Reading up on Responses API

OpenAI's Secure MCP Tunnel lets users connect private MCP servers to OpenAI products via an outbound-only tunnel, keeping servers behind firewalls.

Prompt caching reduces latency by up to 80% and costs by up to 90% by reusing computed key/value tensors for repeated prompt prefixes in OpenAI's API.

OpenAI introduces Skills, a reusable bundle of instructions, scripts, and assets mounted into shell environments, enabling versioned, conditionally invoked workflows that keep system prompts lean.

OpenAI explains the architecture of Codex CLI's agent loop, detailing how it orchestrates model inference, tool calls, and context management using the Responses API.

OpenAI recommends migrating to the Codex-Max agentic model using the codex-cli prompt, compacted context, and specific tools for best performance on complex coding tasks.

OpenAI demonstrates building a GPT-5.1 coding agent that scaffolds NextJS/shadcn apps using shell, web search, apply_patch, and Context7 MCP tools via the Agents SDK and Responses API.