Preview Environments

Production Matrix OS is VPS-native + Cloud Run; previews mirror that. Full reference: docs/dev/preview-environments.md. Spec: specs/093-preview-environments/.

Pick the surface

You changed	Use	How
Shell/gateway/kernel UI, fast iteration	Staging slot (HMR, seconds per change)	./scripts/staging-slot.sh up <worktree>
Shell/gateway/kernel, production-shaped verify; onboarding (needs virgin VPS)	Preview VPS	add the preview-vps label to the PR
Platform (packages/platform)	Platform preview revision	add the preview-platform label to the PR
macOS app	CI artifact + any preview VPS via app.matrix-os.com/vm/<handle>	build artifact from macos-086.yml
CLI	npm dist-tag paired with a preview VPS profile	see docs

Staging slots (inner loop)

Run from the ops VPS, repo root or any checkout:

./scripts/staging-slot.sh up ~/matrix-os.worktrees/<branch>   # claims slot N
# -> https://staging-<N>.matrix-os.com (HMR: edits in the worktree hot-reload)
./scripts/staging-slot.sh status            # who owns what
./scripts/staging-slot.sh down <N>          # release when done — slots are shared!

4 slots max. Always down your slot when finished; status --reap frees slots idle past TTL.

Preview VPS (verify loop)

Label the PR preview-vps. CI builds bundle 0.0.0-pr<N>.<sha7>, registers it without any channel (it can never reach real users), provisions VPS pr-<N>, deploys, and comments the URL. Closed PR ⇒ VPS deleted (daily reaper as backstop, 72h TTL). Manual run: gh workflow run preview-vps.yml -f pr=<N>.

Logs — one interface for everything

./scripts/preview-logs.sh --handle pr-123 [--unit matrix-gateway] [--grep ERROR] [--since 1h]
./scripts/preview-logs.sh --slot 2 --since 30m
./scripts/preview-logs.sh --selector '{env="preview"}' --grep "unhandled"

Runs against the central Loki (loopback on the ops VPS). Slot logs ship automatically (promtail docker discovery). A preview/fleet VPS ships logs after one-time enrollment:

PLATFORM_SECRET=... LOGS_INGEST_USER=fleet LOGS_INGEST_PASSWORD=... \
  ./scripts/enable-vps-logship.sh pr-123 preview

(LOGS_INGEST_* live in ~/matrix-os/.env on the ops VPS.)

Rules

• Never promote a preview bundle to a channel; never deploy channel-wide from a PR.
• Never point a preview at production secrets or the production platform service.
• Tear down what you spin up: staging-slot.sh down, close the PR, or delete the VPS via DELETE /vps/<machineId> — never directly in Hetzner.
• Browser-level inspection: drive the preview URL with Playwright/chrome-devtools MCP; passive browser-log forwarding is deferred (spec 093).