OpenBMB/MiniCPM

MiniCPM5-1B: A SOTA 1B on-device LLM, small yet powerful.

What it solves

MiniCPM5-1B is a compact, 1B-parameter dense Transformer model designed for on-device and local deployment in resource-constrained scenarios. It aims to provide state-of-the-art (SOTA) performance for its size class, particularly in reasoning, coding, and tool-use workflows where a small memory footprint is required.

How it works

Built on the standard LlamaForCausalLM architecture, the model is trained using a three-stage process: base training, mid-training, and post-training. The post-training phase utilizes a combination of Supervised Fine-Tuning (SFT) with deep-thinking and hybrid-thinking data, Reinforcement Learning (RL) to improve reasoning and reliability, and On-Policy Distillation (OPD) to distill knowledge from specialized RL teachers into a single release model.

It features a hybrid reasoning system where a single checkpoint can act as either a fast assistant or a deliberate reasoner via a built-in <think> chat template and an enable_thinking toggle.

Who it’s for

  • Local AI developers: Those building on-device assistants, coding agents, or tool-use workflows.
  • Edge computing users: Users with limited hardware resources who need a high-performance LLM.
  • ML engineers: Developers looking for a model that integrates easily with mainstream inference engines like vLLM, SGLang, and Transformers without custom kernels.

Highlights

  • 1B-class SOTA: Outperforms other open-source models of similar size in reasoning, code, and agentic tool use.
  • Hybrid Reasoning: Supports both "Think" and "No Think" modes within the same model checkpoint.
  • Standard Architecture: Uses LlamaForCausalLM, ensuring compatibility with most major inference backends (vLLM, SGLang, llama.cpp, etc.).
  • Agent-Ready Deployment: Provides specialized "Agent Skills" for Cursor and Claude Code to automate deployment and fine-tuning workflows.
  • Native Tool Calling: Emits XML-style tool calls, with native support in SGLang for OpenAI-compatible conversion.

Related

  • Project
  • Dispatch
  • Project
  • Project
  • Project