What is Agent2Agent protocol (A2A)?

A2A uses familiar web technologies like HTTP, JSON, and server-sent events, making it easy for developers to integrate. It also includes built-in support for security, authentication, and long-running tasks, so agents can collaborate safely and reliably. In short, as businesses move from simple chat-style interactions to agentic AI, the need for agents to collaborate becomes crucial. Agent2Agent provides the shared language and security needed for these autonomous agents to work together across systems.

Why does A2A exists?

Today, most people interact with AI directly. A human user describes a goal, and the agent: 

• Interprets the request 
• Gathers information 
• Performs actions on the user’s behalf 
• Reports back 

This model works well for individual tasks, like writing an email, summarizing a document, generating code, or answering a question. But as soon as tasks require multiple systems, multiple domains, or multiple steps across an organization, A2P is not enough. 

Why? Because no single agent can know or do everything. 

As AI agents become more capable, organizations are creating: 

• Specialized agents (e.g., procurement agent, support agent, billing agent) 
• Domain experts (e.g., security agent, analytics agent) 
• System-connected agents (e.g., Workday, Salesforce, ServiceNow integrations) 

Each agent has knowledge or access to part of the puzzle. But they’re isolated. 

This creates three major gaps: 

1. Fragmentation of automation 

Users end up being the “glue” between agents. You ask one agent for something then manually tell another agent what happened. 

2. Bottlenecks and inefficiency 

An agent might find a problem, but can’t notify or delegate to another agent capable of fixing it. 

3. Broken workflows 

End-to-end automation is impossible if every step depends on a human acting as intermediary. 

This is the moment where A2A open protocol becomes essential. 

Once you have multiple agents, across multiple systems, each with partial context and specialized abilities, you need these agents to collaborate directly, not through a person. 

A2A is the natural next step of AI interaction, from agents helping humans, to agents helping each other to achieve outcomes on behalf of humans. 

How agent to agent protocol works 

The Agent2Agent (A2A) protocol gives AI agents a shared, secure way to discover each other, exchange capabilities, and collaborate on tasks. Instead of relying on custom integrations, A2A defines a common set of rules and message formats so any agent, regardless of vendor, framework, or runtime, can communicate reliably.  

A2A operates alongside the Model Context Protocol (MCP), which provides agents with access to tools and context, while A2A handles the communication layer between agents. 

At a high level, A2A coordination happens through five core mechanisms: 

1. Client agent → Remote agent interaction 

A2A defines two roles in every interaction: 

• Client agent: The agent that initiates a task 
• Remote agent: The agent that receives the task and performs the work 

This mirrors a familiar request–response model, but with richer, structured communication tailored for agent workflows. 

2. Capability discovery (agent cards) 

Before agents collaborate, they first need to understand what each one can do. 

A2A uses agent cards, simple JSON documents that describe an agent’s: 

• Capabilities 
• Supported modalities (text, images, audio, video, etc.) 
• Authentication requirements 
• Endpoint URLs 
• Optional metadata 

This allows a client agent to determine whether a remote agent is the right fit for the task. 

3. Task management & artifacts 

Agent2Agent organizes agent collaboration around tasks, structured objects with a clear lifecycle. 

A task includes: 

• Task ID 
• User request or goal 
• Context or additional messages 
• Status updates 
• Final output, called an artifact 

Tasks can be: 

• Instant: completed in a single response 
• Long-running: spanning minutes, hours, or even days 

For long-running work, agents stay synchronized through incremental updates and notifications. 

4. Real-time communication (HTTP, JSON-RPC, SSE) 

A2A builds on widely adopted web standards so developers can implement it easily: 

• HTTP POST: Used for structured requests between agents 
• JSON-RPC: Used for clear, predictable message formatting 
• Server-Sent Events (SSE): Used for asynchronous push updates, perfect for long-running tasks 

This ensures agents can communicate in a consistent, interoperable way without needing custom protocols. 

5. Collaboration through messages & parts 

Messages exchanged between agents include “parts,” which can contain: 

• Text 
• Images 
• Links 
• Structured data 
• Video 
• Audio 
• UI instructions (e.g., iframes, web forms) 

This makes A2A modality-agnostic, enabling agents to collaborate using whatever format best suits the task. 

Key features of the Agent2Agent protocol 

The Agent2Agent (A2A) protocol introduces a standardized way for AI agents to communicate and collaborate across different systems. To make this possible, A2A includes several core features designed for interoperability, security, and real-world enterprise use. 

1. Agent discovery & capability sharing 

Agents need to know what other agents can do before collaborating. 

A2A solves this through Agent Cards, structured JSON documents that describe: 

• An agent’s capabilities 
• Supported tools or actions 
• Authentication requirements 
• Supported content modalities 
• Available endpoints 

This lets a client agent automatically identify the right remote agent for a given task without manual configuration. 

2. Standardized task management 

A2A defines a consistent structure for creating, tracking, and completing tasks across agents. 

Each task includes: 

• A unique task ID 
• The request or instruction 
• Optional context messages 
• Running status 
• The final output (called an artifact) 

This makes it possible to orchestrate complex, multi-step workflows where tasks move fluidly between agents. 

3. Support for long-running, asynchronous workflows 

Not all tasks finish instantly. Some require minutes, hours, or even days, especially when humans are in the loop. 

A2A supports long-running tasks by enabling: 

• Continuous status updates 
• Partial results 
• Asynchronous push notifications via Server-Sent Events (SSE) 
• State synchronization between agents 

This allows agents to collaborate on deep research, multi-step automation, and extended enterprise processes without blocking or timing out. 

4. Built on familiar web standards 

A2A intentionally avoids reinventing communication protocols. Instead, it builds on widely adopted technologies: 

• HTTP → transport layer 
• JSON-RPC → structured message format 
• SSE → event streaming and updates 

Using these standards makes implementation simpler and integration far more reliable. 

5. Enterprise-grade security 

Agent2Agent is designed from the ground up for secure, compliant agent communication, especially crucial in enterprise environments. 

This open protocol supports: 

• JWT and OIDC authentication 
• Encrypted transport 
• Capability-level authorization 
• Identity verification 
• Secure credential handling 

This ensures agents only access what they’re allowed to, reducing the risk of spoofing, data leakage, or unauthorized actions. 

6. Modality-agnostic communication 

A2A isn’t limited to text exchanges. Agents can exchange: 

• Images 
• Audio 
• Video 
• Structured data 
• UI elements (e.g., forms, iframes) 

Each component is represented as a “part” in the message, allowing agents to negotiate the best format for collaboration. 

Agent2Agent security overview 

As soon as agents begin communicating directly, security becomes absolutely critical. 

Every message, task, and piece of data exchanged between agents must be trusted, authenticated, and properly controlled. A2A is built with enterprise-grade security from the start, ensuring agents can collaborate safely across platforms and environments. 

1. Strong identity & authentication (JWT, OIDC) 

A2A supports modern, standards-based authentication methods, including:

• JWT (JSON Web Tokens) 
• OIDC (OpenID Connect) 

This ensures that: 

• Agents can verify each other’s identity 
• Credentials aren’t shared insecurely 
• Only authorized agents can perform specific actions 

Each agent request carries verifiable proof of who is calling and what they’re allowed to do. 

2. Encrypted, secure communication 

All A2A communication happens over encrypted channels, protecting: 

• Sensitive business data 
• User information 
• Internal system access 

This is essential when agents operate across cloud providers, enterprise networks, or external services. 

3. Fine-grained authorization & policy control 

A2A allows organizations to enforce strict access controls, including: 

• Which agents can call which capabilities 
• What tasks an agent is allowed to perform 
• How data flows between agents 
• Which modalities (text, images, audio, etc.) are permitted 

This prevents unauthorized actions and limits the blast radius of misuse or compromise. 

4. Auditability & compliance support 

Every agent action can be logged, traced, and audited. This provides: 

• Clear records for compliance teams 
• Visibility into task execution 
• Traceability for incident response 
• Easier governance over multi-agent workflows 

As agents scale across an organization, these audit trails become indispensable. 

5. Securing multi-agent workflows 

Agent-to-Agent protocol helps reduce common security issues in multi-agent systems: 

• Spoofing (impersonating another agent) 
• Credential misuse 
• Unmonitored lateral data movement 
• Prompt or instruction injection 
• Agents overstepping permissions 

By standardizing security patterns, A2A ensures that even when agents chain tasks across multiple platforms, each step remains controlled and observable. 

6. Managing data privacy & compliance risks 

When agents share information, organizations must ensure that data handling policies remain intact. Agent2Agent supports: 

• Restricted data sharing rules 
• Redaction of sensitive fields 
• Controlled retention policies 
• Compliance-aware task boundaries 

This helps prevent data from leaking across agents or systems that shouldn’t have access.  

Use cases of the A2A protocol 

By allowing agents to discover each other, share capabilities, and coordinate tasks, organizations can automate complex processes that normally span multiple systems, teams, and tools. 

Here are some of the most compelling examples: 

1. Customer experience automation 

Customer support often involves many disconnected systems: ticketing, billing, product data, authentication, and more. With A2A: 

• A support agent can escalate a billing issue to a payments agent 
• A recommendation agent can prepare personalized solutions 
• A knowledge-base agent can fetch relevant documentation 
• A workflow agent can complete account updates automatically 
• An agent analyzer that reviews all interactions and generates a summary report 

Instead of siloed bots, A2A enables a coordinated team of agents working behind the scenes to deliver faster, smoother customer interactions. 

2. Supply chain optimization 

Supply chains are data-heavy and interconnected, perfect for multi-agent coordination. With Agent-to-Agent protocol: 

• A forecasting agent predicts demand 
• An inventory agent checks stock levels 
• A procurement agent automatically sends purchase requests 
• A logistics agent schedules fulfillment and delivery 
• A compliance or audit agent verifies regulatory requirements 

These agents collaborate across systems (ERP, logistics platforms, warehouse software) to reduce delays, prevent stockouts, and improve planning accuracy. 

3. Healthcare & diagnostics 

Healthcare workflows require multiple steps, multiple systems, and strict privacy controls. Agent2Agent allows: 

• A patient-record agent to retrieve medical history 
• A diagnostics agent to analyze symptoms, images, or lab data 
• A scheduling agent to coordinate follow-up appointments 
• A billing agent to handle insurance processes 

Each agent has only the access it needs, while the workflow remains seamless and secure. 

4. Hiring & candidate sourcing 

The talent lifecycle spans many tools, ATS systems, CRMs, productivity tools, scheduling platforms. With A2A: 

• A sourcing agent pulls qualified candidates based on the job description 
• A screening agent evaluates resumes or coding samples 
• A scheduling agent coordinates interview times 
• A background-check agent runs the necessary verifications 
• A hiring-ops agent processes final tasks 

5. Finance & operations automation 

Complex financial workflows often require multiple checks and validations. A2A enables: 

• Transaction-monitoring agents 
• Fraud-detection agents 
• Reconciliation agents 
• Risk-scoring agents 
• Reporting and compliance agents 

6. IT & internal automation 

Enterprises have countless repetitive internal tasks, perfect for agentic collaboration. A2A makes it possible for: 

• A procurement agent to request new hardware 
• A security agent to validate approvals 
• A directory agent to provision accounts 
• A service desk agent to update internal records 

Everything happens automatically, with agents coordinating across internal systems like Workday, ServiceNow, Okta, Jira, and more. 

A2A unlocks cross-system, multi-agent workflows that were previously impossible or required heavy custom engineering. By letting agents talk to each other directly, organizations can automate entire business processes, not just individual tasks.  

Challenges with Agent-to-Agent protocol adoption  

While the A2A protocol opens the door to powerful multi-agent collaboration, it also introduces new operational and security complexities. Connecting agents across systems is very different from connecting human users to a single agent. As enterprises adopt A2A, they must be prepared to manage a more dynamic, distributed, and unpredictable environment. 

Here are the key challenges organizations face: 

1. Expanded attack surface 

Each agent added to a system becomes a new potential entry point for attackers. A2A introduces risks such as: 

• Agent spoofing or impersonation 
• Stolen or misused credentials 
• Malicious prompt or instruction injection 
• Unauthorized cross-agent data movement 

Because agents now talk directly to each other, any weak link can compromise the entire workflow. 

2. Compliance & data governance blind spots 

Once agents begin exchanging sensitive data, traditional governance models struggle to keep up. Challenges include: 

• Ensuring downstream agents follow data-retention rules 
• Preventing sensitive fields from leaking into systems without clearance 
• Maintaining auditability across chained agent calls 
• Enforcing data sovereignty when workflows cross platforms 

Without strict controls, multi-agent workflows can quickly drift outside compliance boundaries. 

3. Latency, reliability & observability issues 

Agent-to-agent interactions are often asynchronous, chained, and multi-step. This creates challenges around: 

• Unpredictable latency across agent chains 
• Difficulty tracing where failures occur 
• Limited ability to debug or reproduce agent behavior 
• Missing visibility into how tasks flow across systems 

Traditional monitoring tools were not designed for autonomous, distributed agents. 

4. Schema drift & integration overhead 

Even with a standard protocol, agents still evolve over time. This leads to: 

• Mismatched payload formats 
• Outdated or deprecated capabilities 
• Breaking changes across agent versions 
• Brittle integrations that require constant maintenance 

In large environments, dozens of agents may all have slightly different schemas or expectations. 

5. Endpoint sprawl & operational complexity 

As organizations deploy more agents, they create more: 

• Endpoints 
• Authentication rules 
• Routing decisions 
• Coordination logic 
• Failure points 

Infrastructure teams must manage a rapidly expanding agent ecosystem that behaves more like a distributed microservices network, but with far less predictability. 

6. Governance across vendors & environments 

Because agents may live in different: 

• Clouds 
• Business units 
• Vendor environments 
• Versions of the A2A spec 

Without consistent governance, organizations risk fragmentation and policy inconsistencies. 

Agent2Agent is powerful, but it introduces real-world challenges around security, compliance, reliability, and operational management. To fully unlock the benefits of multi-agent collaboration, organizations must pair the A2A standard with strong governance, observability, and safety controls. 

The future of intelligent collaboration 

We’re moving from a world where agents work for people to a world where agents also work with each other, communicating, coordinating, and completing tasks across systems without human handoffs. 

A2A provides the standards, structure, and security needed to make this possible. By enabling agents to discover capabilities, exchange context, manage long-running tasks, and collaborate in real time, the protocol unlocks an entirely new level of automation and intelligence inside the enterprise. 

But for Agent2Agent to deliver its full value, organizations also need a strong foundation for communication, governance, and orchestration. This is where platforms like Infobip play an essential role, offering secure connectivity, compliance, observability, and human–agent interaction across every channel and system. 

With A2A and enterprise platforms working together, the future of automation becomes clear: connected agents, smarter workflows, faster decisions, and seamless experiences. 

FAQs: Agent2Agent (A2A) protocol