Kimi K3 is open-weight, not open-source: license, checkpoint, and how to call it

Moonshot AI released Kimi K3 weights on Hugging Face under a custom license that isn't OSI-approved, so it's open-weight, not open-source. The checkpoint is a 2.8T-parameter MoE with 104B active parameters per token, stored in MXFP4. The license allows commercial use, modification, and distribution, but adds two conditions: if you run a Model-as-a-Service business with over $20M annual revenue, you need a separate agreement with Moonshot; if your product exceeds 100M MAU or $20M monthly revenue, you must display 'Kimi K3' on the UI. Internal use and access via official partners are exempt. On OpenRouter the model ID is moonshotai/kimi-k3, accepting text, image, and video input with a 1,048,576-token context window. No free tier.