* Initial plan
* Add Description property to Implementation type
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
* Add test to validate client Description from server perspective
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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
Co-authored-by: Stephen Toub <stoub@microsoft.com>
Rather than always serializing to a JsonElement, which IChatClients that consume the tool won't be able to reason about, convert the content into AIContents that they can reason about.
* Decouple Handlers and Collections (e.g. ToolsHandler and ToolsCollection) from Capabilities by promoting them to the options types.
Also, group all handlers in container classes, for server, I decided to move McpServerHandlers down to Mcp.Core and move the NotificationHandlers there too.
Also, Fix ListResourceTemplatesHandler issue.
* Add remarks for empty protocol capability types
* Keep JsonIgnore properties and mark them as Obsolete
* Continue supporting Obsolete members
* Update Obsolete messages to indicate the member will be removed
* Add EditorBrowsable Never to the remaining obsolete members
* Update content according to latest spec
* Add Title to a bunch of types
* Add _meta to lots of types
* Address feedback, more cleanup, fix NAOT test failure
* Add McpServer/ClientResource{Template} and friends
This PR copies the same design used by tools and prompts to add McpServerResource, McpServerResourceAttribute, McpServerResourceTypeAttribute, McpClientResource, and then all of those for ResourceTemplate as well.
Unlike the others, [McpServerResource] is permitted not only on methods but also on properties. This convenience is afforded because such resources aren't parameterized, and thus can be easily modeled as properties, likely auto-props, e.g.
```C#
[McpServerResource]
public static BlobResourceContents MyAmazingData { get; } = Create();
```
Details about resources can be encoded into the attributes or provided via McpServerResource{Template}.Create methods. If not URI is explicitly defined, one is derived from the member name and arguments. For templates, this means manufacturing a URI template that includes variables for all non-DI parameters.
This also fixes a few issues discovered along the way:
- McpClientExtensions are updated to use `ValueTask<T>` instead of `Task<T>` where relevant.
- McpServerPrompt was missing handling for progress notifications; that's been rectified. It was also missing configuring the description on the ProtocolPrompt.
- Renamed IMcpServerPrimitive.Name to Id. For resources, names aren't unique.
- After going back and forth, updated McpServer to not fail for missing handlers and to instead register default handlers. It simplifies the implementation and makes it more consistent.
- Added a bunch of primitive types into the McpJsonUtilities JSON source generator context so that such primitives are usable with tools/prompts/resources without folks being required to add them into their own context for Native AOT. I think we should consider pushing this down to AIJsonUtilities, instead, and that will then flow up to McpJsonUtilities automatically.
* Address feedback
* Add idle session pruning tests
* Remove redundant CTS from StreamableHttpHandler
* StreamableHttpServerTransport.HandlePostRequest already creates the equivelant CTS
which DeleteRequest_CompletesSession_WhichCancelsLongRunningToolCalls verifies
* Fix accept header validation for GET
* Use InvalidOperationException for transport-not-connected errors in doc comments
* Fix flaky Cancellation_ThrowsCancellationException test
- Changes IJsonRpcMessage to an abstract base class so RelatedTransport will always be available
- Streamable HTTP supports multiple concurrent HTTP request with their own indpendent SSE response streams
- RelatedTransport indicates the source or destination of the JsonRpcMessage
- Changes the default RequestId to a JSON number for better compatibility with MCP servers in the wild
* Propagate CancellationToken request cancellation to remote endpoint
* Refactor existing tests to have a shared base class
* Add cancellation tests
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Co-authored-by: Stephen Toub <stoub@microsoft.com>
* Remove McpServerConfig and have McpClientFactory accept IClientTransport instances directly.
* Address feedback and use lists when representing stdio arguments.
* Use "Name" for transport descriptors and "EndpointName" for MCP clients and servers.
* Update code samples.
* Fix source file naming
- We still allow notification handlers to be configured pre-creation, eliminating any race conditions that may result from missed notifications. But now we also allow for post-creation notification handler registration.
- Handlers may now also be removed. This permits temporary registrations that may be created in a scoped manner.
- Registration handling is thread-safe.
- Handlers are now cancelable.
- Exceptions from notification handlers trigger all normal exception handling in the dispatch pipeline.
This also:
- Adds a WithStreamServerTransport as a counterpart to WithStdioServerTransport. The latter was used in several tests in a hacky way, and that's now simplified via the former's existence.
* Move notification handler registrations to capabilities
Currently request handlers are set on the capability objects, but notification handlers are set after construction via an AddNotificationHandler method on the IMcpEndpoint interface. This moves handler specification to be at construction as well. This makes it more consistent with request handlers, simplifies the IMcpEndpoint interface to just be about message sending, and avoids a concurrency bug that could occur if someone tried to add a handler while the endpoint was processing notifications.
* Address more feedback and further cleanup
* Allow user-defined JsonSerializerOptions for user-defined and inputs and hardcode everything else to the source generator.
* Add validation for user-defined JsonSerializerOptions.
* Remove out of date comment.
* Address feedback and add tests
- We were adding tools/prompts from the collections on every request. If multiple requests came in with different cursors, we'd re-add the same tools each time.
- We were defeating the purpose of pagination by doing all of the aggregation in the server. If a custom handler returns a paginated result, we should instead propagate that back to the client, who can choose to get more results when needed.
- This also paves the way for better multi-session support
- We should definitely rethink names for the transport API
- For now, I kept the names similar as possible, so we can
focus on the API shape
Co-authored-by: Stephen Toub <stoub@microsoft.com>
