Breaking

OpenAI Keeps GPT-5.5 Available in the API and API-Key Codex Sessions

September 15, 2026 at 16:13 EDT

Foundation Models
AI Agents
Software Dev & Coding

OpenAI said GPT-5.5 will continue to be available through the OpenAI API Platform and in Codex sessions authenticated with an API key, preserving access for developers who have pinned workflows to the previous-generation flagship model. The clarification matters because OpenAI's Codex documentation now steers ChatGPT-signed-in users toward newer recommended models while still listing GPT-5.5 as an available option for API-backed use.

Sep. 15, 2026 · OpenAI

GPT-5.5 stays on the API path

OpenAI is keeping GPT-5.5 available through the API Platform and Codex sessions authenticated with an API key, even as recommended Codex routes move toward GPT-5.6 models.

1,050,000

token context window

128,000

maximum output tokens

$5 / $30

GPT-5.5 input and output per 1M tokens

Price comparison: GPT-5.5 vs GPT-5.6 Sol

Each stacked block represents $1 per 1 million tokens. GPT-5.6 Sol is priced lower than GPT-5.5 for both input and output tokens.

Input tokens

GPT-5.5 $5

Sol $4

Output tokens

GPT-5.5 $30

Sol $20

Output blocks use $5 increments.

Continuity

Pinned API agents, CI jobs, evaluations, and cost dashboards can keep using GPT-5.5 where API access is available.

Migration pressure

ChatGPT-signed-in Codex users are being guided toward GPT-5.6 models, so mixed authentication setups still need review.

What changes in practice

API Platform→API-key Codex→Saved model audit

The key distinction is authentication: API-key routes preserve GPT-5.5 access, while ChatGPT-signed-in Codex defaults are moving to newer recommended models.

Continue reading

The rest of this article is for AI News Blitz readers. Choose an option below to keep reading.