Add ElicitAsync<T> (#630) #715
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- Refactored `ElicitResult` to a generic class `ElicitResult<T>` for typed content. - Added `ElicitAsync<T>` method in `McpServerExtensions.cs` to request user input and construct schemas based on type `T`. - Implemented schema building logic to handle primitive types and enums, ignoring unsupported types. - Introduced `ElicitationTypedTests.cs` for testing the new elicitation functionality with typed forms. - Verified naming policies in tests to ensure correct serialization casing. - Defined `SampleForm` and `CamelForm` classes for expected input shapes, including unsupported properties for schema testing. - Created JSON serialization contexts for both forms using source generation for improved performance.
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@stephentoub Could you review this, please? |
halter73
reviewed
Aug 21, 2025
…ion. modelcontextprotocol#630 Renamed `BuildRequestSchemaFor<T>` to `BuildRequestSchema<T>`. Updated the implementation to use `CreatePrimitiveSchema` and enhanced type checks for supported primitives with `AIJsonUtilities.CreateJsonSchema`. Streamlined handling of unsupported types by consolidating return statements.
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@eiriktsarpalis I've made the changes based on your suggestions, utilizing |
Simplified the `ElicitAsync` method in `McpServerExtensions.cs` by removing unnecessary JSON object construction and directly deserializing `raw.Content`. Updated `CreatePrimitiveSchema` to use `JsonTypeInfo` for type checking and adjusted return logic for unsupported types. In `ElicitationTypedTests.cs`, modified the `Can_Elicit_Typed_Information` test to account for the new `Created` property in `SampleForm`, increasing the expected property count from 5 to 6. Added assertions for the type and format of the `Created` property and included its deserialization in the test setup.
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@eiriktsarpalis I reviewed the MCP specification and realized I was mistaken. It does support datetime, but it’s converted into a string type with 'date-time' formatting, consistent with |
…ocol#630 Introduce exception handling in `McpServerExtensions.cs` for unsupported types. Add a test case in `ElicitationTypedTests.cs` to verify exception throwing for unsupported types. Define a new `UnsupportedForm` class with nested properties and include JSON serialization attributes for proper handling.
Introduce validation to ensure only object types are supported for elicitation requests in the `BuildRequestSchema` method. An exception is thrown for non-object types. Update the test suite with a new test case to verify this behavior, ensuring that an exception is raised when eliciting a non-object generic type (e.g., string) and that the elicitation handler is not invoked in this scenario.
Introduce `TryValidateElicitationPrimitiveSchema` method to validate JSON schemas for elicitation requests. This method checks for object type, verifies the "type" property, and ensures compliance with allowed properties based on primitive types (string, boolean, number). Integrate this validation in the `BuildRequestSchema` method to ensure generated schemas are valid before further processing.
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@eiriktsarpalis I think I've addressed all your feedback. Would you mind reviewing it again? |
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@eiriktsarpalis Now it supports both nullable types like |
Co-authored-by: Eirik Tsarpalis <[email protected]>
…tprotocol#630 Updated the `GetOrAdd` method to use a generic type parameter for .NET, allowing for better handling of `JsonSerializerOptions`. Retained the original implementation for other frameworks to ensure compatibility.
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@eiriktsarpalis All done! |
…tocol#630 - Simplified "type" property handling in Converter. - Changed s_lazyElicitAllowedProperties to nullable type. - Updated ElicitAsync to use static lambda for clarity. - Refactored CreatePrimitiveSchema to handle nullable types. - Initialized allowed properties in TryValidateElicitationPrimitiveSchema. - Updated ElicitationTypedTests for naming conventions and added tests for nullable properties. - Enforced required properties in SampleForm and introduced NullablePropertyForm. - Added JSON source generation context for NullablePropertyForm.
Refactor JSON schema type handling and add integer support This commit simplifies the validation logic for the `type` property in the JSON schema by removing unnecessary conditional checks. It directly retrieves the string value from `typeProperty` and assigns it to `typeKeyword`. Additionally, it enhances the `s_lazyElicitAllowedProperties` dictionary to include support for the `integer` type, allowing it to be recognized as a valid type with its corresponding allowed properties.
- Introduced `IsAccepted` property in `ElicitResult` and `ElicitResult<T>` to indicate if the action was accepted. - Changed `ElicitAsync<T>` to return `ValueTask<ElicitResult<T>>` instead of `ValueTask<ElicitResult<T?>>`, ensuring non-nullable results. - Updated return statements in `ElicitAsync<T>` to reflect the new return type, treating `Content` as non-nullable.
Co-authored-by: Eirik Tsarpalis <[email protected]>
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@eiriktsarpalis All done. |
Co-authored-by: Eirik Tsarpalis <[email protected]>
stephentoub
reviewed
Sep 12, 2025
| ThrowIfElicitationUnsupported(server); | ||
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| serializerOptions ??= McpJsonUtilities.DefaultOptions; | ||
| serializerOptions.MakeReadOnly(); |
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Why is this MakeReadOnly call necessary?
stephentoub
reviewed
Sep 12, 2025
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| var raw = await server.ElicitAsync(request, cancellationToken).ConfigureAwait(false); | ||
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| if (!string.Equals(raw.Action, "accept", StringComparison.OrdinalIgnoreCase) || raw.Content is null) |
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Suggested change
| if (!string.Equals(raw.Action, "accept", StringComparison.OrdinalIgnoreCase) || raw.Content is null) | |
| if (!raw.IsAccepted || raw.Content is null) |
stephentoub
reviewed
Sep 12, 2025
| RequestedSchema = schema, | ||
| }; | ||
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| var raw = await server.ElicitAsync(request, cancellationToken).ConfigureAwait(false); |
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Rather than using this helper that's deserializing the response as a non-generic ElicitResponse, and then needing to manually copy all the content into a JsonObject and deserialize that, could this instead just write out the additional few lines to call the underlying helper with the the generic ElicitResponse<T>?
stephentoub
reviewed
Sep 12, 2025
| obj[kvp.Key] = JsonNode.Parse(kvp.Value.GetRawText()); | ||
| } | ||
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| T? typed = JsonSerializer.Deserialize(obj, serializerOptions.GetTypeInfo<T>()); |
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@eiriktsarpalis, unrelated to this PR, at one point we'd talked about fixing JsonSerializer.Deserialize overloads that take a JsonSerializerOptions to be on the same plan as what we use in MCP and M.E.AI, having them implicitly call GetTypeInfo and not raise linker and AOT warnings. Are we still considering that? Do we have a tracking issue somewhere?
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ElicitResult<T>for typed content.ElicitAsync<T>method inMcpServerExtensions.csto request user input and construct schemas based on typeT.ElicitationTypedTests.csfor testing the new elicitation functionality with typed forms.SampleFormandCamelFormclasses for expected input shapes, including unsupported properties for schema testing.Motivation and Context
It resolves #630
How Has This Been Tested?
I've added proper unit tests for it.
Breaking Changes
No breaking changes
Types of changes
Checklist
Additional context
No additional notes.