Enterprise Protocols

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.

Google's 2025 open protocol for discovery, communication, and collaboration across agents from different vendors or frameworks.

An open protocol announced by Google on 17 September 2025 for securely initiating and settling payments carried out by AI agents across platforms, using signed Mandates as verifiable proof of a user's instructions.

An open standard released by OpenAI with Stripe in September 2025 that lets AI agents, people and businesses complete purchases together, and the basis of Instant Checkout in ChatGPT.