diff --git a/server/pkg/agent/models.go b/server/pkg/agent/models.go
index b16df1627..5c0fe3ed7 100644
--- a/server/pkg/agent/models.go
+++ b/server/pkg/agent/models.go
@@ -362,11 +362,13 @@ func discoverOpenCodeModels(ctx context.Context, executablePath string) ([]Model
 	hideAgentWindow(cmd)
 	out, err := cmd.Output()
 	if err != nil {
-		cmd = exec.CommandContext(runCtx, executablePath, "models")
-		hideAgentWindow(cmd)
-		out, err = cmd.Output()
-		if err != nil {
-			return []Model{}, nil
+		if len(out) == 0 {
+			cmd = exec.CommandContext(runCtx, executablePath, "models")
+			hideAgentWindow(cmd)
+			out, err = cmd.Output()
+			if err != nil && len(out) == 0 {
+				return []Model{}, nil
+			}
 		}
 	}
 	return parseOpenCodeModels(string(out)), nil
@@ -562,7 +564,7 @@ func discoverPiModels(ctx context.Context, executablePath string) ([]Model, erro
 	var stderr strings.Builder
 	cmd.Stderr = &stderr
 	stdout, err := cmd.Output()
-	if err != nil {
+	if err != nil && len(stdout) == 0 && stderr.Len() == 0 {
 		return []Model{}, nil
 	}
 	text := string(stdout)
@@ -606,6 +608,14 @@ func parsePiModels(output string) []Model {
 		} else {
 			continue
 		}
+		// A real row resolves to `provider/model` with both halves present.
+		// Drop anything else — e.g. a stray `Warning: No models match pattern
+		// "..."` line, which pi can interleave with the catalog when an agent
+		// config holds stale patterns (#3729). Without this guard the leading
+		// `Warning:` token becomes a bogus `Warning/` model in the picker.
+		if slash := strings.Index(id, "/"); slash <= 0 || slash == len(id)-1 {
+			continue
+		}
 		if seen[id] {
 			continue
 		}
@@ -942,7 +952,7 @@ func discoverCursorModels(ctx context.Context, executablePath string) ([]Model,
 	cmd := exec.CommandContext(runCtx, executablePath, "--list-models")
 	hideAgentWindow(cmd)
 	out, err := cmd.Output()
-	if err != nil {
+	if err != nil && len(out) == 0 {
 		return cursorStaticModels(), nil
 	}
 	models := parseCursorModels(string(out))
@@ -1039,7 +1049,7 @@ func discoverOpenclawAgents(ctx context.Context, executablePath string) ([]Model
 		cmd := exec.CommandContext(runCtx, executablePath, jsonArgs...)
 		hideAgentWindow(cmd)
 		out, err := cmd.Output()
-		if err != nil {
+		if err != nil && len(out) == 0 {
 			continue
 		}
 		if models, ok := parseOpenclawAgentsJSON(out); ok {
@@ -1053,7 +1063,7 @@ func discoverOpenclawAgents(ctx context.Context, executablePath string) ([]Model
 	cmd := exec.CommandContext(runCtx, executablePath, "agents", "list")
 	hideAgentWindow(cmd)
 	out, err := cmd.Output()
-	if err != nil {
+	if err != nil && len(out) == 0 {
 		return []Model{}, nil
 	}
 	return parseOpenclawAgents(string(out)), nil
diff --git a/server/pkg/agent/models_test.go b/server/pkg/agent/models_test.go
index ba6987c7d..a1611c2dc 100644
--- a/server/pkg/agent/models_test.go
+++ b/server/pkg/agent/models_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
 	"testing"
 )
@@ -450,6 +451,70 @@ bareword-only-line
 	}
 }
 
+// TestDiscoverPiModelsNonZeroExit verifies that discoverPiModels still returns
+// the resolvable catalog when `pi --list-models` exits non-zero. Pi exits
+// non-zero (and warns) when an agent config references stale provider/model
+// patterns that no longer match the local catalog. Before the fix the daemon
+// discarded the populated output on any non-zero exit and returned an empty
+// list, so the UI model picker was blank even though the runtime was online and
+// agents ran fine. See GitHub #3729.
+func TestDiscoverPiModelsNonZeroExit(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("fake pi binary is a /bin/sh script")
+	}
+
+	const table = "provider         model        context  max-out  thinking  images\n" +
+		"glm-coding-plan  glm-4.7      202.8K   16.4K    no        no"
+	const warning = `Warning: No models match pattern "opencode-go/mimo-v2-omni"`
+
+	cases := []struct {
+		name   string
+		script string
+	}{
+		{
+			// Newer pi prints the catalog to stdout; the stale-pattern
+			// warning goes to stderr and the process exits non-zero.
+			name: "catalog on stdout",
+			script: "#!/bin/sh\n" +
+				"cat <<'EOF'\n" + table + "\nEOF\n" +
+				"echo " + strconv.Quote(warning) + " >&2\n" +
+				"exit 1\n",
+		},
+		{
+			// Older pi prints the catalog (and the warning) to stderr; same
+			// non-zero exit. The stderr fallback must still parse the catalog.
+			name: "catalog on stderr",
+			script: "#!/bin/sh\n" +
+				"cat >&2 <<'EOF'\n" + table + "\n" + warning + "\nEOF\n" +
+				"exit 1\n",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			fakePath := filepath.Join(t.TempDir(), "pi")
+			writeTestExecutable(t, fakePath, []byte(tc.script))
+
+			models, err := discoverPiModels(context.Background(), fakePath)
+			if err != nil {
+				t.Fatalf("discoverPiModels: %v", err)
+			}
+			var found bool
+			for _, m := range models {
+				if m.ID == "glm-coding-plan/glm-4.7" {
+					found = true
+				}
+				if m.ID == "Warning/" || m.Provider == "Warning" {
+					t.Errorf("warning line leaked into the catalog as a bogus model: %+v", m)
+				}
+			}
+			if !found {
+				t.Fatalf("expected glm-coding-plan/glm-4.7 despite non-zero exit, got %+v", models)
+			}
+		})
+	}
+}
+
 func TestParseOpenclawAgents(t *testing.T) {
 	input := `deepseek-v4   deepseek-v4
 claude-sonnet claude-sonnet-4-6