docs(community): document GitHub Sponsors tiers, recognition and SPONSORS.md

GOVERNANCE.md

@@ -205,9 +205,14 @@ holds any of the access.
 - **The documentation site**, published from the repository by GitHub Pages.
 - **The project mailbox** named in [`SECURITY.md`](SECURITY.md) and
   [`CODE_OF_CONDUCT.md`](CODE_OF_CONDUCT.md).
-- **Funding accounts.** [Ko-fi](https://ko-fi.com/lusoris) exists today.
-  GitHub Sponsors is planned and will be set up once the funding tiers are
-  finished. Their handover is part of the access list above.
+- **Funding accounts.** [GitHub Sponsors](https://github.com/sponsors/lusoris)
+  (USD, live since 2026-10-08) and [Ko-fi](https://ko-fi.com/lusoris) (EUR)
+  are live; a euro Patreon page is being set up. The GitHub profile belongs to
+  the maintainer's personal account. Sponsorship buys recognition only, listed
+  in [`SPONSORS.md`](SPONSORS.md) and explained on
+  [Support VMAFx](docs/support-vmafx.md)
+  ([ADR-2689](docs/adr/2689-sponsorship-tiers-recognition-only.md)). Their
+  handover is part of the access list above.
 
 ### 8.3 Succession plan
 

README.md

@@ -132,7 +132,16 @@ cover coding and numerical-correctness standards; the
 - [Code of conduct](CODE_OF_CONDUCT.md)
 - [Accessibility](ACCESSIBILITY.md)
 - [Security reporting policy](SECURITY.md)
-- [Support development](https://ko-fi.com/lusoris)
+- [Support development](docs/support-vmafx.md)
+
+## 💖 Support VMAFx
+
+VMAFx is free and stays open source. Sponsor it on
+[GitHub Sponsors](https://github.com/sponsors/lusoris) (USD) or
+[Ko-fi](https://ko-fi.com/lusoris) (EUR) to pay for CI and cloud GPU test
+time; a euro Patreon option is coming. Sponsors are thanked by tier in
+[SPONSORS.md](SPONSORS.md); [Support VMAFx](docs/support-vmafx.md) explains
+what it pays for.
 
 ## 📈 Project status
 

SPONSORS.md

@@ -0,0 +1,80 @@
+<!-- markdownlint-disable MD013 -->
+# Sponsors
+
+You can sponsor VMAFx from $5 a month. Sponsors are thanked here by tier;
+nothing else changes: no paid support, no feature voting, no paywalls.
+Everything stays open source.
+
+Sponsorship pays for CI time, cloud GPU test time on hardware the project does
+not own, and, as the next goal, an AI workstation. The first goal is $250 a
+month. The page [Support VMAFx](docs/support-vmafx.md) explains what the money
+buys.
+
+## How to sponsor
+
+- **GitHub Sponsors (USD):** <https://github.com/sponsors/lusoris>. The
+  profile belongs to the maintainer's personal account and covers VMAFx and
+  the maintainer's related open-source work. GitHub accepts US dollars only.
+- **Ko-fi (EUR):** <https://ko-fi.com/lusoris>.
+- **Patreon (EUR):** a euro Patreon page with the same four tiers (5, 25, 100
+  and 500 euros a month) is coming. It is not live yet; this file is updated
+  when it is.
+
+Custom amounts are allowed on GitHub Sponsors.
+
+## Tiers
+
+<!-- --8<-- [start:tiers] -->
+| Tier | Monthly (USD) | Recognition |
+| --- | --- | --- |
+| Supporter | $5 | Your name or handle in `SPONSORS.md` |
+| Sustainer | $25 | Your name and a link in `SPONSORS.md` and on the documentation site |
+| Company sponsor | $100 | Your logo in the README and on the documentation site |
+| Lead sponsor | $500 | The top-placed logo in the README and on the documentation site, and thanks in every release note |
+
+One-time sponsorships of $10 or $50 are thanked in this file for that month.
+<!-- --8<-- [end:tiers] -->
+
+## Recognised sponsors
+
+<!-- --8<-- [start:recognised] -->
+### Lead sponsors
+
+No sponsors at this tier yet.
+
+### Company sponsors
+
+No sponsors at this tier yet.
+
+### Sustainers
+
+No sponsors at this tier yet.
+
+### Supporters
+
+No sponsors at this tier yet.
+
+### One-time sponsors this month
+
+No sponsors at this tier yet.
+<!-- --8<-- [end:recognised] -->
+
+## Recognition rules
+
+- **Staying anonymous.** Tell the maintainer in your sponsorship message or in
+  a discussion at <https://github.com/VMAFx/vmafx/discussions>, and nothing is
+  listed for you. Nobody is listed without being a sponsor.
+- **Logos.** Company and Lead logos are placed by the maintainer after you
+  send them. Send an SVG or a transparent PNG; the maintainer checks that the
+  logo is yours to use, sizes it to the same height as the others, and links it
+  to the address you give. The Lead logo comes first and is slightly larger.
+- **Links.** Links are plain links to your own site or profile. The maintainer
+  can decline a logo or link that is unlawful, misleading or unrelated to a
+  business, and then lists nothing.
+- **Ending a sponsorship.** When a monthly sponsorship ends, the entry is
+  removed in the next update of this file.
+- **No influence.** Sponsoring does not buy a say in the roadmap, early
+  access, support or a changed licence.
+
+Contact is through GitHub: an issue or a discussion on
+[VMAFx/vmafx](https://github.com/VMAFx/vmafx).

changelog.d/added/sponsors-live.md

@@ -0,0 +1 @@
+- **GitHub Sponsors is live (ADR-2689).** `SPONSORS.md` lists the four monthly tiers ($5, $25, $100, $500), the one-time amounts and the sponsors by tier, and the new documentation page "Support VMAFx" explains what sponsorship pays for (CI time, cloud GPU test time, an AI workstation). Sponsorship buys recognition only; there is no paid support or paywall. Euro routes: Ko-fi now, Patreon coming.

docs/adr/2689-sponsorship-tiers-recognition-only.md

@@ -0,0 +1,63 @@
+<!-- markdownlint-disable MD013 MD060 -->
+# ADR-2689: sponsorship is recognition only, in four monthly tiers, with one source file for the list
+
+- **Status**: Accepted
+- **Date**: 2026-10-08
+- **Deciders**: maintainer, agent
+- **Tags**: docs, community, funding, fork-local
+
+## Context
+
+The project's funding page listed only Ko-fi, and
+[GOVERNANCE.md](../../GOVERNANCE.md) section 8 called GitHub Sponsors planned.
+The GitHub Sponsors listing is now live on the maintainer's personal account.
+A tier ladder, a statement of what sponsors receive, a currency policy and a
+funding goal had to be fixed before the listing could be published, and the
+repository needed one place that names sponsors. GitHub Sponsors takes US
+dollars only; a euro audience needs another route.
+
+## Decision
+
+Sponsorship buys recognition only. There are four monthly tiers: Supporter
+($5, name or handle in `SPONSORS.md`), Sustainer ($25, name and link in
+`SPONSORS.md` and on the documentation site), Company sponsor ($100, logo in
+the README and on the documentation site) and Lead sponsor ($500, top-placed
+logo plus thanks in every release note); one-time $10 and $50 amounts are
+thanked in `SPONSORS.md` for that month. There is no paid support, no feature
+voting and no paywall. GitHub Sponsors carries the dollar amounts, Ko-fi and a
+planned Patreon page the euro amounts (5, 25, 100 and 500 euros). The first
+funding goal is $250 a month for CI and cloud GPU test time; an AI
+workstation is the next goal. The repository root `SPONSORS.md` is the single
+source of the tier table and the sponsor list; the documentation page
+`docs/support-vmafx.md` includes both from it with `pymdownx.snippets`
+instead of repeating them. The Patreon page is linked and added to
+`.github/FUNDING.yml` only when it is live.
+
+## Alternatives considered
+
+| Option | Pros | Cons | Why not chosen |
+| --- | --- | --- | --- |
+| Recognition plus early access | Stronger incentive | Creates two classes of users; conflicts with open development | Recognition only keeps every release public at once |
+| Recognition plus paid support | Revenue per company | Turns the maintainer into a vendor; obligations and response times | Not wanted; support stays the same for everyone |
+| A $3 / $10 / $50 / $250 ladder | Lower entry | Low tiers cost the same effort to administer | The $5 / $25 / $100 / $500 ladder was chosen |
+| Euro as the primary currency on GitHub | Matches the maintainer's currency | GitHub Sponsors takes USD only | Dollars on GitHub, euros on Ko-fi and Patreon |
+| Copy the tier table into the docs page | Simple | Two lists drift apart | One source, included by snippet (HISS-19) |
+
+## Consequences
+
+- **Positive**: one public statement of what sponsorship is and is not; one
+  file to update when a sponsor joins; the docs page cannot disagree with it.
+- **Negative**: the docs build now depends on `pymdownx.snippets` reading a
+  file outside `docs/`; a renamed marker in `SPONSORS.md` fails the strict
+  build, which is the intended signal.
+- **Neutral / follow-ups**: add the Patreon link and `patreon:` entry when the
+  page is live; place logos by hand when a Company or Lead sponsor sends one.
+
+## References
+
+- Maintainer decisions Q-278 (tier ladder), Q-279 (recognition only), Q-280
+  (Patreon page identity), Q-281 (who sets up the listing), Q-282 (currency),
+  Q-283 (approval of the drafts), Q-284 (funding goal) and Q-285 (featured
+  repositories), recorded in the maintainer's local decision log.
+- [GOVERNANCE.md](../../GOVERNANCE.md) section 8, [SPONSORS.md](../../SPONSORS.md),
+  [Support VMAFx](../support-vmafx.md).

docs/adr/_index_fragments/2689-sponsorship-tiers-recognition-only.md

@@ -0,0 +1 @@
+| [ADR-2689](2689-sponsorship-tiers-recognition-only.md) | Sponsorship is recognition only, in four monthly tiers ($5, $25, $100, $500) plus one-time amounts, with no paid support, voting or paywall; the root `SPONSORS.md` is the single source of the tier table and sponsor list, included into the docs page by snippet. | Accepted | docs, community, funding |

docs/support-vmafx.md

@@ -0,0 +1,53 @@
+<!-- markdownlint-disable MD013 -->
+# Support VMAFx
+
+VMAFx is free and open source, and it stays that way. If it saves you time,
+you can sponsor it from $5 a month. Sponsors are thanked on this page and in
+the repository; sponsoring buys recognition only, with no paid support, no
+feature voting and no paywall.
+
+## What the money pays for
+
+- **CI time.** Every change runs the build matrix, the numerical-exactness
+  gates and the sanitizer jobs. This is the largest running cost.
+- **Cloud GPU test time.** VMAFx ships CUDA, SYCL, HIP and Metal backends that
+  must give the same scores as the CPU. Checking that on hardware the project
+  does not own is paid by the hour.
+- **An AI workstation (next goal).** Training and evaluating the tiny quality
+  models needs a machine of its own. This comes after the first goal.
+
+The first goal is **$250 a month** for CI and cloud GPU time.
+
+## How to sponsor
+
+| Route | Currency | Status |
+| --- | --- | --- |
+| [GitHub Sponsors](https://github.com/sponsors/lusoris) | USD (GitHub takes dollars only) | Live |
+| [Ko-fi](https://ko-fi.com/lusoris) | EUR | Live |
+| Patreon | EUR, the same four tiers at 5, 25, 100 and 500 euros | Coming; not live yet |
+
+The GitHub profile belongs to the maintainer's personal account (`lusoris`)
+and covers VMAFx and the maintainer's related open-source work. GitHub
+Sponsors also accepts custom amounts.
+
+## Tiers
+
+--8<-- "SPONSORS.md:tiers"
+
+## What recognition means
+
+- Names, links and logos appear only for sponsors, and only at the placement
+  the tier states. Say so if you would rather stay anonymous.
+- Logos are placed by the maintainer after you send them. The full rules are
+  in [`SPONSORS.md`](https://github.com/VMAFx/vmafx/blob/master/SPONSORS.md).
+- Sponsoring gives no influence over the roadmap, no early access and no
+  support. Questions and bugs go through the normal issue tracker for everyone.
+- The decision and the alternatives are recorded in
+  [ADR-2689](adr/2689-sponsorship-tiers-recognition-only.md).
+
+## Our sponsors
+
+--8<-- "SPONSORS.md:recognised"
+
+Thank you to everyone who sponsors, and to everyone who reports bugs, sends
+patches or tests on their own hardware. Both kinds of help matter.

mkdocs.yml

@@ -80,6 +80,11 @@ markdown_extensions:
       line_spans: __span
       pygments_lang_class: true
   - pymdownx.inlinehilite
+  # Pulls the tier table and sponsor list out of the root SPONSORS.md, the single
+  # source for sponsor recognition (ADR-2689).
+  - pymdownx.snippets:
+      base_path: ['.']
+      check_paths: true
   - pymdownx.tabbed:
       alternate_style: true
   - pymdownx.tasklist:
@@ -178,6 +183,7 @@ nav:
       - Releases and roadmap: roadmap.md
       - Licensing: licensing.md
       - Credits: credits.md
+      - Support VMAFx: support-vmafx.md
   - Choose a backend:
       - backends/index.md
       - x86 SIMD (AVX2 / AVX-512): backends/x86/avx512.md