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OpenAI sanctions Codex API backdoor for immediate GPT-5.5 model access

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OpenAI sanctions Codex API backdoor for immediate GPT-5.5 model access
OpenAI confirmed the Codex backend API is an officially supported route for using personal subscriptions in third-party tools. While the standard gpt-5.5 API is delayed for safety testing, this mechanism provides immediate access to the model and its xhigh reasoning setting (a mode for increased internal deliberation).

This shift positions OpenAI as a developer-friendly alternative to competitors who recently blocked subscription-to-API bridges. Sanctioning this access allows developers to maintain workflows in terminal agents and custom editors without waiting for a formal rollout or incurring per-token costs during early testing.

Access the model now by installing the Codex CLI and the llm-openai-via-codex plugin. Once the official API launches, gpt-5.5 will cost $5 per 1M input tokens and $30 per 1M output tokens—double the price of the previous GPT-5.4 model series.

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Frequently asked questions

How can I access the GPT-5.5 API right now?
While the official developer API is delayed, you can access GPT-5.5 through the Codex backend API. This method is officially supported by OpenAI for use in external tools and terminal-based agents. You need an active ChatGPT or Codex subscription and can use tools like the Codex CLI or the llm-openai-via-codex plugin to connect.
What is the pricing for the GPT-5.5 API?
When the official API launches, GPT-5.5 will cost $5 per 1 million input tokens and $30 per 1 million output tokens. This is exactly double the price of the GPT-5.4 model. For users requiring even higher performance, GPT-5.5 Pro will be available at $30 per 1 million input and $180 per 1 million output tokens.
What is the reasoning effort parameter in GPT-5.5?
GPT-5.5 includes a reasoning effort parameter that allows users to control how much internal deliberation the model performs before answering. The xhigh setting enables the model to spend more time on complex logic or spatial tasks, such as generating detailed SVG code. This mode uses significantly more reasoning tokens and takes longer to produce a final response.
Is the Codex API backdoor officially allowed by OpenAI?
Yes, OpenAI has confirmed that using the Codex backend API to connect personal subscriptions to third-party applications is officially supported. This includes integration with IDEs like Xcode and JetBrains, as well as terminal tools. This policy allows developers to use their existing ChatGPT plans in their preferred coding environments without waiting for the standard API release.
How does GPT-5.5 compare to GPT-5.4 in terms of performance?
GPT-5.5 is positioned as a more capable and expensive successor to GPT-5.4. While GPT-5.4 remains available at half the price, GPT-5.5 offers improved performance on complex tasks, particularly when using high reasoning effort. Early testing shows it can handle intricate spatial reasoning and code generation tasks that previous versions struggled to complete accurately.