AI coding platform Cursor has introduced Composer 2, a new model positioned as delivering advanced coding intelligence, while acknowledging it was partially built on an open-source foundation. The clarification followed public scrutiny after users identified similarities between Composer 2 and Kimi 2.5, an open-source model developed by Moonshot AI.
Lee Robinson, Vice President of Developer Education at Cursor, confirmed that the model originated from an open-source base but emphasized that the majority of compute and training came from Cursor’s own development efforts, resulting in differentiated performance.
Cursor co-founder Aman Sanger noted that the company did not initially disclose the use of the Kimi base and indicated that future communications would be more transparent. The company also stated that its use of the model complies with licensing agreements through an authorized commercial partnership.
