A2A agent cards
type: TechArticle
description: The Agent-to-Agent (A2A) protocol lets an autonomous agent find another autonomous agent and call it over JSON-RPC. Discovery hinges on a single well-known file: `/.well-known/agent-card.json`. Relevant whenever your service exposes agentic behaviour another agent might want to delegate to.
language: en
is part of: Web Specification Studio
author: Web Specification Studio
publisher: Web Specification Studio
license: https://creativecommons.org/licenses/by/4.0/
date modified: 2026-05-29T11:27:49.000Z
citation: A2A Protocol — Specification
  type: CreativeWork
  publisher: A2A Project (Linux Foundation)
citation: A2A Protocol — Agent Discovery
  type: CreativeWork
  publisher: A2A Project (Linux Foundation)
citation: a2aproject/A2A on GitHub
  type: CreativeWork
  publisher: A2A Project
citation: RFC 8615 — Well-Known URIs
  type: CreativeWork
  publisher: IETF

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type: WebSite

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type: Organization

breadcrumb
type: BreadcrumbList
item list element: Home
  type: ListItem
  position: 1
  item: https://webspecification.com/
item list element: Spec
  type: ListItem
  position: 2
  item: https://webspecification.com/spec/
item list element: Agent Readiness
  type: ListItem
  position: 3
  item: https://webspecification.com/spec/agent-readiness/
item list element: A2A agent cards
  type: ListItem
  position: 4
  item: https://webspecification.com/spec/agent-readiness/a2a-agent-cards/