Protocols

Open Responses is an open specification and ecosystem, based on the OpenAI Responses API, that gives applications one shared schema for calling models, streaming results and composing agentic workflows across providers.

Large language modelsOpen sourceDeveloper tools

OpenSandbox is a general-purpose sandbox platform for AI applications, contributed by Alibaba to the Agentic AI Foundation. It offers multi-language SDKs, a unified sandbox API, Docker and Kubernetes runtimes, and a protocol that lets teams plug in custom runtimes.

Open sourceSafety & governanceDeveloper tools

Agent Skills are folders of instructions, scripts and resources that Claude loads when they are relevant to a task. Anthropic introduced them on 16 October 2025 and donated the open standard to the Agentic AI Foundation in October 2026.

Open sourceAgents & tool useDeveloper tools

OpenEnv is an open framework and community hub from Hugging Face for building reinforcement-learning environments as containerized services that expose an agent interface, MCP and the Gym training protocol. It was contributed to the Agentic AI Foundation in October 2026.

Large language modelsOpen sourceDeveloper tools

The Model Context Protocol (MCP) is an open standard for connecting AI assistants to the systems where data lives. Anthropic open-sourced it on 25 November 2024 and later donated it to the Agentic AI Foundation.

Open sourceAgents & tool useDeveloper tools

/llms.txt is a proposed standard file that a website publishes so AI agents can find clean, structured information about it. Jeremy Howard published the proposal on 3 September 2024, and a second version followed two years of adoption.

Open sourceDeveloper toolsInteroperability

GPT Actions let a custom GPT call external APIs, turning a user's request into the JSON input an API needs. Introduced by OpenAI on 6 November 2023, they grew out of the plugins beta and rely on OpenAPI schemas plus authentication settings.

Large language modelsEnterpriseDeveloper tools

Function calling, now also called tool calling, lets an application describe external functions to a model, which then decides whether to emit JSON arguments for one of them — the route by which models reach data and actions outside their training data.

Large language modelsAgents & tool useDeveloper tools

OWL is a W3C Recommendation published on 10 February 2004: a semantic markup language for publishing and sharing ontologies on the Web, giving software formal definitions of terms so it can process the meaning of information, not just display it.

Research historyOpen sourceData & datasets

NLWeb is a set of open protocols and open-source tools that give websites a conversational interface, returning Schema.org JSON over natural language and doubling as an MCP server so the same API serves people and AI agents.

Agents & tool useDeveloper toolsInteroperability

OASF is a standardized, extensible schema system from the AGNTCY project for describing AI agent attributes, skills and capabilities in machine-readable records, so that agents can discover and understand each other across protocols.

Open sourceData & datasetsInteroperability

SLIM (Secure Low-Latency Interactive Messaging) is a secure transport protocol for agent traffic. It carries A2A, MCP and SLIMRPC over one encrypted overlay, lets agents connect outbound and be reached by name, and publishes SDKs for six languages.

Open sourceSafety & governanceInteroperability

ACP (Agent Communication Protocol) is an open protocol for agent interoperability, connecting AI agents, applications and humans through a standardised RESTful API. It was developed under the Linux Foundation alongside BeeAI and now sits within A2A, with a migration guide for existing users.

Open sourceAgents & tool useInteroperability

AG-UI is an open, event-based protocol that connects AI agents to user-facing applications, standardising how agent state, UI intents and user interactions flow between an agent backend and a front end.

Agents & tool useDeveloper toolsInteroperability