Native.Mcp.NativeLambdaRouter 2.1.0

Native.Mcp.NativeLambdaRouter

Hosts a Native.Mcp server inside NativeLambdaRouter — the recommended way to run an MCP server in the Swepay Native ecosystem.

The router owns routing, claims extraction, health checks and the Lambda entry point; Native.Mcp owns the JSON-RPC protocol and per-tool authorization. Responsibilities stay cleanly separated and you reuse the same edge stack as every other Swepay Lambda.

Responsibility split

MCP is a single route. The router can only see the path /mcp, not the tool name (which is in the JSON-RPC body), so per-tool authorization must live in the tools. The MCP route is registered AllowAnonymous at the router (the edge Authorizer is the auth gate); the validated claims still flow through to the tools.

Quickstart

using Amazon.Lambda.APIGatewayEvents;
using Amazon.Lambda.Core;
using Amazon.Lambda.RuntimeSupport;
using Amazon.Lambda.Serialization.SystemTextJson;
using Microsoft.Extensions.DependencyInjection;
using Native.Mcp;
using Native.Mcp.NativeLambdaRouter;

var services = new ServiceCollection();
services.AddNativeMcpServer(o =>
{
    o.ServerName = "swepay-native-guard-trial-provisioner";
    o.ServerVersion = "1.0.0";
    o.AddDiscoveredTools(AppJsonContext.Default);   // or AddTool<...>(...)
});
services.AddNativeMcpTelemetry();

await using var provider = services.BuildServiceProvider();
var function = new McpRoutedApiGatewayFunction(provider);   // routes POST /mcp -> dispatcher

var serializer = new SourceGeneratorLambdaJsonSerializer<AppJsonContext>();
var handler = (APIGatewayHttpApiV2ProxyRequest req, ILambdaContext ctx) => function.FunctionHandler(req, ctx);
await LambdaBootstrapBuilder.Create(handler, serializer).Build().RunAsync();

You do not need to register NativeMediator — the function supplies a no-op mediator to the router (dispatch is handled by Native.Mcp, not the mediator).

Custom route path

public sealed class MyMcpFunction : McpRoutedApiGatewayFunction
{
    public MyMcpFunction(IServiceProvider sp) : base(sp) { }
    protected override string McpPath => "/v1/mcp";
}

What's in the package

• McpRoutedApiGatewayFunction — a RoutedApiGatewayFunction that maps POST /mcp to the MCP dispatcher and returns its response verbatim. Override McpPath to change the route.
• McpRouteContextMapper — maps the router's RouteContext (claims/headers/body) to McpRequestContext (claims, raw JWT, x-correlation-id, x-idempotency-key).

License

MIT.