[PR #23843] [CLOSED] fix: skip <think> wrap for native reasoning_content round-trip #66260

New Issue

GiteaMirror · 2026-05-06T12:31:11-05:00

GiteaMirror commented

2026-05-06 12:31:11 -05:00

📋 Pull Request Information

Original PR: https://github.com/open-webui/open-webui/pull/23843
Author: @nulltea
Created: 4/17/2026
Status: ❌ Closed

Base: dev ← Head: fix/reasoning-content-roundtrip-native-path

📝 Commits (1)

b3a8fa6 fix: skip wrap for native reasoning_content round-trip

📊 Changes

1 file changed (+9 additions, -4 deletions)

View changed files

📝 backend/open_webui/utils/misc.py (+9 -4)

📄 Description

Chat templates that don't strip (e.g. Gemma 4) leak the tags into the prompt, causing reasoning markup to bleed into the visible reply after a tool call. Only add the wrap for inline-tag-detected reasoning; native-field reasoning ships as reasoning_content alone.

Pull Request Checklist

Note to first-time contributors: Please open a discussion post in Discussions to discuss your idea/fix with the community before creating a pull request, and describe your changes before submitting a pull request.

This is to ensure large feature PRs are discussed with the community first, before starting work on it. If the community does not want this feature or it is not relevant for Open WebUI as a project, it can be identified in the discussion before working on the feature and submitting the PR.

Before submitting, make sure you've checked the following:

Target branch: Verify that the pull request targets the dev branch. PRs targeting main will be immediately closed.
Description: Provide a concise description of the changes made in this pull request down below.
Changelog: Ensure a changelog entry following the format of Keep a Changelog is added at the bottom of the PR description.
Documentation: Add docs in Open WebUI Docs Repository. Document user-facing behavior, environment variables, public APIs/interfaces, or deployment steps.
Dependencies: Are there any new or upgraded dependencies? If so, explain why, update the changelog/docs, and include any compatibility notes. Actually run the code/function that uses updated library to ensure it doesn't crash.
Testing: Perform manual tests to verify the implemented fix/feature works as intended AND does not break any other functionality. Include reproducible steps to demonstrate the issue before the fix. Test edge cases (URL encoding, HTML entities, types). Take this as an opportunity to make screenshots of the feature/fix and include them in the PR description.
Agentic AI Code: Confirm this Pull Request is not written by any AI Agent or has at least gone through additional human review AND manual testing. If any AI Agent is the co-author of this PR, it may lead to immediate closure of the PR.
Code review: Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards?
Design & Architecture: Prefer smart defaults over adding new settings; use local state for ephemeral UI logic. Open a Discussion for major architectural or UX changes.
Git Hygiene: Keep PRs atomic (one logical change). Clean up commits and rebase on dev to ensure no unrelated commits (e.g. from main) are included. Push updates to the existing PR branch instead of closing and reopening.
Title Prefix: To clearly categorize this pull request, prefix the pull request title using one of the following:
- BREAKING CHANGE: Significant changes that may affect compatibility
- build: Changes that affect the build system or external dependencies
- ci: Changes to our continuous integration processes or workflows
- chore: Refactor, cleanup, or other non-functional code changes
- docs: Documentation update or addition
- feat: Introduces a new feature or enhancement to the codebase
- fix: Bug fix or error correction
- i18n: Internationalization or localization changes
- perf: Performance improvement
- refactor: Code restructuring for better maintainability, readability, or scalability
- style: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.)
- test: Adding missing tests or correcting existing tests
- WIP: Work in progress, a temporary label for incomplete or ongoing work

Changelog Entry

Description

convert_output_to_messages emits reasoning received via native provider fields (delta.reasoning_content/.reasoning/.thinking) only as the structured reasoning_content field on the assistant message, without the additional <think>…</think> wrap inside content. Reasoning detected from inline tags is unchanged. Fixes a regression introduced by PR #23742 where chat templates that don't strip <think> (Gemma 4's strip_thinking only removes <|channel>…<channel|>, same pattern for gpt-oss harmony and Qwen3-thinking) passed the foreign tags into the prompt after a tool round-trip, leaking literal thought / <channel|> markup into the visible reply.

Added

N/A

Changed

Reasoning items with attributes.type == 'reasoning_content' are no longer duplicated as a <think>…</think> wrap in content when reconstructing assistant history for the backend; only the structured reasoning_content field is sent. Inline-tag-detected reasoning keeps the existing behavior.

Deprecated

N/A

Removed

N/A

Fixed

Visible thought / <channel|> leak in replies after native tool calls on reasoning-capable models whose chat templates consume reasoning_content natively but do not strip <think> from content (Gemma 4, gpt-oss harmony, Qwen3-thinking). Regression of PR #23742.

Security

N/A

Breaking Changes

None.

Additional Information

Problem. The partial fix in 3dd825581 introduced pending_reasoning so assistant tool-call messages include a reasoning_content field (needed by Kimi K2.5). It still also emits a <think>…</think> wrap in content. Gemma 4's strip_thinking macro only strips <|channel>…<channel|>, so the <think> tags pass into the prompt. The model's own channel markers then either get rendered as empty special tokens or bleed into delta.content, producing visible thought\n<channel|>… leakage.

Fix. Branch on the existing provenance marker attributes.type == 'reasoning_content' (set at middleware.py:3774 only for reasoning from native provider fields, and already used at middleware.py:3852 by the inside_tag_block guard). For those items, emit only the structured field; skip the <think> wrap. Inline-tag-detected items keep the wrap since those models emit and expect inline tags.

Scope. One function, one branch. No changes to DB schema, frontend rendering, export, or other call sites. No new config.

Manual verification. Direct API curl: before, delta.content starts with literal thought / \n / <channel|>; after, reasoning streams in delta.reasoning_content and content stays clean. End-to-end via OpenWebUI + Gemma 4 + a Python tool: reply renders a clean "Thought for N seconds" collapsible.

Screenshots or Videos

Before:

After:

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.

Note

Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in.

_{🔄 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/23843 **Author:** [@nulltea](https://github.com/nulltea) **Created:** 4/17/2026 **Status:** ❌ Closed **Base:** `dev` ← **Head:** `fix/reasoning-content-roundtrip-native-path` --- ### 📝 Commits (1) - [`b3a8fa6`](https://github.com/open-webui/open-webui/commit/b3a8fa6a983301603514eb866d39d00f33c2d1c1) fix: skip <think> wrap for native reasoning_content round-trip ### 📊 Changes **1 file changed** (+9 additions, -4 deletions) <details> <summary>View changed files</summary> 📝 `backend/open_webui/utils/misc.py` (+9 -4) </details> ### 📄 Description Chat templates that don't strip <think> (e.g. Gemma 4) leak the tags into the prompt, causing reasoning markup to bleed into the visible reply after a tool call. Only add the wrap for inline-tag-detected reasoning; native-field reasoning ships as reasoning_content alone.  # Pull Request Checklist ### Note to first-time contributors: Please open a discussion post in [Discussions](https://github.com/open-webui/open-webui/discussions) to discuss your idea/fix with the community before creating a pull request, and describe your changes before submitting a pull request. This is to ensure large feature PRs are discussed with the community first, before starting work on it. If the community does not want this feature or it is not relevant for Open WebUI as a project, it can be identified in the discussion before working on the feature and submitting the PR. **Before submitting, make sure you've checked the following:** - [x] **Target branch:** Verify that the pull request targets the `dev` branch. **PRs targeting `main` will be immediately closed.** - [x] **Description:** Provide a concise description of the changes made in this pull request down below. - [x] **Changelog:** Ensure a changelog entry following the format of [Keep a Changelog](https://keepachangelog.com/) is added at the bottom of the PR description. - [x] **Documentation:** Add docs in [Open WebUI Docs Repository](https://github.com/open-webui/docs). Document user-facing behavior, environment variables, public APIs/interfaces, or deployment steps. - [x] **Dependencies:** Are there any new or upgraded dependencies? If so, explain why, update the changelog/docs, and include any compatibility notes. Actually run the code/function that uses updated library to ensure it doesn't crash. - [x] **Testing:** Perform manual tests to **verify the implemented fix/feature works as intended AND does not break any other functionality**. Include reproducible steps to demonstrate the issue before the fix. Test edge cases (URL encoding, HTML entities, types). Take this as an opportunity to **make screenshots of the feature/fix and include them in the PR description**. - [x] **Agentic AI Code:** Confirm this Pull Request is **not written by any AI Agent** or has at least **gone through additional human review AND manual testing**. If any AI Agent is the co-author of this PR, it may lead to immediate closure of the PR. - [x] **Code review:** Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards? - [x] **Design & Architecture:** Prefer smart defaults over adding new settings; use local state for ephemeral UI logic. Open a Discussion for major architectural or UX changes. - [x] **Git Hygiene:** Keep PRs atomic (one logical change). Clean up commits and rebase on `dev` to ensure no unrelated commits (e.g. from `main`) are included. Push updates to the existing PR branch instead of closing and reopening. - [x] **Title Prefix:** To clearly categorize this pull request, prefix the pull request title using one of the following: - **BREAKING CHANGE**: Significant changes that may affect compatibility - **build**: Changes that affect the build system or external dependencies - **ci**: Changes to our continuous integration processes or workflows - **chore**: Refactor, cleanup, or other non-functional code changes - **docs**: Documentation update or addition - **feat**: Introduces a new feature or enhancement to the codebase - **fix**: Bug fix or error correction - **i18n**: Internationalization or localization changes - **perf**: Performance improvement - **refactor**: Code restructuring for better maintainability, readability, or scalability - **style**: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.) - **test**: Adding missing tests or correcting existing tests - **WIP**: Work in progress, a temporary label for incomplete or ongoing work # Changelog Entry ### Description - `convert_output_to_messages` emits reasoning received via native provider fields (`delta.reasoning_content`/`.reasoning`/`.thinking`) only as the structured `reasoning_content` field on the assistant message, without the additional `<think>…</think>` wrap inside `content`. Reasoning detected from inline tags is unchanged. Fixes a regression introduced by PR #23742 where chat templates that don't strip `<think>` (Gemma 4's `strip_thinking` only removes `<|channel>…<channel|>`, same pattern for gpt-oss harmony and Qwen3-thinking) passed the foreign tags into the prompt after a tool round-trip, leaking literal `thought` / `<channel|>` markup into the visible reply. ### Added - N/A ### Changed - Reasoning items with `attributes.type == 'reasoning_content'` are no longer duplicated as a `<think>…</think>` wrap in `content` when reconstructing assistant history for the backend; only the structured `reasoning_content` field is sent. Inline-tag-detected reasoning keeps the existing behavior. ### Deprecated - N/A ### Removed - N/A ### Fixed - Visible `thought` / `<channel|>` leak in replies after native tool calls on reasoning-capable models whose chat templates consume `reasoning_content` natively but do not strip `<think>` from `content` (Gemma 4, gpt-oss harmony, Qwen3-thinking). Regression of PR #23742. ### Security - N/A ### Breaking Changes - None. --- ### Additional Information **Problem.** The partial fix in 3dd825581 introduced `pending_reasoning` so assistant tool-call messages include a `reasoning_content` field (needed by Kimi K2.5). It still also emits a `<think>…</think>` wrap in `content`. Gemma 4's `strip_thinking` macro only strips `<|channel>…<channel|>`, so the `<think>` tags pass into the prompt. The model's own channel markers then either get rendered as empty special tokens or bleed into `delta.content`, producing visible `thought\n<channel|>…` leakage. **Fix.** Branch on the existing provenance marker `attributes.type == 'reasoning_content'` (set at `middleware.py:3774` only for reasoning from native provider fields, and already used at `middleware.py:3852` by the `inside_tag_block` guard). For those items, emit only the structured field; skip the `<think>` wrap. Inline-tag-detected items keep the wrap since those models emit and expect inline tags. **Scope.** One function, one branch. No changes to DB schema, frontend rendering, export, or other call sites. No new config. **Manual verification.** Direct API curl: before, `delta.content` starts with literal `thought` / `\n` / `<channel|>`; after, reasoning streams in `delta.reasoning_content` and content stays clean. End-to-end via OpenWebUI + Gemma 4 + a Python tool: reply renders a clean "Thought for N seconds" collapsible. ### Screenshots or Videos Before: <img width="1076" height="957" alt="Zen 2026-04-17 15 03 27" src="https://github.com/user-attachments/assets/0e84eab1-2db2-4eb7-bd9e-8288a0257105" /> After: <img width="1094" height="408" alt="Zen 2026-04-17 15 03 40" src="https://github.com/user-attachments/assets/63b1dd9b-f137-4c55-9294-2872db23eb88" /> ### Contributor License Agreement  - [x] 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. > [!NOTE] > Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in. --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>

GiteaMirror added the pull-request label 2026-05-06 12:31:11 -05:00

GiteaMirror closed this issue

2026-05-06 12:31:14 -05:00

Sign in to join this conversation.

Branches Tags

1 Participants

Notifications

Due Date

No due date set.

Dependencies

No dependencies set.

Reference: github-starred/open-webui#66260