Secure MCP Filesystem Access

Policy

yaml

deny:
  - capability: filesystem.delete

require_approval:
  - capability: filesystem.write
    path_prefix: "/data/prod"

allow:
  - capability: filesystem.read
  - capability: filesystem.list
  - capability: filesystem.write
    path_prefix: "/data/staging"

Integration

python

from capfence.mcp.gateway import MCPGatewayServer

MCPGatewayServer(
    upstream_command=["python", "-m", "mcp_server_filesystem", "/data"],
    policy_path="policies/mcp.yaml",
    agent_id="mcp-agent",
).run()

Expected result

Deletes are blocked.
Writes to /data/prod require approval.
Reads and writes to /data/staging are allowed.