GPT 5 Codex
OpenAI
openai/gpt-5-codex
Reasoning model, 272K context
Context Window
272K
272,000 tokens
Max Output
128K
128,000 tokens
About this model
GPT-5 Codex β specialized for software engineering tasks
This model supports up to 272K tokens of context. It excels at complex reasoning, mathematical problems, and multi-step tasks. It provides strong code generation and debugging capabilities.
Access it through Chuizi.AI with a single ck- API key β no separate OpenAI account needed.
Highlights
272K context window
128K max output
Advanced reasoning
Strong code generation
Best For
Complex coding tasksAlgorithm designCode reviewTechnical architecture
2025-09-15
Capabilities
ChatReasoningCodetoolscache
Aliases
gpt-5-codexPricing (per 1M tokens)
| Pricing (per 1M tokens) | / 1M tokens |
|---|---|
| Input / 1M | $1.31 |
| Output / 1M | $10.50 |
| Cache Read | $0.13 |
Final prices shown
Quick Start
main.py
from openai import OpenAI client = OpenAI( base_url="https://api.chuizi.ai/v1", api_key="ck-your-key-here", ) response = client.chat.completions.create( model="openai/gpt-5-codex", messages=[{"role": "user", "content": "Hello!"}], ) print(response.choices[0].message.content)