--- title: Deployment lanes description: Two lanes with different jobs. A full certification and a source-convergence bootstrap, both ending in the same atomic frontend swap. sidebar: order: 2 --- UseAgent ships through explicit lanes, each with a different guarantee. Releases run from an **immutable checkout of the committed HEAD**: the lane refuses to deploy uncommitted tracked changes, materializes the commit's tree into a temporary directory, and verifies the checkout's tree hash against the commit before anything is synchronized. ## Before any host mutation Every lane runs the same protective preamble before it touches the host: 1. **Take the host deploy lock** Deploys serialize behind a host-side mutex, so exactly one lane mutates the host at a time. A second concurrent lane fails fast with a clear message instead of racing a live deploy. 2. **Close run admission and drain** Durable run admission closes, then the lane waits a bounded time (180 seconds by default) for in-flight runs to settle. A timeout fails closed; proceeding anyway requires an explicit audited force triple naming the actor and the reason. 3. **Users see an honest pause** While admission is closed, a Slack message that would start a run is answered with "New runs are temporarily paused for a deployment. Retry this message shortly." instead of failing silently. 4. **Reopen when healthy** Admission reopens only after the restarted services answer their health checks. ## Guarded release The full certification, run with `bun run release:hosted`. Eight fail-closed gates cover the candidate end to end: 1. Preserve the exact live environment and build a rollback-bound candidate environment. 2. Activate the candidate source and Caddyfile, then run the preflight canary: upload rejection, wiki generation and retrieval. 3. Prove readiness for each selected credential path, failing fast when one is unavailable. 4. Prove the complete candidate parity matrix without public advertisement. 5. Derive readiness into the offline candidate environment. 6. Atomically activate the fully evidenced candidate. 7. Rerun all hard journeys through the authenticated public APIs. 8. Run the hosted canaries: editable workpieces, live timing, noVNC, focus isolation, and the cutover canary. Any failure triggers automatic rollback of source, environment, Caddy configuration, and services. The Caddyfile is installed only after the live configuration is backed up; the candidate is validated and reloaded, and the prior file is restored on failure. When promoting a newly built Cube runtime, the gate validates the template id, activates it only inside the rollback-bound candidate environment, and restores the exact previous environment if any preflight or parity journey fails. ## Provider-connection bootstrap Run with `bun run release:provider-connection-bootstrap`. It converges production onto a verified commit between certifications and proves the account-lifecycle surface **without** claiming runtime parity: - Validates the authenticated release identity before changing the host. - Closes admission and drains, then snapshots the live source tree before synchronizing the immutable checkout. - Restarts every application service (which includes the frontend swap below), then proves the provider-connection account surface with a dedicated canary. - On failure, restores the source snapshot and restarts services. - Finishes by stating explicitly: "Provider execution readiness was not promoted by this bootstrap." ## The frontend swap inside every restart There is no separate frontend lane. Both lanes above end in the same service restart script, and every restart finishes by swapping the UI atomically: - The candidate UI builds **beside** the live tree, into an isolated `.next-release-` directory, so a failed compilation never corrupts the served build. - The build must carry a `BUILD_ID` equal to the release commit, or it never activates. - The frontend stops, the prior build is parked as `.next-build.previous-`, and the candidate moves into place. - The new build must start and answer its local health check. On failure, the bad build is kept as `.next-build.failed-` for diagnosis and the previous build is restored automatically. Full certification with rollback. Ship path for engine-affecting changes. Converge source onto a verified commit. No parity claim. Not a lane. Runs inside every restart, build-id checked, with a parked rollback. :::warning A release is never run from a live working tree. The lane materializes the committed HEAD into an immutable checkout, refuses uncommitted tracked changes, and verifies the checkout's tree hash against the commit. :::