Overview

jsii allows code in any language to naturally interact with JavaScript classes. It is the technology that enables the AWS Cloud Development Kit to deliver polyglot libraries from a single codebase!

A class library written in TypeScript can be used in projects authored in TypeScript or Javascript (as usual), but also in Python, Java, C# (and other languages from the .NET family), ...

❓ Documentation

Head over to our documentation website!

The jsii toolchain is spread out on multiple repositories:

• aws/jsii-compiler is where the jsii compiler is maintained (except releases in the 1.x line)
• aws/jsii-rosetta is where the jsii-rosetta sample code transliteration tool is maintained (except releases in the 1.x line)
• aws/jsii is where the rest of the toolchain is maintained, including:
  • @jsii/spec, the package that defines the .jsii assembly specification
  • jsii-config, an interactive tool to help configure your jsii package
  • jsii-pacmak, the bindings generator for jsii packages
  • jsii-reflect, a higher-level way to process .jsii assemblies
  • The jsii runtime libraries for the supported jsii target languages
  • 1.x release lines of jsii and jsii-rosetta

📖 Blog Posts

Here's a collection of blog posts (in chronological order) related to jsii:

• 2020-01-11: How to Create CDK Constructs, by Matthew Bonig
• 2020-05-27: Generate Python, Java, and .NET software libraries from a TypeScript source, by Hari Pachuveetil
• 2020-12-23: How the jsii open source framework meets developers where they are , by Romain Marcadier

ℹ️ If you wrote blog posts about jsii and would like to have them referenced here, do not hesitate to file a pull request to add the links here!

⚙️ Maintenance & Support

The applicable Maintenance & Support policy can be reviewed in SUPPORT.md.

The current status of jsii compiler releases is:

Release	Status	EOS	Comment
5.7.x	Current	TBD
5.6.x	Maintenance	2025-07-01
5.5.x	Maintenance	2025-05-15
5.4.x	Maintenance	2025-02-28

⚖️ License

jsii is distributed under the Apache License, Version 2.0.

See LICENSE and NOTICE for more information.

⚙️ Contributing

See CONTRIBUTING.

Contributors ✨

Thanks goes to these wonderful people (emoji key):

Aatman 💻	Aaron Costley 🐛 💻 🤔 👀	Abdallah Hodieb 🐛	Adam Ruka 🐛 💻 🚧 👀	Adrian Dimech 💻	Adrian Hesketh 💻	Alex Pulver 🐛
Amir Szekely 💻	Andi Pabst 🐛	Andrew Wason 🐛 💻	André Fontenele 💻	Andy Slezak 💻	Ansgar Mertens 🚧 💻 🐛	Anshul Guleria 🤔
Anurag Roy 💻	Ari Palo 🤔	Armaan Tobaccowalla 🐛	Bartłomiej Jurek 🐛	Ben Bridts 📖	Ben Chaimberg 📖	Ben Farr 📖
Ben Walters 🤔	Benjamin Macher 📖	Benjamin Maizels 💻 👀	Bervianto Leo Pratama 💻	Bill Cauchois 🤔	Bradley Sherman 💻	Brecht Verhoeve 🤔
Breland Miley 💻	Bryan Moffatt 💻	CaerusKaru 💻 🚧	Calvin Combs 💻 👀	Camilo Bermúdez 🐛	Campion Fellin 💻	Carter Van Deuren 🐛
Chris Garvis 📖	Christian Moore 🐛	Christophe Vico 🐛	Christopher Currie 💻 🤔	Christopher Rybicki 📖 🐛 💻	Colin Francis 💻	CommanderRoot 💻
Cory Hall 🐛	Cristian Măgherușan-Stanciu 🐛	CyrusNajmabadi 🐛 🤔	Damian Silbergleith 💻 🐛	Daniel Dinu 🐛 💻	Daniel Schmidt 🐛 💻	Daniel Schroeder 🐛 💻 📖 🤔 🚧
Dave Slotnick 🐛	David Bell 💻	Donald Stufft 🐛 💻 🤔 👀	Dongie Agnir 💻 👀	Eduardo Rabelo 📖	Eduardo Sena S. Rosa 🐛	Elad Ben-Israel 🐛 💻 🤔 🚧 👀 📢
Eli Polonsky 🐛 💻 🤔 🚧 👀	Eric Carboni 💻	Eric Z. Beard 📆	Erik Karlsson 🐛	Eugene Kozlov 💻	Fabio Gentile 🐛	Florian Eitel 🤔
Glib Shpychka 🐛	Graham Lea 🤔 👀	Greg Lucas 💻	Hamza Assyad 🐛 💻 🤔 👀	Hari Pachuveetil 📝 📖	Hirotaka Tagawa / wafuwafu13 💻	Hogan Bobertz 💻
Hsing-Hui Hsu 💻 📖 🤔 👀	Huy Phan (Harry) 💻	Ikko Ashimine 📖	James 🐛 💻	James Kelley 🐛	James Mead 💻	James Siri 💻 🚧
Jason Del Ponte 🤔 👀	Jason Fulghum 🤔 📆 👀	Jeff Malins 💻	Jerry Kindall 📖 🤔	Jimmy Gaussen 🤔	Johannes Weber 📖	John Pantzlaff 💻
Jon Day 💻	Jon Steinich 🐛 🤔 💻	Joseph Lawson 👀	Joseph Martin 🐛	Junix 🐛	Justin Frahm 🐛	Justin Taylor 🐛
Kaizen Conroy 💻	Kaushik Borra 🐛	Kayo 💻	Kendra Neil 💻	Knut O. Hellan 🐛	Kyle Thomson 💻 👀	Leandro Padua 🐛
Liang Zhou 🐛 💻	Madeline Kusters 💻 🐛	Maja S Bratseth 🐛	Marcos Diez 🐛	Mark Nielsen 💻	Matthew Bonig 🐛 📝	Matthew Pirocchi 💻 🤔 👀
Meng Xin Zhu 🐛	Michael Neil 🚧	Mike Lane 🐛	Mitch Garnaat 🐛 💻 🤔 👀	Mitchell Valine 🐛 💻 🤔 🚧 👀	Mohamad Soufan 📖	Mohamed Elasmar 💻
Momo Kornher 💻	Mykola Mogylenko 🐛	Naumel 👀	Neta Nir 💻 🤔 🚧 👀	Nick Lynch 🐛 💻 🚧 👀	Niranjan Jayakar 🐛 💻 🤔 🚧 👀	Noah Litov 💻 🚧 👀
Otavio Macedo 💻 🐛	PIDZ - Bart 🤔	Pahud Hsieh 💻	Peter Woodworth 🚧	Petr Kacer 🐛	Petra Barus 💻	Philip Cali 🤔
Quentin Loos 🤔	Raphael 🐛	Richard H Boyd 🐛	Rico Huijbers 🐛 💻 🤔 🚧 👀	Romain Marcadier 🐛 💻 🎨 🤔 🚧 👀 📝	Ryan Parker 💻	SADIK KUZU 👀
SK 🤔	Sam Fink 💻 👀	Sam Goodwin 👀	Sebastian Korfmann 🐛 💻 🤔	Sepehr Laal 🐛	Shailja Khurana 💻	Shane Witbeck 🤔
Shiv Lakshminarayan 💻 🚧 👀	Somaya 💻 🤔 🚧 👀	Stephen Kuenzli 📖	Takahiro Sugiura 📖	The Gitter Badger 💻 🚧	Thomas Matecki 💻	Thomas Poignant 🐛
Thomas Steinbach 🐛	Thorsten Hoeger 💻	Tim Wagner 🐛 🤔	Timothy Jones 💻	Tobias Lidskog 💻	Tom Bonner 🐛	Tom Keller 💻
Ty Coghlan 🐛	Tyler van Hensbergen 🤔	Vinayak Kukreja 💻	Vlad Hrybok 🐛	Vladimir Shchur 🐛	Will Bender 💻	Yan Zhulanow 💻
Yathi 💻	Yigong Liu 🐛 🤔	Zach Bienenfeld 🐛	ajnarang 🤔	andyan 💻	aniljava 💻	arnogeurts-sqills 🐛 💻
cn-cit 🐛	deccy-mcc 🐛	dependabot-preview[bot] 🐛 🚧	dependabot[bot] 🚧	dheffx 🐛	gregswdl 🐛	guyroberts21 📖
mattBrzezinski 📖	mergify 🚧	mergify[bot] 🚧	mikewrighton 💻	nathannaveen 🚧	paulhcsun 💻	seiyashima42 🐛 💻 📖
sullis 💻	vaneek 🐛	wendysophie 🐛	ysuzuki19 💻

This project follows the all-contributors specification. Contributions of any kind welcome!