diff --git a/astro.config.ts b/astro.config.ts
index fcf13e786ff74b6..7f194d4ab2f643e 100644
--- a/astro.config.ts
+++ b/astro.config.ts
@@ -14,6 +14,7 @@ import rehypeMermaid from "./src/plugins/rehype/mermaid.ts";
 import rehypeAutolinkHeadings from "./src/plugins/rehype/autolink-headings.ts";
 import rehypeExternalLinks from "./src/plugins/rehype/external-links.ts";
 import rehypeHeadingSlugs from "./src/plugins/rehype/heading-slugs.ts";
+import rehypeRewriteUrls from "./src/plugins/rehype/rewrite-urls.ts";
 
 import { sidebar } from "./src/util/sidebar.ts";
 
@@ -31,6 +32,7 @@ export default defineConfig({
 			rehypeAutolinkHeadings,
 			// @ts-expect-error plugins types are outdated but functional
 			rehypeTitleFigure,
+			rehypeRewriteUrls,
 		],
 	},
 	experimental: {
diff --git a/src/plugins/rehype/rewrite-urls.ts b/src/plugins/rehype/rewrite-urls.ts
new file mode 100644
index 000000000000000..a63e35997a4582d
--- /dev/null
+++ b/src/plugins/rehype/rewrite-urls.ts
@@ -0,0 +1,22 @@
+import config from "../../../astro.config.ts";
+import { visit } from "unist-util-visit";
+import type { Root } from "hast";
+
+// Rewrite relative /api/ links to be absolute, using the `site` base from the Astro config.
+export default function () {
+	return function (tree: Root) {
+		visit(tree, "element", function (element) {
+			if (element.tagName === "a") {
+				if (element.properties.href) {
+					const url = new URL(element.properties.href as string, config.site);
+
+					if (url.origin === config.site) {
+						if (url.pathname.startsWith("/api/")) {
+							element.properties.href = url.toString();
+						}
+					}
+				}
+			}
+		});
+	};
+}