Audience: creative-ops and platform engineers accepting PNG sequence exports on a remote Mac without manual Finder checks. Outcome: a watchdog that turns drops into inspection jobs: match FPS and duration to frame count, enforce per-strip byte budgets, and log JSONL for audits. Structure: install and daemon, watcher templates, thresholds, retries—see the Lottie → PNG sequence matrix for naming and FPS policy.
Table of Contents
Pain points
Exports are messy: bursts of writes, bad padding, shorter strips after timeline edits. Teams then find faults in players or CDN bills. A remote Mac gives one queue, one log format, and OpenClaw skills that run reviewed scripts—not improvised shell from chat.
Decision snapshot
| Signal | Lightweight check | Stricter gate |
|---|---|---|
| Frame rate | PNG count matches ceil(duration_s × fps) from manifest |
Plus spot-check timestamps or sidecar if tool emits them |
| Volume | Total sequence bytes under campaign ceiling | Per-frame min or max bytes versus baseline strip |
| Ops | JSONL per attempt | gzip weekly archives plus disk watermark pause |
OpenClaw minimal install and daemon on remote Mac
Use the OpenClaw install guide for all platforms: pin CLI and Gateway in a shared repo. Give a worker user ~/png_jobs on local NVMe—skip iCloud Desktop paths so placeholders do not break counts.
- Install OpenClaw with the documented package manager path and record the absolute binary location in
install.manifest. - Token file: store Gateway credentials in
~/.openclaw/tokenwith mode600; reference it from both interactive SSH tests andlaunchdEnvironmentVariables. - Daemon: ship a plist that runs your watcher entrypoint, sets
PATHto include Homebrew if used, redirects logs under~/png_jobs/logs/, and appliesThrottleIntervalso crash loops do not hammer CPUs. - Smoke test: from the same environment block the plist uses, invoke one read-only skill against a test folder before enabling production inboxes.
Bind the Gateway to 127.0.0.1 with tokens so shared hosts behave like an internal API.
Folder watch and batch script templates
Write one folder contract: inbox, work, quarantine, out, archive, logs. Use fswatch, launchd WatchPaths, or Python—document the choice. Debounce thirty to sixty seconds after the last write; ignore .DS_Store and temps; use a single-flight lock per batch_id.
Ship templates, not chat one-liners: read job.yaml for fps, duration_s, pad_width; glob and sort *.png; compare ceil(duration_s * fps) to counts; sum sizes; emit reason codes. OpenClaw skills call only git-reviewed scripts. Align logs with the watch, retry, and log archive HowTo.
Thresholds and log archiving
Encode thresholds in YAML beside the job: max_total_bytes, max_frame_bytes, min_frame_bytes, free_disk_gb_floor, and optional median_byte_drift_pct versus a frozen baseline manifest. Before dequeue, evaluate free space; pause the worker when the volume drops below your floor. After inspection, append one JSONL line per attempt with trace_id, batch_id, expected_frames, actual_frames, total_bytes, thresholds, and pass boolean. Operators should grep one file and know whether a batch cleared gates on the first try.
Rotate daily to logs/YYYY-MM-DD.jsonl; gzip older files. Promote passes to archive/YYYY-MM/batch_id/ with JSONL. Typical knobs: CDN-linked byte ceiling, minimum frame bytes, disk watermark before enqueue stops.
Common errors and retries
Classify failures before retrying. Transient: file still open, busy GPU companion process, momentary lock—back off with jitter and cap attempts. Data: wrong frame count, impossible FPS metadata, corrupt PNG magic—route to quarantine without blind retry until a human updates the manifest. Operational: missing binary, expired token, disk watermark—pause the global worker and page ops. Log class on every line so on-call can filter transient noise from data faults.
Double enqueue: two watchers or no mutex. 401: plist missing token env. Byte spikes: compare medians to last release. Allowlist only ~/png_jobs, versioned scripts, no broad deletes.
FAQ
Do I need ffprobe when the manifest lists FPS?
Often no—manifest wins. Use probes only for strips without metadata; log probe fields in JSONL.
Frame-count tolerance?
Default zero unless drop-frame is documented; prefer rational frame counts in a sidecar over rounded seconds.
Replace visual QA?
No—structural gates only; creative sign-off stays elsewhere.
Summary: pin OpenClaw per user, debounce to single-flight jobs, validate FPS against counts and bytes, rotate JSONL. For an always-on worker, see rental and purchase, nodes and pricing, and SSH and VNC—no login. More in Tech Insights.
Run PNG sequence inspection on a dedicated remote Mac
Keep watchdog jobs off designer laptops, pin OpenClaw versions on Apple Silicon, and share threshold + log runbooks across regions.