Main Issue: MCP Supports

[hangfei]

• (WIP) MCP Prompts (Get prompts list from MCP server #684)
• MCP Auth ([Feature] Pre-load MCP servers + MCP Authentication handling #2531, Pass Httpx Auth with token provider to MCPSessionManager #2759, MCPToolset ignores auth_scheme/auth_credential during initialization and tool listing #2168, Implement outbound MCP authentication #805, MCP Tools: No mechanism to pass user JWT token through ADK session.state to MCP server context #1402)
• MCP Resources (MCP Resources in addition to Tools #1779, MCP Prompt and Resources #3030)
• MCP Sampling (MCPToolset Support MCP Sampling #2296)
• MCP progress, notification(Support for MCP Progress, Notifications, and Logging in MCP Toolset #3398)
• MCP Performance
• MCP Elicitation (MCPToolset missing elicitation support #2135)
• compliance with RFC 8707 (MCPToolset is pending compliance with RFC 8707 #2534)

[hsuyuming]

Hi @hangfei :
Do we have an estimated timeline for when this issue will be supported?
#2168

[cedric654]

All the planned and upcoming auth improvements are great, but RFC 8414 (OAuth 2.0 Authorization Server Metadata) is still missing. Without it, the flow can’t be fully standards-compliant, and we’re forced to rely on hard-coded endpoints instead of proper metadata discovery.

While AuthenticatedFunctionTool mostly behaves as expected, the underlying McpToolset still lacks RFC 8414 support, leaving a compliance gap.

Also noting that PR #2061 does address RFC 8414, but it has been open since July with no development.

Adding RFC 8414 would ensure full MCP standards compliance and better alignment with the broader OAuth ecosystem, significantly improving interoperability. A future addition of RFC 7591 (Dynamic Client Registration) would help round out standards support even further.

[DinoChiesa]

"MCP Support" is a big topic. Is it possible to prioritize some of these items?

• As I understand the requirement for DCR (RFC 7591) is now being deprecated in the latest MCP specification. I doubt many people would be upset if ADK just never built support for this.
• Elicitation - is a nifty flourish in MCP, but it also is not highly adopted. As such maybe it's a 2nd (3rd?) priority.
• things like RFC 8414 for discovery will be useful across every OAuth-enabled service. That seems like 1st priority.

just my opinion.