From d76bc16bd177563a61558d341bb53a6c690c8b81 Mon Sep 17 00:00:00 2001 From: Copilot <198982749+Copilot@users.noreply.github.com> Date: Fri, 5 Dec 2025 10:39:30 -0800 Subject: [PATCH] Add ResourceNotFound error code (-32002) (#1062) --- src/ModelContextProtocol.Core/McpErrorCode.cs | 37 ++++++++++++------- .../Server/McpServerImpl.cs | 2 +- .../Program.cs | 2 +- .../Program.cs | 2 +- ...cpServerBuilderExtensionsResourcesTests.cs | 3 +- .../McpServerResourceRoutingTests.cs | 2 +- .../McpProtocolExceptionDataTests.cs | 12 +++--- .../Server/McpServerTests.cs | 2 +- 8 files changed, 36 insertions(+), 26 deletions(-) diff --git a/src/ModelContextProtocol.Core/McpErrorCode.cs b/src/ModelContextProtocol.Core/McpErrorCode.cs index bd7f625..c6610d6 100644 --- a/src/ModelContextProtocol.Core/McpErrorCode.cs +++ b/src/ModelContextProtocol.Core/McpErrorCode.cs @@ -6,12 +6,29 @@ namespace ModelContextProtocol; public enum McpErrorCode { /// - /// Indicates that the JSON received could not be parsed. + /// Indicates that the requested resource could not be found. /// /// - /// This error occurs when the input contains malformed JSON or incorrect syntax. + /// This error should be used when a resource URI does not match any available resource on the server. + /// It allows clients to distinguish between missing resources and other types of errors. /// - ParseError = -32700, + ResourceNotFound = -32002, + + /// + /// Indicates that URL-mode elicitation is required to complete the requested operation. + /// + /// + /// + /// This error is returned when a server operation requires additional user input through URL-mode elicitation + /// before it can proceed. The error data must include the `data.elicitations` payload describing the pending + /// elicitation(s) for the client to present to the user. + /// + /// + /// Common scenarios include OAuth authorization and other out-of-band flows that cannot be completed inside + /// the MCP client. + /// + /// + UrlElicitationRequired = -32042, /// /// Indicates that the JSON payload does not conform to the expected Request object structure. @@ -58,18 +75,10 @@ public enum McpErrorCode InternalError = -32603, /// - /// Indicates that URL-mode elicitation is required to complete the requested operation. + /// Indicates that the JSON received could not be parsed. /// /// - /// - /// This error is returned when a server operation requires additional user input through URL-mode elicitation - /// before it can proceed. The error data must include the `data.elicitations` payload describing the pending - /// elicitation(s) for the client to present to the user. - /// - /// - /// Common scenarios include OAuth authorization and other out-of-band flows that cannot be completed inside - /// the MCP client. - /// + /// This error occurs when the input contains malformed JSON or incorrect syntax. /// - UrlElicitationRequired = -32042, + ParseError = -32700, } diff --git a/src/ModelContextProtocol.Core/Server/McpServerImpl.cs b/src/ModelContextProtocol.Core/Server/McpServerImpl.cs index 706578d..7cea77f 100644 --- a/src/ModelContextProtocol.Core/Server/McpServerImpl.cs +++ b/src/ModelContextProtocol.Core/Server/McpServerImpl.cs @@ -273,7 +273,7 @@ internal sealed partial class McpServerImpl : McpServer listResourcesHandler ??= (static async (_, __) => new ListResourcesResult()); listResourceTemplatesHandler ??= (static async (_, __) => new ListResourceTemplatesResult()); - readResourceHandler ??= (static async (request, _) => throw new McpProtocolException($"Unknown resource URI: '{request.Params?.Uri}'", McpErrorCode.InvalidParams)); + readResourceHandler ??= (static async (request, _) => throw new McpProtocolException($"Unknown resource URI: '{request.Params?.Uri}'", McpErrorCode.ResourceNotFound)); subscribeHandler ??= (static async (_, __) => new EmptyResult()); unsubscribeHandler ??= (static async (_, __) => new EmptyResult()); var listChanged = resourcesCapability?.ListChanged; diff --git a/tests/ModelContextProtocol.TestServer/Program.cs b/tests/ModelContextProtocol.TestServer/Program.cs index 66fef57..1321c5f 100644 --- a/tests/ModelContextProtocol.TestServer/Program.cs +++ b/tests/ModelContextProtocol.TestServer/Program.cs @@ -434,7 +434,7 @@ internal static class Program } ResourceContents contents = resourceContents.FirstOrDefault(r => r.Uri == request.Params.Uri) - ?? throw new McpProtocolException($"Resource not found: '{request.Params.Uri}'", McpErrorCode.InvalidParams); + ?? throw new McpProtocolException($"Resource not found: '{request.Params.Uri}'", McpErrorCode.ResourceNotFound); return new ReadResourceResult { diff --git a/tests/ModelContextProtocol.TestSseServer/Program.cs b/tests/ModelContextProtocol.TestSseServer/Program.cs index 0eb799e..a29c305 100644 --- a/tests/ModelContextProtocol.TestSseServer/Program.cs +++ b/tests/ModelContextProtocol.TestSseServer/Program.cs @@ -273,7 +273,7 @@ public class Program } ResourceContents? contents = resourceContents.FirstOrDefault(r => r.Uri == request.Params.Uri) ?? - throw new McpProtocolException($"Resource not found: '{request.Params.Uri}'", McpErrorCode.InvalidParams); + throw new McpProtocolException($"Resource not found: '{request.Params.Uri}'", McpErrorCode.ResourceNotFound); return new ReadResourceResult { diff --git a/tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsResourcesTests.cs b/tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsResourcesTests.cs index da53616..0dc6ed2 100644 --- a/tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsResourcesTests.cs +++ b/tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsResourcesTests.cs @@ -108,7 +108,7 @@ public partial class McpServerBuilderExtensionsResourcesTests : ClientServerTest }; } - throw new McpProtocolException($"Resource not found: {request.Params?.Uri}"); + throw new McpProtocolException($"Resource not found: {request.Params?.Uri}", McpErrorCode.ResourceNotFound); }) .WithResources(); } @@ -249,6 +249,7 @@ public partial class McpServerBuilderExtensionsResourcesTests : ClientServerTest cancellationToken: TestContext.Current.CancellationToken)); Assert.Contains("Resource not found", e.Message); + Assert.Equal(McpErrorCode.ResourceNotFound, e.ErrorCode); } [Fact] diff --git a/tests/ModelContextProtocol.Tests/Configuration/McpServerResourceRoutingTests.cs b/tests/ModelContextProtocol.Tests/Configuration/McpServerResourceRoutingTests.cs index ca82c64..951e065 100644 --- a/tests/ModelContextProtocol.Tests/Configuration/McpServerResourceRoutingTests.cs +++ b/tests/ModelContextProtocol.Tests/Configuration/McpServerResourceRoutingTests.cs @@ -36,7 +36,7 @@ public sealed class McpServerResourceRoutingTests(ITestOutputHelper testOutputHe Assert.Equal("params: a, b, c", ((TextResourceContents)paramsResult.Contents[0]).Text); var mcpEx = await Assert.ThrowsAsync(async () => await client.ReadResourceAsync("test://params{?a1,a2,a3}", null, TestContext.Current.CancellationToken)); - Assert.Equal(McpErrorCode.InvalidParams, mcpEx.ErrorCode); + Assert.Equal(McpErrorCode.ResourceNotFound, mcpEx.ErrorCode); Assert.Equal("Request failed (remote): Unknown resource URI: 'test://params{?a1,a2,a3}'", mcpEx.Message); } } diff --git a/tests/ModelContextProtocol.Tests/McpProtocolExceptionDataTests.cs b/tests/ModelContextProtocol.Tests/McpProtocolExceptionDataTests.cs index e4579e6..6816f55 100644 --- a/tests/ModelContextProtocol.Tests/McpProtocolExceptionDataTests.cs +++ b/tests/ModelContextProtocol.Tests/McpProtocolExceptionDataTests.cs @@ -33,7 +33,7 @@ public class McpProtocolExceptionDataTests : ClientServerTestBase switch (toolName) { case "throw_with_serializable_data": - throw new McpProtocolException("Resource not found", (McpErrorCode)(-32002)) + throw new McpProtocolException("Resource not found", McpErrorCode.ResourceNotFound) { Data = { @@ -43,7 +43,7 @@ public class McpProtocolExceptionDataTests : ClientServerTestBase }; case "throw_with_nonserializable_data": - throw new McpProtocolException("Resource not found", (McpErrorCode)(-32002)) + throw new McpProtocolException("Resource not found", McpErrorCode.ResourceNotFound) { Data = { @@ -55,7 +55,7 @@ public class McpProtocolExceptionDataTests : ClientServerTestBase }; case "throw_with_only_nonserializable_data": - throw new McpProtocolException("Resource not found", (McpErrorCode)(-32002)) + throw new McpProtocolException("Resource not found", McpErrorCode.ResourceNotFound) { Data = { @@ -79,7 +79,7 @@ public class McpProtocolExceptionDataTests : ClientServerTestBase await client.CallToolAsync("throw_with_serializable_data", cancellationToken: TestContext.Current.CancellationToken)); Assert.Equal("Request failed (remote): Resource not found", exception.Message); - Assert.Equal((McpErrorCode)(-32002), exception.ErrorCode); + Assert.Equal(McpErrorCode.ResourceNotFound, exception.ErrorCode); // Verify the data was propagated to the exception // The Data collection should contain the expected keys @@ -113,7 +113,7 @@ public class McpProtocolExceptionDataTests : ClientServerTestBase await client.CallToolAsync("throw_with_nonserializable_data", cancellationToken: TestContext.Current.CancellationToken)); Assert.Equal("Request failed (remote): Resource not found", exception.Message); - Assert.Equal((McpErrorCode)(-32002), exception.ErrorCode); + Assert.Equal(McpErrorCode.ResourceNotFound, exception.ErrorCode); // Verify that only the serializable data was propagated (non-serializable was filtered out) var hasUri = false; @@ -142,7 +142,7 @@ public class McpProtocolExceptionDataTests : ClientServerTestBase await client.CallToolAsync("throw_with_only_nonserializable_data", cancellationToken: TestContext.Current.CancellationToken)); Assert.Equal("Request failed (remote): Resource not found", exception.Message); - Assert.Equal((McpErrorCode)(-32002), exception.ErrorCode); + Assert.Equal(McpErrorCode.ResourceNotFound, exception.ErrorCode); // When all data is non-serializable, the Data collection should be empty // (the server's ConvertExceptionData returns null when no serializable data exists) diff --git a/tests/ModelContextProtocol.Tests/Server/McpServerTests.cs b/tests/ModelContextProtocol.Tests/Server/McpServerTests.cs index da75459..1ab91e1 100644 --- a/tests/ModelContextProtocol.Tests/Server/McpServerTests.cs +++ b/tests/ModelContextProtocol.Tests/Server/McpServerTests.cs @@ -681,7 +681,7 @@ public class McpServerTests : LoggedTest public async Task Can_Handle_Call_Tool_Requests_With_McpProtocolException_And_Data() { const string ErrorMessage = "Resource not found"; - const McpErrorCode ErrorCode = (McpErrorCode)(-32002); + const McpErrorCode ErrorCode = McpErrorCode.ResourceNotFound; const string ResourceUri = "file:///path/to/resource"; await using var transport = new TestServerTransport();