SEP-1686: Tasks

[mikekistler]

Is your feature request related to a problem? Please describe.

Implement support for SEP-1686, which has been accepted for the next version of the MCP spec.

Note that some details of this SEP are still being finalized within the Core Maintainers.

Describe the solution you'd like

Compliance with the next version of the MCP spec within two weeks of its release.

[mikekistler]

I believe our initial support for this SEP should be to allow servers to support tasks if they choose. In other words, make it possible, but defer convenience features until there is clear signal that developers want them.

I think this means:

• Support sending and handling the new RPCs: tasks/list, tasks/get, tasks/result.
• Support sending notifications/tasks/created
• Allow taskId to be set in and read from requests (maybe no work here, as I think this is just a _meta field)
• Allow related-tasked to be set in requests, notifications, and responses (again, maybe no work)

[mikekistler]

For sending values in _meta of requests / notifications, I think we will want to update the "high-level" methods to accept a Meta to include in the message. Here's a list of methods I think should be updated:

• McpClient

  • CallToolAsync
  • GetPromptAsync
  • ListPromptsAsync
  • ListResourceTemplatesAsync
  • ListResourcesAsync
  • ListToolsAsync
  • PingAsync
  • ReadResourceAsync
  • SetLoggingLevel
  • SubscribeToResourceAsync
  • UnsubscribeFromResourceAsync
  • (whatever high-level method sends the initialize request)

• McpServer

  • ElicitAsync
  • RequestRootsAsync
  • SampleAsync
  • (ping is done with SendRequestAsync)

• McpSession

  • NotifyProgressAsync