Add Arbitus - Security proxy for MCP servers

[nfvelten]

Added Arbitus - Security proxy for MCP servers

• Category: 🧑‍🚀 Tools and code
• Repository: https://github.com/arbitusgateway/arbitus

Description

Arbitus is a security proxy that sits between AI agents (Cursor, Claude, Windsurf, etc.) and MCP servers. It enforces per-agent policies before any tool call reaches the upstream server.

Key Features

• Per-agent auth — API key, JWT/OIDC, or mTLS
• tools/list filtering — Agents only see tools they're allowed to call
• Rate limiting — Sliding window, per-tool, per-IP
• Human-in-the-Loop (HITL) — Approval workflow for sensitive operations
• Shadow mode — Dry-run operations without forwarding
• Payload filtering — Encoding-aware (Base64, URL, Unicode)
• OPA/Rego policies — Custom policy evaluation
• Schema validation — Validate args against inputSchema
• Audit logging — SQLite, webhook, OpenLineage, CloudEvents
• Circuit breaker — Upstream failure isolation
• Both transports — HTTP+SSE and stdio
• Written in Rust — Sub-millisecond overhead

Checklist

• Project is related to MCP security
• Link works
• Added to the TOP of the appropriate section
• Format follows the existing style

Repository Stats

• ⭐ Stars: New project (launching now)
• 📝 License: MIT
• ✅ Tests: 446 unit tests passing
• 📖 Documentation: 6 comprehensive docs
• 🏗️ Governance: GOVERNANCE.md, CONTRIBUTING.md, SECURITY.md, CODE_OF_CONDUCT.md