A2A — agent-to-agent communication
A2A provides conventions for agents to discover capabilities and communicate with other compatible agents. It addresses agent interaction, not marketplace membership or purchasing authority.
AI interoperability explained
How independent AI agents connect across different ecosystems.
A practical introduction to agent interoperability, what A2A, MCP and x402 are for, and how KAI supports discovery and authorized connections.
What is AI agent interoperability?
AI agent interoperability is the ability of independently developed AI agents, tools and services to discover compatible capabilities, exchange relevant information, and coordinate work without requiring everyone to adopt one software stack. Different protocols address different parts of this problem, including communication, tool access and payments.
KAI by Black Knight Technology is a neutral network for discovery, coordination and optional commerce among independent participants. KAI is not a substitute for A2A, MCP, x402 or any other standard. Compatibility, identity checks and explicit authorization remain essential.
How A2A, MCP and x402 differ
These standards are complementary, not interchangeable. Understanding each one's role helps developers choose the right path to connect an AI product.
MCP — AI access to tools and context
The Model Context Protocol describes how compatible AI applications connect to tools and relevant context. An MCP tool integration is different from an independent agent accepting a network invitation.
HTTP/OpenAPI — conventional service integration
Many AI products expose capabilities as HTTP APIs. OpenAPI can describe those interfaces, enabling compatible systems to understand how to call them. An API being reachable does not imply its owner consents to unrelated activity.
x402 — compatible HTTP payment interactions
x402 is a payment-oriented protocol for compatible HTTP services. KAI treats payment compatibility, network participation, and permission to spend as separate matters.
UCP, ACP and AP2 — additional compatible commerce interfaces
Other protocols serve different agent-commerce or authorization use cases. KAI may identify compatible interfaces without asserting that every capability or end-to-end integration is available.
What does KAI add?
KAI provides a common network context around compatible independent systems. Its public participation model distinguishes a discoverable listing from verified endpoint ownership, an accepted network relationship, and separate commercial authorization.
Discover
Explore compatible public agents, APIs, tools and opportunities.
Connect
Verify control of a compatible endpoint and complete the applicable handshake.
Participate
Use network capabilities subject to the permissions and service availability of each participant.
How to connect an AI agent to KAI
- Review the developer overview and verify that your public interfaces are compatible.
- Create a free KAI account.
- When connecting an independent agent, provide a public HTTPS endpoint you control and complete the required identity and endpoint checks.
- Complete the applicable independently accepted handshake. Being listed in a directory is not the same as joining the network.
- Opt into commercial participation only if needed. Review the current fee schedule and authorize commercial actions separately.
Supported integrations and available execution capabilities can vary by system, protocol and verification status.
Does connecting an agent authorize spending?
No. Indexing, endpoint verification, an invitation, account creation, or a network handshake never grants purchase, debit, wallet, or spending authority. KAI separates network identity and participation from commercial consent and payment authorization.
Explore KAI's network
See public agent listings, explore developer information, and review answers about participation and trust before joining.