docs/HOSTING.md

Hosting (DPLY-01)

Decided: 2026-08-27 Chosen path: zerogpu-free

Field	Value
Space	WolfDavid/japanese-learning-avatar
Space page	https://huggingface.co/spaces/WolfDavid/japanese-learning-avatar
SPACE_URL (direct, used by E2E --space-url)	https://wolfdavid-japanese-learning-avatar.hf.space
Visibility	public (private: false)
Hardware requested	zero-a10g (ZeroGPU)
Hardware applied	not yet allocated — runtime.hardware.current is null because runtime.stage is NO_APP_FILE. See "Why hardware.current is null" below.
sdk / sdk_version	gradio / 6.26.0 on the Space today — must be corrected to 6.22.0 by plan 01-05. See "Open handoff to plan 01-05".
python_version	'3.12' on the Space today — must be corrected to 3.12.12 by plan 01-05.
Sleep timeout	48 h (gcTimeout: 172800)
Space repo SHA at time of writing	b70455dcf67ff7db6b1f48f08153982d37a63dd2 (two files: .gitattributes, README.md)
Created	2026-08-27T02:13:12Z

The decisive finding: cpu-basic is no longer creatable, and it fails with a payment error

Creating this Space on the default cpu-basic hardware was rejected with HTTP 402 Payment Required. The message, verbatim:

Static Spaces are free for everyone, but hosting Gradio and Docker Spaces on free cpu-basic requires a PRO subscription.

Re-issuing the identical creation request with ZeroGPU (space_hardware="zero-a10g") succeeded immediately, with no payment prompt and no charge.

This is empirical confirmation of the claim in 01-RESEARCH.md and CLAUDE.md that Gradio Spaces on a free personal account are PRO-gated except for the ZeroGPU carve-out. It is no longer a documentation reading — it is an observed platform response on this account.

Consequence: ZeroGPU is now the only free hosting path for this project. A future phase cannot silently fall back to cpu-basic to save a ZeroGPU slot — that fallback does not exist for a Gradio Space on a non-PRO personal account. Any plan that proposes it is proposing a $9/mo purchase.

Account eligibility evidence (verified against the live public API, 2026-08-27)

Queried in this task, not quoted from RESEARCH:

• isPro: false; account created 2023-11-27T01:45:12.000Z — about 2.7 years old, so the ZeroGPU ">30 days in good standing" criterion is satisfied with enormous margin.

• Email: verified (account is in good standing; ZeroGPU allocation was accepted, which requires it).

• 8 pre-existing Gradio Spaces, every one of them requested: cpu-basic, and zero on ZeroGPU — so both free ZeroGPU slots were open before this Space was created:

  Space	sdk_version	python	hardware requested	stage
  WolfDavid/dino	6.9.0	3.11	cpu-basic	RUNNING
  WolfDavid/fea-surrogate	5.9.1	3.11	cpu-basic	SLEEPING
  WolfDavid/mechspec-qwen-demo	5.9.1	3.11	cpu-basic	SLEEPING
  WolfDavid/agentic-market-analyzer	5.9.1	3.11	cpu-basic	SLEEPING
  WolfDavid/log-anomaly-detector	5.9.1	3.11	cpu-basic	RUNNING
  WolfDavid/vision-edge	5.9.1	3.11	cpu-basic	SLEEPING
  WolfDavid/nllb-translator	5.9.1	3.11	cpu-basic	SLEEPING
  WolfDavid/blip-captioner	5.9.1	3.11	cpu-basic	SLEEPING

• WolfDavid/dino runs sdk_version: 6.9.0, so Gradio 6 is proven to work on this account.

• Note for anyone re-running this check: runtime.hardware.current is null for every SLEEPING Space. current reports what is running right now, not what the Space is entitled to. Read runtime.hardware.requested when auditing hardware tiers, or six of these eight Spaces look unallocated.

• Note also that GET /api/spaces?author=WolfDavid still returned only the original 8 shortly after creation; the list endpoint lags. GET /api/spaces/WolfDavid/japanese-learning-avatar returns the new Space immediately and is the authoritative read.

Why hardware.current is null, and why that is correct

"runtime": { "stage": "NO_APP_FILE",
             "hardware": { "current": null, "requested": "zero-a10g" },
             "gcTimeout": 172800 }

The Space repo contains only .gitattributes and an auto-generated README.md. With no app.py there is nothing to schedule, so no hardware is attached. This is the correct pre-deploy state and is not a failure. requested: zero-a10g is the binding fact — it is the tier the Space will start on the moment plan 01-05 pushes an app.

Reachability today, measured three times consecutively with identical results:

URL	HTTP	Meaning
https://huggingface.co/spaces/WolfDavid/japanese-learning-avatar	200	The Space exists and is public
https://wolfdavid-japanese-learning-avatar.hf.space	503	Your space is in error, check its status on hf.co — no app.py yet

The direct subdomain is provisioned (runtime.domains[0].stage: READY, subdomain: wolfdavid-japanese-learning-avatar), it simply has nothing to serve. Plan 01-05 turns this 503 into a 200, and tests/e2e/test_avatar_loop.py::test_space_reachable — which plan 01-05 creates — is what actually satisfies DPLY-01. DPLY-01 is not satisfied by this plan.

Open handoff to plan 01-05 (which owns README.md)

Space creation auto-generated a README.md whose front-matter conflicts with the pinned stack:

Key	Auto-generated value	Required value	Source of the requirement
sdk_version	6.26.0	6.22.0	requirements.txt line 1 pins gradio==6.22.0; CLAUDE.md says pin exactly
python_version	'3.12'	3.12.12	ZeroGPU provides only 3.10.13 and 3.12.12; .python-version is 3.12.12

Left uncorrected, the Space SDK would install Gradio 6.26.0 while requirements.txt asks for 6.22.0 — the exact "unpinned sdk_version floats you into a breaking release" failure CLAUDE.md warns about, arrived at from the other direction. This plan does not edit README.md; that file belongs to plan 01-05.

Why not the alternatives

• cpu-basic (free) — no longer available. Attempting it returned HTTP 402 Payment Required (quoted verbatim above). This option is closed, not merely discouraged.
• sdk: static — free for everyone, but VOICEVOX cannot run in a browser, so there would be no mora timings and AVTR-02 collapses entirely. ZeroGPU is also Gradio-SDK-only, so Phase 3 would need a rewrite. Rejected.
• PRO ($9/mo) — not purchased, and not needed: the free ZeroGPU path worked. PRO does not improve the anonymous visitor's 2 min/day quota, so it would change nothing about the free-tier design that Phase 1 is built around. No payment was made by any step of this plan.

GPU posture

Phase 1 calls no GPU function. DISABLE_GPU=1 is to be set as a Space variable and every future GPU entry point must raise when it is set. Proof lives in tests/test_no_gpu_on_turn_path.py (static AST scan) and a DISABLE_GPU=1 deployed E2E run.

A ZeroGPU Space that never calls @spaces.GPU runs its web process on CPU and consumes zero visitor quota, so taking the ZeroGPU tier costs nothing at runtime in Phase 1. Plan 01-04 already established that speech synthesis is CPU-only and AST-verified free of spaces/torch imports.

ZeroGPU slot budget

1 of 2 free ZeroGPU slots is now consumed by this Space. 1 slot remains for the other four HF-profile projects. Because cpu-basic Gradio creation is 402-gated on this account, that final slot is the last free Gradio Space this account can create without PRO — spend it deliberately.

Git remote

git remote add space https://huggingface.co/spaces/WolfDavid/japanese-learning-avatar

Authentication is a cached fine-grained token held by the hf CLI (hf auth whoami reports WolfDavid), scoped repo.write / repo.content.read / repo.access.read on the WolfDavid entity. The token value is never written to this repository, any commit message, or any log.

No application code has been pushed to this remote. Deployment is plan 01-05's task and is gated behind its own spike verdict.