OpenAI

OpenAI: GPT-5.3 Codex

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openai/gpt-5.3-codex
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GPT-5.3 Codex is OpenAI's most advanced agentic coding model, released on 2026-02-25, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge of GPT-5.2. It reaches state-of-the-art results on SWE-Bench Pro and performs strongly on Terminal-Bench 2.0 and OSWorld-Verified, reflecting improved multi-language coding, terminal proficiency, and real-world computer-use skills. It supports reasoning, tool use, prompt caching, web search, and image, audio, and video input. Context window: 512K tokens, output: 128K. Accessible via the OpenAI-compatible protocol through Ofox.

Context Window
512K
Max Output Tokens
128K
Released
2026-02-25
Capabilities
VisionFunction CallingReasoningPrompt CachingWeb SearchAudio InputVideo Input
Available Providers
AzureAzure
Supported Protocols
OpenAIopenai

Providers

AzureAzure
Input Tokens
$1.75/M
Output Tokens
$14/M
Cache Read
$0.18/M
Web Search
$0.035/R
Protocols
OpenAIopenai/v1/responses

Code Examples

from openai import OpenAI


client = OpenAI(
    base_url="https://api.ofox.run/v1",
    api_key="YOUR_OFOX_API_KEY",
)


response = client.chat.completions.create(
    model="openai/gpt-5.3-codex",
    messages=[
        {"role": "user", "content": "Hello!"}
    ],
)


print(response.choices[0].message.content)

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Frequently Asked Questions

OpenAI: GPT-5.3 Codex on Ofox.ai costs $1.75/M per million input tokens and $14/M per million output tokens. Pay-as-you-go, no monthly fees.