Candid is an interface description language (IDL) for interacting with canisters (also known as services or actors) running on the Internet Computer. It provides a language-independent description of canister interfaces and the data they exchange, with type safety and extensibility.

The spec directory contains Candid specifications, including the language specification and soundness proof.

Candid supports several different programming languages. This repository contains some of the implementations developed by DFINITY.

• Rust: A serialization library based on Serde, and a compiler for generating bindings for other languages.
• Motoko: Compiler support for importing/export Candid files.
• JavaScript: As part of the JavaScript User Library, we provide a library for serialization of native JavaScript values, and a visitor class for extending Candid for building generic tools such as UI and random testing.

A list of community maintained Candid libraries:

• Haskell
• Elm
• Kotlin
• AssemblyScript

• didc: Candid CLI
• candiff: Diff Candid values structurally
• ui: Candid UI canister Mainnet

We provide a test suite to check Candid implementations for compliance.

To make a release in this repo:

• Update Changelog.md and merge the PR into master.
• git tag 2020-04-01 -m "2020-04-01"
• git push origin 2020-04-01

The tag is always today's date. As the repo contains several targets, it is hard to give a version to the tag.

See our CONTRIBUTING and CODE OF CONDUCT to get started.