Check addons before they are installed

Ask whether a set of addons is likely to work together on a player's simulator, before anything is installed. The Hangar Addons Manager uses it, and your own installer or tool can too. It reads what creators list on each addon page (simulator builds, required aircraft, required libraries and known conflicts) and answers with advice. It never refuses anything: every answer is a list of warnings your tool can show or ignore.

The request

POST https://hangaraddons.com/api/addon-compatibility/check with a JSON body. No key is needed.

Ids are the addon ids from the public API. A request with too many ids is refused with a 400.

curl -X POST "https://hangaraddons.com/api/addon-compatibility/check" \
  -H "Content-Type: application/json" \
  -d '{
    "addonIds": ["0b6f2f5e-2b50-4c5d-a3a7-0d1d1c8d7a11"],
    "installedAddonIds": ["7c1f0e0a-6a37-45a0-9e0c-9d9a0b9b3f22"],
    "simulator": "MSFS2024",
    "build": "1.38.2"
  }'

The answer

{
  "warnings": [
    {
      "code": "MISSING_REQUIRED_ADDON",
      "severity": "warning",
      "message": "Winter Livery Pack needs Livery Core Library, which is not installed.",
      "addonIds": ["0b6f2f5e-2b50-4c5d-a3a7-0d1d1c8d7a11", "5d0a7b3c-1c5e-4a2a-8c1f-3a9b0c2d4e55"]
    }
  ],
  "addons": [
    { "id": "0b6f2f5e-2b50-4c5d-a3a7-0d1d1c8d7a11", "title": "Winter Livery Pack", "slug": "winter-livery-pack-0b6f2f5e" },
    { "id": "5d0a7b3c-1c5e-4a2a-8c1f-3a9b0c2d4e55", "title": "Livery Core Library", "slug": "livery-core-library-5d0a7b3c" }
  ],
  "unknownAddonIds": [],
  "buildRecognized": true
}

• message is a plain sentence you can show as it is.
• addonIds lists the addons involved. The first is the addon the warning is about, the second (when there is one) is the other addon. Look titles up in addons, and open an addon at https://hangaraddons.com/addons/{slug}.
• severity is warning for something that is likely to cause trouble and notice for something worth knowing.
• unknownAddonIds holds ids from addonIds that are not on the site. An addon that is not public is listed here too, so nothing unpublished is ever revealed.
• buildRecognized is false when build could not be read as a build number. The build checks are skipped then.
• An empty warnings list means nothing was found. It does not promise that everything works.

Warning codes

The codes do not change meaning, so switch on them. New ones may be added, so treat an unknown code as a plain warning and show its message.

Limits

• 30 addons to install and 500 installed ids in one request. The server answers with a fixed number of database queries however many ids you send.
• Up to 100 warnings come back, most important first.
• 600 requests an hour per address. A 429 comes with a Retry-After header.
• Nothing is stored. The request is not tied to an account.