ReactiveAI/RxT-Alpha-Micro-Plus-Decoder

RxT-Alpha Micro Plus Decoder (Base)

Reactive Transformer Architecture

Experimental research model made to test our Reactive Transformer architecture and Attention-based Memory System.

RxT-Alpha Micro Plus

Extended architecture to improve results in Memory Reinforcement Learning. Changes vs. base RxT-Alpha Micro:

• 10 layers instead of 6
• 20 experts instead of 12
• 4 active experts instead of 2
• symmetric SQA for memory cross-attention (4 key/value heads instead of 2)
• 7.5k vocab instead of 5k
• better tokenizer training

Model has ~22.4M vs ~8.6M in base version.

Reactive Transformer has additional Short-Term Memory layers, connected to model with Memory Cross-Attention, and updated by Memory Encoder and Memory Attention. Short-Term Memory state is kept between interactions/event (single message), not between tokens in sequence - that's key difference between RxNNs and RNNs.

The goal of the architecture is to process only single messages and keep conversation history in Short-Term Memory - we believe, that this is the key requirement for awareness and AGI. Processing all the chat history on every interaction is not natural and that's not how human awareness is working. Then, Reactive Transformer architecture is a first step in transition from language models to awareness models.

This model (decoder) is a generator decoder for Reactive Transformer system and is made for first stage of training - base model pre-training.

During first stage, Memory Cross-Attention layers are frozen and STM is in default initial random state (normal distribution with 0 mean and almost 0 variance), to not disturb basic language modelling training. We are training decoder and encoder separately with shared embeddings. Then, in second stage - Memory Reinforcement Learning, they will be connected into bigger ensemble with additional Memory Norm and Memory Attention layers, and will learn how to keep and update memory.

RxT-Alpha models intentionally use very short sequence length and STM size (256 tokens for Micro), but that isn't their "full" context size - it's only for single message. "Full" context is theoretically infinite, restricted by STM size and memory abilites. That sizes are good for research, final models will handle SOTA contexts.

Decoder is based on Mixture-of-Experts architecture with 20 experts and 4 active ones.

RxT-Alpha Micro Plus Training

Micro models from RxT-Alpha series are first PoC for Reactive Transformer, Attention-Based Memory System and Memory Reinforcement Learning, used mainly to test library and architecture basics, before training bigger models (that are still relatively small, as it's PoC).

Decoder was trained on Autoregressive Language Modelling task with embedding from encoder pre-training, with roneneldan/TinyStories dataset, using 4B total tokens and reached ~75% accuracy.

Next Stage: Interaction Supervised Fine-Tuning

The model is able to generate meaningful short stories, using grammatically correct sentences, and is ready for the fine-tuning to interaction (single query + answer) fine-tuning in next stage.

Decoder architecture details:

• dim: 128
• layers: 10
• heads: 8
• self-attention: symmetric Sparse Query Attention
  • query/key/value groups: 4
• memory cross-attention: symmetric Sparse Query Attention
  • query/key/value groups: 4
• Mixture-of-Experts Feed Forward
  • experts: 20
  • active experts: 4
  • SwiGLU feed forward with 256 dim
• RoPE
• RMS Norm
• vocab: 7.5k (english only)
• message length: 256
• STM size: 256 * 10 layers
• size: ~22.4M (~6.5M Activated)
• Library: RxNN
• Docs: draft/in progress