MCPSharp

MCPSharp is a .NET library that lets developers build MCP servers and clients using attribute-based annotations, automatically handling JSON-RPC protocol details so .NET methods can be exposed as MCP tools with minimal boilerplate.

Evaluated Mar 06, 2026 (0d ago) vlatest

Homepage ↗ Repo ↗ Other dotnet csharp sdk library semantic-kernel microsoft-extensions-ai nuget json-rpc attribute-based

⚙ Agent Friendliness

/ 100

Can an agent use this?

🔒 Security

/ 100

Is it safe for agents?

⚡ Reliability

/ 100

Does it work consistently?

Score Breakdown

⚙ Agent Friendliness

MCP Quality

Documentation

Error Messages

Auth Simplicity

Rate Limits

🔒 Security

TLS Enforcement

Auth Strength

Scope Granularity

Dep. Hygiene

Secret Handling

C#/.NET MCP server framework. Type-safe MCP implementation. Security depends on tools implemented. Follows .NET security best practices.

⚡ Reliability

Uptime/SLA

Version Stability

Breaking Changes

Error Recovery

Best When

Your team is already building in .NET and wants to add MCP-compatible tool exposure or consumption without learning the raw JSON-RPC protocol.

Avoid When

You need a ready-to-deploy server or gateway rather than a library, or your stack is outside the .NET ecosystem.

Use Cases

• Exposing existing .NET business logic or legacy APIs as MCP tools accessible to Claude Desktop and other AI assistants
• Building MCP client applications in .NET that connect to MCP servers and surface tools as AIFunction objects for Semantic Kernel or Microsoft.Extensions.AI
• Rapidly prototyping MCP-compatible services without implementing the MCP protocol from scratch

Not For

• Non-.NET languages (Python, Node.js, Go, etc.)
• Turnkey gateway or proxy deployments without custom code
• Teams that need built-in authentication, rate limiting, or observability out of the box

Interface

REST API

GraphQL

gRPC

MCP Server

Yes

SDK

Yes

Webhooks

Authentication

OAuth: No Scopes: No

No built-in authentication layer documented. Authentication must be implemented by the consuming application.

Pricing

Model: open_source

Free tier: Yes

Requires CC: No

MIT licensed. Available on NuGet at no cost.

Agent Metadata

Pagination

none

Idempotent

Unknown

Retry Guidance

Not documented

Known Gotchas

⚠ Classes from referenced external libraries require explicit MCPServer.Register<T>() rather than auto-discovery
⚠ No built-in auth means agents connecting to MCPSharp servers must handle credential management themselves
⚠ XML documentation comments must be present for auto-generated tool descriptions to be meaningful

Alternatives

mcp-sdk-python mcp-sdk-typescript mcpo

Full Evaluation Report

Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for MCPSharp.

$99

API endpoint ↗ Agent guide ↗ Report inaccuracy

Scores are editorial opinions as of 2026-03-06.