fix(web,api): fix edit test connection false negative and gate fetch for unsupported providers

- handleTestInlineModel now accepts optional model_index to fall back to stored credentials when api_key is empty, fixing false negatives when testing edited models
- Add supportsFetch to provider registry and FETCHABLE_PROVIDER_KEYS derived set
- Gate Fetch Models button to only show for OpenAI-compatible and Ollama providers
- Add backend guard in handleFetchModels to reject unsupported providers with clear error

web/backend/api/models.go

@@ -17,6 +17,18 @@ import (
 	"github.com/sipeed/picoclaw/pkg/providers"
 )
 
+// fetchableProviders lists providers that support OpenAI-compatible /models listing.
+var fetchableProviders = map[string]bool{
+	"openai": true, "deepseek": true, "openrouter": true,
+	"qwen-portal": true, "qwen-intl": true, "moonshot": true,
+	"volcengine": true, "zhipu": true, "groq": true,
+	"mistral": true, "nvidia": true, "cerebras": true,
+	"venice": true, "shengsuanyun": true, "vivgrid": true,
+	"minimax": true, "longcat": true, "modelscope": true,
+	"mimo": true, "avian": true, "zai": true, "novita": true,
+	"litellm": true, "vllm": true, "lmstudio": true, "ollama": true,
+}
+
 // registerModelRoutes binds model list management endpoints to the ServeMux.
 func (h *Handler) registerModelRoutes(mux *http.ServeMux) {
 	mux.HandleFunc("GET /api/models", h.handleListModels)
@@ -684,6 +696,7 @@ func (h *Handler) handleTestInlineModel(w http.ResponseWriter, r *http.Request)
 		APIBase    string `json:"api_base"`
 		APIKey     string `json:"api_key"`
 		AuthMethod string `json:"auth_method"`
+		ModelIndex *int   `json:"model_index"`
 	}
 	if err := json.Unmarshal(body, &req); err != nil {
 		http.Error(w, "Invalid JSON", http.StatusBadRequest)
@@ -700,6 +713,21 @@ func (h *Handler) handleTestInlineModel(w http.ResponseWriter, r *http.Request)
 		m.SetAPIKey(req.APIKey)
 	}
 
+	// When api_key is empty and model_index is provided, fall back to stored credentials.
+	// This lets the edit form test unsaved field changes while using the saved key.
+	if req.APIKey == "" && req.ModelIndex != nil {
+		cfg, err := config.LoadConfig(h.configPath)
+		if err == nil && *req.ModelIndex >= 0 && *req.ModelIndex < len(cfg.ModelList) {
+			stored := cfg.ModelList[*req.ModelIndex]
+			if stored.APIKey() != "" {
+				m.SetAPIKey(stored.APIKey())
+			}
+			if m.APIBase == "" && stored.APIBase != "" {
+				m.APIBase = stored.APIBase
+			}
+		}
+	}
+
 	// Check if configuration exists
 	if !hasModelConfiguration(m) {
 		w.Header().Set("Content-Type", "application/json")
@@ -784,6 +812,11 @@ func (h *Handler) handleFetchModels(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if !fetchableProviders[strings.ToLower(req.Provider)] {
+		http.Error(w, fmt.Sprintf("provider %q does not support model listing", req.Provider), http.StatusBadRequest)
+		return
+	}
+
 	apiBase := strings.TrimSpace(req.APIBase)
 	if apiBase == "" {
 		apiBase = providers.DefaultAPIBaseForProtocol(req.Provider)

web/frontend/src/api/models.ts

@@ -133,6 +133,7 @@ export interface TestModelInlineRequest {
   api_base?: string
   api_key?: string
   auth_method?: string
+  model_index?: number
 }
 
 export async function testModelInline(

web/frontend/src/components/models/add-model-sheet.tsx

@@ -34,7 +34,7 @@ import { FetchModelsDialog } from "./fetch-models-dialog"
 import { type FieldValidation, validateModelField } from "./model-validation"
 import { ProviderCombobox } from "./provider-combobox"
 import { getProviderKey } from "./provider-label"
-import { PROVIDER_MAP } from "./provider-registry"
+import { FETCHABLE_PROVIDER_KEYS, PROVIDER_MAP } from "./provider-registry"
 import { TestModelDialog } from "./test-model-dialog"
 
 interface AddForm {
@@ -484,16 +484,17 @@ export function AddModelSheet({
                   </div>
                 )}
                 <div className="flex items-center gap-2">
+                  {form.provider && FETCHABLE_PROVIDER_KEYS.has(form.provider) && (
                     <Button
                       variant="outline"
                       size="sm"
                       className="h-7 text-xs"
                       onClick={() => setFetchOpen(true)}
-                    disabled={!form.provider}
                     >
                       <IconDownload className="size-3" />
                       {t("models.fetch.title")}
                     </Button>
+                  )}
                   {!form.provider && (
                     <span className="text-muted-foreground text-xs">
                       {t("models.field.selectProviderFirst")}

web/frontend/src/components/models/edit-model-sheet.tsx

@@ -39,7 +39,7 @@ import { FetchModelsDialog } from "./fetch-models-dialog"
 import { type FieldValidation, validateModelField } from "./model-validation"
 import { ProviderCombobox } from "./provider-combobox"
 import { getProviderKey } from "./provider-label"
-import { PROVIDER_API_BASES, PROVIDER_MAP } from "./provider-registry"
+import { FETCHABLE_PROVIDER_KEYS, PROVIDER_API_BASES, PROVIDER_MAP } from "./provider-registry"
 import { TestModelDialog } from "./test-model-dialog"
 
 interface EditForm {
@@ -441,16 +441,17 @@ export function EditModelSheet({
                   </div>
                 )}
                 <div className="flex items-center gap-2">
+                  {form.provider && FETCHABLE_PROVIDER_KEYS.has(form.provider) && (
                     <Button
                       variant="outline"
                       size="sm"
                       className="h-7 text-xs"
                       onClick={() => setFetchOpen(true)}
-                    disabled={!form.provider}
                     >
                       <IconDownload className="size-3" />
                       {t("models.fetch.title")}
                     </Button>
+                  )}
                 </div>
               </Field>
 
@@ -671,6 +672,7 @@ export function EditModelSheet({
           apiBase: form.apiBase,
           apiKey: form.apiKey,
           authMethod: form.authMethod,
+          modelIndex: model?.index,
         }}
       />
 

web/frontend/src/components/models/provider-registry.ts

@@ -16,6 +16,8 @@ export interface ProviderDefinition {
   priority: number
   commonModels?: string[]
   aliases?: string[]
+  /** Whether this provider supports the OpenAI-compatible /models listing endpoint. */
+  supportsFetch?: boolean
 }
 
 export const PROVIDERS: ProviderDefinition[] = [
@@ -30,6 +32,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     priority: 100,
     commonModels: ["gpt-4o", "gpt-4o-mini", "gpt-4-turbo", "o1", "o3-mini"],
     aliases: ["gpt"],
+    supportsFetch: true,
   },
   {
     key: "anthropic",
@@ -69,6 +72,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 85,
     commonModels: ["deepseek-chat", "deepseek-reasoner"],
+    supportsFetch: true,
   },
   {
     key: "openrouter",
@@ -84,6 +88,7 @@ export const PROVIDERS: ProviderDefinition[] = [
       "anthropic/claude-sonnet-4",
       "google/gemini-2.0-flash",
     ],
+    supportsFetch: true,
   },
   {
     key: "qwen-portal",
@@ -97,6 +102,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     priority: 75,
     commonModels: ["qwen-max", "qwen-plus", "qwen-turbo"],
     aliases: ["qwen"],
+    supportsFetch: true,
   },
   {
     key: "qwen-intl",
@@ -109,6 +115,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     priority: 74,
     commonModels: ["qwen-max", "qwen-plus", "qwen-turbo"],
     aliases: ["qwen-international", "dashscope-intl"],
+    supportsFetch: true,
   },
   {
     key: "moonshot",
@@ -120,6 +127,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 70,
     commonModels: ["moonshot-v1-8k", "moonshot-v1-32k", "moonshot-v1-128k"],
+    supportsFetch: true,
   },
   {
     key: "volcengine",
@@ -132,6 +140,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 69,
     commonModels: ["doubao-1.5-pro", "doubao-1.5-lite"],
+    supportsFetch: true,
   },
   {
     key: "zhipu",
@@ -144,6 +153,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 68,
     commonModels: ["glm-4-plus", "glm-4-flash"],
+    supportsFetch: true,
   },
   {
     key: "groq",
@@ -155,6 +165,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 65,
     commonModels: ["llama-3.3-70b-versatile", "mixtral-8x7b-32768"],
+    supportsFetch: true,
   },
   {
     key: "mistral",
@@ -166,6 +177,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 64,
     commonModels: ["mistral-large-latest", "mistral-small-latest"],
+    supportsFetch: true,
   },
   {
     key: "nvidia",
@@ -177,6 +189,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 63,
     commonModels: ["meta/llama-3.1-405b-instruct"],
+    supportsFetch: true,
   },
   {
     key: "cerebras",
@@ -188,6 +201,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 62,
     commonModels: ["llama3.1-8b", "llama3.1-70b"],
+    supportsFetch: true,
   },
   {
     key: "azure",
@@ -227,6 +241,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: true,
     priority: 50,
     commonModels: ["llama3", "mistral", "codellama", "qwen2.5"],
+    supportsFetch: true,
   },
   {
     key: "vllm",
@@ -237,6 +252,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: false,
     isLocal: true,
     priority: 49,
+    supportsFetch: true,
   },
   {
     key: "lmstudio",
@@ -247,6 +263,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: false,
     isLocal: true,
     priority: 48,
+    supportsFetch: true,
   },
   {
     key: "venice",
@@ -257,6 +274,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 45,
+    supportsFetch: true,
   },
   {
     key: "shengsuanyun",
@@ -267,6 +285,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 44,
+    supportsFetch: true,
   },
   {
     key: "vivgrid",
@@ -276,6 +295,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 43,
+    supportsFetch: true,
   },
   {
     key: "minimax",
@@ -285,6 +305,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 42,
+    supportsFetch: true,
   },
   {
     key: "longcat",
@@ -294,6 +315,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 41,
+    supportsFetch: true,
   },
   {
     key: "modelscope",
@@ -304,6 +326,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 40,
+    supportsFetch: true,
   },
   {
     key: "mimo",
@@ -314,6 +337,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 39,
+    supportsFetch: true,
   },
   {
     key: "avian",
@@ -323,6 +347,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 38,
+    supportsFetch: true,
   },
   {
     key: "zai",
@@ -333,6 +358,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     isLocal: false,
     priority: 37,
     aliases: ["z.ai", "z-ai"],
+    supportsFetch: true,
   },
   {
     key: "novita",
@@ -342,6 +368,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 36,
+    supportsFetch: true,
   },
   {
     key: "litellm",
@@ -351,6 +378,7 @@ export const PROVIDERS: ProviderDefinition[] = [
     requiresApiKey: true,
     isLocal: false,
     priority: 35,
+    supportsFetch: true,
   },
 ]
 
@@ -368,6 +396,10 @@ export const PROVIDER_ALIASES: Record<string, string> = Object.fromEntries(
 
 export const KNOWN_PROVIDER_KEYS = new Set(PROVIDERS.map((p) => p.key))
 
+export const FETCHABLE_PROVIDER_KEYS = new Set(
+  PROVIDERS.filter((p) => p.supportsFetch).map((p) => p.key),
+)
+
 export const PROVIDER_ICON_SLUGS: Record<string, string> = Object.fromEntries(
   PROVIDERS.filter((p) => p.iconSlug).map((p) => [p.key, p.iconSlug!]),
 )

web/frontend/src/components/models/test-model-dialog.tsx

@@ -24,6 +24,7 @@ export interface TestInlineParams {
   apiBase: string
   apiKey: string
   authMethod: string
+  modelIndex?: number
 }
 
 interface TestModelDialogProps {
@@ -62,6 +63,7 @@ export function TestModelDialog({
           api_base: inlineParams.apiBase || undefined,
           api_key: inlineParams.apiKey || undefined,
           auth_method: inlineParams.authMethod || undefined,
+          model_index: inlineParams.modelIndex,
         }
         res = await testModelInline(req)
       } else if (model) {