CosmoApiServer.Core 3.2.3

dotnet add package CosmoApiServer.Core --version 3.2.3
                    
NuGet\Install-Package CosmoApiServer.Core -Version 3.2.3
                    
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="CosmoApiServer.Core" Version="3.2.3" />
                    
For projects that support PackageReference, copy this XML node into the project file to reference the package.
<PackageVersion Include="CosmoApiServer.Core" Version="3.2.3" />
                    
Directory.Packages.props
<PackageReference Include="CosmoApiServer.Core" />
                    
Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.
paket add CosmoApiServer.Core --version 3.2.3
                    
#r "nuget: CosmoApiServer.Core, 3.2.3"
                    
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
#:package CosmoApiServer.Core@3.2.3
                    
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.
#addin nuget:?package=CosmoApiServer.Core&version=3.2.3
                    
Install as a Cake Addin
#tool nuget:?package=CosmoApiServer.Core&version=3.2.3
                    
Install as a Cake Tool

CosmoApiServer

A .NET HTTP server built on System.IO.Pipelines and System.Net.Sockets with support for HTTP/1.1, HTTP/2, and HTTP/3 over QUIC. Includes a middleware pipeline, routing, frontend hosting, and real-time primitives.


Contents


Protocols

Protocol Support
HTTP/1.1 Keep-alive, pipelining
HTTP/2 h2c cleartext + ALPN over TLS
HTTP/3 QUIC via MsQuic (Windows) and Network.framework (macOS). Request/response trailers, streamed bodies, NDJSON streaming, QPACK, graceful GOAWAY.
TLS SslStream with ALPN (h2 / http/1.1)
var builder = CosmoWebApplicationBuilder.Create()
    .ListenOn(9092)
    .UseHttps("cert.pfx", "password")
    .UseHttp3();

Quick Start

# Minimal API server
var builder = CosmoWebApplicationBuilder.Create().ListenOn(9092);
var app = builder.Build();

app.MapGet("/health", ctx => {
    ctx.Response.WriteJson(new { status = "ok" });
    return ValueTask.CompletedTask;
});

app.Run();

Frontend Integration

All framework integrations share the same three-layer structure:

Layer Purpose Method
Dev server Spawn and manage the frontend process UseViteDevServer / UseAngularDevServer / UseNextDevServer
Dev proxy Forward framework module paths to the dev server UseViteDevProxy / UseReactDevProxy / UseNextDevProxy / UseAngularDevProxy
Production Serve the built output with compression + SPA fallback UseStaticFrontend (or framework-specific wrapper)

Nuxt / Vite Dev Mode

UseViteDevServer spawns the frontend dev process as a managed IHostedService, blocking server startup until it is ready. UseViteDevProxy forwards Vite module-graph paths to the dev server so the browser can use a single origin.

builder.UseViteDevServer(o =>
{
    o.WorkingDirectory = "frontend";
    o.Command          = "npm";
    o.Arguments        = "run dev";
    o.ReadyPattern     = "Local:";
    o.ReadyTimeout     = TimeSpan.FromSeconds(45);
    o.LogPrefix        = "[nuxt]";
});

builder.UseViteDevProxy(o =>
{
    o.DevServerUrl    = "http://127.0.0.1:3000";
    o.ProxiedPrefixes = ["/@vite", "/@fs", "/@id", "/_nuxt", "/__nuxt", "/__vite_ping"];
});

The ViteDevServerService shuts down the child process tree (Kill(entireProcessTree: true)) when the host stops, freeing the dev port cleanly.

Nuxt SSR with server-side API calls (nuxt-auth-utils, useFetch in SSR context)

When Nuxt uses SSR and makes API calls during its startup warmup (e.g. session checks via nuxt-auth-utils), set ReadyPattern = null. This lets the .NET HTTP listener open immediately so the backend is reachable when Nuxt's warmup fires. Without this, the default blocking behaviour delays the listener until after Nuxt is ready — causing ECONNREFUSED during warmup.

builder.UseViteDevServer(o =>
{
    o.WorkingDirectory = "frontend";
    o.Command          = "npm";
    o.Arguments        = $"exec nuxt dev -- --host 127.0.0.1 --port 3000";
    o.ReadyPattern     = null;   // .NET opens immediately; Nuxt starts in background
    o.LogPrefix        = "[nuxt]";
    o.Environment["NUXT_SESSION_PASSWORD"] = "...";
    o.Environment["API_BASE"] = "http://127.0.0.1:9183";
});

// For SSR projects UseReverseProxy forwards page requests; UseNuxtIntegrated is for SPA/static only
builder.UseViteDevProxy(o => o.DevServerUrl = "http://127.0.0.1:3000");
builder.UseReverseProxy(o => o.Routes.Add(new ProxyRoute
{
    PathPrefix       = "/",
    Destination      = "http://127.0.0.1:3000",
    ExcludedPrefixes = ["/api"]
}));

Nuxt Integrated Production

Serves a pre-built Nuxt SPA from .output/public with tiered cache headers, Brotli/GZip compression, and SPA fallback.

builder.UseNuxtIntegrated(
    outputPath: "frontend/.output/public",
    configureFallback: o => o.ExcludedPrefixes = ["/api", "/health"]);

Vue / Vite Production

builder.UseViteFrontend(o =>
{
    o.HtmlTemplatePath = "frontend/index.html";
    o.ManifestPath     = "wwwroot/.vite/manifest.json";
    o.ExcludedPrefixes = ["/api", "/health"];
});

// With server-provided initial state
builder.UseViteFrontend(o =>
{
    o.RenderAsync = ctx => ValueTask.FromResult<ViteRenderResult?>(new ViteRenderResult
    {
        HeadHtml     = "<title>Dashboard</title>",
        InitialState = new { user = "alice", route = ctx.HttpContext.Request.Path }
    });
});

Content Security Policy

Generates a per-request nonce and injects it into inline scripts emitted by ViteFrontendMiddleware.

builder.UseCsp(o =>
{
    o.DefaultSrc = ["'self'"];
    o.ScriptSrc  = ["'self'", "'nonce-{nonce}'"];
    o.StyleSrc   = ["'self'", "'unsafe-inline'"];
    o.ConnectSrc = ["'self'"];
    o.ImgSrc     = ["'self'", "data:"];
});

React + Vite

Dev mode — Vite runs on port 5173 by default:

builder.UseViteDevServer(o =>
{
    o.WorkingDirectory = "frontend";
    o.Command          = "npm";
    o.Arguments        = "run dev";
    o.ReadyPattern     = "Local:";
    o.LogPrefix        = "[react]";
});
builder.UseReactDevProxy();  // proxies /@vite, /@fs, /@id, /@react-refresh
builder.UseViteFrontend(o =>
{
    o.EntryName        = "src/main.tsx";
    o.DevServerUrl     = "http://127.0.0.1:5173";
    o.ExcludedPrefixes = ["/api", "/health"];
});

Productionvite build outputs to dist/ with a manifest:

builder.UseViteFrontend(o =>
{
    o.ManifestPath     = "frontend/dist/.vite/manifest.json";
    o.HtmlTemplatePath = "frontend/index.html";
    o.EntryName        = "src/main.tsx";
    o.ExcludedPrefixes = ["/api", "/health"];
});

Angular

Dev mode — Angular CLI doesn't use Vite, so all traffic is reverse-proxied:

builder.UseAngularDevServer(o =>
{
    o.WorkingDirectory = "frontend";
    // defaults: npx ng serve --host 127.0.0.1, ready pattern "Application bundle generation complete"
});
builder.UseAngularDevProxy();  // reverse-proxies / → http://127.0.0.1:4200

Productionng build outputs to dist/<project>/browser/:

builder.UseAngularFrontend(
    outputPath: "frontend/dist/my-app/browser",
    configureFallback: o => o.ExcludedPrefixes = ["/api", "/health"]);

Next.js

Dev mode — Next.js uses its own HMR paths:

builder.UseNextDevServer(o =>
{
    o.WorkingDirectory = "frontend";
    // defaults: npm run dev, ready pattern "Ready"
});
builder.UseNextDevProxy();  // proxies /__next, /_next, /webpack-hmr
builder.UseViteFrontend(o =>
{
    o.DevServerUrl     = "http://127.0.0.1:3000";
    o.ExcludedPrefixes = ["/api", "/health"];
});

Production (static export) — add output: 'export' to next.config.js, then next build outputs to out/:

builder.UseNextStaticExport(
    outputPath: "frontend/out",
    configureFallback: o => o.ExcludedPrefixes = ["/api", "/health"]);

Production (SSR) — proxy all non-API traffic to next start:

builder.UseReverseProxy(o =>
    o.Routes.Add(new ProxyRoute
    {
        PathPrefix       = "/",
        Destination      = "http://127.0.0.1:3000",
        ExcludedPrefixes = ["/api", "/health"]
    }));

SvelteKit

Dev mode — SvelteKit uses Vite:

builder.UseViteDevServer(o =>
{
    o.WorkingDirectory = "frontend";
    o.Command          = "npm";
    o.Arguments        = "run dev";
    o.ReadyPattern     = "Local:";
    o.LogPrefix        = "[svelte]";
});
builder.UseViteDevProxy(o =>
{
    o.DevServerUrl    = "http://127.0.0.1:5173";
    o.ProxiedPrefixes = ["/@vite", "/@fs", "/@id", "/@svelte-kit"];
});

Production (adapter-static)vite build outputs to build/:

builder.UseSvelteKitStatic(
    outputPath: "frontend/build",
    configureFallback: o => o.ExcludedPrefixes = ["/api", "/health"]);

Production (adapter-node) — proxy to the Node server:

builder.UseReverseProxy(o =>
    o.Routes.Add(new ProxyRoute
    {
        PathPrefix       = "/",
        Destination      = "http://127.0.0.1:3000",
        ExcludedPrefixes = ["/api", "/health"]
    }));

Blazor WebAssembly

Blazor WASM runs entirely in the browser — the .NET runtime and your assemblies are compiled to WebAssembly and downloaded once. CosmoApiServer hosts the published output as static files with two additions over a plain SPA:

  • application/wasm MIME type — browsers reject WASM modules served as application/octet-stream
  • Pre-compressed _framework/ file serving — Blazor's publish pipeline emits .br and .gz variants of every framework file. Streaming these directly (with Content-Encoding: br) is far faster than re-compressing dotnet.native.wasm (30–60 MB) on every request

Setup

  1. Publish your Blazor WASM project to the blazor/wwwroot folder of your CosmoApiServer project:
dotnet publish BlazorApp/BlazorApp.csproj -c Release -o blazor
  1. Register the middleware:
builder.UseBlazorWasm(
    outputPath: "blazor/wwwroot",
    configureFallback: o => o.ExcludedPrefixes = ["/api"]);

The SPA fallback returns index.html for all routes not matched by the API, enabling Blazor's client-side router.

Project structure

Keep the Blazor client project in a subdirectory (e.g. BlazorClient/) of the server project. Because Microsoft.NET.Sdk includes all *.cs files recursively by default, you must exclude the client's source files from the server build:


<ItemGroup>
  <Compile Remove="BlazorClient\**\*.cs" />
</ItemGroup>

Without this, the server compiler picks up Blazor client code (e.g. WebAssemblyHostBuilder) and fails with CS0234.

Co-hosting API + Blazor WASM

var app = builder.Build();

app.MapGet("/api/weather", ctx => { ... });

// Blazor WASM handles everything else

Blazor calls your API endpoints the same way any SPA would — using HttpClient with a base address pointing at the same origin.

Dev proxy paths by framework

Framework Dev server default port Paths to proxy
Nuxt 3000 /@vite /@fs /@id /_nuxt /__nuxt /__vite_ping
React + Vite 5173 /@vite /@fs /@id /@react-refresh
SvelteKit 5173 /@vite /@fs /@id /@svelte-kit
Next.js 3000 /__next /_next /__nextjs_original-stack-frame /webpack-hmr
Angular 4200 Full reverse proxy (no Vite module graph)

Reverse Proxy

builder.UseReverseProxy(o =>
    o.Routes.Add(new ProxyRoute
    {
        PathPrefix       = "/",
        Destination      = "http://127.0.0.1:3000",
        ExcludedPrefixes = ["/api", "/health"]
    }));

Real-time

Server-Sent Events

MapSse sets text/event-stream headers and calls BeginSseAsync automatically.

app.MapSse("/api/live/metrics", async ctx =>
{
    using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1));
    while (!ctx.RequestAborted.IsCancellationRequested &&
           await timer.WaitForNextTickAsync(ctx.RequestAborted))
    {
        var json = JsonSerializer.Serialize(new { cpu = 42.1, memory = 68.3 });
        await ctx.Response.WriteSseAsync(json, eventName: "metric",
            cancellationToken: ctx.RequestAborted);
    }
});

Heartbeat helper prevents proxies from closing idle connections:

var heartbeat = ctx.Response.SendSseHeartbeatsAsync(TimeSpan.FromSeconds(15), ctx.RequestAborted);
// ... event loop ...
await heartbeat;

SignalR

var builder = CosmoWebApplicationBuilder.Create().AddSignalR();
var app = builder.Build();
app.MapHub<ChatHub>("/chat");

public sealed class ChatHub : Hub
{
    public async Task SendMessage(string user, string message) =>
        await Clients.All.SendAsync("ReceiveMessage", user, message);
}

Supports JSON and MessagePack protocols, groups, server-push via IHubContext<T>, server streaming, cancellation, and reconnect-after-restart. Compatible with standard ASP.NET SignalR clients.

gRPC

var builder = CosmoWebApplicationBuilder.Create().AddGrpc();
var app = builder.Build();
app.MapGrpcService<GreeterService>();

public sealed class GreeterService : GrpcServiceBase, IGrpcServiceDescriptor
{
    public IReadOnlyList<GrpcMethodDescriptor> Methods =>
    [
        new GrpcMethodDescriptor("Greeter", "SayHello", GrpcMethodType.Unary, typeof(GreeterService),
            async (svc, ctx, ct) =>
            {
                var req = await ctx.ReadRequestAsync<HelloRequest>(ct);
                await ctx.WriteResponseAsync(new HelloReply { Message = $"Hello {req.Name}" }, ct);
            })
    ];
}

Supports unary and server-streaming. Uses standard 5-byte gRPC framing.


Security

JWT / OAuth / OIDC

builder
    .UseJwtAuthentication()
    .UseOAuthAuthentication()   // JWKS discovery
    .AddAuthorization();

Antiforgery

builder.AddAntiforgery();
// ...
app.UseAntiforgery();

app.MapGet("/form", ctx =>
{
    var svc = ctx.RequestServices.GetRequiredService<IAntiforgeryService>();
    var tokens = svc.GetAndStoreTokens(ctx);
    return TypedResults.Text($"<input name='__RequestVerificationToken' value='{tokens.RequestToken}' />");
});

Rate Limiting

Fixed-window per-IP limiter with X-Forwarded-For support:

builder.UseRateLimiting(opts =>
{
    opts.Limit      = 200;
    opts.Window     = TimeSpan.FromMinutes(1);
    opts.StatusCode = 429;
    opts.TrustProxy = true;
});

Middleware & Pipeline

Request
  ↓ GlobalExceptionHandlerMiddleware
  ↓ CorsMiddleware
  ↓ CspMiddleware
  ↓ ViteDevProxyMiddleware   (dev)
  ↓ ViteFrontendMiddleware   (dev) / NuxtIntegratedMiddleware (prod)
  ↓ RouterMiddleware

Registration follows a builder pattern:

var builder = CosmoWebApplicationBuilder.Create()
    .ListenOn(9092)
    .UseLogging()
    .UseExceptionHandler()
    .UseCors(o => { o.AllowAnyOrigin(); o.AllowAnyMethod(); o.AllowAnyHeader(); })
    .UseSession(new SessionOptions { IdleTimeout = TimeSpan.FromMinutes(20) })
    .UseRequestTimeouts(new RequestTimeoutOptions { DefaultTimeout = TimeSpan.FromSeconds(30) })
    .UseRateLimiting(opts => { opts.Limit = 100; opts.Window = TimeSpan.FromMinutes(1); })
    .UseForwardedHeaders()
    .AddOutputCache()
    .AddHealthChecks();

Routing

app.MapGet("/items/{id}", ctx => { ... });
app.MapPost("/items", ctx => { ... });

// Typed results
app.MapGet("/items/{id}", ctx =>
    id is null ? TypedResults.NotFound() : TypedResults.Ok(new { id, name = "Widget" }));

Exception Handling

builder
    .AddExceptionHandler<ValidationExceptionHandler>()
    .AddExceptionHandler<DatabaseExceptionHandler>();

public sealed class ValidationExceptionHandler : IExceptionHandler
{
    public async ValueTask<bool> TryHandleAsync(HttpContext ctx, Exception ex, CancellationToken ct)
    {
        if (ex is not ValidationException vex) return false;
        ctx.Response.StatusCode = 422;
        await ctx.Response.WriteJsonAsync(new { errors = vex.Errors }, ct);
        return true;
    }
}

Scheduling

builder.AddScheduler();
// ...
app.UseScheduler(scheduler =>
{
    scheduler.Schedule(() => Console.WriteLine("tick")).EveryMinute();
    scheduler.ScheduleAsync(async () => await SyncInvoices()).Cron("0 */1 * * *");
    scheduler.Schedule<CleanupJob>().DailyAt(2, 30);
});

Caching

Output Cache

builder.AddOutputCache();
// ...
app.UseOutputCaching();

var policy = OutputCachePolicy.Build()
    .Expire(TimeSpan.FromMinutes(5))
    .VaryByQuery("page", "sort")
    .Tag("products")
    .ToPolicy();

app.MapGet("/products", async ctx =>
{
    ctx.SetOutputCachePolicy(policy);
    await ctx.Response.WriteJsonAsync(GetProducts());
});

// Tag-based invalidation
var store = ctx.RequestServices.GetRequiredService<IOutputCacheStore>();
await store.EvictByTagAsync("products");

Response Cache (ETag / 304)

builder.UseResponseCaching();
// Handlers set ctx.Response.ETag; returns 304 when If-None-Match matches.

Memory & Distributed Cache

builder
    .AddMemoryCache()
    .AddDistributedMemoryCache();

Diagnostics & Observability

Health Checks

builder.AddHealthChecks()
    .AddCheck("db", () => HealthCheckResult.Healthy("Connected"))
    .AddCheck<MyDbHealthCheck>("database");

app.MapHealthChecks("/health");

Problem Details (RFC 7807)

builder.AddProblemDetails();

app.MapGet("/items/{id}", async ctx =>
{
    var svc = ctx.RequestServices.GetRequiredService<IProblemDetailsService>();
    await svc.WriteAsync(new ProblemDetailsContext
    {
        HttpContext    = ctx,
        ProblemDetails = new ProblemDetails { Status = 404, Title = "Not Found" }
    });
});

Distributed Tracing

W3C traceparent propagation, OpenTelemetry-compatible ActivitySource:

builder.UseTracing("MyService");

Razor Components

Full .razor support with @page, [Parameter], [CascadingParameter], @inject, @bind, EventCallback, and validation components.

@page "/hello/{Name}"
@inherits Microsoft.AspNetCore.Components.ComponentBase
@inject NavigationManager Nav

<h1>Hello, @Name!</h1>
<p>Path: @Nav.Uri</p>

@code {
    [Parameter] public string Name { get; set; }
}

Forms

<EditForm Model="@person" Action="/contact" Method="post">
    <InputText     Name="name"    Value="@person.Name" />
    <InputNumber   Name="age"     Value="@person.Age" />
    <InputSelect   Name="country" Value="@person.Country">
        <option value="us">United States</option>
    </InputSelect>
    <ValidationMessage For="Name" />
    <ValidationSummary />
    <button type="submit">Submit</button>
</EditForm>

Change Detection

var ctx = new EditContext(model);
model.Name = "Bob";
ctx.NotifyFieldChanged("Name");

ctx.IsModified("Name");      // true
ctx.GetModifiedFields();     // ["Name"]
ctx.FieldCssClass("Name");   // "modified valid"
ctx.MarkAsUnmodified();

Samples

Sample Description
samples/HelloWorldSample Minimal server with a single route
samples/CosmoKitchenSink Covers most backend features in one project
samples/FeatureShowcase Auth, SignalR, gRPC, output cache, and more
samples/WeatherApp REST API with JWT auth, DI, streaming, and SQL
samples/NuxtUiSample Nuxt 4 + Nuxt UI frontend backed by Cosmo APIs
samples/LiveOpsSample Real-time dashboard: SSE, CSP, Vite dev server, Nuxt integrated deployment
samples/CosmoBlazorSample SSR with Razor components
samples/BlazorWasmSample Blazor WebAssembly co-hosted with a CosmoApiServer API

BlazorWasmSample

cd samples/BlazorWasmSample
./run.sh

Publishes the Blazor WASM client to blazor/wwwroot, then starts the CosmoApiServer backend on http://localhost:5050. Includes Notes (CRUD via /api/notes), Counter, and Weather pages.

LiveOpsSample

cd samples/LiveOpsSample
npm run frontend:install
npm run dev

Benchmarks:

npm run benchmark          # API-only latency (no Nuxt)
npm run benchmark:nuxt     # Cosmo integrated vs Nuxt Nitro standalone

NuxtUiSample

cd samples/NuxtUiSample
npm run dev

Benchmarks

Single-client sequential HTTP/1.1, connection reused across rounds. 100 warmup + 1000 measured per scenario. All times in milliseconds.

macOS arm64

Scenario CosmoApiServer ASP.NET Core
GET /ping P50 0.12ms · 8,600 ops/s P50 0.14ms · 7,300 ops/s
GET /json P50 0.13ms · 8,400 ops/s P50 0.18ms · 5,600 ops/s
GET /large-json P50 0.41ms · 2,400 ops/s P50 0.58ms · 1,700 ops/s
POST /echo P50 0.15ms · 6,500 ops/s P50 0.20ms · 5,000 ops/s
GET /stream P50 0.22ms · 4,500 ops/s P50 0.31ms · 3,200 ops/s

Note: these are single-threaded sequential measurements. Concurrent throughput will differ.

LiveOpsSample API (production mode)

Scenario P50 P99 ops/sec
GET /ping 0.12ms 0.27ms 8,643
GET /health 0.13ms 0.27ms 7,994
GET /api/status 0.12ms 0.27ms 8,432

JSON serialisation of 5 service records (/api/status) adds no measurable latency over a plain text response.


Deployment

HTTP/3 in production

Add UseHttp3() with a valid certificate:

var builder = CosmoWebApplicationBuilder.Create()
    .ListenOn(9092)
    .UseHttps("cert.pfx", "password")
    .UseHttp3();

When running Nuxt through UseNuxtIntegrated, all assets — HTML, JS, CSS — are served by Cosmo over the same QUIC connection. SSE streams benefit from QUIC's per-stream flow control, which avoids head-of-line blocking between concurrent requests.

Cloudflare Pages / Workers

Nuxt can be deployed to Cloudflare using the cloudflare_pages preset:

npx nuxi build --preset=cloudflare_pages

This gives HTTP/3 at the Cloudflare edge automatically. However, there are trade-offs relevant to this architecture:

Cloudflare Cosmo + UseHttp3()
HTTP/3 on browser leg Yes (edge) Yes (direct)
SSE streams Fragile — 100s connection timeout on free plan Native
API colocation No — /api/* still needs an origin server Yes
Cloudflare → origin leg HTTP/2 at best N/A

Cloudflare is suitable for frontends that are mostly static or read-heavy without persistent connections. For SSE-heavy or API-coupled deployments, UseHttp3() on Cosmo keeps the entire stack on one connection and one protocol.


Changelog

v3.2.3

  • BlazorWasmSample — new sample: Notes CRUD + Counter + Weather, Blazor WASM co-hosted with CosmoApiServer
  • UseBlazorWasm project structure: document <Compile Remove="BlazorClient\**\*.cs" /> requirement when client lives in a subdirectory of the server project

v3.2.2

  • UseBlazorWasm — hosts published Blazor WebAssembly apps with pre-compressed _framework/ file serving and application/wasm MIME type
  • StaticFileMiddleware — added .wasm → application/wasm to the MIME table

v3.2.0

  • Frontend integration for React + Vite, Angular, Next.js, and SvelteKit
  • UseStaticFrontend(outputPath) — generic base for all static SPA deployments
  • UseAngularFrontend, UseNextStaticExport, UseSvelteKitStatic — framework-specific wrappers
  • UseReactDevProxy, UseNextDevProxy, UseAngularDevProxy — pre-configured dev proxies per framework
  • UseAngularDevServer, UseNextDevServer — pre-configured dev server process management
  • LiveOpsSample: benchmark scripts (run-benchmark.sh, run-nuxt-benchmark.sh)
  • Documentation rewrite — structured, framework-agnostic

v3.1.0

  • Server-Sent Events, Content Security Policy, Vite Dev Proxy, Vite Dev Server, Nuxt Integrated, Reverse Proxy
  • samples/LiveOpsSample demonstrating all six features
  • Bug fixes: CORS origin spoofing guard, CSRF path bypass, Retry-After off-by-one, ForwardedHeaders trusted-proxy gate, AntiforgeryMiddleware Content-Type guard, SPA fallback cache-control
  • 373 tests

v3.0.3

  • Vue frontend hosting via ViteFrontendMiddleware
  • samples/NuxtUiSample

v3.0.2

  • HtmlEditorComponent for Razor slices

v3.0.1

  • Razor: InputDate, InputRadioGroup, InputRadio, InputFile, RenderTreeBuilder stubs

v3.0.0

  • HTTP/3 production-ready
  • Rate Limiting
  • H3Interop validation tool (32/32 scenarios)
  • Windows benchmark scripts
  • 313 tests

v2.1.0 — v2.1.4

  • SignalR (JSON + MessagePack), gRPC, Sessions, Request Timeouts, Response Caching, Forwarded Headers, Request Decompression, Distributed Tracing, Endpoint Filters, IHttpContextAccessor
  • Output Caching, Antiforgery, TypedResults, IExceptionHandler, IHostedService, WebSockets

v2.0.5 — v2.0.7

  • Health Checks, Problem Details, Policy-Based Authorization, OAuth/OIDC, Memory Cache, Distributed Cache, IHttpClientFactory
  • Stream flush coalescing, HTTP/3 QPACK, trailers, GOAWAY

Credits

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages (1)

Showing the top 1 NuGet packages that depend on CosmoApiServer.Core:

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CosmoS3

Amazon S3-compatible object storage server built on CosmoApiServer.Core.

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2.1.0 81 4/3/2026
2.0.9 82 4/3/2026
2.0.8 80 4/3/2026
2.0.7 90 4/3/2026
2.0.6 90 4/2/2026
2.0.5 114 4/1/2026
2.0.4 81 4/1/2026
2.0.3 101 3/31/2026
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