diff --git a/devlog/_plan/260912_provider_catalog_unified_search/030_r2_note_clamp.md b/devlog/_plan/260912_provider_catalog_unified_search/030_r2_note_clamp.md
index ae9ea4dd96..40c2e3352a 100644
--- a/devlog/_plan/260912_provider_catalog_unified_search/030_r2_note_clamp.md
+++ b/devlog/_plan/260912_provider_catalog_unified_search/030_r2_note_clamp.md
@@ -21,6 +21,13 @@ layout read: `scrollHeight > clientHeight` would need a ref per row plus a resiz
 observer and would make the decision untestable without a DOM. The threshold lives in
 `provider-presets.ts` as a named constant with its own unit test.
 
+> Superseded twice. `016` replaced the nested button with a sibling inside
+> `.provider-catalog-row-wrap`, because `.list-row` is already a `<button>`. And the
+> threshold shipped at **90**, not 120: at the modal width two lines hold roughly 110
+> characters minus the adapter chip, so 120 left notes in the 95-111 range visually
+> clamped with no way to read the rest. Erring short only costs a reveal on a row that
+> did not strictly need one.
+
 **Popup.** A sibling overlay with the same shape as `OAuthTosWarningModal`: a
 `role="dialog" aria-modal="true"` card rendered next to the add-provider overlay rather
 than inside it, holding the provider label, the adapter chip, the full note, and a close
@@ -30,6 +37,18 @@ button. The argument for a popup over grok's inline disclosure is in `015`.
 `if (e.key === "Escape" && !oauthTosPending) onClose()`. The note popup joins that
 guard, so Escape closes the note first and the add-provider modal second.
 
+## The cascade trap, hit again
+
+`gui/src/styles/provider-catalog.css` is `@import`ed at the **top** of `styles.css`,
+while `.link-btn` is declared far below it at equal specificity. A bare
+`.provider-catalog-note-more` therefore loses `background`, `border`, `padding` and
+`font-size` to `.link-btn`, while the `:has()` rule that strips the row's bottom border
+does win — so the row opened at the bottom and the reveal rendered as a full-width
+underlined link floating between two rows. Vite HMR hides this by injecting the edited
+file last; a production bundle does not. The rule is qualified as
+`.link-btn.provider-catalog-note-more`, exactly as
+`.list-row.provider-catalog-account-row--waiting` already had to be.
+
 ## Verification (remote CI only)
 
 - pure: the overflow predicate is true for the opencode-free note and false for
diff --git a/devlog/_plan/260912_provider_catalog_unified_search/evidence/wp3-note-clamp.png b/devlog/_plan/260912_provider_catalog_unified_search/evidence/wp3-note-clamp.png
new file mode 100644
index 0000000000..ac86ca3bce
Binary files /dev/null and b/devlog/_plan/260912_provider_catalog_unified_search/evidence/wp3-note-clamp.png differ
diff --git a/devlog/_plan/260912_provider_catalog_unified_search/evidence/wp3-note-popup.png b/devlog/_plan/260912_provider_catalog_unified_search/evidence/wp3-note-popup.png
new file mode 100644
index 0000000000..24dc27b4f9
Binary files /dev/null and b/devlog/_plan/260912_provider_catalog_unified_search/evidence/wp3-note-popup.png differ
diff --git a/gui/src/components/AddProviderModal.tsx b/gui/src/components/AddProviderModal.tsx
index 09f4fcb1d6..8a55273e20 100644
--- a/gui/src/components/AddProviderModal.tsx
+++ b/gui/src/components/AddProviderModal.tsx
@@ -1,5 +1,5 @@
 import { usageSummary30dResourceKey } from "../usage-summary-resource";
-import { useEffect, useMemo, useReducer, useRef } from "react";
+import { useEffect, useMemo, useReducer, useRef, useState } from "react";
 import { IconX } from "../icons";
 import { useT } from "../i18n/shared";
 import { useKeyedClientResource } from "../client-resource";
@@ -12,6 +12,7 @@ import {
 import { oauthTosRisk } from "../oauth-tos-risk";
 import OAuthTosWarningModal from "./OAuthTosWarningModal";
 import ProviderCatalog from "./provider-catalog/ProviderCatalog";
+import ProviderNoteModal from "./provider-catalog/ProviderNoteModal";
 import type { AccountLoginRow, AccountLoginStatus } from "./provider-catalog/ProviderCatalog";
 import type { CatalogPreset } from "./provider-catalog/provider-presets";
 import type { CatalogLoginHint } from "./provider-catalog/login-hint-visibility";
@@ -62,6 +63,9 @@ export default function AddProviderModal({
   const aliveRef = useRef(true);
   const previousFocusRef = useRef<HTMLElement | null>(null);
   const dialogRef = useRef<HTMLDivElement>(null);
+  // The full-note popup is owned here, not in the catalog: it has to render as a sibling
+  // of this overlay, and its open state has to be visible to the Escape handler below.
+  const [notePreset, setNotePreset] = useState<Preset | null>(null);
 
   const oauthPoll = useKeyedClientResource(
     `add-provider-oauth:${apiBase}`,
@@ -125,11 +129,14 @@ export default function AddProviderModal({
 
   useEffect(() => {
     const onKey = (e: KeyboardEvent) => {
-      if (e.key === "Escape" && !oauthTosPending) onClose();
+      // This listener is on `window` and does not read `defaultPrevented`, so a native
+      // <dialog> cancel does not stop it. Every stacked overlay has to be named here or
+      // Escape closes the whole add-provider modal out from under it.
+      if (e.key === "Escape" && !oauthTosPending && !notePreset) onClose();
     };
     window.addEventListener("keydown", onKey);
     return () => window.removeEventListener("keydown", onKey);
-  }, [onClose, oauthTosPending]);
+  }, [onClose, oauthTosPending, notePreset]);
 
   const presetDescription = (candidate: Preset): string | undefined => {
     const key = codexPresetDescriptionKey(candidate);
@@ -258,6 +265,7 @@ export default function AddProviderModal({
             initialTier={initialTier}
             onSelectPreset={p => choosePreset(p)}
             onSelectCustom={() => choosePreset(fallbackPresets[0]!)}
+            onShowNote={p => setNotePreset(p)}
             accountRows={accountRows}
             accountStatus={accountStatus}
             busyProvider={accountBusy}
@@ -339,6 +347,16 @@ export default function AddProviderModal({
         }}
       />
     )}
+    {notePreset?.note && (
+      <ProviderNoteModal
+        key={notePreset.id}
+        providerId={notePreset.id}
+        label={notePreset.label}
+        adapter={notePreset.adapter}
+        note={notePreset.note}
+        onClose={() => setNotePreset(null)}
+      />
+    )}
     </>
   );
 }
diff --git a/gui/src/components/provider-catalog/ProviderCatalog.tsx b/gui/src/components/provider-catalog/ProviderCatalog.tsx
index 17a793b9ff..d3122316db 100644
--- a/gui/src/components/provider-catalog/ProviderCatalog.tsx
+++ b/gui/src/components/provider-catalog/ProviderCatalog.tsx
@@ -10,6 +10,7 @@ import {
   bucketPresets,
   pinSponsors,
   filterPresets,
+  noteNeedsReveal,
   type CatalogPreset,
   type CatalogTier,
 } from "./provider-presets";
@@ -50,6 +51,7 @@ export default function ProviderCatalog({
   initialTier = "free",
   onSelectPreset,
   onSelectCustom,
+  onShowNote,
   accountRows = EMPTY_ACCOUNT_ROWS,
   accountStatus = EMPTY_ACCOUNT_STATUS,
   busyProvider = null,
@@ -66,6 +68,8 @@ export default function ProviderCatalog({
   initialTier?: CatalogTier;
   onSelectPreset: (preset: CatalogPreset) => void;
   onSelectCustom: () => void;
+  /** Open the full-note popup for a row whose note is clamped. Owned by the modal. */
+  onShowNote?: (preset: CatalogPreset) => void;
   /** Accounts-tab login rows; empty (default) degrades to preset-only rendering. */
   accountRows?: AccountLoginRow[];
   accountStatus?: Record<string, AccountLoginStatus>;
@@ -164,21 +168,35 @@ export default function ProviderCatalog({
           <div className="muted text-control provider-catalog-empty">{t("modal.catalogLoading")}</div>
         )}
         {tier !== "accounts" && rows.map(p => (
-          <button type="button" key={p.id} className="list-row" onClick={() => onSelectPreset(p)}>
-            {/*
-              The one list a user reads to CHOOSE a provider, and until now the only
-              provider surface with no marks at all. `CatalogPreset.id` is the
-              registry id, so this reuses `providerIconSrc` and, with it, the
-              mask/plate decision the rail already owns -- a mark cannot be legible
-              in the workspace and invisible here.
-            */}
-            <ProviderIcon name={p.id} adapter={p.adapter} cls="provider-icon provider-icon-sm" />
-            <div>
-              <div className="title">{p.label}</div>
-              <div className="sub"><code className="chip">{p.adapter}</code>{p.note ? ` · ${p.note}` : ""}</div>
-            </div>
-            <div className="provider-catalog-badges">{badges(p)}</div>
-          </button>
+          // The reveal control is a SIBLING of the row button, never a child of it: the row
+          // is already a <button>, and a button inside a button is invalid HTML that the
+          // parser may hoist out of the row -- at which point `stopPropagation` never runs.
+          <div key={p.id} className="provider-catalog-row-wrap">
+            <button type="button" className="list-row" onClick={() => onSelectPreset(p)}>
+              {/*
+                The one list a user reads to CHOOSE a provider, and until now the only
+                provider surface with no marks at all. `CatalogPreset.id` is the
+                registry id, so this reuses `providerIconSrc` and, with it, the
+                mask/plate decision the rail already owns -- a mark cannot be legible
+                in the workspace and invisible here.
+              */}
+              <ProviderIcon name={p.id} adapter={p.adapter} cls="provider-icon provider-icon-sm" />
+              <div>
+                <div className="title">{p.label}</div>
+                <div className="sub"><code className="chip">{p.adapter}</code>{p.note ? ` · ${p.note}` : ""}</div>
+              </div>
+              <div className="provider-catalog-badges">{badges(p)}</div>
+            </button>
+            {onShowNote && noteNeedsReveal(p.note) && (
+              <button
+                type="button"
+                className="link-btn provider-catalog-note-more"
+                onClick={() => onShowNote(p)}
+              >
+                {t("modal.noteMore")}
+              </button>
+            )}
+          </div>
         ))}
         {tier !== "accounts" && !presetsLoading && rows.length === 0 && (
           <div className="muted text-control provider-catalog-empty">{t("modal.noMatch")}</div>
diff --git a/gui/src/components/provider-catalog/ProviderNoteModal.tsx b/gui/src/components/provider-catalog/ProviderNoteModal.tsx
new file mode 100644
index 0000000000..cbaaf3f0fe
--- /dev/null
+++ b/gui/src/components/provider-catalog/ProviderNoteModal.tsx
@@ -0,0 +1,84 @@
+/**
+ * Full-text popup for a catalog row's provider note.
+ *
+ * The catalog clamps a note to two lines, because a few of them are paragraphs: the
+ * `opencode-free` note is ~1100 characters and `meta-muse` is longer still, and at the
+ * modal width either one fills the entire 360px scroll viewport, so the row it belongs
+ * to becomes the only row a user can see.
+ *
+ * Native `<dialog>` + `showModal()`, deliberately the same shape as
+ * `OAuthTosWarningModal`: it gives focus trapping and a backdrop for free, and — the
+ * part a hand-rolled overlay does not get — it restores focus to the control that
+ * opened it when it closes. It is rendered as a sibling of the add-provider overlay
+ * rather than inside it, so there is no dialog nested in a dialog's DOM.
+ */
+import { useCallback, useEffect, useId, useRef } from "react";
+import { useT } from "../../i18n/shared";
+import { IconX } from "../../icons";
+import { ProviderIcon } from "../provider-workspace/ProviderRail";
+
+export default function ProviderNoteModal({
+  providerId,
+  label,
+  adapter,
+  note,
+  onClose,
+}: {
+  providerId: string;
+  label: string;
+  adapter: string;
+  note: string;
+  onClose: () => void;
+}) {
+  const t = useT();
+  const titleId = useId();
+  const bodyId = useId();
+  const dialogRef = useRef<HTMLDialogElement>(null);
+
+  useEffect(() => {
+    const dialog = dialogRef.current;
+    const trigger = document.activeElement as HTMLElement | null;
+    if (dialog && !dialog.open) dialog.showModal();
+    return () => {
+      if (dialog?.open) dialog.close();
+      if (trigger?.isConnected) trigger.focus({ preventScroll: true });
+    };
+  }, []);
+
+  // Native <dialog> fires "cancel" on Escape — forward it so this popup closes first
+  // and the add-provider modal underneath stays open.
+  const handleCancel = useCallback((e: React.SyntheticEvent) => {
+    e.preventDefault();
+    onClose();
+  }, [onClose]);
+
+  return (
+    <dialog
+      ref={dialogRef}
+      aria-labelledby={titleId}
+      aria-describedby={bodyId}
+      className="modal-overlay"
+      onCancel={handleCancel}
+    >
+      <button type="button" className="modal-backdrop-dismiss" aria-label={t("common.close")} tabIndex={-1} onClick={onClose} />
+      <div className="modal-card provider-note-card" onClick={e => e.stopPropagation()}>
+        <div className="modal-head">
+          <h3 id={titleId} className="provider-note-title">
+            <ProviderIcon name={providerId} adapter={adapter} cls="provider-icon provider-icon-sm" />
+            {label}
+          </h3>
+          <button type="button" className="btn btn-ghost btn-icon" aria-label={t("common.close")} onClick={onClose}>
+            <IconX />
+          </button>
+        </div>
+        <div id={bodyId} className="provider-note-body">
+          <code className="chip">{adapter}</code>
+          <p className="modal-desc provider-note-text">{note}</p>
+        </div>
+        <div className="modal-actions">
+          <button type="button" className="btn btn-ghost" onClick={onClose}>{t("common.close")}</button>
+        </div>
+      </div>
+    </dialog>
+  );
+}
diff --git a/gui/src/components/provider-catalog/provider-presets.ts b/gui/src/components/provider-catalog/provider-presets.ts
index 93119b85fa..416725d512 100644
--- a/gui/src/components/provider-catalog/provider-presets.ts
+++ b/gui/src/components/provider-catalog/provider-presets.ts
@@ -119,6 +119,12 @@ export function filterPresets(presets: CatalogPreset[], query: string): CatalogP
   return presets.filter(p => p.label.toLowerCase().includes(q) || p.id.toLowerCase().includes(q));
 }
 
+/** Every nonempty note has a full-text route: rendered clipping depends on width,
+ * adapter chips and badges, so no character threshold can safely hide the control. */
+export function noteNeedsReveal(note: string | undefined): boolean {
+  return !!note?.trim();
+}
+
 const SPONSOR_RANK: Record<NonNullable<CatalogPreset["sponsor"]>, number> = { main: 0, standard: 1 };
 
 /**
diff --git a/gui/src/i18n/de.ts b/gui/src/i18n/de.ts
index 8153debace..d5280552e9 100644
--- a/gui/src/i18n/de.ts
+++ b/gui/src/i18n/de.ts
@@ -1901,6 +1901,7 @@ export const de: Record<TKey, string> = {
   "modal.tab.free": "Kostenlos",
   "modal.tab.local": "Lokal",
   "modal.tab.paid": "Bezahlt",
+  "modal.noteMore": "Vollständige Beschreibung anzeigen",
   "modal.accountsHint": "Hier ChatGPT/Codex, OAuth-Provider und API-Key-Konten anmelden. OpenAI ist eingebaut — anmelden statt erneut hinzufügen.",
   "modal.accountsCodexAuthLink": "Codex Auth",
   "modal.notListed": "Provider nicht dabei? Eigenen hinzufügen",
diff --git a/gui/src/i18n/en.ts b/gui/src/i18n/en.ts
index c5abf0e2cb..032d5aff46 100644
--- a/gui/src/i18n/en.ts
+++ b/gui/src/i18n/en.ts
@@ -1157,6 +1157,7 @@ export const en = {
   "modal.tab.free": "Free",
   "modal.tab.local": "Local",
   "modal.tab.paid": "Paid",
+  "modal.noteMore": "Show full description",
   "modal.accountsHint": "Sign in to ChatGPT/Codex, OAuth providers, and API-key accounts here. OpenAI is built in — log in rather than adding it again.",
   "modal.accountsCodexAuthLink": "Codex Auth",
   "modal.notListed": "Provider not listed? Add a custom one",
diff --git a/gui/src/i18n/fr.ts b/gui/src/i18n/fr.ts
index 09ff78305a..322d496d6e 100644
--- a/gui/src/i18n/fr.ts
+++ b/gui/src/i18n/fr.ts
@@ -1130,6 +1130,7 @@ export const fr: Record<TKey, string> = {
   "modal.tab.free": "Gratuit",
   "modal.tab.local": "Local",
   "modal.tab.paid": "Payant",
+  "modal.noteMore": "Afficher la description complète",
   "modal.accountsHint": "Connectez-vous ici à ChatGPT/Codex, aux fournisseurs OAuth et aux comptes avec clé API. OpenAI est intégré : connectez-vous au lieu de l’ajouter de nouveau.",
   "modal.accountsCodexAuthLink": "Codex Auth",
   "modal.notListed": "Fournisseur absent de la liste ? Ajoutez-en un personnalisé",
diff --git a/gui/src/i18n/ja.ts b/gui/src/i18n/ja.ts
index 5cb65d9f07..f2ab45b8e9 100644
--- a/gui/src/i18n/ja.ts
+++ b/gui/src/i18n/ja.ts
@@ -1070,6 +1070,7 @@ export const ja: Record<TKey, string> = {
   "modal.tab.free": "無料",
   "modal.tab.local": "ローカル",
   "modal.tab.paid": "有料",
+  "modal.noteMore": "説明をすべて表示",
   "modal.accountsHint": "ChatGPT/Codex、OAuth プロバイダー、API キーアカウントにここからサインインします。OpenAI は組み込み済み — 再度追加せずログインしてください。",
   "modal.accountsCodexAuthLink": "Codex 認証",
   "modal.notListed": "プロバイダーが載っていませんか? カスタムを追加",
diff --git a/gui/src/i18n/ko.ts b/gui/src/i18n/ko.ts
index f7e8c259a0..a79196b3f0 100644
--- a/gui/src/i18n/ko.ts
+++ b/gui/src/i18n/ko.ts
@@ -1940,6 +1940,7 @@ export const ko: Record<TKey, string> = {
   "modal.tab.free": "무료",
   "modal.tab.local": "로컬",
   "modal.tab.paid": "유료",
+  "modal.noteMore": "설명 전체 보기",
   "modal.accountsHint": "여기서 ChatGPT/Codex, OAuth, API 키 계정에 로그인하세요. OpenAI는 기본 제공 — 다시 추가하지 말고 로그인하세요.",
   "modal.accountsCodexAuthLink": "Codex 인증",
   "modal.notListed": "찾는 프로바이더가 없나요? 직접 추가",
diff --git a/gui/src/i18n/ru.ts b/gui/src/i18n/ru.ts
index 2a6b3dc075..394e312abf 100644
--- a/gui/src/i18n/ru.ts
+++ b/gui/src/i18n/ru.ts
@@ -1125,6 +1125,7 @@ export const ru: Record<TKey, string> = {
   "modal.tab.free": "Бесплатные",
   "modal.tab.local": "Локальные",
   "modal.tab.paid": "Платные",
+  "modal.noteMore": "Показать полное описание",
   "modal.accountsHint": "Здесь можно войти в аккаунты ChatGPT/Codex и OAuth-провайдеров, а также в аккаунты с API-ключами. Провайдер OpenAI уже встроен — просто войдите, а не добавляйте его заново.",
   "modal.accountsCodexAuthLink": "Аутентификация Codex",
   "modal.notListed": "Нет нужного провайдера? Добавьте свой",
diff --git a/gui/src/i18n/tr.ts b/gui/src/i18n/tr.ts
index c1a7d958f6..c6438767ea 100644
--- a/gui/src/i18n/tr.ts
+++ b/gui/src/i18n/tr.ts
@@ -1144,6 +1144,7 @@ export const tr: Record<TKey, string> = {
   "modal.tab.free": "Ücretsiz",
   "modal.tab.local": "Yerel",
   "modal.tab.paid": "Ücretli",
+  "modal.noteMore": "Açıklamanın tamamını göster",
   "modal.accountsHint": "ChatGPT/Codex ve OAuth hesaplarına buradan giriş yapın.",
   "modal.accountsCodexAuthLink": "Codex Kimlik Doğrulaması",
   "modal.notListed": "Sağlayıcı listede yok mu? Özel sağlayıcı ekleyin",
diff --git a/gui/src/i18n/zh-TW.ts b/gui/src/i18n/zh-TW.ts
index 7801fdf277..59e4ccfb47 100644
--- a/gui/src/i18n/zh-TW.ts
+++ b/gui/src/i18n/zh-TW.ts
@@ -923,6 +923,7 @@ export const zhTW: Record<TKey, string> = {
   "modal.tab.free": "免費",
   "modal.tab.local": "本地",
   "modal.tab.paid": "付費",
+  "modal.noteMore": "查看完整說明",
   "modal.accountsHint": "在此登入 ChatGPT/Codex、OAuth 與 API 金鑰帳號。OpenAI 為內建供應商 — 請登入，無需再次新增。",
   "modal.accountsCodexAuthLink": "Codex 認證",
   "modal.notListed": "沒有你要的供應商？新增自訂",
diff --git a/gui/src/i18n/zh.ts b/gui/src/i18n/zh.ts
index cccbca8dcd..e4ecec59e8 100644
--- a/gui/src/i18n/zh.ts
+++ b/gui/src/i18n/zh.ts
@@ -1921,6 +1921,7 @@ export const zh: Record<TKey, string> = {
   "modal.tab.free": "免费",
   "modal.tab.local": "本地",
   "modal.tab.paid": "付费",
+  "modal.noteMore": "查看完整说明",
   "modal.accountsHint": "在此登录 ChatGPT/Codex、OAuth 与 API 密钥账户。OpenAI 为内置提供商 — 请登录，无需再次添加。",
   "modal.accountsCodexAuthLink": "Codex 认证",
   "modal.notListed": "没有你要的提供商？添加自定义",
diff --git a/gui/src/styles/provider-catalog.css b/gui/src/styles/provider-catalog.css
index ef2bbe67dd..e7776bfb99 100644
--- a/gui/src/styles/provider-catalog.css
+++ b/gui/src/styles/provider-catalog.css
@@ -56,6 +56,107 @@
   padding: 8px;
 }
 
+/* A preset row and its note-reveal control. The control has to be a SIBLING of the row
+   button rather than a child, because the row is itself a <button> and nesting one is
+   invalid HTML the parser is free to hoist out. The wrapper is what holds the two
+   together as one list item. */
+.provider-catalog-row-wrap {
+  display: flex;
+  flex-direction: column;
+  align-items: stretch;
+}
+
+/* Merge the two children into one visual row: the row button loses its bottom corners
+   and border, the reveal strip grows the matching bottom corners, and they share the
+   raised surface. Without this the control floats on the modal background between two
+   rows and reads as though it belongs to the next provider. */
+.provider-catalog-row-wrap:has(.provider-catalog-note-more) .list-row {
+  border-bottom-left-radius: 0;
+  border-bottom-right-radius: 0;
+  border-bottom: none;
+  padding-bottom: 8px;
+}
+
+/* Two-line clamp on the note. A handful of catalog notes are paragraphs — opencode-free
+   is ~1100 characters — and unclamped, one of them fills the whole 360px scroller and
+   the row it belongs to becomes the only row anyone can see. Scoped through the wrapper
+   so account rows keep their existing single-line ellipsis instead. */
+.provider-catalog-row-wrap .list-row .sub {
+  display: -webkit-box;
+  -webkit-line-clamp: 2;
+  line-clamp: 2;
+  -webkit-box-orient: vertical;
+  overflow: hidden;
+}
+
+/* Qualified with `.link-btn` on purpose, and it is not redundant: this file is
+   @imported at the TOP of styles.css while `.link-btn` is declared far below it, so a
+   bare `.provider-catalog-note-more` loses background, border, padding and font-size to
+   the later equal-specificity rule and the control renders as a full-width underlined
+   link floating between two rows instead of the bottom edge of its own row. Same trap
+   already documented above for `.list-row.provider-catalog-account-row--waiting`. */
+.link-btn.provider-catalog-note-more {
+  align-self: stretch;
+  text-align: right;
+  padding: 0 13px 9px;
+  font-size: var(--text-label);
+  color: var(--muted);
+  text-decoration: none;
+  border: 1px solid var(--border);
+  border-top: none;
+  border-bottom-left-radius: var(--radius-sm);
+  border-bottom-right-radius: var(--radius-sm);
+  background: var(--raised);
+}
+
+.link-btn.provider-catalog-note-more:hover {
+  color: var(--text);
+  text-decoration: underline;
+}
+
+/* The row and its reveal strip highlight together, because they are one row. */
+.provider-catalog-row-wrap:hover .link-btn.provider-catalog-note-more,
+.provider-catalog-row-wrap:hover .list-row {
+  background: var(--raised-hover);
+}
+
+.provider-catalog-row-wrap:hover .list-row {
+  border-color: var(--accent-ring);
+}
+
+.provider-catalog-row-wrap:hover .link-btn.provider-catalog-note-more {
+  border-color: var(--accent-ring);
+}
+
+/* The full-note popup: a native <dialog> sibling of the add-provider overlay. */
+.provider-note-card {
+  max-width: 560px;
+}
+
+.provider-note-title {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+}
+
+.provider-note-body {
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
+  gap: 8px;
+  margin-top: 12px;
+}
+
+/* The note is the reason this popup exists, so it scrolls here rather than being
+   truncated a second time. */
+.provider-note-text {
+  margin: 0;
+  white-space: pre-wrap;
+  max-height: 55vh;
+  overflow-y: auto;
+}
+
 .provider-catalog-account-row .sub {
   overflow: hidden;
   text-overflow: ellipsis;
diff --git a/gui/tests/provider-catalog-note-popup.test.tsx b/gui/tests/provider-catalog-note-popup.test.tsx
new file mode 100644
index 0000000000..069699735b
--- /dev/null
+++ b/gui/tests/provider-catalog-note-popup.test.tsx
@@ -0,0 +1,143 @@
+import { afterEach, beforeEach, expect, test } from "bun:test";
+import { Window } from "happy-dom";
+import { act } from "react";
+import type { Root } from "react-dom/client";
+import { LanguageProvider } from "../src/i18n/provider";
+import AddProviderModal from "../src/components/AddProviderModal";
+
+/**
+ * A few catalog notes are paragraphs — `opencode-free` is ~1100 characters — and an
+ * unclamped one fills the entire 360px scroll viewport, so the row it belongs to becomes
+ * the only row a user can see. The row is clamped to two lines and the rest moves into a
+ * popup.
+ *
+ * These pin the two properties that make the reveal correct rather than merely present:
+ * clicking it must NOT select the provider (the row is a button, and the reveal is its
+ * sibling precisely so a nested button cannot be hoisted out), and the popup must carry
+ * the whole note rather than the clamped text.
+ */
+
+const LONG_NOTE = "No key needed, but this provider gates the tier to its own client and refuses any request that arrives without a session header, so the proxy cannot present itself as that client. Use the keyed provider instead.";
+
+const PRESETS = [
+  { id: "cerebras", label: "Cerebras", adapter: "openai-completions", baseUrl: "https://api.cerebras.ai/v1", auth: "key", note: LONG_NOTE },
+  { id: "together", label: "Together", adapter: "openai-completions", baseUrl: "https://api.together.xyz/v1", auth: "key", note: "Short note." },
+];
+
+const globals = ["document", "window", "navigator", "localStorage", "IS_REACT_ACT_ENVIRONMENT"] as const;
+let previous: Record<(typeof globals)[number], unknown>;
+let win: Window;
+let host: HTMLElement;
+let root: Root | null = null;
+let originalFetch: typeof globalThis.fetch;
+let selected: string[] = [];
+
+beforeEach(() => {
+  previous = Object.fromEntries(globals.map(k => [k, Reflect.get(globalThis, k)])) as typeof previous;
+  originalFetch = globalThis.fetch;
+  selected = [];
+  win = new Window({ url: "http://localhost/" });
+  Object.defineProperty(win.navigator, "language", { configurable: true, value: "en-US" });
+  Object.defineProperties(globalThis, {
+    document: { configurable: true, value: win.document },
+    window: { configurable: true, value: win },
+    navigator: { configurable: true, value: win.navigator },
+    localStorage: { configurable: true, value: win.localStorage },
+  });
+  (globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+  // happy-dom has no native <dialog> behaviour; the popup calls showModal() on mount.
+  const proto = win.HTMLDialogElement?.prototype as unknown as { showModal?: () => void; close?: () => void } | undefined;
+  if (proto && typeof proto.showModal !== "function") {
+    proto.showModal = function showModal(this: HTMLElement) { this.setAttribute("open", ""); };
+    proto.close = function close(this: HTMLElement) { this.removeAttribute("open"); };
+  }
+
+  Object.defineProperty(globalThis, "fetch", {
+    configurable: true,
+    value: async (input: RequestInfo | URL) => {
+      const url = new URL(String(input), "http://localhost");
+      if (url.pathname === "/api/provider-presets") return Response.json({ providers: PRESETS });
+      if (url.pathname === "/api/oauth/providers") return Response.json({ providers: [] });
+      if (url.pathname === "/api/usage") return Response.json({ providers: [] });
+      return Response.json({});
+    },
+  });
+
+  host = win.document.createElement("div") as unknown as HTMLElement;
+  win.document.body.appendChild(host as never);
+});
+
+afterEach(async () => {
+  if (root) {
+    const current = root;
+    await act(async () => { current.unmount(); });
+    root = null;
+  }
+  for (const key of globals) {
+    Object.defineProperty(globalThis, key, { configurable: true, value: previous[key] });
+  }
+  Object.defineProperty(globalThis, "fetch", { configurable: true, value: originalFetch });
+  await win.happyDOM?.close?.();
+});
+
+async function mountCatalog() {
+  const { createRoot } = await import("react-dom/client");
+  await act(async () => {
+    root = createRoot(host);
+    root.render(
+      <LanguageProvider>
+        {/* `paid` is where an API-key preset buckets; the default tab would render an
+            empty list and make these assertions vacuous. */}
+        <AddProviderModal
+          apiBase=""
+          existingNames={[]}
+          initialTier="paid"
+          onClose={() => {}}
+          onAdded={name => { selected.push(name); }}
+        />
+      </LanguageProvider>,
+    );
+  });
+  await act(async () => { await new Promise(r => setTimeout(r, 60)); });
+}
+
+function reveals(): HTMLElement[] {
+  return [...win.document.querySelectorAll<HTMLElement>(".provider-catalog-note-more")] as unknown as HTMLElement[];
+}
+
+test("every nonempty note has a reveal even when a narrow row clips short text", async () => {
+  await mountCatalog();
+  expect(reveals()).toHaveLength(2);
+  // The control is a sibling of the row button, never a child of it: a button nested in
+  // a button is invalid HTML the parser may hoist out of the row.
+  const wrap = reveals()[0]!.parentElement!;
+  expect(wrap.className).toContain("provider-catalog-row-wrap");
+  expect(reveals()[0]!.closest(".list-row")).toBeNull();
+});
+
+test("the reveal opens the full note and does not select the provider", async () => {
+  await mountCatalog();
+  const heading = () => win.document.querySelector(".modal-head h3")?.textContent ?? "";
+  expect(heading()).toBe("Add provider");
+
+  await act(async () => { reveals()[0]!.click(); });
+
+  // Still the catalog, not the per-provider add form: the row was not selected.
+  expect(win.document.querySelector(".provider-catalog")).not.toBeNull();
+  expect(selected).toEqual([]);
+
+  const noteText = win.document.querySelector(".provider-note-text")?.textContent ?? "";
+  expect(noteText).toBe(LONG_NOTE);
+});
+
+test("closing the popup returns keyboard focus to its reveal button", async () => {
+  await mountCatalog();
+  const trigger = reveals()[0]!;
+  trigger.focus();
+  await act(async () => { trigger.click(); });
+  const close = win.document.querySelector(".provider-note-card .btn-icon") as unknown as HTMLElement;
+  await act(async () => { close.click(); });
+  expect(win.document.querySelector(".provider-note-card")).toBeNull();
+  expect(win.document.activeElement).toBe(trigger);
+});
diff --git a/structure/gui-and-management-api.md b/structure/gui-and-management-api.md
index d8347a12fc..d078710d5e 100644
--- a/structure/gui-and-management-api.md
+++ b/structure/gui-and-management-api.md
@@ -301,7 +301,7 @@ single forms, and the shell pattern is the part worth keeping stable:
 | Storage | Rail plus cleanup and trash detail (`gui/src/components/storage-workspace/`). |
 | Subagents | Featured-roster selection workspace (`gui/src/components/subagents-workspace/`). |
 | Combos | Rail, detail panel, and an add flow (`gui/src/components/ComboWorkspace.tsx`). |
-| Add provider | Catalog browser plus form and OAuth panes (`gui/src/components/provider-catalog/`, `gui/src/components/AddProviderModal.tsx`). Catalog tabs are Accounts, Free, Local and Paid; local-auth and loopback presets browse under Local while workspace pricing tiers stay three-way. The tab strip wraps within narrow modals. |
+| Add provider | Catalog browser plus form and OAuth panes (`gui/src/components/provider-catalog/`, `gui/src/components/AddProviderModal.tsx`). Catalog tabs are Accounts, Free, Local and Paid; local-auth and loopback presets browse under Local while workspace pricing tiers stay three-way. The tab strip wraps within narrow modals. Every nonempty note has a full-text button alongside its clamped preview. The native note dialog closes during teardown and restores focus to that button. |
 | Codex accounts | Account pool cards, add-account flow, switch and reset modals (`gui/src/components/CodexAccountPool.tsx`, `gui/src/components/AddCodexAccountModal.tsx`), plus the generic account-targeting picker opt-in on `gui/src/pages/codex-set-multiauth.tsx`. Add/delete/login completion is projected to one boolean before presentation; pending catalog work is a warning, not a failed account mutation. |
 | Dashboard overview | Overview, Providers, and Models tabs at the page level (`gui/src/pages/Dashboard.tsx`), the 30-day token and coverage stats in the overview head (`gui/src/pages/dashboard-overview-head.tsx`), and the effort-cap, injection, maintenance, sidecar, and memory panels below it (`gui/src/pages/dashboard-overview-panels.tsx`). |
 
diff --git a/tests/gui/provider-workspace-data.test.ts b/tests/gui/provider-workspace-data.test.ts
index f60cf4d0be..8c6b0028ae 100644
--- a/tests/gui/provider-workspace-data.test.ts
+++ b/tests/gui/provider-workspace-data.test.ts
@@ -34,6 +34,7 @@ import {
   bucketPresets,
   filterPresets,
   presetTier,
+  noteNeedsReveal,
   type CatalogPreset,
 } from "../../gui/src/components/provider-catalog/provider-presets";
 import { isLocalProvider, providerKind } from "../../gui/src/provider-workspace/kind";
@@ -566,6 +567,14 @@ describe("add-provider catalog presets (WP050a)", () => {
     expect(filterPresets(rows, "").map(p => p.id)).toEqual(["nvidia", "groq"]);
   });
 
+  test("every nonempty note remains readable regardless of rendered width", () => {
+    expect(noteNeedsReveal("Local — key usually blank")).toBe(true);
+    expect(noteNeedsReveal("Short")).toBe(true);
+    expect(noteNeedsReveal("x".repeat(1126))).toBe(true);
+    expect(noteNeedsReveal(undefined)).toBe(false);
+    expect(noteNeedsReveal("   ")).toBe(false);
+  });
+
 });
 
 describe("provider kind classification (WP080a)", () => {