Replace free-text institution entry with a searchable bank picker

GET /api/banking/institutions lists the banks Enable Banking can connect
for a country (personal AIS, connectable consents only), with logos
restricted to https Enable Banking hosts to match the CSP image
allowlist. The connect form offers a filterable dropdown with bank
logos, falling back to the previous free-text input when the list is
unavailable or banking is not configured.

internal/app/consent_test.go

@@ -23,6 +23,10 @@ func (b *historyBank) Authorize(_ context.Context, _, _, state string) (string,
 	return "https://bank.example/authorize", nil
 }
 
+func (b *historyBank) Institutions(context.Context, string) ([]banking.Institution, error) {
+	return []banking.Institution{{Name: "N26", Country: "DE"}}, nil
+}
+
 func (b *historyBank) Transactions(_ context.Context, account domain.Account, from, to string, _ bool) ([]domain.Facts, error) {
 	b.fromDates = append(b.fromDates, from)
 	var rows []domain.Facts

internal/app/import.go

@@ -203,6 +203,21 @@ func (a *App) Authorize(ctx context.Context, institution, country string, histor
 	}
 	return url, err
 }
+
+// Institutions lists connectable banks for the country so the UI can offer
+// a picker instead of free-text entry. Provider failures stay sanitized.
+func (a *App) Institutions(ctx context.Context, country string) ([]banking.Institution, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	if a.bank == nil {
+		return nil, errors.New("Enable Banking is not configured")
+	}
+	list, err := a.bank.Institutions(ctx, country)
+	if err != nil {
+		return nil, bankFailure(err, "institution list unavailable; retry")
+	}
+	return list, nil
+}
 func normalizedIBAN(s string) string { return strings.ToUpper(strings.Join(strings.Fields(s), "")) }
 func connectAccounts(d *domain.Dataset, session *banking.Session, reconnect bool) {
 	for i, account := range session.Accounts {

internal/app/sync_test.go

@@ -24,6 +24,9 @@ type bankScenario struct {
 func (b *bankScenario) Authorize(context.Context, string, string, string) (string, error) {
 	return "https://bank.example/authorize", nil
 }
+func (b *bankScenario) Institutions(context.Context, string) ([]banking.Institution, error) {
+	return []banking.Institution{{Name: "N26", Country: "DE"}}, nil
+}
 func (b *bankScenario) Exchange(context.Context, string) (banking.Session, error) {
 	return b.session, nil
 }

internal/banking/enablebanking.go

@@ -20,6 +20,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -56,6 +57,7 @@ type Provider interface {
 	Status(context.Context, string) (SessionStatus, error)
 	Balances(context.Context, string) ([]Balance, error)
 	Transactions(ctx context.Context, account domain.Account, from, to string, longest bool) ([]domain.Facts, error)
+	Institutions(ctx context.Context, country string) ([]Institution, error)
 }
 type EnableBanking struct {
 	HTTPClient  *http.Client
@@ -450,24 +452,81 @@ func (a accountDTO) account(institution string) (domain.Account, error) {
 	}
 	return domain.Account{ID: "acct_" + digest("enablebanking", stable), DisplayName: name, Institution: institution, Currency: a.Currency, ExternalAccountID: a.UID, IBAN: normalizeIBAN(a.AccountID.IBAN), Active: a.UID != ""}, nil
 }
+
+// Institution describes a bank available for personal account information.
+// Logo is retained only when it is an https Enable Banking URL, matching the
+// Content-Security-Policy image allowlist under which the UI displays it.
+type Institution struct {
+	Name    string `json:"name"`
+	Country string `json:"country"`
+	Logo    string `json:"logo,omitempty"`
+}
+
+// safeLogoURL admits only https Enable Banking brand URLs. Any other
+// provider-supplied location renders no logo rather than a third-party fetch.
+func safeLogoURL(logo string) string {
+	u, err := url.Parse(logo)
+	if err != nil || u.Scheme != "https" || u.User != nil {
+		return ""
+	}
+	host := strings.ToLower(u.Hostname())
+	if host != "enablebanking.com" && !strings.HasSuffix(host, ".enablebanking.com") {
+		return ""
+	}
+	return logo
+}
+
+type aspspDTO struct {
+	institutionDTO
+	Logo                   string `json:"logo"`
+	MaximumConsentValidity int64  `json:"maximum_consent_validity"`
+}
+
+func (p *EnableBanking) aspsps(ctx context.Context, country string) ([]aspspDTO, error) {
+	var list struct {
+		ASPSPs []aspspDTO `json:"aspsps"`
+	}
+	query := url.Values{"country": {country}, "psu_type": {"personal"}, "service": {"AIS"}}
+	if err := p.request(ctx, http.MethodGet, "/aspsps?"+query.Encode(), nil, &list); err != nil {
+		return nil, err
+	}
+	return list.ASPSPs, nil
+}
+
+// Institutions lists the banks connectable for personal account information
+// in a country, excluding entries the Authorize flow would reject anyway.
+func (p *EnableBanking) Institutions(ctx context.Context, country string) ([]Institution, error) {
+	country = strings.ToUpper(strings.TrimSpace(country))
+	if len(country) != 2 {
+		return nil, fmt.Errorf("country must be a two-letter code")
+	}
+	aspsps, err := p.aspsps(ctx, country)
+	if err != nil {
+		return nil, err
+	}
+	result := make([]Institution, 0, len(aspsps))
+	for _, a := range aspsps {
+		if a.Name == "" || a.Country != country || a.MaximumConsentValidity <= 0 {
+			continue
+		}
+		result = append(result, Institution{Name: a.Name, Country: a.Country, Logo: safeLogoURL(a.Logo)})
+	}
+	slices.SortFunc(result, func(a, b Institution) int { return strings.Compare(a.Name, b.Name) })
+	return result, nil
+}
+
 func (p *EnableBanking) Authorize(ctx context.Context, institution, country, state string) (string, error) {
 	country = strings.ToUpper(strings.TrimSpace(country))
 	institution = strings.TrimSpace(institution)
 	if institution == "" || len(country) != 2 || state == "" {
 		return "", fmt.Errorf("institution, country and authorization state are required")
 	}
-	var list struct {
+	aspsps, err := p.aspsps(ctx, country)
-		ASPSPs []struct {
+	if err != nil {
-			institutionDTO
-			MaximumConsentValidity int64 `json:"maximum_consent_validity"`
-		} `json:"aspsps"`
-	}
-	query := url.Values{"country": {country}, "psu_type": {"personal"}, "service": {"AIS"}}
-	if err := p.request(ctx, http.MethodGet, "/aspsps?"+query.Encode(), nil, &list); err != nil {
 		return "", err
 	}
 	var validity int64
-	for _, a := range list.ASPSPs {
+	for _, a := range aspsps {
 		if a.Name == institution && a.Country == country {
 			validity = a.MaximumConsentValidity
 			break

internal/banking/enablebanking_test.go

@@ -251,6 +251,38 @@ func TestEnableBankingLongestStrategyIsOnlySentWhenRequested(t *testing.T) {
 		t.Fatalf("wrong fetching strategies requested: %q", strategies)
 	}
 }
+func TestEnableBankingInstitutionsListsOnlyConnectableBanksWithSafeLogos(t *testing.T) {
+	p, _ := testProvider(t, func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/aspsps" || r.URL.Query().Get("country") != "DE" || r.URL.Query().Get("psu_type") != "personal" || r.URL.Query().Get("service") != "AIS" {
+			t.Errorf("wrong institution listing request: %s", r.URL)
+		}
+		fmt.Fprint(w, `{"aspsps":[
+			{"name":"Sparkasse","country":"DE","maximum_consent_validity":3600,"logo":"https://enablebanking.com/brands/DE/Sparkasse/"},
+			{"name":"N26","country":"DE","maximum_consent_validity":3600,"logo":"http://enablebanking.com/brands/DE/N26/"},
+			{"name":"Tracker Bank","country":"DE","maximum_consent_validity":3600,"logo":"https://tracker.example/pixel.png"},
+			{"name":"Evil","country":"DE","maximum_consent_validity":3600,"logo":"https://evil-enablebanking.com/logo"},
+			{"name":"Dormant","country":"DE","maximum_consent_validity":0},
+			{"name":"Elsewhere","country":"AT","maximum_consent_validity":3600},
+			{"name":"","country":"DE","maximum_consent_validity":3600}
+		]}`)
+	})
+	list, err := p.Institutions(context.Background(), "de")
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := []Institution{
+		{Name: "Evil", Country: "DE"},
+		{Name: "N26", Country: "DE"},
+		{Name: "Sparkasse", Country: "DE", Logo: "https://enablebanking.com/brands/DE/Sparkasse/"},
+		{Name: "Tracker Bank", Country: "DE"},
+	}
+	if !reflect.DeepEqual(list, expected) {
+		t.Fatalf("wrong connectable institutions: %+v", list)
+	}
+	if _, err := p.Institutions(context.Background(), "DEU"); err == nil {
+		t.Fatal("accepted an invalid country code")
+	}
+}
 func TestEnableBankingSurfacesOnlyDocumentedErrorCodes(t *testing.T) {
 	body := ""
 	p, _ := testProvider(t, func(w http.ResponseWriter, r *http.Request) {

internal/server/server.go

@@ -50,6 +50,10 @@ func New(a *app.App, assets fs.FS, publicURL string) (http.Handler, error) {
 	s.mux.HandleFunc("POST /api/settings/openrouter", s.openRouterKey)
 	s.mux.HandleFunc("POST /api/settings/enablebanking", s.bankingSettings)
 	s.mux.HandleFunc("POST /api/banking/authorize", s.authorize)
+	s.mux.HandleFunc("GET /api/banking/institutions", func(w http.ResponseWriter, r *http.Request) {
+		v, e := a.Institutions(r.Context(), r.URL.Query().Get("country"))
+		respond(w, v, e)
+	})
 	s.mux.HandleFunc("GET /api/banking/callback", s.callback)
 	s.mux.HandleFunc("GET /api/balances", func(w http.ResponseWriter, r *http.Request) {
 		v, e := a.Balances(s.manualBankContext(r), r.URL.Query().Get("account_id"))
@@ -97,7 +101,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.Header().Set("Referrer-Policy", "no-referrer")
 	w.Header().Set("X-Frame-Options", "DENY")
-	w.Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; connect-src 'self'; frame-ancestors 'none'; base-uri 'self'; form-action 'self'")
+	w.Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https://enablebanking.com https://*.enablebanking.com; connect-src 'self'; frame-ancestors 'none'; base-uri 'self'; form-action 'self'")
 	// Host allowlisting prevents DNS rebinding against a no-login private service.
 	host := r.Host
 	if h, _, e := net.SplitHostPort(host); e == nil {

web/src/Accounts.tsx

@@ -1,4 +1,4 @@
-import { useRef, useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import {
   Plus,
   Upload,
@@ -7,8 +7,9 @@ import {
   Pencil,
   Trash2,
   RefreshCw,
+  Landmark,
 } from "lucide-react";
-import type { Account, State } from "./api";
+import type { Account, Institution, State } from "./api";
 import { money, request } from "./api";
 import { Empty, ErrorMessage, Field, FormActions, Modal } from "./ui";
 import type { Mutate } from "./ui";
@@ -702,24 +703,22 @@ function ConnectForm({
           }
         }}
       >
-        <Field
+        <InstitutionSelect
-          label="Institution"
+          country={country}
-          hint="Use the institution name recognized by Enable Banking, such as N26."
+          configured={state.status.banking_configured}
-        >
-          <input
-            required
           value={institution}
-            onChange={(e) => setInstitution(e.target.value)}
+          onChange={setInstitution}
-            placeholder="N26"
         />
-        </Field>
         <Field label="Country" hint="Two-letter country code">
           <input
             required
             pattern="[A-Z]{2}"
             maxLength={2}
             value={country}
-            onChange={(e) => setCountry(e.target.value.toUpperCase())}
+            onChange={(e) => {
+              setCountry(e.target.value.toUpperCase());
+              setInstitution("");
+            }}
           />
         </Field>
         <Field
@@ -754,6 +753,141 @@ function ConnectForm({
     </section>
   );
 }
+// InstitutionSelect offers the banks Enable Banking can actually connect for
+// the chosen country, with their logos. When the list cannot be loaded, it
+// degrades to the previous free-text institution input instead of blocking.
+function InstitutionSelect({
+  country,
+  configured,
+  value,
+  onChange,
+}: {
+  country: string;
+  configured: boolean;
+  value: string;
+  onChange: (name: string) => void;
+}) {
+  const [institutions, setInstitutions] = useState<Institution[] | null>(null);
+  const [loadError, setLoadError] = useState("");
+  const [open, setOpen] = useState(false);
+  const [query, setQuery] = useState("");
+  useEffect(() => {
+    setInstitutions(null);
+    setLoadError("");
+    if (!configured || !/^[A-Z]{2}$/.test(country)) return;
+    const controller = new AbortController();
+    request<Institution[]>(
+      `/api/banking/institutions?country=${country}`,
+      undefined,
+      controller.signal,
+    )
+      .then(setInstitutions)
+      .catch((err) => {
+        if (!controller.signal.aborted)
+          setLoadError(err instanceof Error ? err.message : String(err));
+      });
+    return () => controller.abort();
+  }, [country, configured]);
+  if (!configured || loadError)
+    return (
+      <Field
+        label="Institution"
+        hint={
+          loadError
+            ? `The bank list could not be loaded: ${loadError} Enter the institution name recognized by Enable Banking, such as N26.`
+            : "Use the institution name recognized by Enable Banking, such as N26."
+        }
+      >
+        <input
+          required
+          value={value}
+          onChange={(e) => onChange(e.target.value)}
+          placeholder="N26"
+        />
+      </Field>
+    );
+  const filter = query.trim().toLowerCase();
+  const matches = (institutions ?? []).filter((i) =>
+    i.name.toLowerCase().includes(filter),
+  );
+  const shown = matches.slice(0, 60);
+  const selected = institutions?.find((i) => i.name === value);
+  return (
+    <Field
+      label="Institution"
+      hint="Choose your bank as listed by Enable Banking."
+    >
+      <div className="bank-select">
+        <input
+          required
+          role="combobox"
+          aria-expanded={open}
+          aria-autocomplete="list"
+          disabled={!institutions}
+          value={open ? query : value}
+          placeholder={institutions ? "Search your bank" : "Loading banks…"}
+          onFocus={() => {
+            setQuery("");
+            setOpen(true);
+          }}
+          onChange={(e) => {
+            setQuery(e.target.value);
+            setOpen(true);
+          }}
+          onBlur={() => setOpen(false)}
+          onKeyDown={(e) => {
+            if (e.key === "Escape") setOpen(false);
+            if (e.key === "Enter" && open) {
+              e.preventDefault();
+              if (shown.length === 1) {
+                onChange(shown[0].name);
+                setOpen(false);
+              }
+            }
+          }}
+        />
+        {selected?.logo && !open && (
+          <img className="bank-selected-logo" src={selected.logo} alt="" />
+        )}
+        {open && institutions && (
+          <ul className="bank-options" role="listbox">
+            {shown.map((i) => (
+              <li key={i.name}>
+                <button
+                  type="button"
+                  className="bank-option"
+                  role="option"
+                  aria-selected={i.name === value}
+                  onMouseDown={(e) => e.preventDefault()}
+                  onClick={() => {
+                    onChange(i.name);
+                    setOpen(false);
+                  }}
+                >
+                  {i.logo ? (
+                    <img src={i.logo} alt="" loading="lazy" />
+                  ) : (
+                    <Landmark size={16} />
+                  )}
+                  <span>{i.name}</span>
+                </button>
+              </li>
+            ))}
+            {shown.length === 0 && (
+              <li className="bank-empty">No banks match “{query}”.</li>
+            )}
+            {matches.length > shown.length && (
+              <li className="bank-empty">
+                {matches.length - shown.length} more — keep typing to narrow
+                down.
+              </li>
+            )}
+          </ul>
+        )}
+      </div>
+    </Field>
+  );
+}
 function AccountEditor({
   account,
   mutate,

web/src/api.ts

@@ -73,6 +73,11 @@ export interface Connection {
   valid_until: string;
   error: string;
 }
+export interface Institution {
+  name: string;
+  country: string;
+  logo?: string;
+}
 export interface State {
   data: Dataset;
   revision: string;

web/src/styles.css

@@ -2031,6 +2031,71 @@ footer span:first-child {
 .callback-details code {
   font-size: 10px;
 }
+.bank-select {
+  position: relative;
+}
+.bank-select > input {
+  width: 100%;
+  padding-right: 40px;
+}
+.bank-selected-logo {
+  position: absolute;
+  right: 11px;
+  top: 50%;
+  transform: translateY(-50%);
+  width: 22px;
+  height: 22px;
+  object-fit: contain;
+  pointer-events: none;
+}
+.bank-options {
+  position: absolute;
+  z-index: 30;
+  top: calc(100% + 4px);
+  left: 0;
+  right: 0;
+  margin: 0;
+  padding: 4px;
+  list-style: none;
+  background: #fff;
+  border: 1px solid #dbe2ea;
+  border-radius: 8px;
+  box-shadow: 0 10px 30px #10223418;
+  max-height: 264px;
+  overflow-y: auto;
+}
+.bank-option {
+  display: flex;
+  width: 100%;
+  align-items: center;
+  gap: 10px;
+  padding: 8px 10px;
+  border: 0;
+  background: none;
+  border-radius: 6px;
+  cursor: pointer;
+  text-align: left;
+  font-size: 13px;
+  color: inherit;
+}
+.bank-option:hover,
+.bank-option[aria-selected="true"] {
+  background: #f0f7f4;
+}
+.bank-option img,
+.bank-option svg {
+  width: 22px;
+  height: 22px;
+  object-fit: contain;
+  flex: none;
+  color: var(--muted);
+}
+.bank-empty {
+  padding: 8px 10px;
+  color: var(--muted);
+  font-size: 12px;
+}
+
 .category-tree {
   padding: 0 17px 23px;
 }