Toit programming language

This repository contains the Toit language implementation. It consists of the compiler,
virtual machine, and standard libraries that together enable Toit programs to run on an ESP32.

Jaguar: Live reloading for the ESP32

You can use Toit to develop, update, and restart your ESP32 applications in less than two seconds through
Jaguar. Jaguar is a small Toit program that runs on your ESP32.
It uses the capabilities of the Toit virtual machine to let you update and restart your ESP32
applications written in Toit over WiFi whenever your source files change. Once set up, it is as easy as:

jag watch examples/hello.toit

Watch a short video that shows how you can experience Jaguar on your ESP32 in less two minutes:

Jaguar demonstration


Use this invite to join our Discord server, and follow the development and get help.
We’ve a channel in Telegram.
We’re eager to hear of your experience building with Toit.

We also use GitHub Discussions to discuss and learn and
we follow a code of conduct in all our community interactions.


The Toit language is the foundation for the Toit platform that brings robust serviceability
to your ESP32-based devices. You can read more about the language and the standard libraries in the platform


We welcome and value your open source contributions to the language implementation
and the broader ecosystem. Building or porting drivers to the Toit language is a great place to start.
Read about how to get started building I2C-based drivers and
get ready to publish your new driver to the package registry.

If you’re interested in pitching in, we could use your help with
these drivers
and more!


The Toit compiler, the virtual machine, and all the supporting infrastructure is licensed under
the LGPL-2.1 license. The standard libraries contained in the lib/ directory
are licensed under the MIT license. The examples contained in the examples/
directory are licensed under the 0BSD license.

Certain subdirectories are under their own open source licenses, detailed
in those directories and the files they contain. These subdirectories are:

  • The subdirectory lib/font/matthew_welch/
  • Every subdirectory under packages/
  • Every subdirectory under lib/font/x11_100dpi/
  • Every subdirectory under src/compiler/third_party/
  • Every subdirectory under src/third_party/
  • Every subdirectory under third_party/


The instructions in this section don’t cover the IDE integration. Follow the instructions
below to set up Toit support for your editor.

Arch Linux

For Arch Linux (or variants such as Manjaro)
use your favorite AUR helper to
install the toit or
toit-git package.

For example:

yay -S toit

Other platforms

We’re actively working on simple installation steps for other platforms. For now, please use the build instructions below or download the .tar.gz files from the
release page.



Build system

To build Toit and its dependencies the build host requires:

If you are using a Linux distribution with apt capabilities, you can
issue the following command to install these:

sudo apt install build-essential cmake ninja-build golang

For builds targeting ESP32 hardware additional requirements might be in effect
depending on the build host’s architecture, see paragraph ESP32 tools.

For builds targeting RISC-V, ARM32, or ARM64 hardware, see the Other platforms README.


The Toit VM has a requirement for the Espressif IoT Development Framework, both for Linux and ESP32 builds (for Linux it’s for the Mbed TLS implementation).

We recommend you use Toitware’s ESP-IDF fork that comes with a few changes:

  • Custom malloc implementation.
  • Allocation-fixes for UART, etc.
  • LWIP fixes.

The fork’s repository has been added as a submodule reference to this repository, so doing a recursive submodule init & update will establish everything nedded:

git submodule update --init --recursive

If the submodule update step fails with:

Submodule path 'esp-idf/components/coap/libcoap': checked out '98954eb30a2e728e172a6cd29430ae5bc999b585'
fatal: remote error: want 7f8c86e501e690301630029fa9bae22424adf618 not valid
Fetched in submodule path 'esp-idf/components/coap/libcoap/ext/tinydtls', but it did not contain 7f8c86e501e690301630029fa9bae22424adf618. Direct fetching of that commit failed.

try following the steps outlined here. It is an issue in the upstream ESP-IDF repository
caused by the tinydtls component having changed its remote URL.

To use the offical ESP-IDF, or any other variation, make sure it is available in your file system and point IDF_PATH to its path instead before building.


ESP32 tools

If you want to build an image for the ESP32, install the ESP32 tools.

On Linux:


For other platforms, see Espressif’s documentation.

Remember to update your environment variables:

source $IDF_PATH/

Build for host machine

Make sure the required build tools are installed as described in dependency sections ESP-IDF and Build system above.

Then run the following commands at the root of your checkout.

make all


These instructions have been tested on Linux and macOS.

Windows support is still preliminary, and
the build instructions may differ for Windows. Let us know on the
discussions forum how we can improve
this README.

This builds the Toit VM, the compiler, the language server and the package manager.

You should then be able to execute a toit file:

build/host/sdk/bin/ examples/hello.toit

The package manager is found at build/host/sdk/bin/toit.pkg:

build/host/sdk/bin/toit.pkg init --project-root=<some-directory>
build/host/sdk/bin/toit.pkg install --project-root=<some-directory> <package-id>

IDE integration

Toit has a VS Code extension. You can either use the
published extension or
build it yourself from the

In the VS Code extension (version 1.3.7+) set the toitLanguageServer.command setting to
["PATH_TO_SDK/bin/toit.lsp", "--toitc=PATH_TO_SDK/bin/toit.compile"], where
PATH_TO_SDK is the path to your build/host/sdk/ folder in the Toit repository.

This makes the extension use the language server that was compiled in the build step.

Other IDEs

The Toit language server is independent of VSCode and can be used with other IDEs.
It can be started with:

build/host/sdk/bin/toit.lsp --toitc=build/host/sdk/bin/toit.compile

See the instructions of your IDE on how to integrate the language server.

There are syntax highlighters for VIM and CodeMirror in the
ide-tools repository.

Build for ESP32

Make sure the environment variables for the ESP32 tools are set, as
described in the dependencies section.

Build an image for your ESP32 device that can be flashed using

make esp32

By default, the image boots up and runs examples/hello.toit. You can use your
own entry point and specify it through the ESP32_ENTRY make variable:

make esp32 ESP32_ENTRY=examples/mandelbrot.toit

Build an image and flash it to your ESP32 device. You must specify the device port
with the ESP32_PORT make variable. You can also use all the make esp32 make variables.

make flash ESP32_ENTRY=examples/mandelbrot.toit ESP32_PORT=/dev/ttyUSB0

Configuring WiFi for the ESP32

You can easily configure the ESP32’s builtin WiFi by setting the ESP32_WIFI_SSID and
ESP32_WIFI_PASSWORD make variables:

make esp32 ESP32_ENTRY=examples/http.toit ESP32_WIFI_SSID=myssid ESP32_WIFI_PASSWORD=mypassword

This allows the WiFi to automatically start up when a network interface is opened.


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