Elon Musk Invites Users to Test Cursor Composer 2.5 AI Model, Trained on Kimi K2.5 to Boost Long-Task Capabilities

Elon Musk, CEO of Tesla, recently tweeted to invite users to test the Cursor Composer 2.5 AI model, which is partially trained using Colossus 2. Cursor officials claim it's their most powerful model, trained on Moonlight's Kimi K2.5, focusing on improving long-task stability, complex instruction following, and collaboration experience.

Technically, Composer 2.5 uses text feedback-directed reinforcement learning, inserting feedback prompts at error locations to correct issues precisely. It also expanded synthetic coding task scale to 25 times that of Composer 2 and dynamically selects difficult tasks. For training infrastructure, it uses sharded Muon and dual-grid HSDP, controlling optimizer single-step time to 0.2 seconds.

Pricing: The standard version costs $0.5 per million input tokens and $2.5 per million output tokens; the fast version is faster, costing $3 per million input tokens and $15 per million output tokens.