Motor

Motor runs build and test commands for coding agents on remote machines: Linux jobs in a tenant VM on a hosted server, Windows and macOS jobs each in a fresh virtual machine. A client module on the caller's own machine captures a snapshot of the checkout, including uncommitted work, sends only the Git history the runner lacks, and the runner 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, broker leases for Linux jobs, SSH to Windows and macOS runners, ck motor run, attach and cancel.
motor-protocol	The framed client-runner protocol and codec; re-exports the caller types from cortexkit-exec-remote-types.
motor-lease	Lease tokens and signatures, and the byte-pinned copy of the broker contract.
motor-runner	The runner daemon: admission, scheduling, workspaces, Linux sandbox, Windows and macOS VM backends, compile cache.
motor-host	The hosted server agent: TLS admission for leases, relay to the tenant VM's runner, reports to the broker.
motor-vm-helper	Root service owning the Firecracker tenant VMs on a hosted server.
motor-macvm, motor-macagent	The macOS job VM driver and the guest agent inside each macOS job VM.
motor-winagent	The guest agent inside each Windows job VM. A standalone crate outside the workspace.
motor-vm-loader	Snapshot-memory loader. Not used by any runner backend.
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 pass the commit in MOTOR_BUILD_COMMIT; the ck-motor release binary is built with scripts/build-ck-motor-card.sh, which records that provenance. AGENTS.md has the commands.

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 ARCHITECTURE.md: the parts, how a job flows through them, and links to every contract and operator guide. STRUCTURE.md maps the directories and says where code goes. Security reports go through SECURITY.md.

License

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