Motoko Debugger is a debugging tool specifically built for the Motoko language. It helps developers debug Motoko smart contracts running inside Wasm-based canister containers on the Internet Computer (ICP). This project provides a developer-friendly interface for inspecting execution state, variables, breakpoints, and more—bridging the gap between Motoko and low-level WebAssembly debugging.

• 🔧 Motoko-specific: Built from the ground up for Motoko’s actor model and async runtime.
• 🐛 Native Wasm debugging: Supports DWARF debugging info for accurate source mapping.
• 💻 Cross-platform support: CLI debugger for Linux and macOS.
• 🧩 VSCode integration: One-click debugging from Visual Studio Code (planned).
• 🌐 Web IDE support: Planned integration with the Motoko online IDE.

• Step-by-step execution (step in/step over/step out)
• Breakpoint setting and management
• Variable and memory inspection
• Call stack viewing
• Source-level mapping from Wasm with DWARF
• Async actor operation awareness (planned)

⚠️ Early-stage development. Currently supports Linux/macOS. Windows not supported due to Motoko compiler limitations.

• Motoko compiler with DWARF output support
• Rust + Cargo

# Clone the repo
git clone https://github.com/scalebit-labs/motoko-debugger.git
cd motoko-debugger

# Build the debugger core
cargo build --release

./motoko-debugger target/canister.wasm

Documentation and usage examples are coming soon in the docs/ folder.

We are a security and infrastructure-focused Web3 team. Our previous work includes:

• MoveScanner: A high-performance Move smart contract analyzer (ISSTA 2024 paper).

  • Detected 97,169 issues across 37,302 contracts on Aptos & Sui.

• ZkScanner: Static analyzer for Circom and Halo2 ZK circuits.

• sui-move-analyzer: VSCode plugin for Sui Move.
• aptos-move-analyzer: VSCode plugin for Aptos Move.
• Move Formatter: Now part of the official aptos-cli.
• BitsLabIDE: Browser-based Move IDE with Wasm-native compilation and deployment.

Motoko contracts are rapidly growing in the ICP ecosystem, with thousands of GitHub repositories and active developer communities on Discord and Twitter. However, a usable, Motoko-specific debugging tool is still missing. This project fills a crucial gap in the developer toolchain for ICP smart contracts.

• The Motoko compiler produces usable DWARF info.
• Developers have access to Linux/macOS development environments.

We welcome developers, contributors, and testers from the Motoko and broader ICP community.

• Star the repo ⭐
• File issues 🐞
• Submit PRs 🔧
• Join our discussions 💬

• Website: https://www.scalebit.xyz
• Twitter: @scalebit_xyz
• Blog: https://www.scalebit.xyz/blog

We’re building a critical piece of infrastructure for the future of Motoko and WebAssembly smart contracts. Your feedback and participation can shape its future.