modelcontextprotocol
Support `ETag` in listing endpoints
Is your feature request related to a problem? Please describe. The current API spec does not suggest (or mandate) ways for the server to suggest when updates are available. Note that this is different from returning deltas based on timestamps.
Describe the solution you'd like
Responses of GET /v0/servers SHOULD contain an ETag header that the Client SHOULD use on subsequent requests. The Client can still specify a updated_since query parameter, the two are complementary.
The same reasoning could be applied to /v0/servers/{serverName}/versions endpoint.
Describe alternatives you've considered
None, but ETag was suggested in many MCP SEPs and seemed not too controversial to suggest it here as well.
Additional context None
Thanks for the proposal! I'm trying to understand what this would enable beyond what we have with updated_since.
You mention that ETags are "different from returning deltas based on timestamps" and complementary to updated_since. Could you expand on what concrete use cases or client patterns this unlocks? My concern is adding two mechanisms that address similar problems.
