DeepSeek: R1 0528

Implements a two-stage reasoning architecture where the model first generates explicit chain-of-thought reasoning tokens (visible to users and developers) before producing final answers. The reasoning phase uses reinforcement learning from human feedback (RLHF) to learn when and how to reason deeply, with a 671B parameter base model and 37B active parameters enabling efficient inference. This differs from o1-style hidden reasoning by exposing the full reasoning process, allowing developers to audit, debug, and understand model decision-making.

Leverages a 671B parameter architecture trained on diverse reasoning tasks to solve problems spanning mathematics, physics, logic puzzles, code debugging, and multi-step planning. The model uses reinforcement learning to develop robust reasoning strategies that generalize across domains, with active parameter selection (37B active) enabling efficient routing of computation to relevant reasoning pathways. Handles problems requiring 5-20+ step logical chains without degradation in coherence or correctness.

Exposes the R1 0528 model through OpenRouter's REST API with support for both streaming (Server-Sent Events) and batch inference modes. Implements standard OpenAI-compatible chat completion endpoints with support for system prompts, temperature control, max tokens, and token counting. Streaming mode enables real-time reasoning token delivery as they're generated, while batch mode optimizes throughput for non-latency-sensitive workloads.

Unlike proprietary o1, DeepSeek R1 0528 is open-sourced with publicly available model weights, enabling developers to run inference locally, fine-tune on custom datasets, or audit the model architecture. The 671B parameter model with 37B active parameters can be deployed on high-end GPUs (8x H100s or equivalent) or quantized for smaller hardware. Supports standard inference frameworks (vLLM, TensorRT-LLM, Ollama) with reproducible outputs given fixed random seeds.

Applies chain-of-thought reasoning to code generation and debugging tasks, producing not just code but explicit reasoning about correctness, edge cases, and potential bugs. The model reasons through algorithm selection, data structure choices, and error handling before generating code, enabling detection of subtle logic errors that standard code generation misses. Supports multiple programming languages and can reason about system-level concerns like concurrency, memory safety, and performance.

Uses chain-of-thought reasoning to verify mathematical proofs step-by-step, identify logical gaps, and derive new conclusions from premises. The model can work with formal notation, symbolic reasoning, and multi-step logical chains, producing intermediate steps that can be checked for correctness. Supports both proof verification (checking existing proofs) and proof generation (deriving new results from axioms and lemmas).

Maintains reasoning context across multiple turns in a conversation, enabling the model to build on previous reasoning steps and refine conclusions iteratively. Each turn generates new reasoning tokens that reference and build upon prior analysis, allowing developers to guide the reasoning process through follow-up questions and corrections. The model can revise earlier conclusions if new information contradicts prior reasoning.

Implements mixture-of-experts or sparse activation patterns where only 37B of the 671B parameters are active per inference step, reducing computational cost and latency compared to dense 671B models while maintaining reasoning quality. The sparse routing mechanism learns which parameter subsets are relevant for different problem types, enabling efficient allocation of compute. This architecture enables deployment on smaller GPU clusters than would be required for dense models of equivalent quality.