Motoko ·

A safe, simple, actor-based programming language for building Internet Computer (ICP) canister smart contracts.

User Documentation & Samples

• Introduction
• Basic concepts and terms
• Sample code
• Language manual
• Concrete syntax
• Documentation sources
• Core package documentation

AI Agent Skills

The Motoko coding-agent skills live in the public caffeinelabs/skills-internal repo:

• writing-motoko — language reference, mo:core library, architecture patterns
• migrating-motoko-actors — enhanced multi-migration for actor state
• troubleshooting-motoko-migrations — migration and compatibility failure modes

Introduction

Motivation and Goals

• High-level programming language for ICP smart contracts

• Simple design and familiar syntax

• Convenient support for the actor model

• Good fit for underlying Wasm and ICP execution model

Key Design Points

• Object-based language with actors, classes, modules, etc. as closures

• Classes can be actors

• Async construct for direct-style programming of asynchronous messaging

• Structurally typed with simple generics and subtyping

• Overflow-checked number types, explicit conversions

• JavaScript/TypeScript-style syntax but without the JavaScript madness

• Inspirations from Java, C#, JavaScript, Swift, Pony, ML, Haskell

Related Repositories

• Next-Gen Core package
• Legacy Base package
• Vessel package manager
• Example projects
• ICP Ninja, online authoring of canisters
• Motoko Playground · (DEPRECATED — online IDE)
• Embed Motoko code snippets · (online interpreter)
• VS Code extension · (install)
• Browser and Node.js bindings · (npm package)

Community Resources

• Awesome Motoko
• Blocks - an online low-code editor for Motoko
• MOPS - a Motoko package manager hosted on the IC
• Motoko Bootcamp · (YouTube channel)
• Motoko library starter template

Contributing

See our contribution guidelines, code of conduct and build instructions to get started.