diff --git a/scripts/patch-tag-input-autocomplete.mjs b/scripts/patch-tag-input-autocomplete.mjs
new file mode 100644
index 00000000..22e81b01
--- /dev/null
+++ b/scripts/patch-tag-input-autocomplete.mjs
@@ -0,0 +1,121 @@
+/**
+ * Patch: add datalist autocomplete to the <tag-input-field> web component.
+ *
+ * Fetches /micropub?q=category&filter=<value> as the user types (debounced
+ * 300ms) and populates a native <datalist>. Selecting a suggestion fills the
+ * text field; the user confirms with comma or blur as usual.
+ *
+ * Datalist is explicitly cleared in keydown(Comma) and blur handlers because
+ * the existing handlers clear the field via programmatic .value = "" which
+ * does NOT fire the input event (HTML Living Standard).
+ */
+
+import { access, readFile, writeFile } from "node:fs/promises";
+
+const MARKER = "// [patch] tag-input-autocomplete";
+
+const candidates = [
+  "node_modules/@indiekit/frontend/components/tag-input/index.js",
+  "node_modules/@indiekit/indiekit/node_modules/@indiekit/frontend/components/tag-input/index.js",
+];
+
+const OLD_SNIPPET = `    // Capture any value in input not converted to tag (for example, by clicking
+    // outside component before pressing tab key) and add to list of tags.
+    $tagInputInput.addEventListener("blur", () => {
+      if ($tagInputInput.value) {
+        tagInput.addTag($tagInputInput.value, false);
+        $tagInputInput.value = "";
+      }
+    });
+
+    return tagInput;`;
+
+const NEW_SNIPPET = `    // Capture any value in input not converted to tag (for example, by clicking
+    // outside component before pressing tab key) and add to list of tags.
+    $tagInputInput.addEventListener("blur", () => {
+      if ($tagInputInput.value) {
+        tagInput.addTag($tagInputInput.value, false);
+        $tagInputInput.value = "";
+      }
+    });
+
+    // Autocomplete: wire datalist to Micropub q=category endpoint ${MARKER}
+    const _micropubHref =
+      document.querySelector('link[rel="micropub"]')?.href ?? "/micropub";
+    const _datalistId =
+      "tag-suggestions-" + (this.$replacedInput?.getAttribute("name") ?? Math.random().toString(36).slice(2));
+    const _$datalist = document.createElement("datalist");
+    _$datalist.id = _datalistId;
+    this.appendChild(_$datalist);
+    $tagInputInput.setAttribute("list", _datalistId);
+
+    let _autocompleteTimer;
+    $tagInputInput.addEventListener("input", () => {
+      clearTimeout(_autocompleteTimer);
+      const _val = $tagInputInput.value.trim();
+      if (!_val) { _$datalist.replaceChildren(); return; }
+      _autocompleteTimer = setTimeout(async () => {
+        try {
+          const _res = await fetch(
+            \`\${_micropubHref}?q=category&filter=\${encodeURIComponent(_val)}\`
+          );
+          if (!_res.ok) return;
+          const _data = await _res.json();
+          _$datalist.replaceChildren(
+            ...(_data.categories ?? []).map((_cat) => {
+              const _opt = document.createElement("option");
+              _opt.value = _cat;
+              return _opt;
+            })
+          );
+        } catch {}
+      }, 300);
+    });
+
+    // Clear datalist after tag confirmed via comma (programmatic clear doesn't fire input)
+    $tagInputInput.addEventListener("keydown", (_e) => {
+      if (_e.code === "Comma") _$datalist.replaceChildren();
+    });
+
+    // Clear datalist after tag confirmed via blur
+    $tagInputInput.addEventListener("blur", () => {
+      _$datalist.replaceChildren();
+    });
+
+    return tagInput;`;
+
+async function exists(p) {
+  try { await access(p); return true; } catch { return false; }
+}
+
+let totalPatched = 0;
+let totalChecked = 0;
+
+for (const filePath of candidates) {
+  if (!(await exists(filePath))) continue;
+  totalChecked++;
+
+  const source = await readFile(filePath, "utf8");
+  if (source.includes(MARKER)) {
+    console.log(`[postinstall] patch-tag-input-autocomplete: already applied to ${filePath}`);
+    continue;
+  }
+
+  if (!source.includes(OLD_SNIPPET)) {
+    console.warn(`[postinstall] patch-tag-input-autocomplete: snippet not found in ${filePath} (upstream changed?)`);
+    continue;
+  }
+
+  const updated = source.replace(OLD_SNIPPET, NEW_SNIPPET);
+  await writeFile(filePath, updated, "utf8");
+  console.log(`[postinstall] Applied patch-tag-input-autocomplete to ${filePath}`);
+  totalPatched++;
+}
+
+if (totalChecked === 0) {
+  console.log("[postinstall] patch-tag-input-autocomplete: no target files found");
+} else if (totalPatched === 0) {
+  console.log("[postinstall] patch-tag-input-autocomplete: already up to date");
+} else {
+  console.log(`[postinstall] patch-tag-input-autocomplete: patched ${totalPatched} file(s)`);
+}