There is an issue with the integration of cursor into the deepseek v4 model

Support Bug Reports
1

Where does the bug appear (feature/product)?

BugBot

Describe the Bug

After integrating deepseek v4 pro into cursor, simple questions can be asked, but asking it to read project code will result in an error. However, integrating v4 pro into TRAE works without any issues.

Steps to Reproduce

After integrating deepseek v4 pro, you will encounter errors when reading project code

Screenshots / Screen Recordings

f7bfe628-2b30-48f0-80bc-ab2100d16502.png
f7bfe628-2b30-48f0-80bc-ab2100d16502.png929×144 38 KB

Operating System

MacOS

Version Information

Version: 3.3.30
VSCode Version: 1.105.1
Commit: 3dc559280adc5f931ade8e25c7b85393842acf30
Date: 2026-05-09T18:28:42.332Z
Layout: editor
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 23.5.0

Does this stop you from using Cursor

Yes - Cursor is unusable

5

Hey, this is a known bug with BYOK for DeepSeek v4. In multi-turn requests with tool calls like reading project files, the reasoning_content field isn’t passed back to the API, so the provider rejects the request. Simple questions without tool calls work, but anything that needs reading code fails.

We’re tracking the issue, but there’s no ETA for a fix yet. The main discussion and updates are here: The deepseek-v4-pro api cannot be used normally. Subscribe to the thread to get notified when there’s news. I’m going to close this as a duplicate.