AI Agent Protocols in 2026: MCP vs A2A vs ACP — When to Use Each

AI Agent Protocols in 2026: MCP vs A2A vs ACP — When to Use Each

What Are the Three Major AI Agent Protocols in 2026? By mid-2026, the AI agent ecosystem has converged around three dominant protocols: MCP (Model Context Protocol) for connecting agents to tools and data sources, A2A (Agent-to-Agent) for enabling autonomous agent collaboration, and ACP (Agent Communication Protocol) for structured message passing between distributed agents. Each solves a fundamentally different problem, and choosing the wrong one is one of the most common mistakes teams make when building agentic systems today. ...

July 16, 2026 · 8 min · baeseokjae
UCP vs ACP 2026: Agent Commerce Protocols Compared

UCP vs ACP 2026: Agent Commerce Protocols Compared

The Two Protocols Trying to Define How AI Agents Buy Things By mid-2026, two competing standards are vying to become the default way AI agents handle commerce: Google’s Universal Commerce Protocol (UCP) and OpenAI/Stripe’s Agentic Commerce Protocol (ACP). Both solve the same fundamental problem — how does an AI agent discover products, negotiate a purchase, and complete a transaction on behalf of a human — but they approach it from very different angles. ...

July 13, 2026 · 7 min · baeseokjae
JetBrains ACP Agent Registry: Connect AI Agents to Your IDE

JetBrains ACP Agent Registry: Connect AI Agents to Your IDE (2026 Guide)

The JetBrains ACP Agent Registry is a curated, one-click marketplace for AI coding agents inside IntelliJ IDEA, PyCharm, WebStorm, and other JetBrains IDEs. Launched January 28, 2026, it lets you install Claude Code, Cursor, Gemini CLI, and 30+ other agents in seconds — no manual JSON editing required. What Is the JetBrains ACP Agent Registry? The JetBrains ACP Agent Registry is the world’s first open, cross-editor AI agent marketplace, jointly built by JetBrains and Zed Industries and launched on January 28, 2026. It solves a problem that frustrated developers for years: every AI coding agent had its own proprietary installation process — download a binary, edit JSON config files, restart the IDE, repeat. The registry replaces that friction with a browser-like “one-click install” for any ACP-compatible agent directly inside IntelliJ IDEA, PyCharm, WebStorm, GoLand, and other JetBrains IDEs running version 2025.3 or later. As of mid-2026, the registry lists 30+ agents including Claude Code, Cursor, Gemini CLI, GitHub Copilot, OpenHands, Kimi CLI, Goose, Cline, and Koog (JetBrains’ own Junie agent). The registry is open — any developer or company can submit an ACP-compatible agent for inclusion. Both JetBrains and Zed share the same backend registry, meaning an agent listed there works in both editors without duplication. ...

June 2, 2026 · 14 min · baeseokjae