From a45f032fe40a868987ceebbe1fb0b6eff9e138c2 Mon Sep 17 00:00:00 2001
From: Anthony Volk <anth.volk@gmail.com>
Date: Tue, 10 Mar 2026 20:07:14 +0100
Subject: [PATCH] Display policyengine-us and policyengine-uk versions on
 overview page

Fetch latest package versions from PyPI JSON API and show them in a
"Current versions" section at the bottom of the overview page.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/components/microsim/PackageVersions.tsx | 81 +++++++++++++++++++++
 src/data/fetchPackageVersion.ts             | 20 +++++
 src/pages/OverviewPage.tsx                  |  2 +
 3 files changed, 103 insertions(+)
 create mode 100644 src/components/microsim/PackageVersions.tsx
 create mode 100644 src/data/fetchPackageVersion.ts

diff --git a/src/components/microsim/PackageVersions.tsx b/src/components/microsim/PackageVersions.tsx
new file mode 100644
index 0000000..0172f3f
--- /dev/null
+++ b/src/components/microsim/PackageVersions.tsx
@@ -0,0 +1,81 @@
+import { useState, useEffect } from 'react';
+import { motion } from 'framer-motion';
+import { colors } from '../../designTokens';
+import { fetchPackageVersion } from '../../data/fetchPackageVersion';
+
+const PACKAGES = [
+  { id: 'us', pypiName: 'policyengine-us', label: 'policyengine-us' },
+  { id: 'uk', pypiName: 'policyengine-uk', label: 'policyengine-uk' },
+] as const;
+
+export default function PackageVersions() {
+  const [versions, setVersions] = useState<Record<string, string | null>>({});
+  const [loading, setLoading] = useState(true);
+
+  useEffect(() => {
+    let cancelled = false;
+    Promise.all(
+      PACKAGES.map(async (pkg) => {
+        const version = await fetchPackageVersion(pkg.pypiName);
+        return [pkg.id, version] as const;
+      }),
+    ).then((results) => {
+      if (cancelled) return;
+      setVersions(Object.fromEntries(results));
+      setLoading(false);
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  return (
+    <div className="tw:mt-16">
+      <h3 className="tw:text-xl tw:font-bold tw:text-pe-primary-900 tw:mt-0 tw:mb-2 tw:mx-0">
+        Current versions
+      </h3>
+      <p className="tw:text-lg tw:text-[#5A5A5A] tw:leading-[1.7] tw:mb-8 tw:max-w-[720px] tw:mt-2">
+        PolicyEngine's country models are open-source Python packages, published
+        to PyPI with every release.
+      </p>
+      <div className="tw:flex tw:gap-6 tw:flex-wrap">
+        {PACKAGES.map((pkg, i) => (
+          <motion.a
+            key={pkg.id}
+            href={`https://pypi.org/project/${pkg.pypiName}/`}
+            target="_blank"
+            rel="noopener noreferrer"
+            initial={{ opacity: 0, y: 20 }}
+            animate={{ opacity: 1, y: 0 }}
+            transition={{ duration: 0.5, delay: i * 0.15 }}
+            className="tw:flex-1 tw:min-w-[200px] tw:px-5 tw:py-4 tw:rounded-xl tw:no-underline tw:flex tw:items-center tw:justify-between tw:transition-all tw:duration-300 tw:ease-in-out"
+            style={{
+              border: `2px solid ${colors.border.light}`,
+              backgroundColor: colors.white,
+            }}
+            onMouseEnter={(e) => {
+              e.currentTarget.style.borderColor = colors.primary[500];
+              e.currentTarget.style.backgroundColor = colors.primary[50];
+            }}
+            onMouseLeave={(e) => {
+              e.currentTarget.style.borderColor = colors.border.light;
+              e.currentTarget.style.backgroundColor = colors.white;
+            }}
+          >
+            <span className="tw:text-sm tw:font-semibold tw:text-pe-primary-900">
+              {pkg.label}
+            </span>
+            <span
+              className="tw:text-sm tw:font-mono"
+              style={{
+                color: loading ? colors.text.tertiary : colors.text.secondary,
+              }}
+            >
+              {loading ? '...' : versions[pkg.id] ? `v${versions[pkg.id]}` : '—'}
+            </span>
+          </motion.a>
+        ))}
+      </div>
+    </div>
+  );
+}
diff --git a/src/data/fetchPackageVersion.ts b/src/data/fetchPackageVersion.ts
new file mode 100644
index 0000000..eff1295
--- /dev/null
+++ b/src/data/fetchPackageVersion.ts
@@ -0,0 +1,20 @@
+const cache = new Map<string, string>();
+
+export async function fetchPackageVersion(
+  packageName: string,
+): Promise<string | null> {
+  if (cache.has(packageName)) return cache.get(packageName)!;
+
+  try {
+    const res = await fetch(`https://pypi.org/pypi/${packageName}/json`);
+    if (!res.ok) throw new Error(`PyPI returned ${res.status}`);
+    const data = await res.json();
+    const version: string = data.info?.version;
+    if (!version) throw new Error('No version in PyPI response');
+    cache.set(packageName, version);
+    return version;
+  } catch (err) {
+    console.warn(`Failed to fetch version for ${packageName}:`, err);
+    return null;
+  }
+}
diff --git a/src/pages/OverviewPage.tsx b/src/pages/OverviewPage.tsx
index 1423529..c27975c 100644
--- a/src/pages/OverviewPage.tsx
+++ b/src/pages/OverviewPage.tsx
@@ -1,11 +1,13 @@
 import Walkthrough from '../components/microsim/Walkthrough';
 import PageHeader from '../components/layout/PageHeader';
+import PackageVersions from '../components/microsim/PackageVersions';
 
 export default function OverviewPage({ country }: { country: string }) {
   return (
     <div>
       <PageHeader category="The engine" title="How microsimulation works" />
       <Walkthrough country={country} />
+      <PackageVersions />
     </div>
   );
 }