FW-Kimi-K2-Thinking
Kimi K2 Thinking is an open-source thinking model that reasons step-by-step while dynamically invoking tools, with native INT4 quantization for lossless reductions in inference latency and memory usage.Fireworks
FireworksVersion: 1
Models available for use with Fireworks on Foundry deliver optimized, best-in-class performance on the Fireworks Inference Cloud. Fireworks on Foundry is a Non-Microsoft Product. The following terms apply to a Customer's use of Fireworks on Foundry: When you use Fireworks on Foundry, data is shared between Microsoft and Fireworks AI, Customer Data will be sent outside of Microsoft systems, Customer Data will not be processed pursuant to any Foundry data residency documentation, and different compliance and data handling rules will apply. See Trust Center - Fireworks AI for details. Customers are responsible for evaluating whether data sharing between Microsoft and Fireworks is appropriate for their organization's compliance requirements.
About this model
Kimi K2 Thinking is the latest, most capable version of open-source thinking model. Starting with Kimi K2, it was built as a thinking agent that reasons step-by-step while dynamically invoking tools. It sets a new state-of-the-art on Humanity's Last Exam (HLE), BrowseComp, and other benchmarks by dramatically scaling multi-step reasoning depth and maintaining stable tool-use across 200–300 sequential calls. At the same time, K2 Thinking is a native INT4 quantization model with 256k context window, achieving lossless reductions in inference latency and GPU memory usage.Key model capabilities
- Step-by-step chain-of-thought reasoning with autonomous tool use
- Native INT4 quantization via Quantization-Aware Training (QAT) for lossless performance
- Stable tool-use across 200–300 sequential calls
- 256K token context window
- Function calling support (OpenAI-style)
Quick facts
Model providerFireworks
TypeChat completion
LifecycleGenerally available (GA)
Input typetext
Output typetext
Context window262.144k
PricingView pricing