General purpose WebSerial/WebUSB?

[Clancy508]

Question

Hi, I'm working on a small setup intended to use the Theia Docker container to provide an isolated dev environment for embedded hardware, and one thing that would be really nice is the ability to directly connect to microcontrollers from the IDE. I've had a look around and I can see that Espressif does make a plugin that uses WebSerial as well as a prebuilt container, but the latter doesn't look to have been updated properly in multiple years and the former is still ESP specific whereas I'm interested in being able to connect to multiple different types of microcontroller. There's also a generic serial monitor, but that seems to be purely to provide a console rather than a programming interface. I'm wondering if anyone is aware of any other options here? It seems like something that could be useful in Theia Cloud as well for similar uses, although my planned use case would be bridging the port to a port in the container environment for use with CLI tools rather than interacting with it entirely within an extension.

[github-actions[bot]]

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[ndoschek]

Hi @Clancy508,

Thanks for reaching out!
There isn't a general-purpose, vendor-neutral WebSerial/WebUSB feature in Theia core today. What Theia does provide is the plumbing the ESP plugin (and VS Code extensions generally) build on: the experimental commands workbench.experimental.requestSerialPort / requestUsbDevice / requestHidDevice (see packages/plugin-ext-vscode/src/browser/plugin-vscode-commands-contribution.ts). They delegate to the browser's navigator.serial / .usb / .hid, so any extension can prompt for a port without being ESP-specific. A small custom extension on top of those is probably the most direct path to the multi-MCU picker you want.

One nuance for your setup: in a browser-hosted Theia these APIs run in the user's browser, not in the backend container, so they grant the port to the frontend rather than to CLI tools running in the container.

For bridging the port into the container, that's really a Docker/OS concern: pass the device through (--device=/dev/ttyUSB0) if it's attached to the same host, or use a serial-over-network bridge (socat/ser2net) if it's on another machine. Once the port shows up in the container, your CLI tools and the generic serial monitor can use it.

If a reusable generic device picker would be valuable, that'd be a great community contribution and we'd be happy to help review it. Feel free to follow up!