OpenAI API exposes GPT-5.5 Instant through model ID chat-latest. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.
Last refreshed 2026-06-19. Next refresh: weekly.
Quick Start
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Code Examples
pip install openaiOPENAI_API_KEYchat-latestUse the model slug directly, e.g. "gpt-4o" or "gpt-4.1-mini".
import os
from openai import OpenAI
client = OpenAI() # reads OPENAI_API_KEY from env
response = client.chat.completions.create(
model="chat-latest",
messages=[{"role": "user", "content": "Hello"}]
)
print(response.choices[0].message.content)Pricing on OpenAI API
| Type | Price (per 1M) |
|---|---|
| Input tokens | $5.00 |
| Output tokens | $30.00 |
Capabilities
About GPT-5.5 Instant
GPT-5.5 Instant is OpenAI's latest Instant model used in ChatGPT, released May 5, 2026 as the new default ChatGPT model and exposed in the API as chat-latest. OpenAI says the update improves factuality, image analysis, STEM answers, web-search decisions, personalization from past chats/files/connected Gmail, and concise conversational style. OpenAI reports 52.5% fewer hallucinated claims than GPT-5.3 Instant on high-stakes prompts and 37.3% fewer inaccurate claims on difficult conversations flagged for factual errors.