OpenAI chat-latest Launches: Always Tracks ChatGPT's Default Instant Model

Documentation Index

Fetch the complete documentation index at: https://docs.apiyi.com/llms.txt

Use this file to discover all available pages before exploring further.

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Highlights

• Version-less alias: Renamed from gpt-5.3-chat-latest to the cleaner chat-latest — no more version-number coupling
• Always current: Auto-tracks ChatGPT’s active Instant model snapshot (currently GPT-5.5 Instant)
• Big context: 400K tokens input, 128K tokens max output, knowledge cutoff 2025-08-31
• Multimodal input: Text + image input, text-only output (no audio/video)
• Official pricing: Input $5, output $30, cached input $0.50 per 1M tokens — identical to OpenAI’s rates
• Recharge promo: APIYI’s stackable recharge bonus brings effective cost down to 79-86% of OpenAI’s list

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Background

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Detailed Breakdown

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Key Features

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Currently Points to: GPT-5.5 Instant

• ~50%+ fewer hallucinations on factual QA tasks
• More concise replies: default behavior leans “short and precise,” cuts redundant scaffolding
• Better instruction following on complex multi-step instructions
• AIME 2025: 81.2 (vs 65.4 previous generation)
• Multimodal reasoning: measurable gains on visual data interpretation and clinical accuracy
• Cross-conversation memory: can reference past conversations, files, and Gmail (full experience in ChatGPT; API uses call-time context)

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Technical Specs

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Practical Use

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Recommended Scenarios

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Code Example

from openai import OpenAI

client = OpenAI(
    api_key="your-apiyi-key",
    base_url="https://api.apiyi.com/v1"
)

# Plain text
response = client.chat.completions.create(
    model="chat-latest",
    messages=[
        {"role": "system", "content": "You are a concise assistant — keep replies under two sentences."},
        {"role": "user", "content": "What is a token?"}
    ],
    stream=False
)
print(response.choices[0].message.content)

response = client.chat.completions.create(
    model="chat-latest",
    messages=[{
        "role": "user",
        "content": [
            {"type": "text", "text": "What does this image say?"},
            {"type": "image_url", "image_url": {
                "url": "https://example.com/screenshot.png"
            }}
        ]
    }]
)
print(response.choices[0].message.content)

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Best Practices

• Production stability first → use pinned snapshots: If your business is highly sensitive to model behavior and you don’t want auto-upgrades, use gpt-5.5 or a specific snapshot; chat-latest is for the “roll with ChatGPT” scenario.
• Cached input saves money: chat-latest’s cached input is $0.50/M tokens — 1/10 of regular input. Long system prompts and long RAG contexts should actively leverage caching.
• Multimodal cost: Image input is tiled and converted to tokens for billing — complex images can consume more than you’d expect. Estimate with OpenAI’s Tokenizer before going to production.
• Don’t assume fine-tuning: chat-latest does not support fine-tuning — pick another snapshot if you need it.

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Pricing & Availability

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Side-by-side Pricing

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Effective Price (with Recharge Promo)

• Top up $100 → ~86% of list (effective input ~$4.30, output ~$25.80)
• Top up $300+ → as low as 79% of list (depending on the tier; see Recharge Promotions FAQ)

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Available Groups

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Summary & Recommendation

1. Clear naming: version numbers no longer mislead — the alias literally means “same as ChatGPT”
2. Stable integration: integrate once, benefit long-term — no code changes when OpenAI rolls the Instant model
3. Official semantics: currently points to GPT-5.5 Instant, will auto-follow future ChatGPT default upgrades