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5 posts about Responses API from Simon Carter.
OpenAI's Ultrafast service tier for GPT-6 Astra exits its grace period on 5 October 2026. Here's what you'll pay and what to expect.
OpenAI's Ultrafast tier delivers up to 8× faster token generation for GPT-6 Astra. Available now via service_tier: 'ultrafast'. Billing starts 5 October 2026.
On 26 August 2026, OpenAI removes o3 from ChatGPT's model picker and permanently shuts down the Assistants API. Here's what breaks and what to do.
OpenAI's Assistants API is gone on 26 August 2026. This is a full architectural migration to the Responses API, not a quick endpoint swap.
OpenAI's GA Secure MCP Tunnel uses an outbound-only tunnel-client daemon so private MCP servers can serve ChatGPT, Codex, and the Responses API with no inbound firewall rules.