feat: add SIGIL — security middleware for AI agent tool calls

[MyMolt]

Summary

Adding SIGIL (sigil-eu/sigil-py) to the Community Servers list.

SIGIL is a Python security middleware for AI agent tool calls that provides:

• Secret scanning: 43+ patterns (AWS, OpenAI, GitHub tokens, PII, prompt injection)
• Policy enforcement: allow/block tool call arguments at runtime
• Tamper-evident audit logging: cryptographically chained log entries
• Works with MCP, LangChain, CrewAI, AutoGen, and OpenAI Agents SDK

MIT licensed — installable via pip install sigil-protocol.

Placement

Inserted alphabetically in the Community Servers list, between Shopify Storefront and Simple Loki MCP.

[olaservo]

Thanks for contributing to the MCP servers repo!

We've retired the third-party server list from the README in favor of the MCP Registry — see #3950 for context. The Official Integrations and Community Servers sections no longer exist in the README, so this PR no longer has a target.

Going forward, please publish your server to the MCP Registry using the quickstart guide:
https://github.com/modelcontextprotocol/registry/blob/main/docs/modelcontextprotocol-io/quickstart.mdx

That's where server discovery now happens. Thanks for building on MCP!

---

Note: I'm working through the backlog with help from Claude Code to give everyone a prompt response.