test(swarm): also assert handoff to_agent_type enum picks up a custom roster type

Address review: the custom-type recheck only re-read spawnTool, so a regression
leaving handoffTool on the built-in list would have passed.

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/aymanbagabas/go-udiff v0.4.1
 	github.com/charmbracelet/colorprofile v0.4.3
 	github.com/charmbracelet/x/ansi v0.11.7
+	github.com/charmbracelet/x/term v0.2.2
 	github.com/ledongthuc/pdf v0.0.0-20250511090121-5959a4027728
 	golang.org/x/sys v0.46.0
 	mvdan.cc/sh/v3 v3.13.1
@@ -21,7 +22,6 @@ require (
 require (
 	github.com/charmbracelet/ultraviolet v0.0.0-20260615092913-2399af76d5b1 // indirect
 	github.com/charmbracelet/x/exp/golden v0.0.0-20260615092313-b57e5e6d29bb // indirect
-	github.com/charmbracelet/x/term v0.2.2 // indirect
 	github.com/charmbracelet/x/termios v0.1.1 // indirect
 	github.com/charmbracelet/x/windows v0.2.2 // indirect
 	github.com/clipperhouse/displaywidth v0.11.0 // indirect

internal/cli/command_center.go

@@ -277,6 +277,9 @@ func listProviderCatalogSummaries(options commandCenterOptions) ([]providerCatal
 		return nil, err
 	}
 	sort.SliceStable(summaries, func(i int, j int) bool {
+		if summaries[i].Recommended != summaries[j].Recommended {
+			return summaries[i].Recommended
+		}
 		return summaries[i].ID < summaries[j].ID
 	})
 	return summaries, nil
@@ -354,10 +357,17 @@ func formatProviderCatalogSummaries(providers []providerCatalogSummary) string {
 }
 
 func formatProviderCatalogLine(provider providerCatalogSummary) string {
+	name := formatProviderCatalogValue(provider.Name, "unknown")
+	prefix := "  id="
+	if provider.Recommended {
+		prefix = "  ★ id="
+		name += " (recommended)"
+	}
 	lines := []string{
-		fmt.Sprintf("  id=%s name=%s",
+		fmt.Sprintf("%s%s name=%s",
+			prefix,
 			formatProviderCatalogValue(provider.ID, "unknown"),
-			formatProviderCatalogValue(provider.Name, "unknown"),
+			name,
 		),
 		fmt.Sprintf("    transport=%s defaultModel=%s",
 			formatProviderCatalogValue(provider.Transport, "unknown"),

internal/cli/setup.go

@@ -285,6 +285,7 @@ func setupProviderOptions() []tui.SetupProviderOption {
 			EnvVar:       setupProviderEnvVar(descriptor),
 			RequiresAuth: descriptor.RequiresAuth,
 			Local:        descriptor.Local,
+			Recommended:  descriptor.Recommended,
 		})
 	}
 	return options

internal/npmwrapper/npmwrapper_test.go

@@ -140,6 +140,26 @@ func TestPostinstallSkipsUnsupportedPlatform(t *testing.T) {
 	}
 }
 
+func TestPostinstallSkipsWindowsArm64(t *testing.T) {
+	// (win32, arm64) resolves to a valid platform/arch but the release matrix has
+	// no windows-arm64 artifact, so the install must skip gracefully (exit 0)
+	// rather than hard-fail on a 404 download.
+	stdout, stderr, err := runPostinstall(t,
+		"ZERO_INSTALL_DRY_RUN=1",
+		"ZERO_INSTALL_PLATFORM=win32",
+		"ZERO_INSTALL_ARCH=arm64",
+	)
+	if err != nil {
+		t.Fatalf("windows-arm64 should exit 0, got err=%v stderr=%s", err, stderr)
+	}
+	if strings.TrimSpace(stdout) != "" {
+		t.Fatalf("windows-arm64 should not print a plan, got %q", stdout)
+	}
+	if !strings.Contains(stderr, "no prebuilt binary for windows-arm64") {
+		t.Fatalf("stderr=%q, want the windows-arm64 skip message", stderr)
+	}
+}
+
 func TestPostinstallHonorsSkipEnv(t *testing.T) {
 	stdout, stderr, err := runPostinstall(t, "ZERO_SKIP_DOWNLOAD=1")
 	if err != nil {

internal/providercatalog/catalog.go

@@ -58,6 +58,11 @@ type Descriptor struct {
 	// OAuthDeviceFlow reports that RFC 8628 device-code login is supported (for
 	// headless / SSH use) in addition to the browser flow.
 	OAuthDeviceFlow bool
+
+	// Recommended marks the provider that should be surfaced first and badged
+	// (★ … (recommended)) in every catalog-ordered list and picker. At most one
+	// descriptor should set this.
+	Recommended bool
 }
 
 func RuntimeSupported(descriptor Descriptor) bool {
@@ -82,6 +87,11 @@ func RuntimeUnsupportedReason(descriptor Descriptor) string {
 }
 
 var descriptors = []Descriptor{
+	// GitLawb OpenGateway — the recommended default. An OpenAI-compatible gateway
+	// that smart-routes by model id across upstream providers (xiaomi-mimo,
+	// minimax, qwen, google, nvidia, z-ai). Flat /v1/chat/completions with a
+	// Bearer ogw_live_… key; listed first and badged in every picker.
+	recommended(openAICompat("gitlawb-opengateway", "GitLawb OpenGateway", "https://opengateway.gitlawb.com/v1", "mimo-v2.5-pro", []string{"GITLAWB_OPENGATEWAY_API_KEY"}, "gitlawb opengateway", "opengateway")),
 	openAI("openai", "OpenAI", "https://api.openai.com/v1", "gpt-4.1", []string{"OPENAI_API_KEY"}),
 	anthropic("anthropic", "Anthropic", "https://api.anthropic.com", "claude-sonnet-4.5", []string{"ANTHROPIC_API_KEY"}),
 	google("google", "Google", "https://generativelanguage.googleapis.com", "gemini-2.5-pro", []string{"GEMINI_API_KEY", "GOOGLE_API_KEY"}, "gemini"),
@@ -124,7 +134,6 @@ var descriptors = []Descriptor{
 	openAICompat("xiaomi-mimo", "Xiaomi MiMo", "https://api.mimo.xiaomi.com/openai/v1", "mimo-vl", []string{"MIMO_API_KEY", "XIAOMI_API_KEY"}, "xiaomi mimo"),
 	openAICompat("bankr", "Bankr", "https://api.bankr.bot/v1", "bankr-large", []string{"BANKR_API_KEY"}),
 	openAICompat("zai", "Z.ai", "https://open.bigmodel.cn/api/paas/v4", "glm-4.5", []string{"ZAI_API_KEY", "ZHIPU_API_KEY"}),
-	openAICompat("gitlawb-opengateway", "GitLawb OpenGateway", "https://gateway.gitlawb.com/v1", "gpt-4.1", []string{"GITLAWB_OPENGATEWAY_API_KEY"}, "gitlawb opengateway"),
 	openAICompat("atomic-chat", "Atomic Chat", "https://api.atomic.chat/v1", "gpt-4.1", []string{"ATOMIC_CHAT_API_KEY"}),
 	// ChatGPT subscription via a local OAuth proxy. A ChatGPT (Plus/Pro) OAuth
 	// token only works against ChatGPT's own backend (which is Cloudflare-gated to
@@ -266,6 +275,13 @@ func google(id string, name string, baseURL string, model string, env []string,
 	}
 }
 
+// recommended marks a descriptor as the recommended default so list/picker
+// surfaces sort it first and render the ★ … (recommended) badge.
+func recommended(descriptor Descriptor) Descriptor {
+	descriptor.Recommended = true
+	return descriptor
+}
+
 // oauthProvider marks a descriptor as OAuth-capable. mintsKey => the flow returns
 // an API key (OpenRouter); deviceFlow => RFC 8628 device code is also supported.
 func oauthProvider(descriptor Descriptor, mintsKey bool, deviceFlow bool) Descriptor {

internal/providercatalog/catalog_test.go

@@ -8,6 +8,7 @@ import (
 )
 
 var expectedCatalogIDs = []string{
+	"gitlawb-opengateway",
 	"openai",
 	"anthropic",
 	"google",
@@ -33,7 +34,6 @@ var expectedCatalogIDs = []string{
 	"xiaomi-mimo",
 	"bankr",
 	"zai",
-	"gitlawb-opengateway",
 	"atomic-chat",
 	"chatgpt-proxy",
 	"custom-openai-compatible",
@@ -61,6 +61,41 @@ func TestAllHasStableUniqueIDs(t *testing.T) {
 	}
 }
 
+func TestRecommendedProviderIsFirstAndUnique(t *testing.T) {
+	descriptors := All()
+	if len(descriptors) == 0 {
+		t.Fatal("All() returned no descriptors")
+	}
+	if !descriptors[0].Recommended {
+		t.Fatalf("All()[0] = %q, want it to be the recommended provider", descriptors[0].ID)
+	}
+	if descriptors[0].ID != "gitlawb-opengateway" {
+		t.Fatalf("recommended provider = %q, want %q", descriptors[0].ID, "gitlawb-opengateway")
+	}
+	recommended := 0
+	for _, descriptor := range descriptors {
+		if descriptor.Recommended {
+			recommended++
+		}
+	}
+	if recommended != 1 {
+		t.Fatalf("recommended descriptor count = %d, want exactly 1", recommended)
+	}
+}
+
+func TestRecommendedProviderEndpoint(t *testing.T) {
+	descriptor, ok := Get("gitlawb-opengateway")
+	if !ok {
+		t.Fatal("gitlawb-opengateway not found in catalog")
+	}
+	if descriptor.DefaultBaseURL != "https://opengateway.gitlawb.com/v1" {
+		t.Fatalf("OpenGateway base URL = %q, want %q", descriptor.DefaultBaseURL, "https://opengateway.gitlawb.com/v1")
+	}
+	if descriptor.Transport != TransportOpenAICompatible {
+		t.Fatalf("OpenGateway transport = %q, want %q", descriptor.Transport, TransportOpenAICompatible)
+	}
+}
+
 func TestCatalogDescriptorsExposeRequiredDefaults(t *testing.T) {
 	for _, descriptor := range All() {
 		if descriptor.ID == "" {
@@ -229,7 +264,7 @@ func TestListByTransportPreservesCatalogOrder(t *testing.T) {
 		TransportBedrock:         {"bedrock"},
 		TransportVertex:          {"vertex"},
 		TransportAnthropicCompat: {"minimax", "custom-anthropic-compatible"},
-		TransportOpenAICompat:    {"ollama-cloud", "ollama", "lmstudio", "openrouter", "huggingface", "chatgpt", "groq", "deepseek", "together", "dashscope", "moonshot", "nvidia-nim", "mistral", "github", "xai", "venice", "xiaomi-mimo", "bankr", "zai", "gitlawb-opengateway", "atomic-chat", "chatgpt-proxy", "custom-openai-compatible"},
+		TransportOpenAICompat:    {"gitlawb-opengateway", "ollama-cloud", "ollama", "lmstudio", "openrouter", "huggingface", "chatgpt", "groq", "deepseek", "together", "dashscope", "moonshot", "nvidia-nim", "mistral", "github", "xai", "venice", "xiaomi-mimo", "bankr", "zai", "atomic-chat", "chatgpt-proxy", "custom-openai-compatible"},
 	}
 
 	for transport, wantIDs := range cases {

internal/providerhealth/providerhealth.go

@@ -326,6 +326,9 @@ func healthRequest(ctx context.Context, profile config.ProviderProfile, kind con
 		return nil, false, err
 	}
 	endpoint := baseURL + healthPath(kind)
+	if override, ok := overrideHealthEndpoint(profile, baseURL); ok {
+		endpoint = override
+	}
 	// Loopback is permitted only when the user's OWN configured base_url is loopback
 	// (a local provider like Ollama/LM Studio) — never for a redirect target. This is
 	// the flag returned to the caller so the dial path applies the same policy. (AUDIT-H1)
@@ -592,6 +595,22 @@ func blockedAddrReason(addr netip.Addr) string {
 	return ""
 }
 
+// overrideHealthEndpoint returns a provider-specific connectivity probe URL when
+// the default {baseURL}+/models path does not exist. GitLawb OpenGateway is a
+// smart-routing gateway whose flat /v1/models endpoint 404s by design ("Use
+// /v1/<provider>/<path>"), so probe its public /health endpoint at the host root
+// instead, which reports real reachability without a per-model call.
+func overrideHealthEndpoint(profile config.ProviderProfile, baseURL string) (string, bool) {
+	if profile.CatalogID != "gitlawb-opengateway" {
+		return "", false
+	}
+	parsed, err := url.Parse(baseURL)
+	if err != nil || parsed.Scheme == "" || parsed.Host == "" {
+		return "", false
+	}
+	return parsed.Scheme + "://" + parsed.Host + "/health", true
+}
+
 func healthPath(kind config.ProviderKind) string {
 	switch kind {
 	case config.ProviderKindAnthropic, config.ProviderKindAnthropicCompat:

internal/providerhealth/providerhealth_additional_test.go

@@ -170,3 +170,20 @@ func TestProbeConnectivityRedactsProviderErrorDetails(t *testing.T) {
 		t.Fatalf("custom header secret leaked in connectivity check: %s", rendered)
 	}
 }
+
+func TestOverrideHealthEndpointOpenGateway(t *testing.T) {
+	got, ok := overrideHealthEndpoint(config.ProviderProfile{CatalogID: "gitlawb-opengateway"}, "https://opengateway.gitlawb.com/v1")
+	if !ok {
+		t.Fatal("expected OpenGateway to override the health endpoint")
+	}
+	if got != "https://opengateway.gitlawb.com/health" {
+		t.Fatalf("OpenGateway health endpoint = %q, want host-root /health", got)
+	}
+
+	if _, ok := overrideHealthEndpoint(config.ProviderProfile{CatalogID: "openai"}, "https://api.openai.com/v1"); ok {
+		t.Fatal("non-OpenGateway providers must not override the health endpoint")
+	}
+	if _, ok := overrideHealthEndpoint(config.ProviderProfile{CatalogID: "gitlawb-opengateway"}, "::not a url"); ok {
+		t.Fatal("an unparseable base URL must not produce an override")
+	}
+}

internal/providermodelcatalog/catalog.go

@@ -129,10 +129,18 @@ var curatedModels = map[string][]Model{
 		{ID: "glm-4.6", Description: "latest general model"},
 		{ID: "glm-z1-air", Description: "reasoning model"},
 	},
+	// OpenGateway smart-routes by model id across its upstream providers
+	// (see /health: xiaomi-mimo, minimax, qwen, google, nvidia, z-ai). These are
+	// the curated coding defaults; the gateway accepts any model its upstreams
+	// expose, so users can also type an id the picker doesn't list.
 	"gitlawb-opengateway": {
-		{ID: "gpt-4.1", Description: "catalog default"},
-		{ID: "claude-sonnet-4.5", Description: "coding model"},
-		{ID: "gemini-2.5-pro", Description: "long-context model"},
+		{ID: "mimo-v2.5-pro", Description: "catalog default (Xiaomi MiMo)"},
+		{ID: "mimo-v2.5-pro-ultraspeed", Description: "fast model (Xiaomi MiMo)"},
+		{ID: "MiniMax-M3", Description: "MiniMax model"},
+		{ID: "qwen-plus", Description: "Qwen model"},
+		{ID: "gemini-2.5-pro", Description: "long-context model (Google)"},
+		{ID: "glm-4.6", Description: "Z.ai model"},
+		{ID: "nvidia/llama-3.1-nemotron-70b-instruct", Description: "NVIDIA NIM model"},
 	},
 	"atomic-chat": {
 		{ID: "gpt-4.1", Description: "catalog default"},

internal/providermodelcatalog/logic_test.go

@@ -54,7 +54,7 @@ func TestDefaultedOpenGatewayURL(t *testing.T) {
 	if got := defaultedOpenGatewayURL(providercatalog.Descriptor{DefaultBaseURL: "https://gw.example.com/v1"}, ""); got != "https://gw.example.com/zero/models.json" {
 		t.Fatalf("derived = %q", got)
 	}
-	if got := defaultedOpenGatewayURL(providercatalog.Descriptor{DefaultBaseURL: "::not a url"}, ""); got != "https://gateway.gitlawb.com/zero/models.json" {
+	if got := defaultedOpenGatewayURL(providercatalog.Descriptor{DefaultBaseURL: "::not a url"}, ""); got != "https://opengateway.gitlawb.com/zero/models.json" {
 		t.Fatalf("fallback = %q", got)
 	}
 }

internal/providermodelcatalog/remote.go

@@ -223,7 +223,7 @@ func defaultedOpenGatewayURL(provider providercatalog.Descriptor, override strin
 	}
 	parsed, err := url.Parse(provider.DefaultBaseURL)
 	if err != nil || parsed.Scheme == "" || parsed.Host == "" {
-		return "https://gateway.gitlawb.com/zero/models.json"
+		return "https://opengateway.gitlawb.com/zero/models.json"
 	}
 	return parsed.Scheme + "://" + parsed.Host + "/zero/models.json"
 }

internal/providers/openai/provider.go

@@ -385,6 +385,14 @@ func sendBufferedEvent(events chan<- zeroruntime.StreamEvent, event zeroruntime.
 func (provider *Provider) openAIRequest(request zeroruntime.CompletionRequest) chatCompletionRequest {
 	messages := make([]chatMessage, 0, len(request.Messages))
 	for _, message := range request.Messages {
+		// Drop a degenerate assistant turn that carries neither text nor tool calls
+		// (e.g. a sub-agent that failed with no output). The Anthropic/Gemini mappers
+		// already skip empty turns; without this, the contentless message reaches
+		// strict OpenAI-compatible servers and is rejected.
+		if message.Role == zeroruntime.MessageRoleAssistant &&
+			strings.TrimSpace(message.Content) == "" && len(message.ToolCalls) == 0 {
+			continue
+		}
 		messages = append(messages, mapMessage(message))
 	}
 
@@ -445,11 +453,12 @@ func mapMessage(message zeroruntime.Message) chatMessage {
 	// message that happens to carry Images keeps the plain string/nil content
 	// path (its images are simply not serialized).
 	if len(message.Images) == 0 || message.Role != zeroruntime.MessageRoleUser {
-		// Preserve the legacy behavior: only non-empty text is serialized, so
-		// empty content is omitted by the `omitempty` tag.
-		if message.Content != "" {
-			mapped.Content = message.Content
-		}
+		// Always set content (to "" when empty) so it serializes as `"content":""`
+		// rather than being dropped. Strict OpenAI-compatible servers reject a
+		// message with no content field; tool results and assistant-with-tool-calls
+		// turns must still carry an (empty) content. Truly empty assistant turns are
+		// dropped upstream in openAIRequest.
+		mapped.Content = message.Content
 	} else {
 		parts := make([]contentPart, 0, len(message.Images)+1)
 		if message.Content != "" {

internal/providers/openai/provider_test.go

@@ -1000,57 +1000,6 @@ func TestStreamCompletionEmitsDroppedOnNamelessToolCall(t *testing.T) {
 	}
 }
 
-func TestOpenAIRequestTextOnlyOmitsEmptyContent(t *testing.T) {
-	provider, err := New(Options{Model: "gpt-test"})
-	if err != nil {
-		t.Fatalf("New returned error: %v", err)
-	}
-
-	got, err := json.Marshal(provider.openAIRequest(zeroruntime.CompletionRequest{
-		Messages: []zeroruntime.Message{
-			{Role: zeroruntime.MessageRoleSystem, Content: "system"},
-			{Role: zeroruntime.MessageRoleUser, Content: "hello"},
-			{
-				Role:    zeroruntime.MessageRoleAssistant,
-				Content: "", // assistant turn that is *only* a tool call -> empty content must drop
-				ToolCalls: []zeroruntime.ToolCall{{
-					ID:        "call_1",
-					Name:      "read_file",
-					Arguments: `{"path":"README.md"}`,
-				}},
-			},
-			{Role: zeroruntime.MessageRoleTool, Content: "contents", ToolCallID: "call_1"},
-		},
-	}))
-	if err != nil {
-		t.Fatalf("marshal request: %v", err)
-	}
-
-	// String content round-trips as a JSON string, and empty content is omitted.
-	if !strings.Contains(string(got), `"content":"hello"`) {
-		t.Fatalf("user content not serialized as string: %s", got)
-	}
-	if strings.Contains(string(got), `"content":""`) {
-		t.Fatalf("empty assistant content must be omitted, got: %s", got)
-	}
-
-	// Decode the assistant message and assert no content key at all.
-	var decoded chatCompletionRequest
-	var raw struct {
-		Messages []map[string]any `json:"messages"`
-	}
-	if err := json.Unmarshal(got, &raw); err != nil {
-		t.Fatalf("unmarshal request: %v", err)
-	}
-	_ = decoded
-	if _, present := raw.Messages[2]["content"]; present {
-		t.Fatalf("assistant (tool-only) message must omit content key, got: %#v", raw.Messages[2])
-	}
-	if raw.Messages[1]["content"] != "hello" {
-		t.Fatalf("user content = %#v, want \"hello\"", raw.Messages[1]["content"])
-	}
-}
-
 func TestContentPartImageURLMarshalsDataURI(t *testing.T) {
 	parts := []contentPart{
 		{Type: "text", Text: "look"},
@@ -1076,38 +1025,6 @@ func TestContentPartImageURLMarshalsDataURI(t *testing.T) {
 	}
 }
 
-func TestOpenAIRequestEmptyContentStaysOmittedAfterAnyRefactor(t *testing.T) {
-	provider, err := New(Options{Model: "gpt-test"})
-	if err != nil {
-		t.Fatalf("New returned error: %v", err)
-	}
-	got, err := json.Marshal(provider.openAIRequest(zeroruntime.CompletionRequest{
-		Messages: []zeroruntime.Message{
-			{
-				Role:    zeroruntime.MessageRoleAssistant,
-				Content: "",
-				ToolCalls: []zeroruntime.ToolCall{{
-					ID:        "call_1",
-					Name:      "read_file",
-					Arguments: `{}`,
-				}},
-			},
-		},
-	}))
-	if err != nil {
-		t.Fatalf("marshal: %v", err)
-	}
-	var raw struct {
-		Messages []map[string]any `json:"messages"`
-	}
-	if err := json.Unmarshal(got, &raw); err != nil {
-		t.Fatalf("unmarshal: %v", err)
-	}
-	if _, present := raw.Messages[0]["content"]; present {
-		t.Fatalf("empty content boxed in any must stay omitted, got: %#v", raw.Messages[0])
-	}
-}
-
 func TestMapMessageBuildsImageURLContentParts(t *testing.T) {
 	msg := mapMessage(zeroruntime.Message{
 		Role:    zeroruntime.MessageRoleUser,
@@ -1165,8 +1082,8 @@ func TestMapMessageTextOnlyKeepsStringContent(t *testing.T) {
 		t.Fatalf("Content = %#v, want string \"hi\"", msg.Content)
 	}
 	empty := mapMessage(zeroruntime.Message{Role: zeroruntime.MessageRoleAssistant, Content: ""})
-	if empty.Content != nil {
-		t.Fatalf("empty text content = %#v, want nil so omitempty drops it", empty.Content)
+	if got, ok := empty.Content.(string); !ok || got != "" {
+		t.Fatalf("empty text content = %#v, want \"\" so it serializes as content:\"\" (strict servers reject a missing/null content)", empty.Content)
 	}
 }
 
@@ -1246,3 +1163,66 @@ func TestStreamCompletionSerializesImageContentParts(t *testing.T) {
 		t.Fatalf("image url = %#v, want data:image/png;base64,QUJD", imageURL["url"])
 	}
 }
+
+// TestOpenAIRequestEmptyContentHandling locks in the fix for strict OpenAI-
+// compatible servers (e.g. glm-* on Ollama-cloud) that reject a message whose
+// `content` is absent/null with "invalid message content type: <nil>": a
+// contentless assistant turn with no tool calls is dropped, and every other
+// message serializes an explicit `"content"` field (empty string when there is
+// no text) instead of omitting it.
+func TestOpenAIRequestEmptyContentHandling(t *testing.T) {
+	provider, err := New(Options{Model: "gpt-test"})
+	if err != nil {
+		t.Fatalf("New returned error: %v", err)
+	}
+
+	req := provider.openAIRequest(zeroruntime.CompletionRequest{
+		Messages: []zeroruntime.Message{
+			{Role: zeroruntime.MessageRoleUser, Content: "hi"},
+			// Degenerate empty assistant turn (e.g. a sub-agent that failed with no
+			// output): must be dropped, not sent.
+			{Role: zeroruntime.MessageRoleAssistant, Content: "   "},
+			// Assistant with tool calls but no text: kept, content present as "".
+			{Role: zeroruntime.MessageRoleAssistant, Content: "", ToolCalls: []zeroruntime.ToolCall{{
+				ID: "call_1", Name: "read_file", Arguments: "{}",
+			}}},
+			// Tool result with empty content: kept, content present as "".
+			{Role: zeroruntime.MessageRoleTool, Content: "", ToolCallID: "call_1"},
+		},
+	})
+
+	if len(req.Messages) != 3 {
+		t.Fatalf("empty assistant turn should be dropped; got %d messages: %#v", len(req.Messages), req.Messages)
+	}
+
+	// No message may serialize with an absent/null content field.
+	for i, message := range req.Messages {
+		if message.Content == nil {
+			t.Fatalf("message %d has nil content (would serialize as null/omitted): %#v", i, message)
+		}
+		data, err := json.Marshal(message)
+		if err != nil {
+			t.Fatalf("marshal message %d: %v", i, err)
+		}
+		if !strings.Contains(string(data), `"content":`) {
+			t.Fatalf("message %d omits the content field: %s", i, data)
+		}
+	}
+
+	if req.Messages[0].Content != "hi" {
+		t.Fatalf("user content = %#v, want \"hi\"", req.Messages[0].Content)
+	}
+	// The kept-but-textless messages must send content as an explicit empty string.
+	for _, idx := range []int{1, 2} {
+		data, err := json.Marshal(req.Messages[idx])
+		if err != nil {
+			t.Fatalf("marshal message %d: %v", idx, err)
+		}
+		if !strings.Contains(string(data), `"content":""`) {
+			t.Fatalf("message %d should send content:\"\", got %s", idx, data)
+		}
+	}
+	if len(req.Messages[1].ToolCalls) != 1 {
+		t.Fatalf("assistant tool calls dropped: %#v", req.Messages[1])
+	}
+}

internal/providers/openai/types.go

@@ -18,8 +18,13 @@ type streamOptions struct {
 }
 
 type chatMessage struct {
-	Role       string            `json:"role"`
-	Content    any               `json:"content,omitempty"`
+	Role string `json:"role"`
+	// Content has no omitempty: strict OpenAI-compatible servers (e.g. some
+	// Ollama-cloud models like glm-*) reject a message whose `content` is absent
+	// or null with "invalid message content type: <nil>". mapMessage always sets
+	// this (to "" when there's no text), so a contentless message serializes as
+	// `"content":""` rather than being dropped.
+	Content    any               `json:"content"`
 	ToolCalls  []requestToolCall `json:"tool_calls,omitempty"`
 	ToolCallID string            `json:"tool_call_id,omitempty"`
 }

internal/swarm/tools.go

@@ -103,6 +103,25 @@ func errResult(format string, a ...any) tools.Result {
 	return tools.Result{Status: tools.StatusError, Output: "Error: " + fmt.Sprintf(format, a...)}
 }
 
+// agentTypeProperty builds the schema for an agent-type parameter, constraining it
+// to the roster's currently registered types (the built-ins plus any user-registered
+// agents) via an enum so a model can't spawn or hand off to an unknown type — the
+// schema teaches the valid set up front instead of the model learning it from a
+// failed call. Falls back to a free-form string if the roster is unavailable or
+// empty (so the tool never advertises an empty, un-satisfiable enum).
+func agentTypeProperty(sw *Swarm, description string) tools.PropertySchema {
+	prop := tools.PropertySchema{Type: "string", Description: description}
+	if sw == nil {
+		return prop
+	}
+	if registry := sw.Registry(); registry != nil {
+		if types := registry.AgentTypes(); len(types) > 0 {
+			prop.Enum = types
+		}
+	}
+	return prop
+}
+
 // ---- swarm_spawn -----------------------------------------------------------
 
 type spawnTool struct {
@@ -118,7 +137,7 @@ func (t *spawnTool) Parameters() tools.Schema {
 	return tools.Schema{
 		Type: "object",
 		Properties: map[string]tools.PropertySchema{
-			"agent_type": {Type: "string", Description: "Roster agent type to spawn (e.g. teammate, subagent)."},
+			"agent_type": agentTypeProperty(t.sw, "Roster agent type to spawn."),
 			"task":       {Type: "string", Description: "The focused task/briefing for the member."},
 			"team":       {Type: "string", Description: "Team to spawn into. Defaults to \"default\"."},
 		},
@@ -353,7 +372,7 @@ func (t *handoffTool) Parameters() tools.Schema {
 		Type: "object",
 		Properties: map[string]tools.PropertySchema{
 			"task_id":       {Type: "string", Description: "Task id to hand off."},
-			"to_agent_type": {Type: "string", Description: "Roster agent type to take over."},
+			"to_agent_type": agentTypeProperty(t.sw, "Roster agent type to take over."),
 			"note":          {Type: "string", Description: "Optional handoff note delivered to the new member's inbox."},
 			"team":          {Type: "string", Description: "Team the task belongs to. Defaults to \"default\"."},
 		},

internal/swarm/tools_test.go

@@ -2,6 +2,7 @@ package swarm
 
 import (
 	"context"
+	"slices"
 	"strings"
 	"testing"
 	"time"
@@ -10,6 +11,46 @@ import (
 	"github.com/Gitlawb/zero/internal/tools"
 )
 
+func TestSpawnAndHandoffAgentTypeEnumReflectsRoster(t *testing.T) {
+	sw := newSwarmFor(t, newLauncher(okFor))
+	want := sw.Registry().AgentTypes() // sorted built-ins: subagent, teammate
+
+	spawnEnum := (&spawnTool{sw: sw}).Parameters().Properties["agent_type"].Enum
+	if !slices.Equal(spawnEnum, want) {
+		t.Fatalf("spawn agent_type enum = %v, want roster %v", spawnEnum, want)
+	}
+	if !slices.Contains(spawnEnum, "subagent") || !slices.Contains(spawnEnum, "teammate") {
+		t.Fatalf("enum missing built-in roster types: %v", spawnEnum)
+	}
+	handoffEnum := (&handoffTool{sw: sw}).Parameters().Properties["to_agent_type"].Enum
+	if !slices.Equal(handoffEnum, want) {
+		t.Fatalf("handoff to_agent_type enum = %v, want roster %v", handoffEnum, want)
+	}
+
+	// A user-registered custom type must extend the enum (not a hardcoded list).
+	if err := sw.Registry().Register(Definition{AgentType: "researcher"}); err != nil {
+		t.Fatalf("register custom agent: %v", err)
+	}
+	spawnEnum = (&spawnTool{sw: sw}).Parameters().Properties["agent_type"].Enum
+	if !slices.Contains(spawnEnum, "researcher") {
+		t.Fatalf("custom agent type not reflected in spawn enum: %v", spawnEnum)
+	}
+	handoffEnum = (&handoffTool{sw: sw}).Parameters().Properties["to_agent_type"].Enum
+	if !slices.Contains(handoffEnum, "researcher") {
+		t.Fatalf("custom agent type not reflected in handoff enum: %v", handoffEnum)
+	}
+}
+
+func TestAgentTypePropertyFallsBackWithoutRoster(t *testing.T) {
+	prop := agentTypeProperty(nil, "desc")
+	if prop.Type != "string" || prop.Description != "desc" {
+		t.Fatalf("unexpected property: %+v", prop)
+	}
+	if prop.Enum != nil {
+		t.Fatalf("nil swarm must not advertise an (empty) enum, got %v", prop.Enum)
+	}
+}
+
 func TestCollapseRuneSafeTruncation(t *testing.T) {
 	// 300 multi-byte runes: truncation must not split a rune (no invalid UTF-8).
 	got := collapse(strings.Repeat("🚀", 300))

internal/tui/onboarding.go

@@ -1495,7 +1495,14 @@ func (m model) setupProviderLines(width int, height int) []string {
 			marker = "❯ "
 			style = zeroTheme.accent.Bold(true)
 		}
-		line := marker + style.Render(displayValue(option.Name, option.ID))
+		label := displayValue(option.Name, option.ID)
+		if option.Recommended {
+			label = "★ " + label
+		}
+		line := marker + style.Render(label)
+		if option.Recommended {
+			line += zeroTheme.faint.Render("  (recommended)")
+		}
 		lines = append(lines, padSetupLine(line, rowWidth))
 	}
 	// A failed OAuth login drops back here with oauthPending cleared, so the

internal/tui/options.go

@@ -99,6 +99,7 @@ type SetupProviderOption struct {
 	EnvVar       string
 	RequiresAuth bool
 	Local        bool
+	Recommended  bool
 }
 
 // SetupSelection is the user's setup choice.

internal/tui/provider_wizard.go

@@ -1240,13 +1240,26 @@ func (wizard *providerWizardState) renderSelectableProvider(width int, index int
 		surface = zeroTheme.onSel
 		marker = surface(zeroTheme.accent).Render("❯ ")
 	}
-	left := marker + surface(zeroTheme.ink).Render(provider.Name)
-	if badge := providerWizardOAuthBadge(provider); badge != "" {
+	name := provider.Name
+	if provider.Recommended {
+		name = "★ " + name
+	}
+	left := marker + surface(zeroTheme.ink).Render(name)
+	if badge := providerWizardBadge(provider); badge != "" {
 		left += surface(zeroTheme.faint).Render("   " + badge)
 	}
 	return fitStyledLine(left, width)
 }
 
+// providerWizardBadge is the faint hint shown next to a provider row. The
+// recommended provider takes precedence over the OAuth hint.
+func providerWizardBadge(provider providercatalog.Descriptor) string {
+	if provider.Recommended {
+		return "(recommended)"
+	}
+	return providerWizardOAuthBadge(provider)
+}
+
 // providerWizardOAuthBadge is the faint mode hint shown next to OAuth providers.
 func providerWizardOAuthBadge(provider providercatalog.Descriptor) string {
 	if !provider.OAuth {

internal/tui/provider_wizard_test.go

@@ -53,7 +53,7 @@ func TestProviderCommandOpensOnboardingWizard(t *testing.T) {
 	updated, _ = next.Update(testKey(tea.KeyEnter))
 	next = updated.(model)
 	listView := plainRender(t, next.View())
-	for _, want := range []string{"Choose provider", "OpenAI", "Anthropic", "Google", "Groq", "OpenRouter", "Ollama"} {
+	for _, want := range []string{"Choose provider", "GitLawb OpenGateway", "OpenAI", "Anthropic", "Google", "OpenRouter", "Ollama"} {
 		assertContains(t, listView, want)
 	}
 }
@@ -172,8 +172,12 @@ func TestProviderWizardAdvancesProviderAPIKeyAndModelSteps(t *testing.T) {
 	m := newModel(context.Background(), Options{})
 	m = openProviderWizardForTest(t, m)
 
+	// Index 0 is the recommended OpenGateway entry, so two downs land on anthropic
+	// (opengateway → openai → anthropic).
 	updated, _ := m.Update(testKey(tea.KeyDown))
 	next := updated.(model)
+	updated, _ = next.Update(testKey(tea.KeyDown))
+	next = updated.(model)
 	if got := next.providerWizard.currentProvider().ID; got != "anthropic" {
 		t.Fatalf("after down, selected provider = %q, want anthropic", got)
 	}
@@ -309,8 +313,15 @@ func TestProviderWizardRightAllowsExistingCredentialEnv(t *testing.T) {
 	m := newModel(context.Background(), Options{})
 	m = openProviderWizardForTest(t, m)
 
-	updated, _ := m.Update(testKey(tea.KeyEnter))
+	// Move off the recommended OpenGateway entry (index 0) onto openai so the
+	// OPENAI_API_KEY env credential is the one in play.
+	updated, _ := m.Update(testKey(tea.KeyDown))
 	next := updated.(model)
+	if got := next.providerWizard.currentProvider().ID; got != "openai" {
+		t.Fatalf("after down, selected provider = %q, want openai", got)
+	}
+	updated, _ = next.Update(testKey(tea.KeyEnter))
+	next = updated.(model)
 	if next.providerWizard.step != providerWizardStepCredential {
 		t.Fatalf("enter from provider step = %v, want credential", next.providerWizard.step)
 	}

internal/tui/run.go

@@ -7,10 +7,22 @@ import (
 
 	tea "charm.land/bubbletea/v2"
 	"github.com/charmbracelet/colorprofile"
+	"github.com/charmbracelet/x/term"
 )
 
 // Run starts the Zero Bubble Tea shell and returns a process-style exit code.
 func Run(ctx context.Context, options Options) int {
+	// The interactive shell needs a real terminal on stdin: with piped or
+	// redirected input Bubble Tea blocks forever waiting for events that never
+	// arrive (e.g. `echo "" | zero`). Fail fast with guidance toward the headless
+	// path instead of hanging. term.IsTerminal is a true TTY check (it rejects
+	// pipes, regular files, and non-terminal char devices like /dev/null) and
+	// fails closed — anything that is not a verified terminal blocks the shell.
+	if !term.IsTerminal(os.Stdin.Fd()) {
+		fmt.Fprintln(os.Stderr, "zero: the interactive shell needs a terminal (stdin is not a TTY). For non-interactive use, run: zero exec \"<prompt>\"")
+		return 2
+	}
+
 	externalSink := options.RuntimeMessageSink
 	var program *tea.Program
 	options.RuntimeMessageSink = func(msg tea.Msg) {

internal/tui/run_test.go

@@ -1,6 +1,11 @@
 package tui
 
-import "testing"
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+)
 
 func TestUseAltScreenForInteractiveChat(t *testing.T) {
 	if !useAltScreen(Options{}) {
@@ -10,3 +15,31 @@ func TestUseAltScreenForInteractiveChat(t *testing.T) {
 		t.Fatal("setup takeover should also use the alternate screen")
 	}
 }
+
+// TestRunRejectsNonTTYStdin pins that the interactive shell fails fast with a
+// non-zero code when stdin is not a terminal, instead of blocking forever in the
+// Bubble Tea event loop (e.g. `echo "" | zero`). The guard runs before any model
+// construction, so empty Options are fine.
+func TestRunRejectsNonTTYStdin(t *testing.T) {
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("os.Pipe: %v", err)
+	}
+	w.Close() // a pipe read-end is not a character device
+
+	old := os.Stdin
+	os.Stdin = r
+	defer func() { os.Stdin = old; r.Close() }()
+
+	done := make(chan int, 1)
+	go func() { done <- Run(context.Background(), Options{}) }()
+
+	select {
+	case code := <-done:
+		if code != 2 {
+			t.Fatalf("Run with non-TTY stdin returned %d; want exit code 2 from the stdin TTY guard", code)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("Run blocked on non-TTY stdin instead of failing fast")
+	}
+}

internal/zerocommands/contracts.go

@@ -86,6 +86,7 @@ type ProviderCatalogSnapshot struct {
 	Local                    bool     `json:"local"`
 	RuntimeSupported         bool     `json:"runtimeSupported"`
 	RuntimeUnsupportedReason string   `json:"runtimeUnsupportedReason,omitempty"`
+	Recommended              bool     `json:"recommended,omitempty"`
 }
 
 type SessionSnapshot struct {
@@ -218,6 +219,9 @@ func ProviderCatalogSnapshots(options ProviderCatalogSnapshotOptions) ([]Provide
 		snapshots = append(snapshots, ProviderCatalogSnapshotFromDescriptor(descriptor))
 	}
 	sort.SliceStable(snapshots, func(i int, j int) bool {
+		if snapshots[i].Recommended != snapshots[j].Recommended {
+			return snapshots[i].Recommended
+		}
 		return snapshots[i].ID < snapshots[j].ID
 	})
 	return snapshots, nil
@@ -244,6 +248,7 @@ func ProviderCatalogSnapshotFromDescriptor(descriptor providercatalog.Descriptor
 		Local:                    descriptor.Local,
 		RuntimeSupported:         providercatalog.RuntimeSupported(descriptor),
 		RuntimeUnsupportedReason: providercatalog.RuntimeUnsupportedReason(descriptor),
+		Recommended:              descriptor.Recommended,
 	}
 }
 

internal/zerocommands/contracts_test.go

@@ -164,11 +164,16 @@ func TestProviderCatalogSnapshotsExposeStableDescriptors(t *testing.T) {
 	if len(snapshots) < 4 {
 		t.Fatalf("expected provider catalog descriptors, got %#v", snapshots)
 	}
+	if !snapshots[0].Recommended {
+		t.Fatalf("expected the recommended provider first, got %#v", snapshots[0])
+	}
 	for index, snapshot := range snapshots {
 		if snapshot.ID == "" || snapshot.Name == "" || snapshot.Transport == "" {
 			t.Fatalf("catalog snapshot missing identity fields: %#v", snapshot)
 		}
-		if index > 0 && snapshots[index-1].ID > snapshot.ID {
+		// The recommended provider is hoisted to the front; everything after it is
+		// sorted by id.
+		if index > 0 && !snapshots[index-1].Recommended && snapshots[index-1].ID > snapshot.ID {
 			t.Fatalf("provider catalog snapshots are not sorted by id: %#v", snapshots)
 		}
 	}

package.json

@@ -38,5 +38,5 @@
   "bugs": {
     "url": "https://github.com/Gitlawb/zero/issues"
   },
-  "license": "SEE LICENSE IN LICENSE"
+  "license": "MIT"
 }

scripts/postinstall.mjs

@@ -102,6 +102,19 @@ if (!platform || !arch) {
   );
 }
 
+// The release matrix builds linux/macos {x64,arm64} and windows-x64 — there is no
+// windows-arm64 artifact. (win32, arm64) otherwise resolves to a valid
+// platform/arch, so it would proceed to download a non-existent asset and hard
+// -fail npm install on a 404. Guard it explicitly to skip gracefully; Windows on
+// ARM runs the x64 build under emulation, so the x64 package is the fallback.
+if (platform === 'windows' && arch === 'arm64') {
+  warnSkip(
+    `no prebuilt binary for windows-arm64 (the windows-x64 build runs under ` +
+      `emulation on Windows on ARM). Build from source or install the x64 package: ` +
+      `https://github.com/${REPO} (go run ./cmd/zero).`,
+  );
+}
+
 const ext = platform === 'windows' ? 'zip' : 'tar.gz';
 const binaryName = platform === 'windows' ? 'zero.exe' : 'zero';
 const tag = `v${VERSION}`;