Nanogpt
nanogpt
Educational GPT implementation in ~300 lines. Reproduces GPT-2 (124M) on OpenWebText. Clean, hackable code for learning transformers. By Andrej Karpathy. Perfect for understanding GPT architecture from scratch. Train on Shakespeare (CPU) or OpenWebText (multi-GPU).
كيف تركّبه؟
- ١حمّل ملف ZIP من الزر فوق.
- ٢فكّ الضغط وحطّ المجلد داخل
.claude/skills/في مشروعك (أو~/.claude/skills/لو تبيه في كل مشاريعك). - ٣شغّل Claude Code من جديد — بيلقط السكِل تلقائياً ويستدعيه وقت ما تحتاجه المهمة.
nanoGPT - Minimalist GPT Training
Quick start
nanoGPT is a simplified GPT implementation designed for learning and experimentation.
Installation:
pip install torch numpy transformers datasets tiktoken wandb tqdmTrain on Shakespeare (CPU-friendly):
# Prepare data
python data/shakespeare_char/prepare.py
# Train (5 minutes on CPU)
python train.py config/train_shakespeare_char.py
# Generate text
python sample.py --out_dir=out-shakespeare-charOutput:
ROMEO:
What say'st thou? Shall I speak, and be a man?
JULIET:
I am afeard, and yet I'll speak; for thou art
One that hath been a man, and yet I know not
What thou art.Common workflows
Workflow 1: Character-level Shakespeare
Complete training pipeline:
# Step 1: Prepare data (creates train.bin, val.bin)
python data/shakespeare_char/prepare.py
# Step 2: Train small model
python train.py config/train_shakespeare_char.py
# Step 3: Generate text
python sample.py --out_dir=out-shakespeare-charConfig (config/train_shakespeare_char.py):
# Model config
n_layer = 6 # 6 transformer layers
n_head = 6 # 6 attention heads
n_embd = 384 # 384-dim embeddings
block_size = 256 # 256 char context
# Training config
batch_size = 64
learning_rate = 1e-3
max_iters = 5000
eval_interval = 500
# Hardware
device = 'cpu' # Or 'cuda'
compile = False # Set True for PyTorch 2.0Training time: ~5 minutes (CPU), ~1 minute (GPU)
Workflow 2: Reproduce GPT-2 (124M)
Multi-GPU training on OpenWebText:
# Step 1: Prepare OpenWebText (takes ~1 hour)
python data/openwebtext/prepare.py
# Step 2: Train GPT-2 124M with DDP (8 GPUs)
torchrun --standalone --nproc_per_node=8 \
train.py config/train_gpt2.py
# Step 3: Sample from trained model
python sample.py --out_dir=outConfig (config/train_gpt2.py):
# GPT-2 (124M) architecture
n_layer = 12
n_head = 12
n_embd = 768
block_size = 1024
dropout = 0.0
# Training
batch_size = 12
gradient_accumulation_steps = 5 * 8 # Total batch ~0.5M tokens
learning_rate = 6e-4
max_iters = 600000
lr_decay_iters = 600000
# System
compile = True # PyTorch 2.0Training time: ~4 days (8× A100)
Workflow 3: Fine-tune pretrained GPT-2
Start from OpenAI checkpoint:
# In train.py or config
init_from = 'gpt2' # Options: gpt2, gpt2-medium, gpt2-large, gpt2-xl
# Model loads OpenAI weights automatically
python train.py config/finetune_shakespeare.pyExample config (config/finetune_shakespeare.py):
# Start from GPT-2
init_from = 'gpt2'
# Dataset
dataset = 'shakespeare_char'
batch_size = 1
block_size = 1024
# Fine-tuning
learning_rate = 3e-5 # Lower LR for fine-tuning
max_iters = 2000
warmup_iters = 100
# Regularization
weight_decay = 1e-1Workflow 4: Custom dataset
Train on your own text:
# data/custom/prepare.py
import numpy as np
# Load your data
with open('my_data.txt', 'r') as f:
text = f.read()
# Create character mappings
chars = sorted(list(set(text)))
stoi = {ch: i for i, ch in enumerate(chars)}
itos = {i: ch for i, ch in enumerate(chars)}
# Tokenize
data = np.array([stoi[ch] for ch in text], dtype=np.uint16)
# Split train/val
n = len(data)
train_data = data[:int(n*0.9)]
val_data = data[int(n*0.9):]
# Save
train_data.tofile('data/custom/train.bin')
val_data.tofile('data/custom/val.bin')Train:
python data/custom/prepare.py
python train.py --dataset=customWhen to use vs alternatives
Use nanoGPT when:
- Learning how GPT works
- Experimenting with transformer variants
- Teaching/education purposes
- Quick prototyping
- Limited compute (can run on CPU)
Simplicity advantages:
- ~300 lines: Entire model in
model.py - ~300 lines: Training loop in
train.py - Hackable: Easy to modify
- No abstractions: Pure PyTorch
Use alternatives instead:
- HuggingFace Transformers: Production use, many models
- Megatron-LM: Large-scale distributed training
- LitGPT: More architectures, production-ready
- PyTorch Lightning: Need high-level framework
Common issues
Issue: CUDA out of memory
Reduce batch size or context length:
batch_size = 1 # Reduce from 12
block_size = 512 # Reduce from 1024
gradient_accumulation_steps = 40 # Increase to maintain effective batchIssue: Training too slow
Enable compilation (PyTorch 2.0+):
compile = True # 2× speedupUse mixed precision:
dtype = 'bfloat16' # Or 'float16'Issue: Poor generation quality
Train longer:
max_iters = 10000 # Increase from 5000Lower temperature:
# In sample.py
temperature = 0.7 # Lower from 1.0
top_k = 200 # Add top-k samplingIssue: Can't load GPT-2 weights
Install transformers:
pip install transformersCheck model name:
init_from = 'gpt2' # Valid: gpt2, gpt2-medium, gpt2-large, gpt2-xlAdvanced topics
Model architecture: See references/architecture.md for GPT block structure, multi-head attention, and MLP layers explained simply.
Training loop: See references/training.md for learning rate schedule, gradient accumulation, and distributed data parallel setup.
Data preparation: See references/data.md for tokenization strategies (character-level vs BPE) and binary format details.
Hardware requirements
- Shakespeare (char-level):
- CPU: 5 minutes
- GPU (T4): 1 minute
- VRAM: <1GB
- GPT-2 (124M):
- 1× A100: ~1 week
- 8× A100: ~4 days
- VRAM: ~16GB per GPU
- GPT-2 Medium (350M):
- 8× A100: ~2 weeks
- VRAM: ~40GB per GPU
Performance:
- With
compile=True: 2× speedup - With
dtype=bfloat16: 50% memory reduction
Resources
- GitHub: https://github.com/karpathy/nanoGPT ⭐ 48,000+
- Video: "Let's build GPT" by Andrej Karpathy
- Paper: "Attention is All You Need" (Vaswani et al.)
- OpenWebText: https://huggingface.co/datasets/Skylion007/openwebtext
- Educational: Best for understanding transformers from scratch
سكِلات في نفس المجال
Agent Evaluation
Testing and benchmarking LLM agents including behavioral testing, capability assessment, reliability metrics, and produc…
Agent Management
Create, manage, and orchestrate AI agents using the AI Maestro CLI. Use when the user asks to "create agent", "list agen…
Agent Manager Skill
Manage multiple local CLI agents via tmux sessions (start/stop/monitor/assign) with cron-friendly scheduling.…
Agent Memory Mcp
A hybrid memory system that provides persistent, searchable knowledge management for AI agents (Architecture, Patterns, …
Agent Memory Systems
Memory is the cornerstone of intelligent agents. Without it, every interaction starts from zero. This skill covers the a…
Agent Messaging
Send and receive cryptographically signed messages between AI agents using the Agent Messaging Protocol (AMP). Use when …
تبي سكِل مفصّل على شغلك أنت؟
نبني لك سكِلات ووكلاء ذكاء اصطناعي يفهمون نظامك ويشتغلون عليه.