Secure VS Code AI agents with a local MCP gateway

VS Code’s agent integrations execute tool calls with your local privileges. The model deciding what to run has no knowledge of which systems are production, what your compliance rules forbid, or what last week’s incident taught your team.

Mergen is the local control plane in between: a stdio MCP proxy that evaluates every tool call against rules a human wrote or approved — deterministically, in under 1ms, entirely on your machine.

What is covered, precisely

Set up in two minutes

Install the server
npm install -g mergen-server
Configure VS Code
mergen-server setup
Start the gate
mergen-server start

What gets stopped

gcloud projects delete my-prod-project
Cloud-destructive operations are hard-blocked by immutable policy.
npm publish (from an agent session)
Supply-chain-sensitive actions escalate to HOLD for a human decision.
git reset --hard && git clean -fdx
Work-destroying combinations are matched structurally, not by string.

Human-in-the-loop approvals

Held calls notify Slack with approve/deny buttons; identity is signature-verified and RBAC-mapped. Decisions resolve the suspended call in place.

Install Mergen →Quick start guide →See the benchmark →
Also available for: Claude Code · Cursor · Windsurf · GitHub Actions