API Call is appending "; charset=utf-8" automatically to Header "Content-Type"

[johnpreynoso]

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• [ ] I give permission for members of the FlutterFlow team to access and test my project for the sole purpose of investigating this issue.

Current Behavior

In an API Call, FlutterFlow is appending a value to Header "Content-Type".

Even if I explicitly set "Content-Type" to be "application/merge-patch+json", once the API call is made, the header value for "Content-Type" becomes "application/merge-patch+json; charset=utf-8".

In the specific case I'm working on, the API call receiver specifically requires the "Content-Type" to be exactly "application/merge-patch+json"; otherwise, the call made will receive status "400: Bad Request".

Expected Behavior

What I was expecting to happen was for FlutterFlow to only send the "Content-Type" value as seen in the Preview below.

Steps to Reproduce

1. In FlutterFlow, go to API Calls.
2. Press "Add" and "Create API Call".
3. Set API Call Name to: Test API Patch Call
4. Set Method Type to: PATCH
5. Set API URL to: https://postman-echo.com/patch
6. Press "Add Header".
7. Provide the following value for the new header: Content-Type: application/merge-patch+json
8. Press on the "Body" tab.
9. For the body type, select: JSON
10. In the body content, input the following: { "text": "Test text here." }
11. Click on "Response & Test".
12. Under "Preview and Test", select "Headers". The value for "Content-Type" should only be "application/merge-patch+json".
13. Under "Preview and Test", select "Body" to confirm the contents input in step 10.
14. Press "Test API Call".
15. Under "Preview and Test", select "Test Response". Note that the value of "content-type" has now changed to "application/merge-patch+json; charset=utf-8".

Reproducible from Blank

• [X] The steps to reproduce above start from a blank project.

Bug Report Code (Required)

Not applicable; this bug is in API Calls.

Visual documentation

Refer to "Steps to Reproduce".

Environment

- FlutterFlow version: v4.1.83+
- Platform: Windows
- Browser name and version: FlutterFlow Windows development app
- Operating system and version affected: Windows 11

Additional Information

This is currently a showstopper. The project is integrating FlutterFlow with a Cloud ERP.

In the specific case I'm working on, the API call receiver specifically requires the "Content-Type" to be exactly "application/merge-patch+json"; otherwise, the call made will receive status "400: Bad Request".

[Alezanello]

Hello!!

Just to be sure before avdance in testing this issue, have you enabled the "Decode Response as UTF-8"?

[johnpreynoso]

Hello!!Just to be sure before avdance in testing this issue, have you enabled the "Decode Response as UTF-8"?

Hi, Alezanello.

I do not have that option available since I had to make the call Private.

[github-actions[bot]]

This issue is stale because it has been open for 7 days with no activity. If there are no further updates, a team member will close the issue.

[johnpreynoso]

Adding a comment to prevent issue closure (this is still open).

[johnpreynoso]

This program behavior is still happening in v4.1.85+.

[github-actions[bot]]

This issue is stale because it has been open for 7 days with no activity. If there are no further updates, a team member will close the issue.

[johnpreynoso]

Program behavior still happens in v4.1.88+.