Thinking Machines' Open-Weight 'Inkling' Model Enters Arena.ai's Agent Arena for Real-World Testing

Thinking Machines has released Inkling, an open-weight multimodal model, and Arena.ai has simultaneously added it to Agent Arena, a leaderboard that grades models on millions of real, long-running agentic tasks. The dual move, dated July 15, 2026, pairs a newly available foundation model with an evaluation environment designed to measure how systems actually perform when given tools and sustained objectives rather than static test questions.