Changelog | OpenAI API

6 min read Original article ↗

December, 2025

Feature

gpt-image-1.5

chatgpt-image-latest

Feature

gpt-realtime-mini

gpt-audio-mini

gpt-4o-mini-transcribe

gpt-4o-mini-tts

Released four new dated audio snapshots. These updates deliver reliability, quality, and voice fidelity improvements for real-time, voice-driven applications: gpt-realtime-mini-2025-12-15 gpt-audio-mini-2025-12-15 gpt-4o-mini-transcribe-2025-12-15 gpt-4o-mini-tts-2025-12-15

Read more here.

Feature

gpt-5.2

gpt-5.2-chat-latest

v1/responses

v1/chat/completions

Released GPT-5.2, the newest flagship model in the GPT-5 model family. GPT-5.2 shows improvements over the previous GPT-5.1 in:

  • General intelligence
  • Instruction following
  • Accuracy and token efficiency
  • Multimodality—especially vision
  • Code generation—especially front-end UI creation
  • Tool calling and context management in the API
  • Spreadsheet understanding and creation.

What's new in 5.2 is a new xhigh reasoning effort level, concise reasoning summaries, and new context management using compaction.

November, 2025

Feature

gpt-5.1

gpt-5.1-codex

gpt-5.1-chat-latest

gpt-5.1-codex-mini

v1/responses

v1/chat/completions

Released GPT-5.1, the newest flagship model in the GPT-5 model family. GPT-5.1 is trained to be especially proficient in:

  • Steerability and faster responses when less thinking's required
  • Code generation and coding use cases
  • Agentic workflows

Note that GPT-5.1 defaults to a new none reasoning setting for faster responses when less thinking's required—different from the previous medium default setting in GPT-5.

October, 2025

Feature

gpt-5-pro

gpt-realtime-mini

gpt-audio-mini

gpt-image-1-mini

sora-2

sora-2-pro

v1/responses

v1/batch

v1/chat/completions

v1/videos

v1/realtime

v1/images/generations

September, 2025

Feature

gpt-5-codex

v1/responses

Launched special-purpose model gpt-5-codex, built and optimized for use with the Codex CLI.

August, 2025

Added support for connectors to the Responses API. Connectors are OpenAI-maintained MCP wrappers for popular services like Google apps, Dropbox, and more that can be used to give model read access to data stored in those services.

Feature

v1/conversations

v1/responses

v1/assistants

Released the Conversations API, which allows you to create and manage long-running conversations with the Responses API. See the migration guide to see a side-by-side comparison and learn how to migrate from an Assistants API integration to Responses and Conversations.

Feature

v1/chat/completions

v1/responses

Released GPT-5 family of models in the API, including gpt-5, gpt-5-mini, and gpt-5-nano.

Introduced the minimal reasoning effort value to optimize for fast responses in GPT-5 models (which support reasoning).

Introduced custom tool call type, which allows for freeform inputs to and outputs from the model when tool calling.

June, 2025

Feature

o3-deep-research

o3-deep-research-2025-06-26

o4-mini-deep-research

o4-mini-deep-research-2025-06-26

v1/responses

New reusable prompts are now available in the dashboard and Responses API. Via API, you can now reference templates created in the dashboard via the prompt parameter (with a prompt id, optional version) and supply dynamic variables that can include strings, images, or file inputs. Reusable prompts are not available in Chat Completions. Learn more.

Feature

o3-pro

v1/responses

v1/batch

Released o3-pro, a version of the o3 reasoning model that uses more compute to answer hard problems with better reasoning and consistency. Prices for the o3 model have also been reduced for all API requests, including batch and flex processing.

Added fine-tuning support with direct preference optimization for the models gpt-4.1-2025-04-14, gpt-4.1-mini-2025-04-14, and gpt-4.1-nano-2025-04-14.

Feature

v1/chat/completions

v1/realtime

May, 2025

Feature

v1/responses

v1/chat/completions

Added support for using strict mode for tool schemas when using parallel tool calling with non-fine-tuned models. Added new schema features, including string validation for email and other patterns and specifying ranges for numbers and arrays.

Feature

codex-mini-latest

v1/responses

v1/chat/completions

Feature

v1/fine-tuning

v1/responses

v1/chat/completions

April, 2025

Feature

v1/images/generations

v1/images/edits

Added a new image generation model, gpt-image-1. This model sets a new standard for image generation, with improved quality and instruction following.

Updated the Image Generation and Edit endpoints to support new parameters specific to the gpt-image-1 model.

Feature

v1/chat/completions

v1/responses

Added two new o-series reasoning models, o3 and o4-mini. They set a new standard for math, science, and coding, visual reasoning tasks, and technical writing.

Launched Codex, our code generation CLI tool.

Feature

gpt-4.1

gpt-4.1-mini

gpt-4.1-nano

v1/responses

v1/chat/completions

v1/fine_tuning

Added gpt-4.1, gpt-4.1-mini, and gpt-4.1-nano models to the API. These new models feature improved instruction following, coding, and a larger context window (up to 1M tokens). gpt-4.1 and gpt-4.1-mini are available for supervised fine-tuning. Announced deprecation of gpt-4.5-preview.

March, 2025

Added gpt-4o-mini-tts, gpt-4o-transcribe, gpt-4o-mini-transcribe, and whisper-1 models to the Audio API.

Feature

o1-pro

v1/responses

v1/batch

Released o1-pro, a version of the o1 reasoning model that uses more compute to answer hard problems with better reasoning and consistency.

Feature

gpt-4o-search-preview

gpt-4o-mini-search-preview

computer-use-preview

v1/chat/completions

v1/assistants

v1/responses

Released several new models and tools and a new API for agentic workflows:

  • Released the Responses API, a new API for creating and using agents and tools.
  • Released a set of built-in tools for the Responses API: web search, file search, and computer use.
  • Released the Agents SDK, an orchestration framework for designing, building, and deploying agents.
  • Announced new models: gpt-4o-search-preview, gpt-4o-mini-search-preview, computer-use-preview.
  • Announced plans to bring all Assistants API features to the easier to use Responses API, with an anticipated sunset date for Assistants in 2026 (after achieving full feature parity).

Feature

v1/fine_tuning/jobs

Added metadata field support to fine-tuning jobs.

February, 2025

Feature

GPT-4.5

v1/chat/completions

v1/assistants

v1/batch

Released a research preview of GPT-4.5—our largest and most capable chat model yet. GPT-4.5's high "EQ" and understanding of user intent make it better at creative tasks and agentic planning.

January, 2025

Feature

o3-mini

o3-mini-2025-01-31

v1/chat/completions

Launched o3-mini, a new small reasoning model that is optimized for science, math, and coding tasks.

December, 2024

Launched Admin API Key Rotations, enabling customers to programmatically rotate their admin api keys.

Updated Admin API Invites, enabling customers to programmatically invite users to projects at the same time they are invited to organizations.

Feature

o1

gpt-4o

gpt-4o-mini

v1/fine_tuning

v1/chat/completions

v1/realtime

Launched Usage API, enabling customers to programmatically query activities and spending across OpenAI APIs.

November, 2024

Update

v1/chat/completions

Feature

v1/chat/completions

Released Predicted Outputs, which greatly reduces latency for model responses where much of the response is known ahead of time. This is most common when regenerating the content of documents and code files with only minor changes.

October, 2024

Feature

gpt-4o-realtime-preview

gpt-4o-audio-preview

v1/chat/completions

Feature

gpt-4o-audio-preview

v1/chat/completions

Feature

v1/realtime

v1/chat/completions

v1/fine_tuning

Released several new features at OpenAI DevDay in San Francisco:

Realtime API: Build fast speech-to-speech experiences into your applications using a WebSockets interface.

Model distillation: Platform for fine-tuning cost-efficient models with your outputs from a large frontier model.

Image fine-tuning: Fine-tune GPT-4o with images and text to improve vision capabilities.

Evals: Create and run custom evaluations to measure model performance on specific tasks.

Prompt caching: Discounts and faster processing times on recently seen input tokens.

Generate in playground: Easily generate prompts, function definitions, and structured output schemas in the playground using the Generate button.

September, 2024

Feature

omni-moderation-latest

v1/moderations

Released new omni-moderation-latest moderation model, which supports both images and text (for some categories), supports two new text-only harm categories, and has more accurate scores.

Feature

o1-preview

o1-mini

v1/chat/completions

Released o1-preview and o1-mini, new large language models trained with reinforcement learning to perform complex reasoning tasks.

August, 2024

Feature

gpt-4o

v1/fine_tuning

Update

gpt-4o

v1/chat/completions

Launched Admin and Audit Log APIs, allowing customers to programmatically administer their organization and monitor changes using the audit logs. Audit logging must be enabled within settings.

July, 2024

Launched self-serve SSO configuration, allowing Enterprise customers on custom and unlimited billing to set up authentication against their desired IDP.

Released GPT-4o mini, our affordable an intelligent small model for fast, lightweight tasks.

Released Uploads to upload large files in multiple parts.

June, 2024

May, 2024

Released GPT-4o in the API. GPT-4o is our fastest and most affordable flagship model.

Added a new endpoint to delete a message from a thread in the Assistants API.

April, 2024

Introduced project based hierarchy for organizing work by projects, including the ability to create API keys and manage rate and cost limits on a per-project basis (cost limits available only for Enterprise customers).

March, 2024

Added support for streaming in the Assistants API

February, 2024

January, 2024

Released embedding V3 models and an updated GPT-4 Turbo preview

Added dimensions parameter to the Embeddings API

December, 2023

November, 2023

October, 2023