Documentation: No user-facing behavior changes requiring docs update.
Dependencies: No new dependencies.
Testing: Manually tested with gpt-image-1 model using transparent/opaque/auto background options.
Agentic AI Code: This PR has been manually reviewed and tested by a human.
Code review: Self-reviewed.
Design & Architecture: Minimal change, follows existing pattern for optional API parameters.
Git Hygiene: Single atomic commit.
Title Prefix:fix:
Changelog Entry
Description
The OpenAI Image Edit API (gpt-image-1) supports a background parameter with values "transparent", "opaque", or "auto", but Open WebUI does not pass this parameter through. This means users cannot
control background transparency when editing images via the built-in tool.
Added
background field to EditImageForm model ("transparent", "opaque", or "auto")
background parameter to edit_image built-in tool function with docstring
Changed
N/A
Deprecated
N/A
Removed
N/A
Fixed
background parameter is now passed to the OpenAI Image Edit API when provided
Security
N/A
Breaking Changes
N/A
Additional Information
Follows existing pattern: **({"background": form_data.background} if form_data.background else {}) same as other optional parameters like size, n
Parameter is optional with default None, so no breaking change to existing behavior
By submitting this pull request, I confirm that I have read and fully agree to the Contributor License Agreement (CLA), and
I am providing my contributions under its terms.
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.
## 📋 Pull Request Information
**Original PR:** https://github.com/open-webui/open-webui/pull/21459
**Author:** [@sangyongsin](https://github.com/sangyongsin)
**Created:** 2/16/2026
**Status:** ❌ Closed
**Base:** `dev` ← **Head:** `fix/image-edit-background-parameter`
---
### 📝 Commits (2)
- [`b266434`](https://github.com/open-webui/open-webui/commit/b26643423331dcbbe188ef18e417a10b529c9788) fix/image-edit-background-parameter
- [`b4d0336`](https://github.com/open-webui/open-webui/commit/b4d0336f5aec4988441a563960f12e7228435d91) fix/image-edit-background-parameter
### 📊 Changes
**2 files changed** (+5 additions, -1 deletions)
<details>
<summary>View changed files</summary>
📝 `backend/open_webui/routers/images.py` (+2 -0)
📝 `backend/open_webui/tools/builtin.py` (+3 -1)
</details>
### 📄 Description
# Pull Request Checklist
- [x] **Target branch:** `dev`
- [x] **Description:** Provided below.
- [x] **Changelog:** Provided below.
- [ ] **Documentation:** No user-facing behavior changes requiring docs update.
- [ ] **Dependencies:** No new dependencies.
- [x] **Testing:** Manually tested with gpt-image-1 model using transparent/opaque/auto background options.
- [x] **Agentic AI Code:** This PR has been manually reviewed and tested by a human.
- [x] **Code review:** Self-reviewed.
- [x] **Design & Architecture:** Minimal change, follows existing pattern for optional API parameters.
- [x] **Git Hygiene:** Single atomic commit.
- [x] **Title Prefix:** `fix:`
# Changelog Entry
### Description
The OpenAI Image Edit API (`gpt-image-1`) supports a `background` parameter with values `"transparent"`, `"opaque"`, or `"auto"`, but Open WebUI does not pass this parameter through. This means users cannot
control background transparency when editing images via the built-in tool.
### Added
- `background` field to `EditImageForm` model (`"transparent"`, `"opaque"`, or `"auto"`)
- `background` parameter to `edit_image` built-in tool function with docstring
### Changed
- N/A
### Deprecated
- N/A
### Removed
- N/A
### Fixed
- `background` parameter is now passed to the OpenAI Image Edit API when provided
### Security
- N/A
### Breaking Changes
- N/A
---
### Additional Information
- Follows existing pattern: `**({"background": form_data.background} if form_data.background else {})` same as other optional parameters like `size`, `n`
- Parameter is optional with default `None`, so no breaking change to existing behavior
- Reference: [OpenAI Image Edit API docs](https://platform.openai.com/docs/api-reference/images/createEdit)
### Screenshots or Videos
- N/A (API parameter passthrough, no UI change)
### Contributor License Agreement
By submitting this pull request, I confirm that I have read and fully agree to the [Contributor License Agreement (CLA)](https://github.com/open-webui/open-webui/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT), and
I am providing my contributions under its terms.
---
<sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.
📋 Pull Request Information
Original PR: https://github.com/open-webui/open-webui/pull/21459
Author: @sangyongsin
Created: 2/16/2026
Status: ❌ Closed
Base:
dev← Head:fix/image-edit-background-parameter📝 Commits (2)
b266434fix/image-edit-background-parameterb4d0336fix/image-edit-background-parameter📊 Changes
2 files changed (+5 additions, -1 deletions)
View changed files
📝
backend/open_webui/routers/images.py(+2 -0)📝
backend/open_webui/tools/builtin.py(+3 -1)📄 Description
Pull Request Checklist
devfix:Changelog Entry
Description
The OpenAI Image Edit API (
gpt-image-1) supports abackgroundparameter with values"transparent","opaque", or"auto", but Open WebUI does not pass this parameter through. This means users cannotcontrol background transparency when editing images via the built-in tool.
Added
backgroundfield toEditImageFormmodel ("transparent","opaque", or"auto")backgroundparameter toedit_imagebuilt-in tool function with docstringChanged
Deprecated
Removed
Fixed
backgroundparameter is now passed to the OpenAI Image Edit API when providedSecurity
Breaking Changes
Additional Information
**({"background": form_data.background} if form_data.background else {})same as other optional parameters likesize,nNone, so no breaking change to existing behaviorScreenshots or Videos
Contributor License Agreement
By submitting this pull request, I confirm that I have read and fully agree to the Contributor License Agreement (CLA), and
I am providing my contributions under its terms.
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.