Agent2Agent (A2A)
AI agents are reshaping how tasks are automated, decisions are made and software systems collaborate. AI agents are getting smarter and can handle complex tasks but they are limited because they can’t easily team up and collaborate. To resolve this agent2agent protocol was introduced.

As the name suggest A2A is a standardized communication framework that allows AI agents to discover, interact and collaborate with each other on tasks without being constrained by their underlying technologies or platforms. It uses Agent Card that list agents capabilities which allow others to discover and interact with them. It supports task management, real-time messaging and sharing of results which makes cooperation efficient and flexible.
Key characteristics of agents in A2A systems:
- Autonomy: Each agent operates independently without human intervention.
- Interaction: Agents can interact with other agents to exchange information, delegate tasks or compete.
- Communication: Communication between agents is done to solve problems collaboratively or competitively.
- Adaptability: Agents can adapt their strategies based on interactions and external factors.
Key Components of Agent2Agent (A2A)
Here we will see key components of Agent2Agent protocol:

- Agent Abilities: It allows agents to collaborate effectively even if they don’t share memory or tools which enables them to work independently while still cooperating seamlessly.
- Use Common Web Standards: It established web standards like HTTP, Server-Sent Events (SSE) and JSON-RPC rather than creating new technologies which makes it easier to integrate with existing systems.
- Built-in Security: The protocol is designed with strong security features from the start, supporting standard authentication and permission checks which is essential for business applications.
- Support for Long Tasks: It is capable of managing tasks that take extended periods, providing real-time updates throughout the process which is crucial for complex business operations.
- Handling Multiple Data Types: It supports various data formats like text, audio, video and interactive elements which allows agents to choose the best format for the task at hand.
Workflow of Agent2Agent
The agent to agent protocol uses a client-server setup for organized communication. Lets understand the workflow with the help of an OrderBot example where one agnet give order to other.
1. Client-Server Model

- One agent i.e "client" (CustomerBot) requests a task such as checking if a product is in stock. Another agent "server" or "remote" agent (OrderBot) performs the task by querying the inventory.
- These roles can switch during the conversation which is a core feature of the communication protocol.
- Example: CustomerBot (the client) asks OrderBot (the server) to check if an item is available for purchase.
2. Agent Card
- An Agent Card is a JSON file that acts as an agent’s profile.
- It includes the agent’s ID, name, role, security needs and available capabilities.
- This helps client agents find the right server agent for a specific task.
- Example: CustomerBot consults OrderBot’s Agent Card to see if OrderBot has the capability to check inventory.

3. Task-Based Workflow
- The main unit of work is called a task.
- The stages it goes through are: Submitted (started), Working (in progress), Input-required (needs more information), Completed (finished successfully), Failed (encountered an error) or Cancelled (stopped early).
- Example: OrderBot goes through the task stages, starting with checking inventory and finally confirming availability.

4. Message Structure
- During task execution, agents communicate using messages.
- Messages contain parts that hold content such as text, files, data or forms allowing exchange of rich information.
- Example: CustomerBot requests inventory information by sending a message to OrderBot.
5. Artifacts for Results
- The output of a completed task is delivered as artifacts.
- These artifacts are structured results, ensuring the final output is consistent and easy to use.
- Example: Once OrderBot completes the inventory check it provides an artifact with structured results.

Types of Agent Interactions in A2A
A2A systems can be categorized based on the way agents interact:
1. Cooperative Agent Interaction
- In cooperative A2A agents collaborate to achieve a shared goal. They exchange resources, strategies or plans to tackle tasks that would be difficult to complete individually.
- Example: In a supply chain, agents representing suppliers, warehouses and retailers coordinate to optimize inventory management and ensure timely deliveries.
2. Competitive Agent Interaction
- In competitive A2A interaction, agents have conflicting goals and may compete with each other to achieve their individual objectives. This is commonly seen in auctions, games or resource allocation scenarios.
- Example: In an online auction like eBay, agents representing bidders compete for limited items each striving to place the highest bid.
3. Negotiative Agent Interaction
- This interaction involves agents negotiating to reach mutually beneficial agreements. Such interactions typically occur when agents need to resolve conflicts or come to an agreement on terms of collaboration.
- Example: In a supply negotiation two agents representing a buyer and a seller negotiate pricing, delivery schedules and other conditions.
4. Mediated Communication
- In mediated A2A systems an intermediary agent often called a "mediator," facilitates communication between agents. This approach is useful when direct communication between agents would be inefficient or difficult.
- Example: A traffic management system where individual vehicles (agents) communicate with a central traffic control system (mediator) to optimize the flow of traffic.
A2A vs. MCP
The following table provides a comparative overview of A2A and Model Context Protocol MCP:
Feature | Agent2Agent (A2A) | Model Context Protocol (MCP) |
|---|---|---|
Primary Focus | Facilitates communication and collaboration between autonomous agents. | Enables interaction between a model and external tools or data sources. |
Originator | Anthropic | |
Key Technical Concepts | Agent Cards, Tasks, Messages (Parts), HTTP/JSON-RPC, SSE for real-time streaming. | Host, Client, Server, Tools, Resources, Prompts. |
Communication | Task-based, asynchronous communication with potential natural language tasks. | Structured requests for accessing external tools and contextual data, typically using specific schemas like JSON Schema. |
Primary Use Case | Supports collaborative workflows across independent agents in various systems. | Facilitates AI models access to external data, files and APIs. |
Applications of A2A Systems
A2A systems have a broad range of applications across various fields:
- Robotics and Autonomous Vehicles: It is used to coordinate the movement of autonomous vehicles in fleets, ensuring efficient traffic flow, collision avoidance and route optimization. Vehicles communicate with each other to exchange information about road conditions, traffic and obstacles.
- Smart Grids: In smart grid systems it coordinates energy units like solar panels, wind turbines and batteries to maintain grid stability. These agents communicate to balance supply and demand for electricity, optimize energy storage and minimize waste.
- Supply Chain Management: It optimizes operations in supply chains where agents represent suppliers, manufacturers and distributors. These agents communicate to manage inventory, predict demand and ensure timely deliveries.
- Online Auctions and Markets: It enables communication between agents in online marketplaces like eBay where buyers and sellers interact, negotiate and finalize transactions.
Advantages of Agent2Agent
- Interoperability: It uses common web protocols like HTTP and JSON-RPC that ensures seamless communication between agents across different platforms and technologies, promoting integration in heterogeneous environments.
- Flexibility: It supports various data formats such as text, audio and video which allows agents to adapt to different types of tasks and environments, making it versatile in real-world applications.
- Built-in Security: It uses standard authentication and permission checks which ensures secure and authorized communication between agents, protecting sensitive data and maintaining privacy.
- Real-Time Collaboration: It is well-suited for long-running tasks and providing real-time updates which is crucial for industries like supply chain management where continuous progress tracking is essential.
Challenges in Agent2Agent
A2A systems face several challenges:
- Coordination and Conflict Resolution: Ensuring smooth collaboration and resolving goal conflicts is vital for system efficiency.
- Scalability: More agents increase communication and coordination complexity, requiring advanced management techniques.
- Privacy and Security: Preventing data leaks and resisting attacks demands strong security measures.
- Communication Protocols: Different protocols or languages complicate interactions; standardization or adaptability is needed.
- Decentralized Control: Without central oversight, aligning agents toward shared goals is harder and can cause inefficiency, which requires careful management.