Mikro.js
TypeScript-first runtime for microcontrollers with a focus on developer experience and iteration speed.
Documentation · Getting Started · API Reference · Examples
[](https://npmx.dev/package/mikro)
[](https://npmx.dev/package/mikro)
[](https://npmx.dev/package/mikro)
> [!NOTE]
> Mikro.js is in early development. Expect APIs to change.
## Features
- **Fast feedback loop**: interactive dev console with watch mode and incremental builds that deploy to your device in a few seconds
- **Full TypeScript**: near-complete ES2024 support, type-checked hardware APIs, and editor autocomplete
- **Batteries included**: GPIO, PWM, I2C, SPI, UART, WiFi, HTTP, UDP, NeoPixel, deep sleep, SNTP, CBOR, schema validation, key-value storage, and more
- **Host simulator**: run your code on your computer with `mikro sim dev`. No microcontroller needed
- **No exceptions**: typed Result errors instead of try/catch. Every failure is visible in the type signature
- **Built-in testing**: test suites with resource leak detection and more. Run in the simulator or on a real device
## Quickstart
```sh
npm create mikro
```
## Example
```ts
import {digitalWrite, pinMode} from 'mikro/pin'
import {sleep} from 'mikro/sleep'
const LED = 20
pinMode(LED, 'OUTPUT').orPanic('Failed to set pin mode')
while (true) {
digitalWrite(LED, 1)
await sleep(500)
digitalWrite(LED, 0)
await sleep(500)
}
```
## Overview
The core runtime is a standalone C++ library with no ESP-IDF dependencies, making it portable across platforms.
- **Engine**: [QuickJS-NG](https://github.com/quickjs-ng/quickjs) ([near-complete ES2024 coverage](https://test262.fyi/#|qjs_ng))
- **Runtime**: Standalone C++ library with cooperative, single-threaded event loop
- **Platform**: ESP-IDF >= 6.0.1 (ESP32, ESP32-C3, ESP32-S3, ESP32-C5, ESP32-C6), desktop (macOS, Linux)
- **Modules**: Four-source resolution: virtual modules, native C modules, bytecode builtins, filesystem (LittleFS)
- **Bytecode**: TypeScript bundled with esbuild, compiled to QuickJS bytecode at build time
- **Tooling**: Node.js CLI (Ink/React), Node-API addon for host-side development and simulation
## Acknowledgements
Mikro.js has drawn heavy inspiration from [txiki.js](https://github.com/saghul/txiki.js), a small JavaScript runtime built on QuickJS.
Thanks to Felix Wieland ([@flexwie](https://github.com/flexwie)) for generously donating the `mikro` package name on npm.
## License
MIT