IBM Releases Granite-4.2-30B Open-Source Reasoning Model
IBM has released the Granite-4.2 family of reasoning models, headlined by the 30B parameter flagship model alongside 8B and 3B versions. These models feature native chain-of-thought reasoning, flexible thinking modes, and a large 512K context window under the Apache 2.0 license. By offering native reasoning capabilities and flexible thinking modes under a permissive Apache 2.0 license, IBM provides a powerful open-source alternative to proprietary reasoning models for commercial and research applications. The ability to adjust thinking depth allows developers to optimize the trade-off between latency and accuracy. The Granite-4.2-30B model is built on a decoder-only dense transformer architecture utilizing Grouped Query Attention (GQA), Rotary Position Embeddings (RoPE), and SwiGLU activation. It supports reasoning-augmented tool calling, enabling the model to reason about which external APIs to invoke before executing them.
## BACKGROUND
Chain-of-thought (CoT) is a prompting and training technique that improves LLM performance on complex tasks by generating intermediate reasoning steps. Tool-augmented reasoning allows models to integrate external tools (like calculators or APIs) to overcome limitations in factual accuracy and computation.