Motor

Motor runs build and test commands for coding agents on a remote Linux build server, or in a fresh Windows virtual machine per job. A client module on the caller's Mac captures a snapshot of the checkout, including uncommitted work, sends only the Git history the server lacks, and the server checks it out at the same absolute path and runs the command in an isolated sandbox. Output streams back as it is produced, jobs survive dropped connections, and a command is never run twice: a job either ran, provably did not start, or is reported as unknown. Motor is the exec-remote/v1 provider for the CortexKit daemon; the daemon and its callers are separate projects.

Crates

Crate	Role
motor-module	ck-motor, the client module: caller admission, snapshots, SSH transport, ck motor run and attach.
motor-protocol	The framed client-runner protocol and codec; re-exports the caller types from cortexkit-exec-remote-types.
motor-runner	The build-server daemon: admission, scheduling, workspaces, Linux sandbox, Windows VM backend, compile cache.
motor-winagent	The guest agent inside each Windows job VM. A standalone crate outside the workspace.
motor-vm-helper	Root service owning a pool of Firecracker VM slots. Not used by any runner backend in this build.
motor-vm-loader	Static userfaultfd snapshot-memory loader for those VMs.
motor-vm-guest	Supervisor that runs one command inside such a VM.
prefrontal-build-slot	Compiler-slot supervisor that limits concurrent compiles across jobs; vendored, see VENDORED.md.

Build and test

The portable suite needs Rust, cargo-nextest and Python 3; some runner tests need a few more tools, listed below the commands. It needs no running daemon, vault or build server. If your shell injects Git configuration through GIT_CONFIG_COUNT, clear it first, because some tests compare Git behavior exactly:

unset GIT_CONFIG_COUNT GIT_CONFIG_KEY_0 GIT_CONFIG_VALUE_0
cargo check --workspace --all-targets --locked
cargo nextest run --workspace --locked
python3 crates/motor-protocol/tests/generate_vectors.py --check

On Linux, point TMPDIR at a reflink-capable filesystem such as XFS; runner tests clone workspaces with reflinks. The runner's JavaScript tests also need Node, npm, Bun and pnpm, and the SSH transport test needs sshd.

Release builds: ck-motor on macOS, motor-runner on Linux.

cargo build --release -p motor-module --bin ck-motor --locked
cargo build --release -p motor-runner --locked

CONTRIBUTING.md lists the full CI gate, the server gate, and the tests that need a privileged operator host. A passing portable suite does not prove the isolation boundaries; those tests run only on a dedicated server.

Documentation

Start with docs/architecture.md: the parts, how a job flows through them, and links to every contract and operator guide. Security reports go through SECURITY.md.

License

MIT; see LICENSE. Adapted third-party material is listed in THIRD-PARTY-NOTICES.md.