Independent project: Cageforge is not affiliated with, sponsored by, or endorsed by OpenAI.

This crate is a supporting component of the cageforge crate, a cross-platform Rust sandbox for AI agents and untrusted code.

cageforge-bwrap

Read the shared configuration guide for TOML profiles, symbolic paths, local IPC, and first-launch resource rules.

cageforge-bwrap builds the official upstream Bubblewrap executable used as the bundled Linux resource for Cageforge and provides the reviewed architecture-specific bytes to cageforge-linux. It keeps the Bubblewrap implementation separate from Cageforge's Apache-2.0 Rust crates.

The source snapshot is Bubblewrap 0.12.0 at commit 014a04330642e5c870418beb621532cb896e0002. Its original LGPL-2.1-or-later notices are retained under vendor/bubblewrap/. The standalone license text is also available at licenses/bubblewrap-COPYING in this crate.

The upstream release includes --not-a-security-boundary for callers that only need filesystem layout changes. Cageforge does not pass that option: Bubblewrap setup failures remain fatal because Cageforge uses it as a security boundary.

The build-from-source feature is the release-builder mode. On Linux it requires a C compiler, pkg-config, and the development files for libcap. Set CAGEFORGE_BWRAP_SOURCE_DIR to build from another reviewed Bubblewrap source checkout; otherwise the pinned vendor snapshot is used. This mode is used by Cageforge's native CI and release tooling.

The embedded feature supplies the prebuilt target resource selected by target_arch; it does not invoke a C compiler. The supported Linux resources are built independently for x86_64 and aarch64, then included in the published package together with their SHA-256 manifests. cageforge-linux materializes and validates the selected bytes privately before using them as a fallback for a compatible system Bubblewrap executable.

The cageforge-linux/bundled-bubblewrap feature enables embedded, so an application does not need a local C toolchain or a separate staging step for the bundled mode. The embedded executable still has the host's normal Linux runtime and kernel prerequisites; embedding only removes the build-time Bubblewrap toolchain requirement.