* 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
We special-case string enumerables, translating them to an array of text content blocks, but other enumerables just get serialized, and there's a reasonable expectation that returning a string[] would produce a JSON array of strings. Just delete the special-casing.
* 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
* Propagate CancellationToken request cancellation to remote endpoint
* Refactor existing tests to have a shared base class
* Add cancellation tests
---------
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.
* Improve progress reporting
- Enable injecting an `IProgress<>` into a tool call to report progress when the client has supplied a progress token
- Add a custom type for ProgressToken and ProgressNotification to map to the schema
- Simplify RequestId to match ProgressToken's shape
- Serialize StdioClientTransport's SendMessageAsync implementation
- Add strongly-typed names for all request methods
- Change all request IDs created by McpJsonRpcEndpoint to include a guid for that endpoint
* Address PR feedback
- 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>
* List tools from DI once
- Follow best practice to not mutate options outside of IConfigureOptions
- Long-term, we should move the repeated work from SetToolsHandler into
an IPostConfigureOptions service or IMcpServerConnectionFactory
* Add Can_Create_Multiple_Servers_From_Options_And_List_Registered_Tools
* Flip stdin and stdout in StreamClientTransport
* s/McpToolType/McpServerToolType
* Clarify stdin and stdout refers to server process in StreamClientTransport
* fixup
* Add [McpServerTool] support for instance methods
By popular demand, enables [McpServerTool] on instance methods. The instance is constructed per invocation, using ActivatorUtilities.CreateInstance when possible so that constructor arguments are satisfied from DI.
* Add disposal tests
* Overhaul tool handling
- Renames [McpTool{Type}] to [McpServerTool{Type}], in order to distinguish representations of tools on the server from tools on the client.
- Enables [McpServerTool] methods to have arguments injected from DI, as well as a specific set of types from the implementation directly, like IMcpServer.
- Renames WithTools to WithToolsFromAssembly.
- All of the WithToolsXx methods now publish each individual McpServerTool into DI; other code can do so as well. The options setup code gathers all of the tools from DI and combines them into a collection which is then stored in McpServerOptions and used to construct the server.
- The server tools specified via DI as well as manually-provided handlers, using CallToolHandler as a fallback in case the requested tool doesn't exist in the tools collection, and ListToolsHandler augments the information for whatever tools exist.
- The tools are stored in McpServerOptions in a new McpServerToolCollection type, which is a thread-safe container that exposes add/removal notification. Adding/removing tools triggers a change notification that in turn sends a notification to the client about a tools update.
- The ServerOptions are exposed from the server instance.
- Removed cursor-based APIs from McpClientExtensions.
- Changed McpClientExtensions APIs to return `Task<IList<...>` rather than `IAsyncEnumerable<...>`.
I'm sure this will need to evolve further before we're "done", but it's a significant improvement from where we are now. One area I'm not super happy with is the notifying collection; that might work ok for a stdio server, where you can grab the created collection from the server's options and mutate it, but I don't know how well that's going to work for sse servers.
* Make McpServerTool{Collection} extensible
* Fix README.md example
* Add notifications test
* Address feedback
