tekspry/DotnetFastMCP

Enterprise security, governance, and observability layer for Model Context Protocol (MCP) servers in .NET — OAuth 2.0/OIDC authentication, per-tool MFA enforcement, OpenTelemetry instrumentation, and zero-config health checks. Built on ASP.NET Core.
## 🎯 Overview
DotnetFastMCP adds enterprise-grade security, governance, and observability to your MCP servers. While the core protocol is simple, running MCP tools in production requires OAuth 2.0/OIDC authentication, per-tool MFA enforcement, distributed tracing, and health monitoring — none of which the base protocol provides. DotnetFastMCP handles all of this with a clean attribute-based API on ASP.NET Core, plus a native .NET client library for consuming MCP servers.
### ⭐ Key Features
#### 🖼️ Multimodal Content & Universal Media Loader (NEW! v2.2.0)
✅ Universal Media Loader (McpMediaLoader) - Ingest and resolve images/media from any location: remote HTTP/HTTPS, local file paths, file:// URIs, and RFC 2397 data:...;base64,... URIs without boilerplate.
✅ Eliminates Repetitive Helper Code - Replaces duplicate ~40-line FetchImageDataAsync methods across multimodal agent servers with a single line: await McpMediaLoader.LoadAsBase64Async(url, httpClient).
✅ Smart MIME Sniffing - Magic-byte inspection for JPEG, PNG, GIF, WebP, BMP with HTTP Content-Type header inspection and file extension fallbacks.
✅ Zero-Allocation Fast-Path - Data URIs with Base64 payloads are parsed directly without allocating intermediate byte arrays.
✅ Expanded McpContent Factory Methods - First-class helpers for McpContent.Json(obj), McpContent.ImageFromBytes(bytes, mime), McpContent.ImageFromStreamAsync(stream, mime), McpContent.ImageFromUriAsync(uri), McpContent.ResourceText(), McpContent.ResourceBlob(), and McpContent.Composite(...).
#### ⚡ Zero-Boilerplate MCP Servers (v2.1.0)
✅ Automatic DI Registration - Non-static tool, resource, and prompt classes scanned via WithComponentsFrom() are automatically registered as Transient services in the DI container. Zero manual builder.Services.AddTransient () boilerplate.
✅ Preserves Custom Lifetimes - Built on TryAddTransient semantics to honor custom Singleton or Scoped registrations without collision.
✅ [McpDescription] Parameter Attributes - Annotate method parameters with rich descriptions emitted directly into JSON Schema inputSchema (tools/list), significantly enhancing LLM tool-calling accuracy.
✅ Smart Schema Filtering - Automatically hides framework-injected types (McpContext, CancellationToken, ClaimsPrincipal, IMcpSession) from schema exposure so LLMs only see valid user inputs.
#### 🚀 .NET 10 LTS & .NET 8 LTS Dual Support (v2.0.0)
✅ Dual-Targeting - Ships both net8.0 and net10.0 binaries in a single package
✅ Zero Breaking Changes - 100% backward compatible for existing .NET 8 applications
✅ Modern Non-Blocking Async Streams - High-performance SSE parsing compliant with .NET 10 CA2024 rules
✅ Comprehensive Test Matrix - Dual-targeted unit & in-memory integration tests covering positive & negative scenarios
#### Core Framework
✅ Simple Attribute-Based API - Declare tools and resources with [McpTool] and [McpResource] attributes