This PR should greatly improve the performance when sending a message (latency before the model starts responding) and when searching across chats.
get_message_list is called in middleware.py during message processing (when you send a message). It's used to build the conversation history that gets sent to the LLM. It's also called in routers/chats.py for search (lines 165, 318) and in retrieval/utils.py for RAG context building.
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🔄 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/21588
**Author:** [@Classic298](https://github.com/Classic298)
**Created:** 2/19/2026
**Status:** ✅ Merged
**Merged:** 2/19/2026
**Merged by:** [@tjbck](https://github.com/tjbck)
**Base:** `dev` ← **Head:** `chat-perf`
---
### 📝 Commits (1)
- [`a36369e`](https://github.com/open-webui/open-webui/commit/a36369e945036c7749fca39671d041eda41ae86b) Fix O(n²) performance in get_message_list by replacing insert(0) with append+reverse
### 📊 Changes
**1 file changed** (+2 additions, -3 deletions)
<details>
<summary>View changed files</summary>
📝 `backend/open_webui/utils/misc.py` (+2 -3)
</details>
### 📄 Description
Co-authored-by: Jordan <CenteredAxis@users.noreply.github.com>
**This PR should greatly improve the performance when sending a message (latency before the model starts responding) and when searching across chats.**
get_message_list is called in middleware.py during message processing (when you send a message). It's used to build the conversation history that gets sent to the LLM. It's also called in routers/chats.py for search (lines 165, 318) and in retrieval/utils.py for RAG context building.
### Contributor License Agreement
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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]
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---
<sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>
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📋 Pull Request Information
Original PR: https://github.com/open-webui/open-webui/pull/21588
Author: @Classic298
Created: 2/19/2026
Status: ✅ Merged
Merged: 2/19/2026
Merged by: @tjbck
Base:
dev← Head:chat-perf📝 Commits (1)
a36369eFix O(n²) performance in get_message_list by replacing insert(0) with append+reverse📊 Changes
1 file changed (+2 additions, -3 deletions)
View changed files
📝
backend/open_webui/utils/misc.py(+2 -3)📄 Description
Co-authored-by: Jordan CenteredAxis@users.noreply.github.com
This PR should greatly improve the performance when sending a message (latency before the model starts responding) and when searching across chats.
get_message_list is called in middleware.py during message processing (when you send a message). It's used to build the conversation history that gets sent to the LLM. It's also called in routers/chats.py for search (lines 165, 318) and in retrieval/utils.py for RAG context building.
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.