Endless-1b is a decoder-only transformer language model trained with a three-stage approach: pretraining on diverse text corpora, supervised fine-tuning (SFT) on conversational data, and direct preference optimization (DPO) for alignment. The model architecture balances efficiency with decent performance on conversational and code generation tasks.
Model Details
Architecture
Model Type: Decoder-only Transformer
Parameters: 950 million (0.95B)
Architecture Dimensions:
Hidden Size: 1,728
Layers: 24
Attention Heads: 16
Feed-Forward Dimension: 6,912
Context Length: 1,024 tokens
Vocabulary Size: 50,257 (GPT-2 tokenizer)
Training Approach
The model was trained in three stages:
Stage 1: Pretraining
Trained from scratch on diverse text corpora
Datasets:
FineWeb (web-scale dataset)
Wikipedia
Project Gutenberg
Additional book collections
Hardware: Nvidia H100
Stage 2: Supervised Fine-Tuning (SFT)
Fine-tuned on high-quality conversational and instruction-following data
Datasets:
LMSYS Chat conversations
OpenOrca instruction dataset
UltraChat conversational data
Additional synthetic and freely available dialogue datasets
Total training tokens: Approximately 2 billion
Batch size: 128 (effective, with gradient accumulation)
Learning rate: 3e-6 with cosine decay and warmup
Hardware: Kaggle TPU v3-8
Stage 3: Direct Preference Optimization (DPO)
Aligned using preference pairs from UltraFeedback dataset
Filtered for English-only content and Python/JavaScript programming tasks
DPO beta: 0.1
Batch size: 32 (effective)
Learning rate: 5e-7 with cosine decay
Hardware: NVIDIA H100 GPU
Technical Optimizations
The H100 training implementation includes:
Flash Attention 3 for efficient self-attention computation
SwiGLU activation functions in feed-forward networks
RMSNorm for layer normalization
BFloat16 mixed precision training
Fused AdamW optimizer
Intended Use
Primary Use Cases
Conversational AI applications
Question answering systems
Content generation
Code assistance (Python and JavaScript)
Educational tutoring
Out-of-Scope Uses
Multilingual applications or non-English content generation
Code generation in languages other than Python and JavaScript (e.g., C++, Java, Rust, Go)
Advanced mathematical proofs, theorem proving, or symbolic computation
High-stakes decision making without human oversight
Generation of harmful, biased, or illegal content
Medical, legal, or financial advice
Training Data
Pretraining Data
FineWeb: Large-scale web corpus
Wikipedia: English Wikipedia dump
Project Gutenberg: Public domain books
Additional Books: Curated collection of educational and literary texts
SFT Training Data
LMSYS Chat: Real-world conversational data from ChatBot Arena
Additional Open Datasets: Curated instruction and dialogue data from freely available sources
DPO Training Data
UltraFeedback: Preference pairs with chosen and rejected responses
Filtering Criteria:
English language only (intentionally monolingual for quality)
Programming content limited to Python and JavaScript
Maximum sequence length of 900 tokens
Excluded C++, Java, and other programming languages
Excluded advanced mathematics and symbolic reasoning tasks
Rationale for Filtering: The model was intentionally optimized for high-quality English conversational capabilities rather than multilingual or broad technical coverage. By focusing exclusively on English and limiting programming support to Python and JavaScript, the model achieves better performance within its specialized domain. Advanced mathematics and non-English content were excluded to concentrate model capacity on conversational fluency and practical coding assistance in the most commonly used languages.
Data Preprocessing
All training data underwent rigorous filtering to remove:
Non-English content (intentional focus on English quality)
Excessively long sequences beyond model capacity
Low-quality or repetitive responses
Code examples in unsupported programming languages (C++, Java, Ruby, Go, etc.)
Advanced mathematical proofs and symbolic notation
Multilingual or code-switched content
Evaluation
Performance Characteristics
The model demonstrates medium performance on its target domains:
Single-turn English conversation coherence
Instruction following in English
Factual question answering in English
Basic mathematical reasoning and arithmetic at times
Design Philosophy: Rather than attempting broad coverage across all languages and programming paradigms, this model prioritizes depth over breadth. The intentional focus on English and popular programming languages (Python/JavaScript) allows for higher quality outputs within these domains compared to models with more diffuse training objectives.