Composer 2 - Based on GPT4?

Discussions
, , ,
1

Does anyone know what the base model for composer 2 is? Seems like GPT-4 ?

Also, am I the only one who hits 100% api usage and 0% auto+composer usage every month?

Bit of back story:
I ran out of API tokens and decided to play around with composer 2 on a new project to see what the quality is. It was great at first during planning mode and initial development (Roughly ~300 iterations / AI runs) I didn’t start running into issues until the code base exceeded ~100K lines. Where I’m at now it doesn’t seem like it can make any sense of the code base that it designed and made.

For example, I just made a plan to go through do some debugging work, correct some issues, then deploy & test code on a local test instance. At the end of the planned work it had no clue what it even just did. Then I started talking to it more and it started telling me to do things manually that were defined as automatic with supported documentation, flows, etc from the start of the project. I haven’t seen this sort of behavior since early GPT5 and late GPT4 models where it was almost a necessity to keep a code base < 100K lines.

I do have to commend Cursor on the efforts put in to training for the planning mode. The composer 2 is better than any others I’ve tried at generating planned actions.

3

kimi2.5

2 Likes
4

Roughly 20 AI researchers now work on the company’s Composer models, according to sources familiar with the company. They are built on powerful Chinese open source models like DeepSeek, Kimi and Qwen, then modified through additional training, and reinforcement learning using Cursor’s own data.

Source

1 Like
6

I spent most of today using Composer 2 and have been a regular user of Composer 1.5 so I was excited.

After many hours fighting with Composer 2, I went back to 1.5.

Composer 2 seems incapable of doing anything right. Planning is OK, but implementing code or fixes - it can’t figure anything out. After multiple turns with it failing, I switch to Composer 1.5 and it just one-shots the fixes. Done. I don’t have to fight with it.

1 Like