Agent-to-agent protocols

The following table provides an overview of agentic protocols that enable multiple agents to collaborate, delegate tasks, and share information.

Protocol	Ideal for	Considerations
MCP inter-agent communication	Organizations seeking flexible agent collaboration patterns	An extension to the Model Context Protocol (MCP) proposed by AWS that builds on its existing foundation for agent-to-agent communication Enables seamless agent collaboration with OAuth-based security
A2A protocol	Cross-platform agent ecosystems	Backed by Google Newer standard with more limited adoption compared to MCP
AutoGen multi-agent	Research-focused multi-agent systems	Backed by Microsoft Strong for complex agent interactions
CrewAI	Role-based agent teams	Independent implementation Good for simulating organizational structures

Deciding among protocol options

When implementing agent-to-agent communication, match your specific communication requirements with the appropriate protocol capabilities. Different interaction patterns require different protocol features. The following table outlines common communication patterns and recommends the most suitable protocol choices for each scenario.

Pattern	Description	Ideal protocol choice
Simple request and response	One-off interactions between agents	MCP with stateless flows
Stateful dialogues	Ongoing conversations with context	MCP with session management
Multi-agent collaboration	Complex interactions between multiple agents	MCP inter-agent or AutoGen
Team-based workflows	Hierarchical agent teams with defined roles	MCP inter-agent, CrewAI, or AutoGen

Beyond communication patterns, several technical and organizational factors can influence your protocol selection. The following table outlines key considerations that can help you evaluate which protocol aligns most closely with your specific implementation requirements.

Consideration	Description	Example
Security model	Authentication and authorization requirements	OAuth 2.0 in MCP
Deployment environment	Where agents will run and communicate	Distributed or single machine
Ecosystem compatibility	Integration with existing agent frameworks	LangChain or Strands Agents
Scalability needs	Expected growth in agent interactions	Streaming capabilities of MCP