C# SDK: migrate to ModelContextProtocol 2.1.0 (MCP spec 2026-07-28) (#34)
## Summary
Bumps the MCP C# SDK dependency from 1.1.0 to 2.1.0 across all 9
projects and aligns the implementation with the 2.x surface and the
2026-07-28 spec — not just a version bump.
### Compile fixes
- Removed the gateway's `Capabilities.Tasks = null` suppression and its
test: the experimental Tasks API was removed from SDK core in 2.0 (moved
to a separate, wire-incompatible `ModelContextProtocol.Extensions.Tasks`
package).
- Added `ResolveInputRequestsAsync` (new abstract MRTR member on
`McpClient`) overrides to the test doubles. MRTR forwarding is
deliberately out of scope for this PR; the gateway's server reports
`IsMrtrSupported == false`.
- Deleted all `MCPEXP001` pragmas — `ServerCapabilities.Extensions`
(which carries `io.modelcontextprotocol/interceptors`) is stable in 2.x.
`MCPEXP002` subclassing pragmas are kept.
### Spec deprecations (SEP-2577 / SEP-2575)
- The gateway intentionally keeps proxying `logging/setLevel` and
`resources/subscribe` for down-level clients/backends, with targeted
`MCP9005` suppressions.
- On negotiated `2026-07-28` connections the SDK rejects these methods
at the session layer (replaced by per-request `_meta` log levels and
`subscriptions/listen`), so the affected tests now pin `protocolVersion:
"2025-06-18"` through a new fixture parameter — making them genuine
down-level-compatibility tests.
### Defensive hardening
- `Tool.inputSchema` is required and validated on deserialization in
2.x. The gateway's `ListToolsHandler` now fetches the backend
`tools/list` result as raw JSON and runs
`GatewayProxyConfigurator.EnsureToolInputSchemas` before and after the
interceptor chain, coercing missing/invalid schemas to the spec-default
`{"type":"object"}` so down-level backends and schema-stripping
interceptors can't fail the request.
### Tests & docs
- New tests: end-to-end schema-stripping coercion,
`EnsureToolInputSchemas` unit cases, and `2026-07-28` protocol-version
negotiation through the gateway (implicitly exercising
`server/discover`).
- `CLAUDE.md` gains an "SDK 2.x / spec 2026-07-28 notes" section;
`ARCHITECTURE_PHASES.md` no longer lists `Tasks` as a mirrored
capability.
## Test plan
- [x] `dotnet build` — 0 errors, 0 warnings (library, tests, all 7
samples)
- [x] `dotnet test` — 105/105 passing (was 98: −1 removed Tasks test, +8
new)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: Ola Hungerford <olahungerford@gmail.com>
This commit is contained in:
Peder Holdgaard Pedersen
GitHub
parent
8704137635
commit
57d4facc8f
17 changed files with 207 additions and 92 deletions
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@ -1,21 +1,27 @@
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# MCP Interceptors - C# SDK
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## What this is
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C# implementation of gateway-level interceptors from [SEP-2624](https://github.com/modelcontextprotocol/modelcontextprotocol/issues/2624). NuGet package additive to the official [C# MCP SDK](https://github.com/modelcontextprotocol/csharp-sdk) (v1.1.0). Focus is on the protocol-level extension (client → interceptor server → server), NOT in-process middleware.
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C# implementation of gateway-level interceptors from [SEP-2624](https://github.com/modelcontextprotocol/modelcontextprotocol/issues/2624). NuGet package additive to the official [C# MCP SDK](https://github.com/modelcontextprotocol/csharp-sdk) (v2.1.0, MCP spec 2026-07-28). Focus is on the protocol-level extension (client → interceptor server → server), NOT in-process middleware.
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## Build & test
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```
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dotnet build # from csharp/sdk/
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dotnet test # 98 tests across the interceptor test project
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dotnet test # 105 tests across the interceptor test project
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```
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## Key architectural constraints
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**Why message filter, not handlers**: `McpServerHandlers` and `McpServerImpl` are `internal` in the SDK. We can't register handlers for new JSON-RPC methods from outside. Instead we use `McpServerOptions.Filters.Message.IncomingFilters` to intercept `interceptors/list` and `interceptor/invoke`, handle them, send `JsonRpcResponse` via `context.Server.SendMessageAsync()`, and skip calling `next`. See `InterceptorMessageFilter.cs`. Chain execution is no longer a wire method — it's SDK orchestration in `Client/InterceptorChainOrchestrator.cs`.
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**Why `ServerCapabilities.Extensions`**: The SDK's intended mechanism for protocol extensions. Requires `#pragma warning disable MCPEXP001`. We advertise `InterceptorsCapability { SupportedEvents }` under `Extensions["io.modelcontextprotocol/interceptors"]`.
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**Why `ServerCapabilities.Extensions`**: The SDK's intended mechanism for protocol extensions (stable since SDK 2.x — no experimental pragma needed). We advertise `InterceptorsCapability { SupportedEvents }` under `Extensions["io.modelcontextprotocol/interceptors"]`.
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**Client `SendRequestAsync`**: The public overload (`McpSession.Methods.cs:24`) takes `JsonSerializerOptions`. We pass `InterceptorJsonUtilities.DefaultOptions` which chains `McpJsonUtilities.DefaultOptions` + our `InterceptorJsonContext`. The internal overload takes `JsonTypeInfo<T>` — we can't use it.
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**Client `SendRequestAsync`**: The public `SendRequestAsync<TParameters, TResult>` endpoint extension takes `JsonSerializerOptions` (call it with named `cancellationToken:` — 2.x inserted an optional `RequestId` parameter before it). We pass `InterceptorJsonUtilities.DefaultOptions` which chains `McpJsonUtilities.DefaultOptions` + our `InterceptorJsonContext`. The internal overload takes `JsonTypeInfo<T>` — we can't use it.
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**SDK 2.x / spec 2026-07-28 notes**:
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- Tasks moved out of SDK core into a separate, wire-incompatible `ModelContextProtocol.Extensions.Tasks` package; the gateway no longer needs to suppress a backend `Tasks` capability.
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- Logging (`logging/setLevel`) and `resources/subscribe` are deprecated by the spec (SEP-2577 / SEP-2575) and rejected on `2026-07-28` connections, but the gateway intentionally keeps proxying them for down-level clients/backends (`#pragma warning disable MCP9005` at those sites; tests pin `protocolVersion: "2025-06-18"`).
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- `Tool.inputSchema` is required and validated on deserialization; the gateway fetches `tools/list` as raw JSON and coerces missing/invalid schemas to `{"type":"object"}` (`GatewayProxyConfigurator.EnsureToolInputSchemas`) so down-level backends and schema-stripping interceptors can't fail the request.
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- MRTR (multi-round-trip requests) is not forwarded; the gateway's server reports `IsMrtrSupported == false`.
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**`InterceptingMcpClient` is composition**: `McpClient` has an internal constructor; subclassing is `[Experimental]`. We wrap it as a concrete class exposing `.Inner` for direct access.
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@ -46,7 +46,7 @@ Changes:
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1. Extract capability composition into a dedicated internal component or helper
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2. Start from the backend `ServerCapabilities` rather than hand-mirroring only selected properties
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3. Mirror standard and experimental capability surfaces, including `Experimental`, `Extensions`, and `Tasks` where present
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3. Mirror standard and experimental capability surfaces, including `Experimental` and `Extensions` where present
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4. Overlay interceptor capability only when `ExposeInterceptorProtocol = true`
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Expected result:
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@ -15,7 +15,7 @@
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<PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="9.0.0" />
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<PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="9.0.0" />
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<PackageReference Include="Microsoft.Extensions.Hosting" Version="9.0.0" />
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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<ProjectReference Include="..\..\src\ModelContextProtocol.Interceptors\ModelContextProtocol.Interceptors.csproj" />
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</ItemGroup>
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@ -9,7 +9,7 @@
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</PropertyGroup>
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<ItemGroup>
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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<ProjectReference Include="..\..\src\ModelContextProtocol.Interceptors\ModelContextProtocol.Interceptors.csproj" />
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</ItemGroup>
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@ -9,7 +9,7 @@
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</PropertyGroup>
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<ItemGroup>
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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<ProjectReference Include="..\..\src\ModelContextProtocol.Interceptors\ModelContextProtocol.Interceptors.csproj" />
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</ItemGroup>
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@ -9,7 +9,7 @@
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</PropertyGroup>
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<ItemGroup>
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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<ProjectReference Include="..\..\src\ModelContextProtocol.Interceptors\ModelContextProtocol.Interceptors.csproj" />
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</ItemGroup>
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@ -9,7 +9,7 @@
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</PropertyGroup>
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<ItemGroup>
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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<ProjectReference Include="..\..\src\ModelContextProtocol.Interceptors\ModelContextProtocol.Interceptors.csproj" />
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</ItemGroup>
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@ -10,7 +10,7 @@
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<ItemGroup>
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<PackageReference Include="Microsoft.Extensions.Hosting" Version="9.0.0" />
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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<ProjectReference Include="..\..\src\ModelContextProtocol.Interceptors\ModelContextProtocol.Interceptors.csproj" />
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</ItemGroup>
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@ -9,7 +9,7 @@
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</PropertyGroup>
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<ItemGroup>
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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<ProjectReference Include="..\..\src\ModelContextProtocol.Interceptors\ModelContextProtocol.Interceptors.csproj" />
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</ItemGroup>
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@ -34,7 +34,6 @@ internal sealed class GatewayInterceptorProtocolBridge
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foreach (var client in _interceptorClients)
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{
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#pragma warning disable MCPEXP001
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if (client.ServerCapabilities?.Extensions is { } extensions &&
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extensions.TryGetValue(InterceptorProtocolConstants.ExtensionCapabilityKey, out var capObj))
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{
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@ -59,7 +58,6 @@ internal sealed class GatewayInterceptorProtocolBridge
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{
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}
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}
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#pragma warning restore MCPEXP001
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}
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if (!anyInterceptorCapabilityFound)
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@ -67,13 +65,11 @@ internal sealed class GatewayInterceptorProtocolBridge
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return;
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}
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#pragma warning disable MCPEXP001
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serverOptions.Capabilities ??= new ServerCapabilities();
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serverOptions.Capabilities.Extensions ??= new Dictionary<string, object>();
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serverOptions.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
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new InterceptorsCapability { SupportedEvents = allEvents.ToList() },
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InterceptorJsonUtilities.DefaultOptions);
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#pragma warning restore MCPEXP001
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}
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private void ConfigurePassthroughFilter(McpServerOptions serverOptions)
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@ -49,11 +49,6 @@ internal sealed class GatewayProxyConfigurator
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? CloneCapabilities(backendCaps)
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: serverOptions.Capabilities ?? new ServerCapabilities();
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// Task passthrough is not implemented yet, so do not advertise backend task support.
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#pragma warning disable MCPEXP001
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serverOptions.Capabilities.Tasks = null;
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#pragma warning restore MCPEXP001
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ConfigureTools(serverOptions, backendCaps);
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ConfigurePrompts(serverOptions, backendCaps);
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ConfigureResources(serverOptions, backendCaps);
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@ -85,15 +80,23 @@ internal sealed class GatewayProxyConfigurator
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var mutatedParams = JsonSerializer.Deserialize<ListToolsRequestParams>(requestPayload, _jsonOptions)
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?? request.Params!;
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var result = await _backend.ListToolsAsync(mutatedParams, ct);
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// Fetch the backend result as raw JSON: deserializing into ListToolsResult rejects
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// tools whose inputSchema is missing or invalid, which would fail the whole request
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// for a down-level backend before the proxy could compensate.
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var backendNode = await _backend.SendRequestAsync<ListToolsRequestParams, JsonNode>(
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RequestMethods.ToolsList, mutatedParams, _jsonOptions, cancellationToken: ct);
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EnsureToolInputSchemas(backendNode);
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var result = JsonSerializer.Deserialize<ListToolsResult>(backendNode, _jsonOptions)
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?? throw new InvalidOperationException("The backend returned a null tools/list result.");
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if (chainRunner.ShouldIntercept(InterceptionEvents.ToolsList))
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{
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var responsePayload = JsonSerializer.SerializeToNode(result, _jsonOptions)!;
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var (processed, responseStatus) = await chainRunner.RunChainPhaseAsync(
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InterceptionEvents.ToolsList, InterceptorPhase.Response, responsePayload, ct);
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InterceptionEvents.ToolsList, InterceptorPhase.Response, backendNode, ct);
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if (responseStatus != InterceptorChainStatus.Success)
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InterceptorChainRunner.ThrowChainFailure("tools/list", InterceptorPhase.Response, responseStatus);
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EnsureToolInputSchemas(processed);
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result = JsonSerializer.Deserialize<ListToolsResult>(processed, _jsonOptions) ?? result;
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}
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@ -321,6 +324,9 @@ internal sealed class GatewayProxyConfigurator
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await _backend.CompleteAsync(request.Params!, ct);
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}
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// Logging is deprecated upstream (SEP-2577) but the gateway intentionally keeps proxying it
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// for down-level clients/backends.
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#pragma warning disable MCP9005
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private void ConfigureLogging(McpServerOptions serverOptions, ServerCapabilities? backendCaps)
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{
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if (backendCaps?.Logging is null)
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return new EmptyResult();
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};
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}
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#pragma warning restore MCP9005
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/// <summary>
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/// SDK 2.x requires tools/list entries to carry an inputSchema that is a JSON object with
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/// "type":"object"; missing schemas throw during deserialization and invalid ones are
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/// rejected by the Tool setter. As a transparent proxy we coerce missing or invalid schemas
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/// from down-level backends or interceptor mutations to the spec-default {"type":"object"}.
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/// </summary>
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internal static void EnsureToolInputSchemas(JsonNode? listToolsPayload)
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{
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if (listToolsPayload?["tools"] is not JsonArray tools)
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{
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return;
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}
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foreach (var node in tools)
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{
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if (node is not JsonObject tool)
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{
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continue;
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}
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var valid = tool["inputSchema"] is JsonObject schema
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&& schema["type"] is JsonValue typeValue
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&& typeValue.TryGetValue<string>(out var type)
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&& type == "object";
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if (!valid)
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{
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tool["inputSchema"] = new JsonObject { ["type"] = "object" };
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}
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}
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}
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private ServerCapabilities CloneCapabilities(ServerCapabilities capabilities)
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{
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@ -185,7 +185,6 @@ internal sealed class InterceptorServerOptionsSetup : IConfigureOptions<McpServe
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// Advertise interceptor capability via Extensions
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options.Capabilities ??= new();
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#pragma warning disable MCPEXP001 // We intentionally use the experimental Extensions API for protocol extensions
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options.Capabilities.Extensions ??= new Dictionary<string, object>();
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// Serialize to JsonElement so the SDK's own serializer (which doesn't know about
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// InterceptorsCapability) can write it without type-info issues.
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@ -195,6 +194,5 @@ internal sealed class InterceptorServerOptionsSetup : IConfigureOptions<McpServe
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};
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options.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
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capability, InterceptorJsonUtilities.DefaultOptions);
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#pragma warning restore MCPEXP001
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}
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}
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@ -9,7 +9,7 @@
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</PropertyGroup>
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<ItemGroup>
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<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
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<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
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</ItemGroup>
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<ItemGroup>
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@ -1,4 +1,5 @@
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using System.Text.Json;
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using System.Text.Json.Nodes;
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using System.IO.Pipes;
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using System.Security.Claims;
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using Microsoft.Extensions.DependencyInjection;
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@ -30,10 +31,46 @@ public class GatewayComponentsTests
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bridge.Configure(serverOptions);
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#pragma warning disable MCPEXP001
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Assert.NotNull(serverOptions.Capabilities.Extensions);
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Assert.True(serverOptions.Capabilities.Extensions!.ContainsKey(InterceptorProtocolConstants.ExtensionCapabilityKey));
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#pragma warning restore MCPEXP001
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}
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[Theory]
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[InlineData("""{"name":"t"}""")] // missing inputSchema
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[InlineData("""{"name":"t","inputSchema":{}}""")] // empty object, no "type"
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[InlineData("""{"name":"t","inputSchema":{"type":"string"}}""")] // wrong type
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[InlineData("""{"name":"t","inputSchema":"not-an-object"}""")] // not a JSON object
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public void EnsureToolInputSchemas_CoercesMissingOrInvalidSchemaToSpecDefault(string toolJson)
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{
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var payload = JsonNode.Parse($$"""{"tools":[{{toolJson}}]}""");
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GatewayProxyConfigurator.EnsureToolInputSchemas(payload);
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var schema = payload!["tools"]![0]!["inputSchema"];
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Assert.Equal("object", schema!["type"]!.GetValue<string>());
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}
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[Fact]
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public void EnsureToolInputSchemas_LeavesValidSchemaUntouched()
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{
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var payload = JsonNode.Parse(
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"""{"tools":[{"name":"t","inputSchema":{"type":"object","properties":{"x":{"type":"string"}},"required":["x"]}}]}""");
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var original = payload!["tools"]![0]!["inputSchema"]!.ToJsonString();
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GatewayProxyConfigurator.EnsureToolInputSchemas(payload);
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Assert.Equal(original, payload["tools"]![0]!["inputSchema"]!.ToJsonString());
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}
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[Fact]
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public void EnsureToolInputSchemas_IgnoresPayloadWithoutToolsArray()
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{
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var payload = JsonNode.Parse("""{"resources":[]}""");
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GatewayProxyConfigurator.EnsureToolInputSchemas(payload);
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Assert.Null(payload!["tools"]);
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GatewayProxyConfigurator.EnsureToolInputSchemas(null);
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}
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[Fact]
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@ -93,9 +130,7 @@ public class GatewayComponentsTests
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var serverOptions = new McpServerOptions();
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gateway.ConfigureServerOptions(serverOptions);
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#pragma warning disable MCPEXP001
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Assert.True(serverOptions.Capabilities?.Extensions?.ContainsKey(InterceptorProtocolConstants.ExtensionCapabilityKey) ?? false);
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#pragma warning restore MCPEXP001
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}
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[Fact]
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@ -262,12 +297,10 @@ public class GatewayComponentsTests
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var filter = new InterceptorMessageFilter(collection);
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options.Filters.Message.IncomingFilters.Add(filter.CreateFilter);
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options.Capabilities ??= new();
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#pragma warning disable MCPEXP001
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options.Capabilities.Extensions ??= new Dictionary<string, object>();
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options.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
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new InterceptorsCapability { SupportedEvents = [InterceptionEvents.ToolsCall] },
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InterceptorJsonUtilities.DefaultOptions);
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#pragma warning restore MCPEXP001
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});
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disposables.Add(interceptorServer);
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disposables.Add(interceptorClient);
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@ -301,12 +334,10 @@ public class GatewayComponentsTests
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var filter = new InterceptorMessageFilter(collection);
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serverOptions.Filters.Message.IncomingFilters.Add(filter.CreateFilter);
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serverOptions.Capabilities ??= new();
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#pragma warning disable MCPEXP001
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serverOptions.Capabilities.Extensions ??= new Dictionary<string, object>();
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serverOptions.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
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new InterceptorsCapability { SupportedEvents = [InterceptionEvents.ToolsCall] },
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InterceptorJsonUtilities.DefaultOptions);
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#pragma warning restore MCPEXP001
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var serverTransport = new StreamServerTransport(serverFromClient, serverToClient);
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var server = McpServer.Create(serverTransport, serverOptions);
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@ -360,7 +391,10 @@ public class GatewayComponentsTests
|
|||
public override Implementation? ClientInfo => null;
|
||||
public override McpServerOptions ServerOptions => new();
|
||||
public override IServiceProvider? Services => null;
|
||||
// Logging is deprecated upstream (SEP-2577) but remains part of the abstract surface.
|
||||
#pragma warning disable MCP9005, CS0672
|
||||
public override LoggingLevel? LoggingLevel => null;
|
||||
#pragma warning restore MCP9005, CS0672
|
||||
public override ValueTask DisposeAsync() => ValueTask.CompletedTask;
|
||||
public override IAsyncDisposable RegisterNotificationHandler(string method, Func<JsonRpcNotification, CancellationToken, ValueTask> handler) => throw new NotSupportedException();
|
||||
public override Task RunAsync(CancellationToken cancellationToken) => throw new NotSupportedException();
|
||||
|
|
@ -384,6 +418,7 @@ public class GatewayComponentsTests
|
|||
public override IAsyncDisposable RegisterNotificationHandler(string method, Func<JsonRpcNotification, CancellationToken, ValueTask> handler) => throw new NotSupportedException();
|
||||
public override Task SendMessageAsync(JsonRpcMessage message, CancellationToken cancellationToken = default) => throw new NotSupportedException();
|
||||
public override Task<JsonRpcResponse> SendRequestAsync(JsonRpcRequest request, CancellationToken cancellationToken = default) => throw new NotSupportedException();
|
||||
public override ValueTask<IDictionary<string, InputResponse>> ResolveInputRequestsAsync(IDictionary<string, InputRequest> inputRequests, CancellationToken cancellationToken) => throw new NotSupportedException();
|
||||
}
|
||||
|
||||
private sealed class TestInterceptor : McpServerInterceptor
|
||||
|
|
|
|||
|
|
@ -195,12 +195,10 @@ public class InterceptorChainTests
|
|||
options.Filters.Message.IncomingFilters.Add(filter.CreateFilter);
|
||||
|
||||
options.Capabilities ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Extensions ??= new Dictionary<string, object>();
|
||||
options.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
|
||||
new InterceptorsCapability { SupportedEvents = [InterceptionEvents.All] },
|
||||
InterceptorJsonUtilities.DefaultOptions);
|
||||
#pragma warning restore MCPEXP001
|
||||
}
|
||||
|
||||
public async ValueTask DisposeAsync()
|
||||
|
|
|
|||
|
|
@ -49,6 +49,75 @@ public class McpInterceptorGatewayTests
|
|||
Assert.Equal("test-tool", tools[0].Name);
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public async Task Gateway_NegotiatesLatestProtocolVersion()
|
||||
{
|
||||
await using var fixture = await GatewayTestFixture.CreateAsync(
|
||||
backendConfigure: (options) =>
|
||||
{
|
||||
options.Capabilities ??= new();
|
||||
options.Capabilities.Tools ??= new();
|
||||
options.Handlers.ListToolsHandler = (request, ct) =>
|
||||
new ValueTask<ListToolsResult>(new ListToolsResult { Tools = [] });
|
||||
options.Handlers.CallToolHandler = (request, ct) =>
|
||||
new ValueTask<CallToolResult>(new CallToolResult());
|
||||
});
|
||||
|
||||
Assert.Equal("2026-07-28", fixture.ProxyClient.NegotiatedProtocolVersion);
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public async Task ListTools_InjectsDefaultInputSchemaWhenInterceptorStripsIt()
|
||||
{
|
||||
await using var fixture = await GatewayTestFixture.CreateAsync(
|
||||
backendConfigure: (options) =>
|
||||
{
|
||||
options.Capabilities ??= new();
|
||||
options.Capabilities.Tools ??= new();
|
||||
options.Handlers.ListToolsHandler = (request, ct) =>
|
||||
{
|
||||
return new ValueTask<ListToolsResult>(new ListToolsResult
|
||||
{
|
||||
Tools = [new Tool { Name = "stripped-tool", Description = "Loses its schema" }],
|
||||
});
|
||||
};
|
||||
options.Handlers.CallToolHandler = (request, ct) =>
|
||||
new ValueTask<CallToolResult>(new CallToolResult());
|
||||
},
|
||||
interceptors: [CreateMutationInterceptor("schema-stripper", (req, _, _, _) =>
|
||||
{
|
||||
// Only the response phase carries a tools array; pass the request phase through.
|
||||
if (req.Payload?["tools"] is not JsonArray)
|
||||
{
|
||||
return new ValueTask<InterceptorResult>(new MutationInterceptorResult
|
||||
{
|
||||
Modified = false,
|
||||
Payload = req.Payload,
|
||||
});
|
||||
}
|
||||
|
||||
var payload = req.Payload!.DeepClone();
|
||||
foreach (var tool in payload["tools"]!.AsArray())
|
||||
{
|
||||
tool!.AsObject().Remove("inputSchema");
|
||||
}
|
||||
|
||||
return new ValueTask<InterceptorResult>(new MutationInterceptorResult
|
||||
{
|
||||
Modified = true,
|
||||
Payload = payload,
|
||||
});
|
||||
}, events: [InterceptionEvents.ToolsList])]);
|
||||
|
||||
// Without the gateway coercing the stripped inputSchema back to the spec default,
|
||||
// deserializing the mutated payload would fail and the request would error out.
|
||||
var tools = await fixture.ProxyClient.ListToolsAsync();
|
||||
Assert.Single(tools);
|
||||
Assert.Equal("stripped-tool", tools[0].Name);
|
||||
Assert.Equal(JsonValueKind.Object, tools[0].JsonSchema.ValueKind);
|
||||
Assert.Equal("object", tools[0].JsonSchema.GetProperty("type").GetString());
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public async Task CallToolAsync_PassesThroughInterceptors()
|
||||
{
|
||||
|
|
@ -223,33 +292,6 @@ public class McpInterceptorGatewayTests
|
|||
Assert.True(caps.Experimental!.ContainsKey("com.example/feature"));
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public async Task ConfigureServerOptions_DoesNotAdvertiseBackendTasksCapability()
|
||||
{
|
||||
await using var fixture = await GatewayTestFixture.CreateAsync(
|
||||
backendConfigure: (options) =>
|
||||
{
|
||||
options.Capabilities ??= new();
|
||||
options.Capabilities.Tools ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Tasks = new McpTasksCapability
|
||||
{
|
||||
List = new ListMcpTasksCapability(),
|
||||
Cancel = new CancelMcpTasksCapability(),
|
||||
};
|
||||
#pragma warning restore MCPEXP001
|
||||
options.Handlers.ListToolsHandler = (request, ct) =>
|
||||
new ValueTask<ListToolsResult>(new ListToolsResult { Tools = [] });
|
||||
options.Handlers.CallToolHandler = (request, ct) =>
|
||||
new ValueTask<CallToolResult>(new CallToolResult());
|
||||
});
|
||||
|
||||
var caps = fixture.ProxyClient.ServerCapabilities;
|
||||
#pragma warning disable MCPEXP001
|
||||
Assert.Null(caps.Tasks);
|
||||
#pragma warning restore MCPEXP001
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public async Task ConfigureServerOptions_MirrorsBackendExtensionsInTransparentMode()
|
||||
{
|
||||
|
|
@ -258,22 +300,18 @@ public class McpInterceptorGatewayTests
|
|||
{
|
||||
options.Capabilities ??= new();
|
||||
options.Capabilities.Tools ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Extensions ??= new Dictionary<string, object>();
|
||||
options.Capabilities.Extensions["com.example/backend"] = JsonSerializer.SerializeToElement(new { version = 1 });
|
||||
#pragma warning restore MCPEXP001
|
||||
options.Handlers.ListToolsHandler = (request, ct) =>
|
||||
new ValueTask<ListToolsResult>(new ListToolsResult { Tools = [] });
|
||||
options.Handlers.CallToolHandler = (request, ct) =>
|
||||
new ValueTask<CallToolResult>(new CallToolResult());
|
||||
});
|
||||
|
||||
#pragma warning disable MCPEXP001
|
||||
var caps = fixture.ProxyClient.ServerCapabilities;
|
||||
Assert.NotNull(caps.Extensions);
|
||||
Assert.True(caps.Extensions!.ContainsKey("com.example/backend"));
|
||||
Assert.False(caps.Extensions.ContainsKey("io.modelcontextprotocol/interceptors"));
|
||||
#pragma warning restore MCPEXP001
|
||||
}
|
||||
|
||||
[Fact]
|
||||
|
|
@ -290,10 +328,8 @@ public class McpInterceptorGatewayTests
|
|||
new ValueTask<CallToolResult>(new CallToolResult());
|
||||
});
|
||||
|
||||
#pragma warning disable MCPEXP001
|
||||
var caps = fixture.ProxyClient.ServerCapabilities;
|
||||
Assert.False(caps?.Extensions?.ContainsKey("io.modelcontextprotocol/interceptors") ?? false);
|
||||
#pragma warning restore MCPEXP001
|
||||
}
|
||||
|
||||
[Fact]
|
||||
|
|
@ -304,10 +340,8 @@ public class McpInterceptorGatewayTests
|
|||
{
|
||||
options.Capabilities ??= new();
|
||||
options.Capabilities.Tools ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Extensions ??= new Dictionary<string, object>();
|
||||
options.Capabilities.Extensions["com.example/backend"] = JsonSerializer.SerializeToElement(new { version = 1 });
|
||||
#pragma warning restore MCPEXP001
|
||||
options.Handlers.ListToolsHandler = (request, ct) =>
|
||||
new ValueTask<ListToolsResult>(new ListToolsResult { Tools = [] });
|
||||
options.Handlers.CallToolHandler = (request, ct) =>
|
||||
|
|
@ -315,12 +349,10 @@ public class McpInterceptorGatewayTests
|
|||
},
|
||||
exposeInterceptorProtocol: true);
|
||||
|
||||
#pragma warning disable MCPEXP001
|
||||
var caps = fixture.ProxyClient.ServerCapabilities;
|
||||
Assert.NotNull(caps?.Extensions);
|
||||
Assert.True(caps!.Extensions!.ContainsKey("io.modelcontextprotocol/interceptors"));
|
||||
Assert.True(caps.Extensions.ContainsKey("com.example/backend"));
|
||||
#pragma warning restore MCPEXP001
|
||||
}
|
||||
|
||||
[Fact]
|
||||
|
|
@ -538,7 +570,10 @@ public class McpInterceptorGatewayTests
|
|||
Modified = true,
|
||||
Payload = JsonNode.Parse(payloadStr),
|
||||
});
|
||||
}, events: [InterceptionEvents.ResourcesSubscribe])]);
|
||||
}, events: [InterceptionEvents.ResourcesSubscribe])],
|
||||
// resources/subscribe was replaced by subscriptions/listen in spec 2026-07-28;
|
||||
// the gateway keeps proxying it for down-level connections, so pin one here.
|
||||
protocolVersion: "2025-06-18");
|
||||
|
||||
await fixture.ProxyClient.SubscribeToResourceAsync("resource://original");
|
||||
|
||||
|
|
@ -773,9 +808,7 @@ public class McpInterceptorGatewayTests
|
|||
},
|
||||
exposeInterceptorProtocol: true);
|
||||
|
||||
#pragma warning disable MCPEXP001
|
||||
Assert.True(fixture.ProxyClient.ServerCapabilities.Extensions?.ContainsKey(InterceptorProtocolConstants.ExtensionCapabilityKey) ?? false);
|
||||
#pragma warning restore MCPEXP001
|
||||
|
||||
var tools = await fixture.ProxyClient.ListToolsAsync();
|
||||
Assert.Single(tools);
|
||||
|
|
@ -934,6 +967,9 @@ public class McpInterceptorGatewayTests
|
|||
Assert.Contains("alpha", result.Completion.Values);
|
||||
}
|
||||
|
||||
// Logging is deprecated upstream (SEP-2577) but the gateway intentionally keeps proxying it
|
||||
// for down-level clients/backends.
|
||||
#pragma warning disable MCP9005
|
||||
[Fact]
|
||||
public async Task SetLoggingLevelAsync_ProxiesToBackend()
|
||||
{
|
||||
|
|
@ -949,7 +985,10 @@ public class McpInterceptorGatewayTests
|
|||
receivedLevel = request.Params!.Level;
|
||||
return new ValueTask<EmptyResult>(new EmptyResult());
|
||||
};
|
||||
});
|
||||
},
|
||||
// logging/setLevel was replaced by per-request _meta log levels in spec 2026-07-28;
|
||||
// the gateway keeps proxying it for down-level connections, so pin one here.
|
||||
protocolVersion: "2025-06-18");
|
||||
|
||||
var caps = fixture.ProxyClient.ServerCapabilities;
|
||||
Assert.NotNull(caps?.Logging);
|
||||
|
|
@ -957,6 +996,7 @@ public class McpInterceptorGatewayTests
|
|||
await fixture.ProxyClient.SetLoggingLevelAsync(LoggingLevel.Warning);
|
||||
Assert.Equal(LoggingLevel.Warning, receivedLevel);
|
||||
}
|
||||
#pragma warning restore MCP9005
|
||||
|
||||
// ── Test helpers ──────────────────────────────────────────────────
|
||||
|
||||
|
|
@ -1042,7 +1082,8 @@ public class McpInterceptorGatewayTests
|
|||
Action<McpServerOptions> backendConfigure,
|
||||
McpServerInterceptor[]? interceptors = null,
|
||||
int? timeoutMs = null,
|
||||
bool exposeInterceptorProtocol = false)
|
||||
bool exposeInterceptorProtocol = false,
|
||||
string? protocolVersion = null)
|
||||
{
|
||||
var disposables = new List<IAsyncDisposable>();
|
||||
|
||||
|
|
@ -1051,7 +1092,8 @@ public class McpInterceptorGatewayTests
|
|||
// 1. Create backend server + client via pipes
|
||||
var (backendServer, backendClient) = await CreateServerClientPair(
|
||||
"test-backend",
|
||||
backendConfigure);
|
||||
backendConfigure,
|
||||
protocolVersion: protocolVersion);
|
||||
disposables.Add(backendServer);
|
||||
disposables.Add(backendClient);
|
||||
|
||||
|
|
@ -1079,12 +1121,10 @@ public class McpInterceptorGatewayTests
|
|||
options.Filters.Message.IncomingFilters.Add(filter.CreateFilter);
|
||||
|
||||
options.Capabilities ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Extensions ??= new Dictionary<string, object>();
|
||||
options.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
|
||||
new InterceptorsCapability { SupportedEvents = allEvents.ToList() },
|
||||
InterceptorJsonUtilities.DefaultOptions);
|
||||
#pragma warning restore MCPEXP001
|
||||
});
|
||||
disposables.Add(interceptorServer);
|
||||
disposables.Add(interceptorClient);
|
||||
|
|
@ -1105,7 +1145,8 @@ public class McpInterceptorGatewayTests
|
|||
options =>
|
||||
{
|
||||
gateway.ConfigureServerOptions(options);
|
||||
});
|
||||
},
|
||||
protocolVersion: protocolVersion);
|
||||
disposables.Add(proxyServer);
|
||||
disposables.Add(proxyClient);
|
||||
|
||||
|
|
@ -1159,12 +1200,10 @@ public class McpInterceptorGatewayTests
|
|||
var filter = new InterceptorMessageFilter(collection);
|
||||
options.Filters.Message.IncomingFilters.Add(filter.CreateFilter);
|
||||
options.Capabilities ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Extensions ??= new Dictionary<string, object>();
|
||||
options.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
|
||||
new InterceptorsCapability { SupportedEvents = allEvents.ToList() },
|
||||
InterceptorJsonUtilities.DefaultOptions);
|
||||
#pragma warning restore MCPEXP001
|
||||
});
|
||||
disposables.Add(server);
|
||||
disposables.Add(client);
|
||||
|
|
@ -1225,12 +1264,10 @@ public class McpInterceptorGatewayTests
|
|||
options.Filters.Message.IncomingFilters.Add(filter.CreateFilter);
|
||||
|
||||
options.Capabilities ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Extensions ??= new Dictionary<string, object>();
|
||||
options.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
|
||||
new InterceptorsCapability { SupportedEvents = [] },
|
||||
InterceptorJsonUtilities.DefaultOptions);
|
||||
#pragma warning restore MCPEXP001
|
||||
});
|
||||
disposables.Add(interceptorServer);
|
||||
disposables.Add(interceptorClient);
|
||||
|
|
@ -1302,12 +1339,10 @@ public class McpInterceptorGatewayTests
|
|||
options.Filters.Message.IncomingFilters.Add(filter.CreateFilter);
|
||||
|
||||
options.Capabilities ??= new();
|
||||
#pragma warning disable MCPEXP001
|
||||
options.Capabilities.Extensions ??= new Dictionary<string, object>();
|
||||
options.Capabilities.Extensions[InterceptorProtocolConstants.ExtensionCapabilityKey] = JsonSerializer.SerializeToElement(
|
||||
new InterceptorsCapability { SupportedEvents = [] },
|
||||
InterceptorJsonUtilities.DefaultOptions);
|
||||
#pragma warning restore MCPEXP001
|
||||
});
|
||||
disposables.Add(interceptorServer);
|
||||
disposables.Add(interceptorClient);
|
||||
|
|
@ -1370,7 +1405,8 @@ public class McpInterceptorGatewayTests
|
|||
private static async Task<(McpServer server, McpClient client)> CreateServerClientPair(
|
||||
string name,
|
||||
Action<McpServerOptions> configure,
|
||||
Action<string>? onRegisterNotificationHandler = null)
|
||||
Action<string>? onRegisterNotificationHandler = null,
|
||||
string? protocolVersion = null)
|
||||
{
|
||||
// Create anonymous pipes for communication
|
||||
var clientToServer = new AnonymousPipeServerStream(PipeDirection.Out);
|
||||
|
|
@ -1394,7 +1430,13 @@ public class McpInterceptorGatewayTests
|
|||
|
||||
// Client writes to clientToServer, reads from clientFromServer
|
||||
var clientTransport = new StreamClientTransport(clientToServer, clientFromServer);
|
||||
var client = await McpClient.CreateAsync(clientTransport);
|
||||
var clientOptions = new McpClientOptions();
|
||||
if (protocolVersion is not null)
|
||||
{
|
||||
clientOptions.ProtocolVersion = protocolVersion;
|
||||
}
|
||||
|
||||
var client = await McpClient.CreateAsync(clientTransport, clientOptions);
|
||||
|
||||
return (server, client);
|
||||
}
|
||||
|
|
@ -1437,6 +1479,8 @@ public class McpInterceptorGatewayTests
|
|||
inner.SendMessageAsync(message, cancellationToken);
|
||||
public override Task<JsonRpcResponse> SendRequestAsync(JsonRpcRequest request, CancellationToken cancellationToken = default) =>
|
||||
inner.SendRequestAsync(request, cancellationToken);
|
||||
public override ValueTask<IDictionary<string, InputResponse>> ResolveInputRequestsAsync(IDictionary<string, InputRequest> inputRequests, CancellationToken cancellationToken) =>
|
||||
inner.ResolveInputRequestsAsync(inputRequests, cancellationToken);
|
||||
}
|
||||
|
||||
private sealed record NamedClient(string Name, McpClient Client);
|
||||
|
|
|
|||
|
|
@ -12,7 +12,7 @@
|
|||
<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
|
||||
<PackageReference Include="xunit" Version="2.9.3" />
|
||||
<PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
|
||||
<PackageReference Include="ModelContextProtocol" Version="1.1.0" />
|
||||
<PackageReference Include="ModelContextProtocol" Version="2.1.0" />
|
||||
</ItemGroup>
|
||||
|
||||
<ItemGroup>
|
||||
|
|
|
|||
Loading…
Reference in a new issue