Design system owners and automation engineers need scheduled PNG handoffs without manual re-exports. This guide chains launchd, a Node 22 client on the Figma REST image endpoint, and OpenClaw Gateway checks for manifest pixels and sRGB before promotion. The contract is API-first: the inbox stages bytes; JSONL on a remote Mac proves compliance—not a watch on someone’s export folder alone.
Table of Contents
Why API-First Inspection
- Human variance: Manual exports drift when frame names change; REST calls bind to stable
node_idvalues from your manifest. - Color surprises: Display P3 slices look fine in macOS Preview yet fail CSS assumptions documented in your Figma Dev Mode PNG matrix.
- Rate limits: Bursty retries without backoff burn Figma API quotas and stall the whole queue.
Folder watchers still help after bytes land, but they cannot invent missing scales or prove which file version the API rendered. Lead with REST, then let OpenClaw Skills treat the inbox like a tiny CI worker.
Decision Matrix
| Source of PNG bytes | Strength | Weakness | When to pick it |
|---|---|---|---|
| Designer export folder watch | Matches muscle memory in the studio | Hard to prove which frame version shipped | Exploratory work, not regulated libraries |
Scheduled REST /v1/images |
Git-versioned node list, repeatable scales | Requires token hygiene and HTTP discipline | Design tokens, marketing components, app chrome |
| Plugin push | Rich metadata from inside Figma | Another runtime to secure and upgrade | Teams already standardized on a vendor plugin |
Tokens and Minimum Permissions
Put the PAT in ~/.config/figma-design-system.token mode 0600 for the launchd user; grant only read scopes for metadata plus image export—never an admin token. Rotate quarterly and bind one token per file tree. Align UNIX ownership with the OpenClaw install guide so Gateway allowlists and SSH tutorials describe the same account.
0600, batch HTTP budget under 120s, at most four scales per job.
Export Task Template
Pin Node 22 LTS with engines.node in package.json. Job YAML lists file_key, node_id list, format: png, integer scale, and stems like ${nodeId}@${scale}x.png. Exporter: POST /v1/images/{file_key}, stream each URL to inbox/*.part, fsync, rename—no half-written PNGs for Skills.
Directory Listening and Retries
The inbox is an API landing zone: debounce, ignore *.part, require two stable size polls, mutex per file_key. On 429, honor Retry-After else capped exponential backoff. Log fields per watch, retry, archive; post-pass shell steps follow CLI chain retry with optimizers allowlisted only when needed.
Color Space and sRGB Validation Rules
Run magick identify -verbose: require Colorspace: sRGB and reject Display P3 or mystery ICC. Match WxH to the manifest per node and scale; align naming with the Dev Mode PNG matrix. Print-side sources go through CMYK → sRGB policy before this gate.
Failure Alert Examples
One JSON line per failure—no secrets, only token aliases. ICC fault: {"ok":false,"reason":"icc_display_p3","file":"btn_primary@2x.png","trace_id":"7c2f9a"}. Rate limit: {"ok":false,"reason":"http_429","retry_in_sec":45,"attempt":2}.
Reproducible Gateway Runbook
- Layout on APFS NVMe:
inbox,quarantine,promoted,logsunder one git-tracked root. - Install with
npm ci; pinnode -vin README. - OpenClaw: loopback Gateway, disable stray MCP tools, Skill allowlists
inspect_png.shandmvinside that root only. launchd: setThrottleIntervalso/v1/imagesis not hammered during rapid saves.- Alerts: stream
logs/compliance.jsonlthroughjqto webhooks onok:false. - CI replay: freeze thirty
node_idrows per branch; operators use public SSH/VNC help without a login wall.
Troubleshooting FAQ
Images endpoint returns 200 but URLs are null—what happened?
Stale node_id after component detaches. Refresh the manifest from Dev Mode; CI should fail when ids leave the file graph.
Node fetch works in Terminal but not under launchd—why?
Set HOME, PATH, FIGMA_TOKEN_FILE in the plist; reload with launchctl bootstrap.
Should OpenClaw call Figma directly?
No—keep HTTP in Node so tokens never hit chat logs; OpenClaw handles schedule, moves, inspection.
How do I prove parity with designer slices?
YAML expected WxH per node and scale; gate on magick identify -format '%wx%h' before promoted/.
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Run design automation reliably on a remote Mac
Dedicated Apple Silicon hosts keep Figma API pulls, OpenClaw gates, and PNG compliance logs on stable NVMe so token rotation, launchd schedules, and ImageMagick upgrades happen once per fleet—not per laptop.