Step 5 — Hugging Face demo Space (discovery plumbing, free tier only)

Discovery plumbing (secondary). This page makes the service findable by someone already searching; it does not replace pipeline work (page 00). Do it once; no paid tier, listing or upgrade (hard rule 6).

What this is: a free browser demo where a stranger uploads a hologram and gets a reconstruction, powered by our public endpoint. The complete Space is already built in the repository at integrations/demo_space/ (app.py, requirements.txt, README.md with the HF YAML frontmatter). You are uploading, not writing.

Free tier only — or skip

This is discovery plumbing (secondary), so it gets no money: the "No paid acquisition" hard rule on page 00 applies. Interactive Gradio Spaces require a paid PRO plan on personal accounts; the single free exemption is 2 ZeroGPU Gradio Spaces per free account (checked 2026-09-22). Our app needs no GPU.

• The only route ($0): free account, create the Space as ZeroGPU even though the app never uses the GPU. Open question (flagged, unresolved): whether ZeroGPU imposes the spaces package / @spaces.GPU structural requirement on an app with no GPU function. Try it once.
• If the free route fails: skip the page. Log "skipped — free tier refused" in the table below and move on. Do not upgrade to PRO and do not ask for one; the no-account upload form on the API site already does the same job for a stranger.

Get the company account credentials from the operator first.

Do this

1. Create/log into the company HF account (free tier).
2. New Space → SDK: Gradio → name apertureapi-demo → ZeroGPU (free).
3. Upload the three files from integrations/demo_space/ (web upload or git push to the Space repo — the repository's UPLOAD_CHECKLIST.md has the exact commands).
4. Wait for build; open the Space; upload the sample hologram (linked in the Space README) and confirm a reconstruction renders.
5. Known limitation to expect: all Space visitors share one egress IP and the public endpoint rate-limits per IP (5/hour), so a busy Space rate-limits as a group — the app already explains this to users and shows the curl fallback. That is by design; do not "fix" it.

Artifact

• Live https://huggingface.co/spaces/<org>/apertureapi-demo URL producing a reconstruction from a fresh upload (screenshot it, dated) — or a logged "skipped — free tier refused" row. Either one closes the page.

Buyer pages to pair with this page: workflow fit · reproducibility bundle. Pipeline stages and KPIs: page 00.