diff --git a/docs/adr/0001-tipjar-support-button.md b/docs/adr/0001-tipjar-support-button.md
new file mode 100644
index 0000000..828909a
--- /dev/null
+++ b/docs/adr/0001-tipjar-support-button.md
@@ -0,0 +1,30 @@
+---
+public: false
+---
+
+# 0001: A floating tipjar button complements the footer's Ko-fi link
+
+- **Status:** Accepted
+- **Date:** 2026-11-07
+- **PR:** (this PR)
+
+## Context
+
+The landing page's only support link was the footer's "☕ Support future projects" (Ko-fi), which most
+visitors never scroll to. Matt's own `tipjar` package (npm, MIT, zero dependencies) draws a floating support
+button. Options: replace the footer line with the button, add the button and keep the line, or leave it.
+The site's CSP is `script-src 'self'` and the site self-hosts everything it loads.
+
+## Decision
+
+We add the tipjar button to the landing page and keep the footer line. Both go to https://ko-fi.com/mtblck,
+and the button tucks itself away (`hideWhenVisible: 'footer'`) while the footer is on screen, so only one
+shows at a time. `tools/site.mjs` copies `tipjar/dist/*.js` and `style.css` from node_modules into
+`dist/site/tipjar/`, and `site/tip.js` (a module file) mounts it, so no CDN and no CSP change. It takes the
+page's cobalt via `--tipjar-*` in `site.css`, so it follows `data-theme`. The docs pages don't get it: they
+are for reading, and their footer has no support link to hand over to.
+
+## Consequences
+
+Upgrading the button is a `tipjar` version bump in package.json. Clicks are not counted: a new event name
+would need adding to Boards' events list first. Revisit if the button crowds the playground on phones.
diff --git a/package-lock.json b/package-lock.json
index ce5ebd0..40ca8ab 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,7 +10,8 @@
         "@fontsource-variable/bricolage-grotesque": "^5.3.0",
         "@fontsource-variable/jetbrains-mono": "^5.3.0",
         "marked": "^16.4.2",
-        "playwright": "1.64.1"
+        "playwright": "1.64.1",
+        "tipjar": "^1.2.0"
       },
       "engines": {
         "node": ">=22"
@@ -77,6 +78,19 @@
       "engines": {
         "node": ">=20"
       }
+    },
+    "node_modules/tipjar": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/tipjar/-/tipjar-1.2.0.tgz",
+      "integrity": "sha512-5M/yHG9WEUcxahX9uNiKh84AoyaMzdjLMaSDOTorLBdnR8rr400W66m7oT5OlXwqM4Y9CLq7GiG9IE2jYbhQEA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=22"
+      },
+      "funding": {
+        "url": "https://ko-fi.com/mtblck"
+      }
     }
   }
 }
diff --git a/package.json b/package.json
index b3e23fe..3c3f376 100644
--- a/package.json
+++ b/package.json
@@ -19,6 +19,7 @@
     "@fontsource-variable/bricolage-grotesque": "^5.3.0",
     "@fontsource-variable/jetbrains-mono": "^5.3.0",
     "marked": "^16.4.2",
-    "playwright": "1.64.1"
+    "playwright": "1.64.1",
+    "tipjar": "^1.2.0"
   }
 }
diff --git a/site/index.html b/site/index.html
index bb533a4..73396bb 100644
--- a/site/index.html
+++ b/site/index.html
@@ -15,6 +15,7 @@
   <link rel="preload" as="font" type="font/woff2" crossorigin href="/fonts/bricolage.woff2" />
   <script src="/theme.js"></script>
   <script src="/analytics.js" defer></script>
+  <link rel="stylesheet" href="/tipjar/style.css" />
   <link rel="stylesheet" href="/site.css" />
 </head>
 <body>
@@ -258,5 +259,6 @@ <h2 id="install-h">Install</h2>
   <script src="/isogram.js"></script>
   <script src="/examples.js"></script>
   <script src="/site.js"></script>
+  <script type="module" src="/tip.js"></script>
 </body>
 </html>
diff --git a/site/site.css b/site/site.css
index 3c35012..f5abd8d 100644
--- a/site/site.css
+++ b/site/site.css
@@ -212,3 +212,12 @@ footer p { margin: 0 0 8px; max-width: 60em; }
 
 @media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; } }
 .prose :not(pre) > code { overflow-wrap: anywhere; }
+
+/* the floating support button (tipjar): the page's cobalt, ringed in paper; it tucks away at the footer */
+:root {
+  --tipjar-bg: var(--accent);
+  --tipjar-label: var(--accent-ink);
+  --tipjar-ring: var(--paper);
+  --tipjar-font: var(--sans);
+  --tipjar-icon-size: 24px;   /* pixel icons sit on a 12px grid */
+}
diff --git a/site/tip.js b/site/tip.js
new file mode 100644
index 0000000..07f573d
--- /dev/null
+++ b/site/tip.js
@@ -0,0 +1,12 @@
+// getisogram.com: the floating "Support" button (the tipjar package, copied in by tools/site.mjs).
+// It goes to the same Ko-fi page as the footer's support line and tucks itself away while the
+// footer is on screen, so the two never show at once. A module from a file: the CSP is script-src 'self'.
+import { mount } from '/tipjar/index.js'
+
+mount({
+  href: 'https://ko-fi.com/mtblck',
+  description: 'future projects on Ko-fi',
+  icon: 'coffee',
+  iconStyle: 'pixel',
+  hideWhenVisible: 'footer',
+})
diff --git a/test/site.test.mjs b/test/site.test.mjs
index ce6cd2f..ec4d37e 100644
--- a/test/site.test.mjs
+++ b/test/site.test.mjs
@@ -10,7 +10,7 @@ const out = path.join(ROOT, 'dist', 'site')
 test('the site builds', () => {
   const r = spawnSync(process.execPath, [path.join(ROOT, 'tools/site.mjs')], { encoding: 'utf8' })
   assert.equal(r.status, 0, r.stderr)
-  for (const f of ['index.html', 'docs/index.html', 'docs/skill/index.html', 'docs/api/index.html', 'docs/craft/index.html', 'isogram.js', 'examples.js', 'isogram.skill', 'fonts/bricolage.woff2', 'og.png'])
+  for (const f of ['index.html', 'docs/index.html', 'docs/skill/index.html', 'docs/api/index.html', 'docs/craft/index.html', 'isogram.js', 'examples.js', 'isogram.skill', 'fonts/bricolage.woff2', 'og.png', 'tip.js', 'tipjar/index.js', 'tipjar/style.css'])
     assert.ok(fs.existsSync(path.join(out, f)), `${f} missing`)
 })
 
diff --git a/tools/site.mjs b/tools/site.mjs
index eb9e60a..7f080b3 100644
--- a/tools/site.mjs
+++ b/tools/site.mjs
@@ -19,7 +19,7 @@ const LOGO = '<svg viewBox="0 0 32 32" aria-hidden="true"><path d="M16 3 28 10 1
 
 // ---- landing page and static files ----
 write('index.html', fs.readFileSync(src('index.html'), 'utf8').replaceAll('{{logo}}', LOGO))
-for (const f of ['site.css', 'site.js', 'theme.js', 'analytics.js', 'docs.js', 'icon.svg', 'og.png']) if (fs.existsSync(src(f))) fs.copyFileSync(src(f), path.join(out, f))
+for (const f of ['site.css', 'site.js', 'theme.js', 'analytics.js', 'docs.js', 'tip.js', 'icon.svg', 'og.png']) if (fs.existsSync(src(f))) fs.copyFileSync(src(f), path.join(out, f))
 write('isogram.js', read('assets/isogram.js'))
 write('examples.js', examples().map(f => read(`examples/${f}`)).join('\n'))
 const files = skillFiles()
@@ -32,6 +32,12 @@ fs.mkdirSync(path.join(out, 'fonts'), { recursive: true })
 font('@fontsource-variable/bricolage-grotesque', 'bricolage-grotesque-latin-standard-normal.woff2', 'bricolage.woff2')
 font('@fontsource-variable/jetbrains-mono', 'jetbrains-mono-latin-wght-normal.woff2', 'jetbrains-mono.woff2')
 
+// the floating support button (tipjar), self-hosted like the fonts: its ES modules and stylesheet
+const tipjar = path.dirname(req.resolve('tipjar/package.json'))
+fs.mkdirSync(path.join(out, 'tipjar'), { recursive: true })
+for (const f of fs.readdirSync(path.join(tipjar, 'dist'))) if (f.endsWith('.js')) fs.copyFileSync(path.join(tipjar, 'dist', f), path.join(out, 'tipjar', f))
+fs.copyFileSync(path.join(tipjar, 'style.css'), path.join(out, 'tipjar', 'style.css'))
+
 // ---- docs: one page written for people (site/docs/), then the skill's own markdown, as Claude reads it ----
 const PAGES = [
   { path: '/docs/', source: 'site/docs/start.md', nav: 'Using isogram', description: 'Install the isogram skill, ask Claude for a good diagram, embed it with one tag, and every attribute it takes.' },