OpenAI for Developers in 2025

This post details the 2025 evolution of OpenAI's platform for developers, emphasizing the shift towards agent-native APIs and improved models for production AI systems. Key technical contributions include: the convergence of reasoning, tool use, and conversational quality into flagship model lines (e.g., GPT-5.x family); the GA of the Realtime API for low-latency, bidirectional audio streaming; new image generation models (GPT Image 1, 1.5) with enhanced quality and editing; Sora 2 & 2 Pro for higher-fidelity video generation with remixing support; the Video API exposing video generation and editing; PDF inputs and PDF-by-URL for document-heavy workflows; the maturation of Codex into a "Software Engineer teammate" with GPT-5.2-Codex, an open-source CLI for local repo interaction, and integrations for sandboxing, approval modes, AGENTS.md, and MCP; the Responses API supporting multiple inputs/outputs across modalities and reasoning controls; the open-source Agents SDK and AgentKit for easier agent orchestration; improved state management with Conversation state and the Conversations API; standardized tools like web search, file search (RAG), Code Interpreter, and computer use; and primitives for scaling agent jobs including prompt caching, background mode, webhooks, and mature rate limits.