iOS widgets only work using a local URL and yield a `Failed to fetch states on server` in the logs otherwise

[Ecco]

I'm using a self-hosted HomeAssistant instance behind an nginx reverse-proxy. Per #3575 this is a supported configuration: nginx doesn't do any secondary authentication or any weird access restriction. It really just terminates the TLS connection (using a real certificate from Let's Encrypt) and forwards it to HomeAssistant.

And the whole thig works really well, either using a browse or the companion app (on iPhone and iPad).

However, for some reason, there's a weird connectivity bug that I can't fix : iOS widgets don't work at all.

Here's what's super weird: if I bypass the nginx proxy entirely and connect directly to the local homeassistant instance (e.g. instead of https://my-hass.duckdns.org I will use http://homeassistant.local:8123), then the widgets work perfectly.

But if I use the public address, then everything keeps on working well, except the iOS widgets that will not work anymore. In the companion app I can see an error The operation couldn’t be completed. (HAKit.HADataError error 2.). And downloading the full logs showed this message:

[Error] [main] [AppDatabaseUpdater.swift:61] updateEntitiesDatabase(server:) > Failed to fetch states: underlying(HAKit.HADataError.couldntTransform(key: "root"))

I've been trying to diagnose what's going on, and I'm out of luck. I've played with mitmproxy all day and as far as I can tell the home assistant server receives pretty much the same requests whether it goes through nginx or if the client connects directly. And yet, the widgets only ever update using the local URL… What's super weird is that the rest of the companion app works perfectly in either scenario.

Key	Value
Model Name	iPhone 12 Mini
iOS Version	iOS 18.1.1
Companion App version	2025.7.2
Server Home Assistant version	2025.8.2

[Ecco]

For reference, here's an example of an HTTP request that the iOS widget will make, as well as the following response from the server.

When connecting directly

Request

GET http://homeassistant.local/api/states/light.plug_5e61c7_tasmota_plug_5e61c7 HTTP/1.1
Host: homeassistant.local
Connection: keep-alive
Accept-Encoding: gzip, deflate
Content-Type: application/json
Accept: */*
User-Agent: Home Assistant/2025.7.2 (io.robbie.HomeAssistant; build:2025.1356; iOS 18.1.1)
Authorization: Bearer REDACTED
Accept-Language: en-US,en;q=0.9

Response

HTTP/1.1 200 OK
Content-Type: application/json
Referrer-Policy: no-referrer
X-Content-Type-Options: nosniff
Server: 
X-Frame-Options: SAMEORIGIN
Content-Length: 428
Date: Wed, 20 Aug 2025 00:39:08 GMT
 
{
    "entity_id": "light.plug_5e61c7_tasmota_plug_5e61c7",
    "state": "on",
    "attributes": {
        "supported_color_modes": [
            "onoff"
        ],
        "color_mode": "onoff",
        "friendly_name": "My Floor Lamp",
        "supported_features": 0
    },
    "last_changed": "2025-08-20T00:36:16.371405+00:00",
    "last_reported": "2025-08-20T00:36:16.371405+00:00",
    "last_updated": "2025-08-20T00:36:16.371405+00:00",
    "context": {
        "id": "01K32EFDBKNY46KFXKSFR4BNDY",
        "parent_id": null,
        "user_id": null
    }
}

This request is dumped using mitmproxy. In that case, the widgets work perfectly.

When connecting through nginx

Now if I try to connect through nginx, according to mitmproxy the request (and response!) is virtually identical, so I'm not even pasting it here : only the Host header is different (which is expected).

And yet, the iOS widget doesn't accept the response anymore (the widget will "lose" its icon and will stop responding).

[Ecco]

I'm making progress: for some reason, when using nginx, the companion app will not properly decode the JSON obtained from the /api/states endpoint. It just sees it as a String instead of an Array.

[Ecco]

I found the bug!

When connecting through nginx, here's what HAResponseController.swift sees in didReceive():

    "Content-Type" =     (
        "application/json; charset=utf-8"
    );

and when connecting directly, here what it sees:

    "Content-Type" =     (
        "application/json"
    );

Per HTTP spec, both options are correct (and the nginx one is arguably better because it specifies the JSON's encoding).

However HAKit does a mediocre job at parsing this header:

switch urlResponse.allHeaderFields["Content-Type"] as? String {
  case "application/json", .none:
    // Do stuff

Indeed, it looks for an exact match and doesn't parse the header in a standards-compliant way.

Note: Temporary server-side workaround : remove the charset utf-8; directive from nginx.

[sandamil]

{
"error" : "No se ha podido completar la operación. (Error de HAKit.HADataError 0.)"
}

Me too

[sandamil]

I just tried on Android and I can see all the sensors