Back to feed
News Story
APriority74
Hacker News (AI filter)
1 sources

Show HN: cMCP, deny an AI agent's tool call and get a signed receipt

cMCP is a new tool that allows users to deny an AI agent's tool call and receive a signed receipt, providing a verifiable audit trail for AI agent interactions.

SynthePulse Insight · AI deep readingMembers

cMCP: Enforcing AI Tool Call Policies Inside TEEs with Signed Receipts

Version 1 · 1 source

cMCP is an open-source gateway that moves MCP tool call policy enforcement into a hardware Trusted Execution Environment (TEE), generating verifiable signed TRACE claims for each session to prevent policy tampering or bypass.

  • cMCP intercepts and evaluates every MCP tool call inside the TEE, returning allow, deny, or edit based on Cedar policies.
  • Policy package hashes are measured into hardware attestation reports before code runs, ensuring policies are not replaced.
  • Each session generates a signed TRACE claim that verifiers can check without trusting the operator.
Open section navigationThe Problem: Trust Gap in Software-Level MCP Governance

The Problem: Trust Gap in Software-Level MCP Governance

cMCP's README points out that software-level MCP governance cannot guarantee that policy packages are not replaced, decisions are not tampered with, or audit logs are authentic. Because hash checks run in the same operating system as the administrator, attackers can exploit supply chain vulnerabilities to flip in-memory decisions or hold signing keys to rebuild the audit chain.

Therefore, the control plane must run in a place that governed processes cannot touch: a hardware TEE.

Free for now

Read the full analysis

3 more sections of analysis, plus the full takeaway

Loading

Credibility boundary

This report is based on cMCP's GitHub README, which is the project's self-description and has not been independently verified. All functional descriptions are as claimed by the project; actual effectiveness requires testing.

Sources for this version

  1. Show HN: cMCP, deny an AI agent's tool call and get a signed receiptHacker News (AI filter)

Primary report

Hacker News (AI filter)

Primary source