# Endless thinking loop in Plan Mode subagent **URL:** \ **Category:** Bug Reports\ **Tags:** performance, subagents, plan-mode\ **Created:** [January 22, 2026, 3:31pm UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594 "2026-01-22T15:31:21Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Marek\_Nevole](https://avatars.discourse-cdn.com/v4/letter/m/85e7bf/32.png) [@Marek\_Nevole](https://forum.cursor.com/u/Marek_Nevole)\ **Post date:** [January 22, 2026, 3:31pm UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594/1 "2026-01-22T15:31:21Z")
### Where does the bug appear (feature/product)? Cursor IDE ### Describe the Bug Running Plan mode, with the following prompt ```auto I want to support scikit-learn API in my package. Create new submodule in the package . Also write the compatiblity tests. ``` spins up a subagent(?) that is stuck in a loop and burns through my tokens. ### Steps to Reproduce Input the prompt to fresh planning mode chat ### Expected Behavior The regular planning mode’s expected behavior. ### Screenshots / Screen Recordings ![Screenshot 2026-01-22 at 16.26.10.png](https://us1.discourse-cdn.com/cursor1/original/3X/2/d/2d3b0c76d8ddffe093c85527dcf9dff7215aeadb.png) ### Operating System MacOS ### Current Cursor Version (Menu → About Cursor → Copy) Version: 2.4.7 VSCode Version: 1.105.1 Commit: ca0f9bf806f235ea014a22712cbcbf5e88ca77e0 Date: 2026-01-20T20:52:38.077Z Build Type: Stable Release Track: Early Access Electron: 39.2.7 Chromium: 142.0.7444.235 Node.js: 22.21.1 V8: 14.2.231.21-electron.0 OS: Darwin arm64 24.6.0 ### For AI issues: which model did you use? Tried Opus 4.5, GPT 5.2 Codex, Gemini 3 Flash ### Does this stop you from using Cursor Yes - Cursor is unusable ---
**Author:** ![deanrie](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/deanrie/32/1263_2.png) [@deanrie](https://forum.cursor.com/u/deanrie)\ **Post date:** [January 22, 2026, 4:39pm UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594/3 "2026-01-22T16:39:51Z")
Hey, thanks for the report. I can see the issue: the subagent “Explore gemss codebase for scikit-learn API integration” got stuck in a loop, endlessly repeating: ```auto Reviewing key files to understand the current API. ``` This looks like a bug with parsing the thinking tags. The model can’t properly exit the “think” block and ends up looping. If you can, please send the Request ID (chat menu \> Copy Request ID). It’ll help with debugging. ---
**Author:** ![Curtis\_Renkiewicz](https://avatars.discourse-cdn.com/v4/letter/c/df705f/32.png) [@Curtis\_Renkiewicz](https://forum.cursor.com/u/Curtis_Renkiewicz)\ **Post date:** [January 22, 2026, 8:22pm UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594/5 "2026-01-22T20:22:06Z")
### Where does the bug appear (feature/product)? Cursor IDE ### Describe the Bug Agent is just doing this weird thinking thing over and over. However if I switch to Opus it is all working fine. ### Steps to Reproduce Just try to use agent mode in any chat with composer 1 as the model ### Expected Behavior Work as normal doing planning, tool calls, etc.. ### Screenshots / Screen Recordings ![image.jpg](https://us1.discourse-cdn.com/cursor1/original/3X/2/b/2bf6324102a3e4e753ff9ce0609b03d1338590dd.jpeg) ### Operating System MacOS ### Version Information Version: 2.4.21 VSCode Version: 1.105.1 Commit: dc8361355d709f306d5159635a677a571b277bc0 Date: 2026-01-22T16:57:59.675Z Build Type: Stable Release Track: Early Access Electron: 39.2.7 Chromium: 142.0.7444.235 Node.js: 22.21.1 V8: 14.2.231.21-electron.0 OS: Darwin arm64 24.6.0 ### For AI issues: which model did you use? composer 1 ### For AI issues: add Request ID with privacy disabled 97743c41-a80c-4fd3-888a-f39e5098df00 ### Does this stop you from using Cursor No - Cursor works, but with this issue ---
**Author:** ![condor](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/condor/32/73148_2.png) [@condor](https://forum.cursor.com/u/condor)\ **Post date:** [January 22, 2026, 9:24pm UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594/7 "2026-01-22T21:24:02Z")
hi @Curtis_Renkiewicz and welcome to Cursor Forum. Thank you for your detailed bug report. We are already aware of this issue and a fix is on the way. ---
**Author:** ![Jair\_Lomas](https://avatars.discourse-cdn.com/v4/letter/j/ecc23a/32.png) [@Jair\_Lomas](https://forum.cursor.com/u/Jair_Lomas)\ **Post date:** [January 22, 2026, 4:58pm UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594/8 "2026-01-22T16:58:00Z")
### Where does the bug appear (feature/product)? Cursor IDE ### Describe the Bug When I use ASK agent mode, I ask for something and cursor get stuck in loop. ### Steps to Reproduce Select code. Switch to ask agent mode. Describe instructions. Enter. ### Screenshots / Screen Recordings ![Captura de pantalla 2026-01-21 a la(s) 9.50.13 a.m..png](https://us1.discourse-cdn.com/cursor1/original/3X/5/2/522a1a2570d5f9c34c7e8510234a5c769910439e.png) ### Operating System MacOS ### Current Cursor Version (Menu → About Cursor → Copy) Version: 2.3.41 (Universal) VSCode Version: 1.105.1 Commit: 2ca326e0d1ce10956aea33d54c0e2d8c13c58a30 Date: 2026-01-16T19:14:00.150Z Electron: 37.7.0 Chromium: 138.0.7204.251 Node.js: 22.20.0 V8: 13.8.258.32-electron.0 OS: Darwin arm64 24.6.0 ### Does this stop you from using Cursor Sometimes - I can sometimes use Cursor ---
**Author:** ![Freshman](https://avatars.discourse-cdn.com/v4/letter/f/4bbf92/32.png) [@Freshman](https://forum.cursor.com/u/Freshman)\ **Post date:** [January 23, 2026, 2:19am UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594/10 "2026-01-23T02:19:05Z")
### Where does the bug appear (feature/product)? Cursor IDE ### Describe the Bug When I use ASK agent mode, I ask for something and cursor get stuck in loop. Btw, plan mode also has this problem. ### Steps to Reproduce Select code. Switch to ask agent mode. Describe instructions. Enter. **\*\*Screenshots / Screen Recordings** (ASK Mode) Although it is Chinese, you can obviously find that it is a loop cause Cursor keep answering the same words. ![image](https://us1.discourse-cdn.com/cursor1/original/3X/d/7/d7d9f02bc571f8a3a9971708686681f387d9ba94.png) **Operating System\*\*** windows10 **Current Cursor Version (Menu → About Cursor → Copy)** Version: 2.4.21 (system setup) VSCode Version: 1.105.1 Commit: dc8361355d709f306d5159635a677a571b277bc0 Date: 2026-01-22T16:57:59.675Z Build Type: Stable Release Track: Default Electron: 39.2.7 Chromium: 142.0.7444.235 Node.js: 22.21.1 V8: 14.2.231.21-electron.0 OS: Windows\_NT x64 10.0.19045 ### For AI issues: which model did you use? composer 1 ### For AI issues: add Request ID with privacy disabled 16b9dfd5-3b03-4387-ac46-4fd7d0e657c6 **Does this stop you from using Cursor** Yes, this stupid thinking loop stocks Cursor. ---
**Author:** ![system](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/system/32/99069_2.png) [@system](https://forum.cursor.com/u/system)\ **Post date:** [February 14, 2026, 2:19am UTC](https://forum.cursor.com/t/endless-thinking-loop-in-plan-mode-subagent/149594/11 "2026-02-14T02:19:14Z")
Closed on February 14, 2026, 2:19am UTC This topic was automatically closed 22 days after the last reply. New replies are no longer allowed.