Proposal: Support for Client-Aware AgentCard Serving in A2A

[vishalmysore]

Hi A2A Team,

I'd like to propose a flexible enhancement to the A2A protocol to support client-specific agent experiences. Currently, AgentCard objects are generally served uniformly to all clients, regardless of the context or identity of the requesting client. In many real-world applications, however, different clients may need different views, capabilities, or even agent skillsets based on:

Their identity (e.g., clientId)

Their type (e.g., mobile vs. desktop, internal vs. external)

Runtime context (e.g., device info, region, tenant)

Proposal Summary
Introduce a ClientInfo object in the A2A request schema that allows clients to optionally identify themselves, enabling the server to tailor AgentCard responses accordingly.

Example Schema:

"clientInfo": {
  "type": "object",
  "properties": {
    "clientId": { "type": "string" },
    "clientType": { "type": "string" },
    "deviceId": { "type": "string" },
    "tags": {
      "type": "array",
      "items": { "type": "string" }
    }
  },
  "required": ["clientId"]
}

Optionally, enhance AgentCard with:

"audience": {
  "type": "array",
  "items": { "type": "string" },
  "description": "List of client IDs or tags this card is intended for."
}

Use Cases
Multi-tenant SaaS: Serve different capabilities to clients based on their subscription plan.

Context-aware agents: Deliver simplified AgentCards to mobile clients and full-featured ones to desktop.

Security filtering: Hide certain skills or capabilities for restricted clients or user roles.

A/B testing: Dynamically adjust agent exposure based on experiment tags.

Benefits
Backward-compatible: Clients that don’t provide clientInfo can continue receiving the default card.

Enhances personalization and UX.

Enables richer agent ecosystem logic (like context-specific cards or private/internal agent networks).

Would love to hear thoughts from the community on this, and whether similar use cases are being explored. I’d be happy to provide a PR or schema extension prototype if it helps move the idea forward.