mcp-server-toolkit

Production-ready Model Context Protocol server starter with auth, tracing, and a plugin system.

Built by Sarma Linux.

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What this is

MCP went from niche spec to default integration layer in late 2025. Every serious agent now speaks it. Most reference servers are toys: a single tool, no auth, no observability. This toolkit is the opinionated batteries-included alternative.

Scaffold an MCP server in one command. Drop tool handlers into a plugins directory. Get OAuth 2.1 with PKCE, structured logging, OpenTelemetry traces, rate limiting, and a typed tool registry for free. Runs over stdio for local agents and streamable HTTP for remote ones, same code path.

Architecture

graph TD
  Client[MCP Client<br/>Desktop / Cursor / IDE]
  Client -->|stdio JSON-RPC| Stdio[stdio transport]
  Client -->|streamable HTTP| HTTP[FastAPI HTTP transport]
  Stdio --> Reg[Tool Registry]
  HTTP --> Auth[OAuth 2.1 / API key]
  Auth --> Reg
  Reg --> P1[plugin: filesystem]
  Reg --> P2[plugin: postgres]
  Reg --> P3[plugin: github]
  Reg --> P4[plugin: sarmalink]
  P4 -->|api.sarmalink.ai| SLAI[SarmaLink-AI]

  classDef ext fill:#a78bfa,stroke:#a78bfa,color:#fff
  class SLAI ext

Quick start

git clone https://github.com/sarmakska/mcp-server-toolkit.git
cd mcp-server-toolkit
uv sync
cp .env.example .env
uv run mcp-toolkit run --transport stdio

Plugin authoring

from mcp_toolkit.registry import registry

@registry.tool("search_docs", description="Search internal docs")
async def search_docs(query: str) -> dict:
    return {"results": [...]}

Configuration

Env var	Purpose	Default
MCP_TRANSPORT	stdio or http	stdio
MCP_AUTH	none, api_key, oauth	none
OTEL_EXPORTER_OTLP_ENDPOINT	OTel collector URL	unset
SARMALINK_API_KEY	for the sarmalink plugin	unset

Deployment

Distroless Docker image, ~120MB. Runs on Fly.io, Render, Railway, k8s.

docker build -t mcp-toolkit .
docker run -p 8000:8000 --env-file .env mcp-toolkit

Roadmap

See docs/OPEN-ISSUES.md. PRs welcome.

License

MIT.

Built by Sarma Linux.