diff --git a/backend/internal/service/openai_codex_models_service.go b/backend/internal/service/openai_codex_models_service.go
index 934f770979..911672d5d8 100644
--- a/backend/internal/service/openai_codex_models_service.go
+++ b/backend/internal/service/openai_codex_models_service.go
@@ -546,6 +546,9 @@ func newConfiguredCodexModelDescriptor(modelID string) configuredCodexModelDescr
 		}
 		descriptor.Slug = modelID
 		descriptor.officialMetadata = openai.CodexGPT61SolMetadata
+		// The October 12, 2026 Codex/Work default increased to 500k after
+		// the bundled official snapshot. Explicit upstream metadata still wins.
+		descriptor.ContextWindow = 500_000
 	}
 	return descriptor
 }
diff --git a/backend/internal/service/openai_codex_models_service_test.go b/backend/internal/service/openai_codex_models_service_test.go
index a825ba2208..1b5d701335 100644
--- a/backend/internal/service/openai_codex_models_service_test.go
+++ b/backend/internal/service/openai_codex_models_service_test.go
@@ -2403,7 +2403,7 @@ func TestFetchCodexModelsManifestAPIKeyDisablesResponsesLiteForAffectedModels(t
 }
 
 func TestFetchCodexModelsManifestOAuthPreservesResponsesLite(t *testing.T) {
-	const manifestBody = ` {"models":[{"slug":"gpt-5.6-sol","use_responses_lite":true}]} `
+	const manifestBody = ` {"models":[{"slug":"gpt-5.6-sol","use_responses_lite":true},{"slug":"gpt-6.1-sol","context_window":500000,"max_context_window":1000000,"use_responses_lite":true}]} `
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		_, _ = w.Write([]byte(manifestBody))
 	}))
@@ -3798,7 +3798,7 @@ func TestGPT61SolOfflineCodexCatalog(t *testing.T) {
 	m := catalog.Models[0]
 	require.Equal(t, "gpt-6.1-sol", m["slug"])
 	require.Equal(t, "low", m["default_reasoning_level"])
-	require.EqualValues(t, 272000, m["context_window"])
+	require.EqualValues(t, 500000, m["context_window"])
 	require.EqualValues(t, 872000, m["max_context_window"])
 	require.Equal(t, "xhigh", m["multi_agent_reasoning_effort"])
 	require.Equal(t, "v2", m["multi_agent_version"])
@@ -3851,3 +3851,25 @@ func TestGPT61SolAPIKeyCatalogUsesFullResponses(t *testing.T) {
 	require.Equal(t, false, catalog.Models[0]["use_responses_lite"])
 	require.Equal(t, "low", catalog.Models[0]["default_reasoning_level"])
 }
+
+func TestGPT61SolAPIKeyCatalogContextWindow(t *testing.T) {
+	account := &Account{Platform: PlatformOpenAI, Type: AccountTypeAPIKey, Credentials: map[string]any{"base_url": "https://api.openai.com"}}
+	for _, tc := range []struct {
+		name string
+		body string
+		want int64
+	}{
+		{"missing uses updated default", `{"models":[{"slug":"gpt-6.1-sol"}]}`, 500_000},
+		{"null uses updated default", `{"models":[{"slug":"gpt-6.1-sol","context_window":null}]}`, 500_000},
+		{"lower upstream window is preserved", `{"models":[{"slug":"gpt-6.1-sol","context_window":272000}]}`, 272_000},
+		{"higher upstream window is preserved", `{"models":[{"slug":"gpt-6.1-sol","context_window":1000000,"max_context_window":1000000}]}`, 1_000_000},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			body, err := completeAPIKeyCodexModelsManifestMetadata([]byte(tc.body), true, account)
+			require.NoError(t, err)
+			models := decodeCodexManifestModels(t, body)
+			require.Len(t, models, 1)
+			require.EqualValues(t, tc.want, models[0]["context_window"])
+		})
+	}
+}