Open source Protocols

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.

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.

/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.

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.

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 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.

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.

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.

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.

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.