bun-runner-mcp

The server employs robust sandboxing, offering two main modes: preload and container. Preload mode uses Bun's `--preload` to intercept dangerous APIs (like `fetch`, `Bun.write`, `Bun.spawn`, `process.env` access) and routes them through a permission-checking proxy. Container mode (recommended for untrusted code) leverages Apple Containers (macOS 26+) for VM-level isolation, resource limits (CPU, memory), and package management. The accompanying Docker configuration (`docker-compose.yml`, `seccomp-profile.json`) further demonstrates a high level of security consciousness, implementing read-only filesystems, dropped capabilities, and syscall filtering. Hardcoded secrets are not apparent; environment variables are loaded securely from files or prefixed process environment variables.