diff --git a/static/app.js b/static/app.js
index 7bcadde..3dbe386 100644
--- a/static/app.js
+++ b/static/app.js
@@ -126,6 +126,7 @@ async function loadLibraries() {
         <td>${l.language ? esc(languageName(l.language)) : "—"}</td>
         <td class="row">
           <button class="secondary" data-edit-lib="${l.id}">${t("common.edit")}</button>
+          <button class="secondary" data-adopt-lib="${l.id}" title="${esc(t("adopt.buttonTitle"))}">${t("adopt.button")}</button>
           <button class="danger" data-del-lib="${l.id}">${t("common.delete")}</button>
         </td>
       </tr>`
@@ -134,6 +135,9 @@ async function loadLibraries() {
   tbody.querySelectorAll("[data-edit-lib]").forEach((b) =>
     b.addEventListener("click", () => startLibraryEdit(parseInt(b.dataset.editLib)))
   );
+  tbody.querySelectorAll("[data-adopt-lib]").forEach((b) =>
+    b.addEventListener("click", () => openAdopt(parseInt(b.dataset.adoptLib)))
+  );
   tbody.querySelectorAll("[data-del-lib]").forEach((b) =>
     b.addEventListener("click", async () => {
       if (!confirm(t("lib.confirmDelete"))) return;
@@ -664,7 +668,7 @@ $("#missing-bulk-delete").addEventListener("click", () => bulkDeleteRequests("mi
 
 // ---- activity ----
 let historyRows = [];
-const HISTORY_STATE = { imported: "done", appended: "done", failed: "failed" };
+const HISTORY_STATE = { imported: "done", appended: "done", adopted: "done", failed: "failed" };
 
 async function loadHistory() {
   try {
@@ -1818,6 +1822,75 @@ function setImportProgress(done, total) {
     `${done}/${total} · ${Math.round((done / total) * 100)} %`;
 }
 
+// ---- adopt files already in a library ----
+let adoptLib = null;
+let adoptScan = null;
+
+async function openAdopt(id) {
+  adoptLib = libraries.find((l) => l.id === id);
+  adoptScan = null;
+  $("#adopt-heading").textContent = t("adopt.heading", { name: adoptLib.name });
+  $("#adopt-intro").innerHTML = `<span class="spinner"></span> ${t("import.scanning")}`;
+  $("#adopt-list").innerHTML = "";
+  $("#adopt-submit").disabled = true;
+  $("#adopt-dialog").showModal();
+  try {
+    adoptScan = await api("/api/import/library/" + id);
+  } catch (err) {
+    $("#adopt-intro").textContent = "";
+    toast(err.message, true);
+    return;
+  }
+  renderAdopt();
+}
+
+function renderAdopt() {
+  if (!adoptScan) return;
+  // only files with a suggestion: a select per unmatched file would bury them
+  const matched = adoptScan.items.filter((i) => i.suggested_request_id);
+  $("#adopt-intro").textContent = t("adopt.intro", {
+    n: matched.length, rest: adoptScan.items.length - matched.length,
+  });
+  const options = adoptScan.requests
+    .map((r) => [r.id, r.authors ? `${r.authors}: ${r.title}` : r.title]);
+  $("#adopt-list").innerHTML = matched
+    .map((item) => `<label>
+        <input type="checkbox" checked data-adopt-path="${esc(item.path)}" />
+        <span>${esc(item.name)} <span class="muted">${esc(item.rel_dir)}</span></span>
+        <select>${options.map(([id, label]) =>
+          `<option value="${id}"${id === item.suggested_request_id ? " selected" : ""}>${esc(label)}</option>`
+        ).join("")}</select>
+      </label>`)
+    .join("");
+  $("#adopt-submit").disabled = matched.length === 0;
+}
+
+$("#adopt-cancel").addEventListener("click", () => $("#adopt-dialog").close());
+
+$("#adopt-submit").addEventListener("click", async () => {
+  const items = [...$$("#adopt-list [data-adopt-path]:checked")].map((box) => ({
+    path: box.dataset.adoptPath,
+    request_id: parseInt(box.closest("label").querySelector("select").value),
+  }));
+  if (!items.length) return;
+  $("#adopt-submit").disabled = true;
+  try {
+    const { results } = await api("/api/import/library/" + adoptLib.id, {
+      method: "POST", body: JSON.stringify({ items }),
+    });
+    const failed = results.filter((r) => !r.ok);
+    toast(failed.length
+      ? t("adopt.partial", { n: results.length - failed.length, failed: failed.map((r) => `${r.path}: ${r.error}`).join("; ") })
+      : t("adopt.done", { n: results.length }), failed.length > 0);
+    $("#adopt-dialog").close();
+    refreshMissingBadge();
+  } catch (err) {
+    toast(err.message, true);
+  } finally {
+    $("#adopt-submit").disabled = false;
+  }
+});
+
 // ---- language ----
 function updateLangButton() {
   $("#lang-toggle").textContent = lang === "de" ? "EN" : "DE";
@@ -1836,6 +1909,7 @@ function onLangChange() {
   const editId = $("#lib-form").dataset.editId;
   editId ? startLibraryEdit(parseInt(editId)) : endLibraryEdit();
   if (scanItems.length) renderImportTable();
+  renderAdopt();
 }
 
 // ---- version ----
diff --git a/static/i18n.js b/static/i18n.js
index 745278b..14bb8dc 100644
--- a/static/i18n.js
+++ b/static/i18n.js
@@ -56,6 +56,14 @@ const STRINGS = {
     "history.retagged": "neu getaggt",
     "history.deleted": "gelöscht",
     "history.failed": "fehlgeschlagen",
+    "history.adopted": "übernommen",
+    "adopt.button": "Einlesen",
+    "adopt.buttonTitle": "Dateien, die schon in der Library liegen, offenen Anfragen zuordnen",
+    "adopt.heading": "„{name}“ einlesen",
+    "adopt.intro": "{n} Dateien passen zu offenen Anfragen dieser Library und bleiben, wo sie sind. {rest} weitere ohne Treffer.",
+    "adopt.submit": "Übernehmen",
+    "adopt.done": "{n} übernommen",
+    "adopt.partial": "{n} übernommen, Fehler: {failed}",
 
     "search.languageTitle": "Sprache der Ausgabe — filtert Ebook- und Audiobook-Suche",
     "search.allLanguages": "Alle Sprachen",
@@ -296,6 +304,14 @@ const STRINGS = {
     "history.retagged": "retagged",
     "history.deleted": "deleted",
     "history.failed": "failed",
+    "history.adopted": "adopted",
+    "adopt.button": "Scan",
+    "adopt.buttonTitle": "Link files already in the library to open requests",
+    "adopt.heading": "Scan “{name}”",
+    "adopt.intro": "{n} files match open requests of this library and stay where they are. {rest} more without a match.",
+    "adopt.submit": "Adopt",
+    "adopt.done": "{n} adopted",
+    "adopt.partial": "{n} adopted, errors: {failed}",
 
     "search.languageTitle": "Edition language — filters the ebook and audiobook search",
     "search.allLanguages": "All languages",
diff --git a/static/index.html b/static/index.html
index 73331d6..b92f1ca 100644
--- a/static/index.html
+++ b/static/index.html
@@ -379,6 +379,16 @@
       </form>
     </dialog>
 
+    <dialog id="adopt-dialog">
+      <h3 id="adopt-heading"></h3>
+      <p class="muted" id="adopt-intro"></p>
+      <div id="adopt-list" class="series-list"></div>
+      <div class="row">
+        <button type="button" id="adopt-cancel" class="secondary" data-i18n="common.cancel"></button>
+        <button type="button" id="adopt-submit" data-i18n="adopt.submit"></button>
+      </div>
+    </dialog>
+
     <div id="toast" hidden></div>
     <script src="/i18n.js"></script>
     <script src="/app.js"></script>