Agent2Agent (A2A) works as an open protocol from Google, giving independent AI agents a common way to communicate and collaborate securely, no matter which framework or platform they were built on.
What Is A2A?
Google introduced A2A in April 2025 as a direct response to a core problem in agentic AI. Custom-building every agent-to-agent connection by hand used to be the norm, simply because different frameworks couldn’t talk to each other. A2A was developed to address this challenge, drawing early support from more than 50 major partners like Atlassian, PayPal, and Salesforce. Google then handed the protocol to the Linux Foundation to guarantee it remained a vendor-neutral, open standard. IBM’s Agent Communication Protocol (ACP) was merged into A2A shortly after.
Technically, A2A runs on familiar web standards: HTTP, JSON-RPC, and Server-Sent Events. Each agent publishes an Agent Card, a JSON file describing its skills and requirements, so other agents can find and delegate tasks to it. Paired with MCP, which handles an agent’s access to tools and data, A2A is the layer that adtech-specific standards like AdCP build on.
Benefits of A2A
In digital advertising specifically, A2A is already showing up inside agentic buying systems. IAB Tech Lab’s ARTF framework supports A2A communication, enabling agents running as co-located containers within a single platform to negotiate and coordinate directly during real-time bidding. Platforms like PubMatic’s AgenticOS have already run live campaigns built on this kind of agent-to-agent coordination, with agents handling the media strategy, the buy, and the real-time optimization entirely on their own.
Beyond these specific cases, A2A helps avoid vendor lock-in. Because it’s an open protocol, not tied to any single company’s platform, advertisers, publishers, and adtech providers can pick whichever agent works best for a given task instead of being stuck with one provider. Authentication and security requirements are defined in the Agent Card, enabling partners to collaborate safely without exposing how their agents work internally.
Perspectives of Adoption
A2A adoption accelerated once the Linux Foundation assumed control of the protocol in mid-2025. Major platforms like AWS, Microsoft, SAP, ServiceNow, and Salesforce moved into production within the first year. By March 2026, the protocol hit its stable v1.0 release, with over 150 organizations running it.
This is a pretty typical pattern for young standards: big platforms with the resources to move fast are usually first to jump in, and smaller, more specialized vendors follow once the tooling matures. For programmatic advertising, that second wave is likely to arrive around 2027, once more supply- and demand-side platforms have working integrations and the industry settles on how agents verify and trust one another.