diff --git a/provider_anthropic.go b/provider_anthropic.go
index d48b0b9..03c675b 100644
--- a/provider_anthropic.go
+++ b/provider_anthropic.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -270,11 +271,18 @@ type anthropicModelsPayload struct {
 // anthropicListModelsPageCap bounds how many pages listModels follows
 // (M7 fix): a misbehaving upstream that never reports has_more:false, or
 // whose last_id never advances, would otherwise page forever. 20 pages
-// at Anthropic's own default page size (20 per page) covers 400 models —
-// comfortably above any real catalog as of this writing — without
-// risking an unbounded discovery loop against a single provider.
+// at anthropicListModelsPageSize covers far more models than any real
+// catalog without risking an unbounded discovery loop against a single
+// provider.
 const anthropicListModelsPageCap = 20
 
+// anthropicListModelsPageSize is the `limit` sent on every /v1/models
+// page: Anthropic's documented maximum (default 20, range 1-1000). At the
+// default page size a full catalog took several sequential requests, which
+// could overrun registry.go's warmFillTimeout at pod start; one request
+// at the maximum returns the whole catalog.
+const anthropicListModelsPageSize = 1000
+
 // listModels implements providerAdapter: GET {base}/v1/models, following
 // Anthropic's has_more/last_id cursor pagination (M7 fix) via the
 // after_id query parameter, up to anthropicListModelsPageCap pages —
@@ -307,10 +315,12 @@ func (a *anthropicAdapter) listModels(ctx context.Context) ([]string, error) {
 // model ids alongside has_more/last_id for listModels' own pagination
 // loop above.
 func (a *anthropicAdapter) listModelsPage(ctx context.Context, afterID string) (ids []string, hasMore bool, lastID string, err error) {
-	endpoint := a.baseURL + anthropicModelsPath
+	query := url.Values{}
+	query.Set("limit", strconv.Itoa(anthropicListModelsPageSize))
 	if afterID != "" {
-		endpoint += "?after_id=" + url.QueryEscape(afterID)
+		query.Set("after_id", afterID)
 	}
+	endpoint := a.baseURL + anthropicModelsPath + "?" + query.Encode()
 	resp, err := upstreamJSON(ctx, a.client, http.MethodGet, endpoint, a.requestHeaders(false), nil, a.retry, a.timeout, a.adapterName)
 	if err != nil {
 		return nil, false, "", err
diff --git a/provider_anthropic_test.go b/provider_anthropic_test.go
index a5c5365..e45bb7f 100644
--- a/provider_anthropic_test.go
+++ b/provider_anthropic_test.go
@@ -471,9 +471,10 @@ func TestAnthropicAdapter_ListModels(t *testing.T) {
 // page via ?after_id=<last_id> and return the union of both pages, not
 // just the first page's 20 (Anthropic's own default page size).
 func TestAnthropicAdapter_ListModels_FollowsPagination(t *testing.T) {
-	var gotAfterIDs []string
+	var gotAfterIDs, gotLimits []string
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		gotAfterIDs = append(gotAfterIDs, r.URL.Query().Get("after_id"))
+		gotLimits = append(gotLimits, r.URL.Query().Get("limit"))
 		w.Header().Set("Content-Type", "application/json")
 		if r.URL.Query().Get("after_id") == "" {
 			_, _ = w.Write([]byte(`{"data":[{"id":"claude-opus-5"},{"id":"claude-sonnet-5"}],"has_more":true,"last_id":"claude-sonnet-5"}`))
@@ -504,6 +505,13 @@ func TestAnthropicAdapter_ListModels_FollowsPagination(t *testing.T) {
 	if len(gotAfterIDs) != 2 || gotAfterIDs[0] != "" || gotAfterIDs[1] != "claude-sonnet-5" {
 		t.Errorf("after_id sequence = %#v, want [\"\", \"claude-sonnet-5\"] (first page unqualified, second page's after_id = first page's last_id)", gotAfterIDs)
 	}
+	// Every page asks for Anthropic's maximum page size, so a real catalog
+	// arrives in one request inside warmFillTimeout.
+	for i, l := range gotLimits {
+		if l != "1000" {
+			t.Errorf("page %d limit = %q, want \"1000\"", i, l)
+		}
+	}
 }
 
 // TestAnthropicAdapter_ListModels_PageCapStopsRunawayPagination proves
diff --git a/provider_gemini.go b/provider_gemini.go
index 6defdf3..2a1d68a 100644
--- a/provider_gemini.go
+++ b/provider_gemini.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -386,6 +387,13 @@ type geminiModelsListPayload struct {
 // provider.
 const geminiListModelsPageCap = 20
 
+// geminiListModelsPageSize is the pageSize sent on every models.list page:
+// the documented maximum (default 50, at most 1000 per page). Gemini
+// requires the same parameters on every page of one listing, so it is sent
+// with the pageToken too. One request at the maximum returns the whole
+// catalog within registry.go's warmFillTimeout.
+const geminiListModelsPageSize = 1000
+
 // listModels implements providerAdapter: GET {base}/v1beta/models,
 // stripping the "models/" prefix off each entry's "name" to return bare
 // model ids, matching the shape openai-type and anthropic-type adapters
@@ -414,10 +422,12 @@ func (a *geminiAdapter) listModels(ctx context.Context) ([]string, error) {
 // model ids alongside nextPageToken for listModels' own pagination loop
 // above.
 func (a *geminiAdapter) listModelsPage(ctx context.Context, pageToken string) (ids []string, nextPageToken string, err error) {
-	endpoint := a.baseURL + "/v1beta/models"
+	query := url.Values{}
+	query.Set("pageSize", strconv.Itoa(geminiListModelsPageSize))
 	if pageToken != "" {
-		endpoint += "?pageToken=" + url.QueryEscape(pageToken)
+		query.Set("pageToken", pageToken)
 	}
+	endpoint := a.baseURL + "/v1beta/models?" + query.Encode()
 	resp, err := upstreamJSON(ctx, a.client, http.MethodGet, endpoint, a.requestHeaders(false), nil, a.retry, a.timeout, a.adapterName)
 	if err != nil {
 		return nil, "", err
diff --git a/provider_gemini_test.go b/provider_gemini_test.go
index b25fd1f..6c68462 100644
--- a/provider_gemini_test.go
+++ b/provider_gemini_test.go
@@ -688,9 +688,10 @@ func TestGeminiAdapter_ListModels(t *testing.T) {
 // test: a non-empty nextPageToken must make listModels fetch a second
 // page via ?pageToken=<token> and return the union of both pages.
 func TestGeminiAdapter_ListModels_FollowsPagination(t *testing.T) {
-	var gotPageTokens []string
+	var gotPageTokens, gotPageSizes []string
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		gotPageTokens = append(gotPageTokens, r.URL.Query().Get("pageToken"))
+		gotPageSizes = append(gotPageSizes, r.URL.Query().Get("pageSize"))
 		w.Header().Set("Content-Type", "application/json")
 		if r.URL.Query().Get("pageToken") == "" {
 			_, _ = w.Write([]byte(`{"models":[{"name":"models/gemini-2.5-pro"},{"name":"models/gemini-2.5-flash"}],"nextPageToken":"page2"}`))
@@ -721,6 +722,13 @@ func TestGeminiAdapter_ListModels_FollowsPagination(t *testing.T) {
 	if len(gotPageTokens) != 2 || gotPageTokens[0] != "" || gotPageTokens[1] != "page2" {
 		t.Errorf("pageToken sequence = %#v, want [\"\", \"page2\"] (first page unqualified, second page's pageToken = first page's nextPageToken)", gotPageTokens)
 	}
+	// Gemini requires identical parameters on every page of one listing,
+	// so pageSize must ride along with the pageToken too.
+	for i, s := range gotPageSizes {
+		if s != "1000" {
+			t.Errorf("page %d pageSize = %q, want \"1000\"", i, s)
+		}
+	}
 }
 
 // TestGeminiAdapter_ListModels_PageCapStopsRunawayPagination proves the