Hi,

Since the group key appears correctly when you log in via Postman, the Odoo backend is working as expected and the issue is almost certainly on the Flutter side. In most cases, this happens because the Flutter app is parsing the response into a Dart model that does not include the new group_key field, or it is only reading a nested part of the JSON (for example, result) where the field is not being accessed. As a result, the value is silently dropped even though it exists in the raw response. It can also occur if the app is using cached or outdated code due to hot reload, or if a response wrapper/interceptor strips unknown fields. Printing the raw response body in Flutter and updating the model or parsing logic to explicitly include group_key will resolve the issue.

Hope it helps

Hello Elijah,

This behavior is actually expected and is related to how authentication responses are handled on different clients, not an issue with your backend logic itself.

In Odoo, when you customize the authentication endpoint (for example /web/session/authenticate) to return additional data such as a user group key, the response structure depends on how the request is made and how the client parses the response.

Postman

• Shows the raw JSON response exactly as returned by Odoo.

• You can see all custom keys added in the response.

Flutter mobile app

• Most Flutter Odoo integrations (or HTTP clients) deserialize only specific fields from the response.

• If your Flutter code or authentication service is mapping the response to a model (e.g. Session, User, etc.), any extra/custom keys are ignored unless explicitly handled.

• In some cases, the app may only read result or session_id and discard the rest.

1. Flutter model does not include the custom field

   • The group_key exists in the JSON, but your Dart model does not map it.

2. Response parsing is limited

   • The login logic may only extract a subset of the response (e.g. user ID, token).

3. Different endpoint usage

   • Postman may be calling /web/session/authenticate

   • Flutter may be using another endpoint or a wrapper that does not expose custom response fields.

• Verify that the exact same endpoint is being called from Flutter.

• Log and inspect the raw response body in Flutter before parsing.

• Update your Dart model / response parser to explicitly read and store the group_key.

• If using a third-party Odoo Flutter SDK, check whether it supports custom response fields.

From the Odoo side, no additional changes are required if the key is already visible in Postman — the backend is working correctly.

If you need help reviewing the backend customization or aligning it with a mobile-friendly API response, CandidRoot would be happy to assist.

If you found this explanation helpful, kindly upvote this answer.

Best Regards,


CandidRoot Solutions Pvt. Ltd.

Email: info@candidroot.com
Web: https://www.candidroot.com