// COMPARISON
MCP vs A2A: Which Agent Protocol Should You Use?
MCP (Model Context Protocol) and A2A (Agent2Agent Protocol) serve different but complementary purposes. MCP connects agents to tools and resources, while A2A enables agents to communicate with each other. Understanding when to use each is critical for AI agent architecture.
02 Detailed Breakdown
Architecture
MCP uses a client-server model where an MCP client (the agent) connects to MCP servers (tools, databases, APIs). A2A uses a peer-to-peer model where agents discover each other via Agent Cards and exchange tasks and artifacts. MCP is for tool access; A2A is for agent collaboration.
Use Cases
Use MCP when your agent needs to access external tools — databases, file systems, APIs. Use A2A when multiple agents need to collaborate on a task — e.g., a research agent handing off to a writing agent. Many agents support both protocols for full-stack interoperability.
Maturity
MCP launched in late 2024 and has broad adoption across major registries. A2A launched in 2025 and is growing rapidly but has fewer production deployments. For stability, MCP is the safer choice today. For cutting-edge multi-agent workflows, A2A is worth exploring.
// VERDICT
Winner: MCP
MCP wins for tool integration and is the more mature, broadly adopted protocol today. A2A is essential for multi-agent collaboration workflows. Most production agents should support both — MCP for tools, A2A for agent-to-agent communication.
03 Frequently Asked Questions
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