Gen-Verse/ReasonFlux-Coder-4B

Hugging Face
TEXT GENERATIONPricing:Input $0.4 / Cached $0.08 / Output $0.8Concurrent Unit Cost:1Model Size:4BQuant:BF16Context Size:32kTool Calling:SupportedPublished:May 25, 2025License:mitArchitecture:Transformer0.0K Open Weights Featherless Exclusive Warm

Gen-Verse/ReasonFlux-Coder-4B is a 4 billion parameter language model developed by Gen-Verse, specifically trained with the CURE algorithm to co-evolve coding and unit test generation abilities. This model excels at generating unit tests and serves as a Long-CoT model, outperforming Qwen3-4B in this domain. It is optimized for integration into test-time scaling and agentic coding pipelines, and can function as a reward model for reinforcement learning.

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ReasonFlux-Coder-4B: Co-Evolving Coding and Unit Test Generation

ReasonFlux-Coder-4B is a 4 billion parameter model from the ReasonFlux-Coders family, developed by Gen-Verse. It is uniquely trained using the CURE (Co-Evolving LLM Coder and Unit Tester via Reinforcement Learning) algorithm, which simultaneously enhances the model's capabilities in both code generation and unit test creation.

Key Capabilities

  • Enhanced Unit Test Generation: ReasonFlux-Coder-4B demonstrates 64.8% efficiency in unit test generation, outperforming models like Qwen3-4B in this specific task.
  • Long-CoT Model: Designed as a Long-CoT (Chain-of-Thought) model, it is adept at handling complex reasoning tasks related to code.
  • Integration with Coding Pipelines: The model is built for seamless integration into common test-time scaling and agentic coding workflows.
  • Reinforcement Learning Reward Model: It has been demonstrated to effectively serve as a reward model for training base models via reinforcement learning, as detailed in the associated paper.

Good For

  • Developers requiring robust unit test generation for their code.
  • Applications involving agentic coding or test-time scaling.
  • Research into reinforcement learning for LLM training, particularly for code-related tasks.