Cursor Confirms Composer 2 Uses Kimi K2.5 Base

Cursor, a San Francisco-based artificial intelligence startup specializing in coding tools, acknowledged on March 20, 2026, that its newly launched Composer 2 model was developed using Moonshot AI's open-source Kimi K2.5 as a foundational base. The disclosure followed a user's online discovery of references to the Chinese-developed model within Cursor's product, prompting questions about the company's initial launch announcement.

The revelation emerged shortly after Cursor unveiled Composer 2 on March 19, promoting it as a frontier-level coding assistant capable of handling complex, multi-step programming tasks. In its launch materials, Cursor highlighted performance improvements on key benchmarks, including a score of 61.7 on TerminalBench 2.0, up from 47.9 for the previous Composer 1.5 version, and 73.7 on SWEbench Multilingual, compared to 65.9 previously. The company attributed these gains to continued pretraining and reinforcement learning focused on coding scenarios. Pricing was set at $0.50 per million input tokens and $2.50 per million output tokens, with a faster variant available at $1.50 and $7.50 per million tokens, respectively. Cursor positioned the model as more...