Agent skill · security · sickn33
protect-mcp-governance
Agent governance skill for MCP tool calls — Cedar policy authoring, shadow-to-enforce rollout, and Ed25519 receipt verification.
Why this skill is useful
Adds specific Cedar policy authoring techniques and Ed25519 receipt verification processes that the AI wouldn't reliably generate on its own.
What it needs
Requires npx installed locally. About 5k tokens when loaded. Last updated 2026-08-07. 44,571 stars on the source repository.
What this skill does
MCP Agent Governance with protect-mcp Overview Guidance for governing AI agent tool calls using Cedar policies and Ed25519 signed receipts. This skill teaches how to write access-control policies for MCP servers, run them in shadow mode for observation, and verify the cryptographic audit trail. When to Use This Skill Use when you need to control which MCP tools an agent can call and under what conditions Use when you want a tamper-evident audit trail for agent tool executions Use when rolling out governance policies gradually (shadow mode first, then enforce) Use when authoring Cedar policies for MCP tool access control Use when verifying that a receipt or audit bundle has not been tampered with Do Not Use This Skill When you need general application security auditing (use @security-auditor) When you need to scan code for vulnerabilities (use @security-audit) When you need compliance framework guidance without agent-specific governance How It Works protect-mcp intercepts MCP tool calls, evaluates them against Cedar policies (the same policy engine used by AWS Verified Permissions), and signs every decision as an Ed25519 receipt. The receipt is a cryptographic proof that a specific policy was evaluated against a specific tool call at a specific time. Three modes of operation: 1. Shadow mode (default) — logs decisions without blocking. Use this to observe what your policies would do before enforcing them. 2. Enforce mode — blocks tool calls that violate policy. Use after shadow-mode validation. 3. Hooks mode — integrates with Claude Code hooks for pre/post tool-call governance. Core Concepts Cedar Policies Cedar is a policy language designed for authorization. Policies are evaluated locally via WASM — no network calls required. Signed Receipts Every policy decision produces a signed receipt: The receipt format follows IETF Internet-Draft draft-farley-acta-signed-receipts. Step-by-Step Guide 1. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills sickn33/protect-mcp-governance