mcpcut MCP server

mcpcut

See every tool call your AI agent makes over MCP, hold the risky ones for your approval, and keep a secret-redacted journal that is tamper-evident with an external anchor.

Self-hosted · Apache-2.0 · Node.js 24+ · two runtime dependencies. Start with one server on your laptop; grow into a control plane for many agents.

Quick start

Requires Node.js 24+ (node -v); on older Node, mcpcut prints one line and exits — install Node 24 with nvm, fnm or volta. Nothing else to install.

See. Put mcpcut in front of a server — here for Claude Code; in any other client, the server's command becomes npx -y mcpcut@0.2.4 wrap -- :

claude mcp add fs -- npx -y mcpcut@0.2.4 wrap --server fs -- npx -y @modelcontextprotocol/server-filesystem ~/project

The first start downloads mcpcut and the server; if your client gives up on it, start it once more. Let the agent work, then npx -y mcpcut@0.2.4 sessions and npx -y mcpcut@0.2.4 show : every request and response, secrets redacted (with a policy, every decision too). --server fs names the server in the decisions a policy writes to the journal and in the approval queue.

Stop. Save this as policy.json — reads pass, everything else waits for you (quarantine of new tools is off, so the first minute shows one gate: see Quarantine) — and re-add the server with --policy "$PWD/policy.json" right after wrap (claude mcp remove fs first):

{ "version": 1, "defaultDecision": "require-approval", "classDefaults": { "read": "allow" }, "quarantine": { "enabled": false } }

A write now waits. Approve it from another terminal within the agent's wait (60 s; after it, the agent's retry passes) — no token needed until you add your first admin (Approvals):

npx -y mcpcut@0.2.4 approvals list npx -y mcpcut@0.2.4 approvals approve

Prove. Sign the history, export it, and check it offline — with nothing but the directory:

npx -y mcpcut@0.2.4 keygen && npx -y mcpcut@0.2.4 export --report --out ./report npx -y mcpcut@0.2.4 verify --report ./report npx -y mcpcut@0.2.4 verify --sign

The last line signs the chain head: keep what it prints somewhere this host cannot rewrite — the out-of-band anchor is what makes the journal tamper-evident, not the hashes alone.

Grow. npm install -g mcpcut, then mcpcut: a setup wizard, then a server registry, per-agent keys and grants, a credential vault, a web UI, a terminal console and one address per agent (Install and first run).

What you get

Shortened. The full README is on GitHub.