OpenAI Donates Open Responses API Spec to Agentic AI Foundation

OpenAI gives Open Responses to AAIF

OpenAI said Thursday it is donating the Open Responses API specification to the open source Agentic AI Foundation (AAIF). The foundation is part of the Linux Foundation and launched in December 2025 with MCP, goose, and AGENTS.md as its first projects. Open Responses joins other AAIF projects, including the MCP and A2A protocols, AGENTS.md, goose, agentgateway, and Agent Router.

In addition, OpenSandbox, Anthropic's Agent Skills, and Hugging Face's OpenEv framework for agent environments are joining the foundation. An OpenAI spokesperson said the company co-founded AAIF and contributed AGENTS.md to give coding agents project-specific instructions.

A shared format across providers

The core idea behind Open Responses is to give developers core API calls that work across large language model providers. OpenAI first announced the specification in January and noted that virtually all LLM providers now offer the same building blocks, such as messages, tool calls, and function calling, but represent them differently in their APIs.

Open Responses aims to standardize these primitives so developers do not have to translate between each vendor's idiosyncratic API when they switch models. The OpenAI spokesperson said Open Responses addresses another part of building agents by giving developers a shared format for working with models across endpoints that support it, so they have fewer provider-specific integrations to maintain.

Who supports it

Supporters listed include AWS in Bedrock, Databricks, LM Studio, Ollama, Hugging Face, Nvidia, OpenRouter, Red Hat, Vercel, and open source projects such as vLLM and OGC, previously known as Llama Stack. Vercel AI Gateway and Databricks Model Serving already implement the specification.

Anthropic is absent from that list. The company defines its own Messages API for giving developers access to its models, although it is a member of AAIF. Google also has its own default through the Interactions API. Open Responses does not hide its lineage: its contributor guide notes that its core schema files are copied from OpenAI's API.

Fragmentation and neutral governance

OpenAI's earlier Chat Completions API became an early standard that others modeled their offerings after. Anthropic's Messages API has also left a clear mark, in large part thanks to the success of Claude Code, with DeepSeek, Moonshot, Z.ai, MiniMax, and others exposing Anthropic-compatible endpoints.

That split is the kind of fragmentation a vendor-neutral specification is meant to fix. Companies donate projects to foundations partly for a neutral home. The AAIF is part of the Linux Foundation, which has become a de facto standard for providing vendor-neutral homes for popular open source projects. A technical steering committee, initially made up of project maintainers, will handle technical discussions.

Sources: The New Stack