Released GPT-6 Astra, our most capable model, built for the hardest end-to-end work. Use GPT-6 Astra for reasoning, coding, computer use, research, and document creation. It combines these capabilities to carry complex tasks from an initial request to a finished result, using the context and tools you provide. Key changes to consider when migrating: GPT-6 Astra does not support the none reasoning effort level. GPT-6 Astra does not support custom temperature or top_p values or log probabilities (logprobs). Tool calling requires the Responses API. If you use tools with Chat Completions, follow the Responses migration guide. Misalignment monitoring asynchronously checks for potential issues during agent work in supported Responses API requests. Checks can trigger safety alerts or stop a conversation for review. Start with Using GPT-6 Astra for capabilities, prompting, and migration guidance. Explore computer use for browser and desktop workflows, and see pricing for available inference tiers.
Added new controls for long-running work with GPT-6 Astra in the Responses API: Async tool calling: Let the model continue working while your application runs function or custom tools, then return results as they become available. Mid-turn steering: Send additional instructions while a response is in progress over WebSockets, so the model can incorporate corrections or changing requirements. Change reasoning effort mid-conversation: Increase effort for difficult work or reduce it for routine follow-ups while preserving the cached prompt prefix.
Updated API errors so applications can distinguish traffic that increases too quickly from temporary model overload. Traffic that increases too quickly can return a 429 error with the slow_down code. Temporary model overload returns a 503 error with the server_is_overloaded code. Both responses may include Retry-After. When the header is present, wait at least as long as it specifies before retrying. If it's missing, use exponential backoff. See the error codes guide and rate limits guide.
Mutual TLS (mTLS) and X.509 workload identity federation are now generally available for the OpenAI API. Configure certificates and X.509 identity providers directly in the Platform console, with access controlled by your organization's roles and permissions.
Announced the deprecation of whisper-1, gpt-4o-transcribe, gpt-4o-mini-transcribe, and gpt-4o-transcribe-diarize. These models will shut down on February 26, 2027. Migrate to gpt-live-transcribe or gpt-transcribe. See the transcription guide and deprecations page. The Assistants API shut down on August 26, 2026. Migrate to the Responses API and Conversations API using the migration guide.
API customers can now select regional processing for an individual request by using a prefixed domain with an API key from a project having Global geography. Existing eligibility, data retention control, endpoint, and model support requirements continue to apply. Learn more in the data controls guide.
GPT-5.6 Sol now costs $4 per million input tokens and $20 per million output tokens, representing 20% lower input pricing and 33% lower output pricing. GPT-5.6 Sol’s promotional pricing is available at least through November 21, 2026. See pricing details.
Released the Prompt Caching dashboard on the OpenAI API platform. Track your cache hit rate over time, cache reads per write, and the breakdown of cache-read, cache-write, and uncached tokens to understand your caching efficiency and identify opportunities to improve. Filter metrics by model and service tier.
Transparent backgrounds are now available in preview for gpt-image-2 and gpt-image-2-2026-04-21 in the Images API and the Responses API image generation tool. Set background to transparent and use png or webp output; jpeg does not support transparent backgrounds. Learn more in the image generation guide.
Announced Ultrafast mode, a new API service tier for GPT-5.6 Sol that runs up to 14x faster than Standard processing. Available in limited preview to select customers. Sign up to receive updates on Ultrafast mode here.
Daybreak now offers two access tiers for approved defenders: Daybreak Blue and Daybreak Red. Use them to move from security findings to validated fixes in explicitly authorized engagements. Start with Daybreak Blue for most defensive security work. It provides access to general-purpose models such as GPT-5.6 Sol for vulnerability discovery, secure code review, detection engineering, incident response, malware analysis, and patch validation. Read more here. Daybreak Red provides separately approved access to purpose-trained models such as GPT-5.6 Cyber for authorized vulnerability reproduction, exploit validation, penetration testing, red teaming, and complex system analysis. These models require separate approval and provisioning. You can apply to join the Daybreak program here. More details on pricing here.