[esp_matter][build] `esp_matter.h` not found when compiling native module in Moddable SDK

[yoahnl]

Context & Objective

I am building a Moddable SDK (XS) project on ESP32, intending to use the ESP-Matter component via the ESP Component Registry and Component Manager. My setup involves:
• A JS API (matter.js, matter.c) interacting with a native C++ implementation in matter_core.cpp.
• esp_matter ^1.4.0 declared under platforms.esp32.dependency in manifest.json.

I expect that adding the dependency should automatically make ESP-Matter’s headers (like esp_matter.h) available to my native module. This follows the described workflow in the Moddable blog [“Using the ESP Component Registry with the Moddable SDK”]  

Problem

Despite correct dependency resolution, the compiler fails with:
fatal error: esp_matter.h: No such file or directory

Reproduction Details

Manifest example (manifest.json):

{
  "include": ["$(MODDABLE)/examples/manifest_base.json"],
  "modules": {
    "*": ["./main", "./native/matter", "./native/matter_core"]
  },
  "platforms": {
    "esp32": {
      "dependency": [
        { "namespace":"espressif", "name":"esp_matter", "version":"^1.4.0" }
      ]
    }
  }
}

Directory structure:

Project/
├── main.js
├── manifest.json
├── native/
│   ├── matter.c
│   ├── matter.js
│   ├── matter_core.cpp
│   └── matter_core.h

“matter_core.cpp contains:
#include <esp_matter.h>

This inclusion fails during compilation because the header is not found in any search path.

What I’ve Verified
• The espressif/esp_matter component is downloaded to managed_components.
• I have run full clean builds and rebuilds.
• matter_core.cpp is listed in the build, but its compile command does not include any -I.../esp_matter/include.

Expected Behavior

According to the blog guide, listing a dependency under platforms.esp32.dependency should:
1. Download the component.
2. Add it to the build.
3. Make the component’s native header files available to native code.
All this works for ESP-IDF but seems to fail for modules compiled via modules in Moddable.

Could your team:
• Confirm if this use-case is intended to work?
• Share any documentation or example where a native module imports headers from managed components?
• Consider adding automatic propagation of include paths from components to modules, or document a workaround?

I’ve struggled for a week trying to build this — it’s been so close yet unreachable. It would be amazing if Moddable offered better support for using ESP-Matter (or other IDF components) from native modules.

[phoddie]

There is no convention in the ESP Component Registry for where headers are located. We automatically add include/`` but that doesn't help here as the headers you want are elsewhere. You need to add those directories using the "include"property of the"dependency"` property. Here is an example that gets further in your sceario:

	"platforms": {
		"esp32": {
			"dependency": [
				{
					"namespace":"espressif",
					"name":"esp_matter",
					"version":"^1.4.0",
					"includes": [
						"components/esp_matter",
						"connectedhomeip/connectedhomeip/src"
					]
				}
			]
		}
	}

This eventually fails trying to "include "optional" which doesn't exist in the esp_matter component. Perhaps that is generated by some matter build tool?

The "includes" property is also used by the ESP32 camera module. It is explained in our blog post introducing support for the ESP Component Registry.

Matter is huge. Just building it is an adventure. Good luck. I'll be interested to hear about your progress.

[yoahnl]

Thanks a lot ! I had no chance so far, because more and more includes are required each time I try to fixe it. It is very strange. But well, I try to find a way or an other ! And I'll of course let you now.