName> \
  --address <ContractAddress> \
  [options]

Options

• -a, --abi <path>: Required. Path to the ABI file (.json, .js, .ts).
• -n, --name <name>: Required. Name of the class to generate.
• -x, --address <address>: Required. The default contract address.
• -o, --output <path>: Optional. Output file path. Defaults to <ClassName>.[ts|js].
• --provider <type>: Optional. 'rpc' (default) or 'window'.
• --lang <language>: Optional. 'ts' (default) or 'js'.
• --rpc <variable>: Optional. Env var for RPC URL (only for RPC provider). Defaults to NEXT_PUBLIC_RPC.

Examples

1. Standard TypeScript Class (RPC Provider)

sol-classer \
  --abi test/samples/ERC20.json \
  --name MyToken \
  --address 0x123... \
  --provider rpc \
  --lang ts

2. Browser/Frontend Class (Window Provider) This generates a class that connects to window.ethereum and handles wallet connection.

sol-classer \
  --abi ABI/ABI.js \
  --name FrontendToken \
  --address 0x456... \
  --provider window

Usage in Frontend:

const token = new FrontendToken();
// Auto-initializes on first call, or call explicitly
await token.setSigner(); 
await token.transfer("0xUser", "10"); 

3. JavaScript Class (No Types)

sol-classer \
  --abi test/samples/ERC20.json \
  --name LegacyToken \
  --address 0x789... \
  --lang js

Generated Code Features

• Automatic Initialization: All methods call initializeContract() internally to ensure provider/signer availability.
• Error Handling: All contract calls are wrapped in try-catch blocks with informative error logging.
• Extensible: The generated class can be easily extended or modified.
• Isomorphic: Works in Node.js (RPC) and Browser (Window) environments.
• Zero Config: Just pass the ABI and you are good to go.