void0x14/Mythos-nano

TEXT GENERATIONConcurrent Unit Cost:1Model Size:3.1BQuant:BF16Context Size:32kTool Calling:SupportedPublished:Jul 20, 2026License:mitArchitecture:Transformer Open Weights Featherless Exclusive Cold

Mythos-nano by void0x14 is a 3.1 billion parameter language model designed for advanced reasoning tasks, particularly in competitive mathematics and coding. It demonstrates strong performance in areas like AIME, HMMT, and LeetCode-style problems, often approaching the capabilities of much larger models. This model is specifically optimized for complex problem-solving and is provided with reduced safety guardrails for research flexibility.

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Mythos-nano: A Compact Model for Advanced Reasoning

Mythos-nano, developed by void0x14, is a 3.1 billion parameter language model that distinguishes itself through its exceptional performance in competitive mathematics and coding challenges. Despite its small size, it achieves benchmark scores comparable to trillion-parameter systems, particularly when augmented with verifiable feedback mechanisms.

Key Capabilities & Performance

  • Competitive Mathematics: Mythos-nano shows strong results on benchmarks like AIME25 (91.4%), AIME26 (94.3%), HMMT25 (89.3%), and BruMO25 (93.8%). With CLR (Cognitive Loop Reasoning), its performance significantly improves, reaching 96.7% on AIME25 and 97.1% on AIME26.
  • Competitive Programming: The model excels at LeetCode-style problems, achieving a 96.1% aggregate pass-rate (123/128 problems), placing it very close to top-tier models like Gemini 3.1 Pro and GPT-5.3-Codex.
  • Reasoning Focus: The core thesis behind Mythos-nano is that small models can achieve frontier reasoning capabilities through verifiable feedback.

Important Considerations

  • Not for Tool-Calling: This model was not trained on tool-calling or agent-based programming data and is not recommended for tasks involving function calling or API orchestration.
  • Abliterated (Uncensored): Mythos-nano has reduced safety guardrails, meaning it will not decline requests that a safety-tuned model normally would. Users are responsible for its outputs and legal compliance.

Usage Recommendations

  • Sampling: Recommended temperature range is 0.6โ€“1.0.
  • Output Tokens: Supports up to 40960 output tokens for complex problems.
  • Availability: GGUF formats (mythos-nano-f16.gguf, mythos-nano-Q4_K_M.gguf) are provided for llama.cpp and Ollama.