The same evidence package, rendered as a downloadable PDF (Pro).

ONE route declares both methods on purpose: two routes side by side on one path do not coexist the way they read, because _grant_head_to_get_routes() and Starlette's first-full-match ordering left the cheap HEAD unreachable and a link-checker paid for the rendering half (measured 2026-09-16 on /sitemap-models-{n}.xml).

Gated on tier: public is refused before any database read, because the roadmap sells this artifact at Pro while the JSON proof stays open to a signed-in caller. A pro API KEY is already refused one layer down, in _enforce_dev_gate inside _rate_limit - browser-tier keys do not spend on programmatic surfaces - so this gate is what stops the signed-in public caller, and it costs nothing to refuse. The refusal splits 401/403 the way _enforce_search_trial does for the JSON sibling: no credential is an identity problem (401), a credentialed free-tier caller is a tier problem (403). Telling a keyless client to upgrade teaches it the wrong next move.